US Pat. No. 9,131,589

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS AND CONTROL METHOD FOR LASER APPARATUS IN EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus that generates extreme ultraviolet light by irradiating a target with
a pulse laser beam and producing plasma, the apparatus comprising:
a chamber containing a plasma generation region irradiated by a pulse laser beam from a laser apparatus;
a target supply device configured to supply a plurality of targets consecutively to the plasma generation region in the chamber;
a target detection unit configured to detect a target outputted from the target supply device that has passed a predetermined
position between the target supply device and the plasma generation region; and

laser control circuitry configured to control the laser apparatus, wherein:
the laser control circuitry includes a light emission trigger generation circuit configured to generate a light emission trigger
instructing a laser device included in the laser apparatus to emit a pulse laser beam, and output the generated light emission
trigger to the laser apparatus,

the light emission trigger generation circuit is configured to generate a dummy light emission trigger and output the generated
dummy light emission trigger to the laser apparatus after a detection signal has been received from the target detection unit
and a second time has passed following the reception of the detection signal without a subsequent detection signal being received,

the laser apparatus further includes an optical shutter that controls transmission of the pulse laser beam from the laser
device,

the laser control circuitry is further configured to control the optical shutter to block the pulse laser beam emitted from
the laser device in accordance with the dummy light emission trigger,

the laser device is a main pulse laser device,
the laser apparatus further includes a pre-pulse laser device that emits a pre-pulse laser beam before the pulse laser beam
is emitted from the main pulse laser device and a second optical shutter that controls transmission of the pre-pulse laser
beam, and

the laser control circuitry further configured to:
output a light emission trigger to the main pulse laser device after outputting a light emission trigger to the pre-pulse
laser device upon receiving the detection signal from the target detection unit indicating that a target has been detected;

output a second dummy light emission trigger to the main pulse laser device after outputting a first dummy light emission
trigger to the pre-pulse laser device when the second time has passed following the reception of the previous detection signal
from the target detection unit;

control the second optical shutter to block the pre-pulse laser beam emitted from the pre-pulse laser device in accordance
with the first dummy light emission trigger; and

control the optical shutter to block the pulse laser beam emitted from the main pulse laser device in accordance with the
second dummy light emission trigger.

US Pat. No. 9,153,927

REGENERATIVE AMPLIFIER, LASER APPARATUS, AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A regenerative amplifier used in combination with a laser device, the regenerative amplifier comprising:
a slab amplifier provided between the pair of the resonator mirrors for amplifying a laser beam with a predetermined wavelength
outputted from the laser device;

a first optical system disposed to configure a multipass optical path along which the laser beam is reciprocated inside the
amplifier, the first optical system transferring an optical image of the laser beam at a first position on a light of the
laser beam including the multipass optical path as an optical image of the laser beam at a second position on the optical
path and transferring the optical image of the laser beam at the second position as the optical image of the laser beam at
the first position;

a second optical system located at one end of the optical path; and
a third optical system located at the other end of the optical path, wherein
the first position is positioned between the second optical system and the slab amplifier,
the second position is positioned between the third optical system and the slab amplifier,
the second optical system transfers the optical image of the laser beam at the first position as the optical image of the
laser beam at the first position, and

the third optical system transfers the optical image of the laser beam at the second position as the optical image of the
laser beam at the second position.

US Pat. No. 9,229,192

MIRROR DEVICE

Gigaphoton Inc., Tochigi...

1. A minor device, comprising:
a minor including
a base plate having a first surface, a second surface opposite to the first surface, and a side surface different from the
first and second surfaces,

a reflective surface on the first surface of the base plate, and
a plurality of first protrusions on the second surface of the base plate;
a plurality of support parts for respectively supporting the plurality of the first protrusions, each support part having
a groove for guiding the first protrusion; and

a plurality of clamps each having a first portion secured on corresponding one of the plurality of support parts and a second
portion positioned for pressing one of the plurality of first protrusions toward the groove through the side surface, the
plurality of clamps being configured to press respectively the plurality of the first protrusions against grooves in the plurality
of the support parts.

US Pat. No. 9,130,345

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT, AND LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation system used with a laser apparatus, the extreme ultraviolet light generation system
comprising:
a chamber including at least one window for first and second laser beams and a target supply unit for supplying a droplet
of a target material into the chamber;

a collector mirror provided in the chamber and configured for selectively reflecting at least ultraviolet light emitted from
a plasma generated by irradiating the droplet with the first and second laser beams;

a first polarization control unit, provided on a light path of the first laser beam, for converting the first laser beam into
one of a radially polarized laser beam, an azimuthally polarized laser beam and an elliptically polarized laser beam; and

a second polarization control unit on a light path of the second laser beam, for converting the second laser beam into one
of a radially polarized laser beam, an azimuthally polarized laser beam and an elliptically polarized laser beam, wherein:

the first laser beam strikes the droplet not having been irradiated with a laser beam, and
the second laser beam strikes the target material have been irradiated with the first laser beam.

US Pat. No. 9,099,836

LASER BEAM AMPLIFIER AND LASER APPARATUS USING THE SAME

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:
a master oscillator configured to generate a pulse laser beam;
a preamplifier including a first container configured to accommodate a laser medium, a first optical system including a first
concave mirror configured to transfer an image of the pulse laser beam at a first point to form a first transfer image at
a second point, and a pair of first electrodes arranged in the first container and configured to perform discharge in the
laser medium to form an amplification region between the first point and the second point;

relay optics configured to transfer the first transfer image at the second point to form a second transfer image at a third
point; and

a main amplifier including a second container configured to accommodate a laser medium, a second optical system including
a second concave mirror configured to transfer the second transfer image at the third point to form a third transfer image
at a fourth point, and a pair of second electrodes arranged in the second container and configured to perform discharge in
the laser medium to form an amplification region between the third point and the fourth point.

US Pat. No. 9,147,993

MASTER OSCILLATOR SYSTEM AND LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A master oscillator system comprising:
a grating that functions as one of a plurality of resonator mirrors in an optical resonator;
an optical element disposed within an optical path between said plurality of resonator mirrors; and
an attitude control mechanism that adjusts the attitude of said optical element,
wherein said optical element is a prism; and
wherein said attitude control mechanism adjusts the attitude of said prism so that an axis at which two surfaces, a surface
into which laser light is input and a surface from which the laser light is output, in said prism intersect is tilted around
a rotational axis which is parallel to one of an upper face and a bottom face of said prism.

US Pat. No. 9,318,864

LASER BEAM OUTPUT CONTROL WITH OPTICAL SHUTTER

GIGAPHOTON INC., Tochigi...

1. A laser apparatus, comprising:
a master oscillator configured to output a pulsed laser beam continually at a repetition rate;
a plurality of amplifiers disposed on a beam path of the pulsed laser beam;
a plurality of optical shutters disposed on the beam path of the pulsed laser beam; and
a controller configured to switch the plurality of optical shutters, wherein
each of the plurality of optical shutters includes:
an electro-optic device;
a first optical filter disposed at an input side of the electro-optic device;
a second optical filter disposed at an output side of the electro-optic device; and
a power source coupled to the electro-optic device for applying voltage to the electro-optic device, and wherein
the controller is configured to switch the plurality of optical shutters based on a signal inputted from an external apparatus
while the master oscillator oscillates the pulsed laser beam, to perform a burst operation to repeatedly alternate a period
for which the pulsed laser beam is outputted at the repetition rate and a period for which the pulsed laser beam is not outputted,
and to control the plurality of optical shutters to open sequentially from an upstream side optical shutter to a downstream
side optical shutter.

US Pat. No. 9,167,678

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. A system comprising:
a target supply unit configured to supply a target material for generating extreme ultraviolet light;
a first laser apparatus configured to generate a first pre-pulse laser beam with which the target material is irradiated,
the first pre-pulse laser beam having a pulse width of 1 ns or less and having a pulse energy of 0.15 mJ or less;

a second laser apparatus configured to generate a second pre-pulse laser beam with which the target material irradiated with
the first pre-pulse laser beam is irradiated;

a third laser apparatus configured to generate a main pulse laser beam with which the target material irradiated with the
second pre-pulse laser beam is irradiated;

a first beam combiner configured to coincide a first optical path of the first pre-pulse laser beam and a second optical path
of the second pre-pulse laser beam with each other to be a third optical path, and output the first and second pre-pulse laser
beams, respectively, along the third optical path; and

a second beam combiner configured to coincide the third optical path of the first and second pre-pulse laser beams output
from the first beam combiner and a fourth optical path of the main pulse laser beam with each other.

US Pat. No. 9,059,554

DISCHARGE-PUMPED GAS LASER DEVICE

GIGAPHOTON INC., Tochigi...

1. A discharge-pumped gas laser device, comprising:
a laser chamber configured to generate laser light;
a pair of discharge electrodes provided in the laser chamber;
a fan with a magnetic bearing being provided in the laser chamber and configured to be capable of circulating a gas in the
laser chamber;

a magnetic bearing controller connected to the magnetic bearing electrically, and being capable of controlling the magnetic
bearing; and

a laser controller configured to control generation of the laser light,
wherein the fan includes a rotor and the magnetic bearing includes a magnetic floatation actuator configured to float the
rotor and a displacement sensor configured to detect a position of the rotor,

wherein the laser controller causes the magnetic bearing controller to execute calibration of the displacement sensor and
the magnetic floatation actuator and to calculate and set a control parameter necessary for a control of the magnetic bearing
by using the calibrated displacement sensor and magnetic floatation actuator,

wherein the laser controller causes the magnetic bearing controller to execute calculation and setting of the control parameter
in a case where at least one of installation of the laser chamber after replacement thereof, touchdown of the magnetic bearing,
and an error in the magnetic bearing controller is detected, and

wherein the laser controller causes the magnetic bearing controller to execute calculation and setting of the control parameter
in a case where at least one of a predetermined time course, a predetermined number of an output of the laser light, a predetermined
change of a predetermined gas pressure in the laser chamber, vibration of the laser chamber, a predetermined change of a wavelength
stability of the laser light, a predetermined change of an energy stability of the laser light, touchdown of the magnetic
bearing, and an error in the magnetic bearing controller is detected after replacement of the laser chamber.

US Pat. No. 9,301,379

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An apparatus for generating extreme ultraviolet light, comprising:
a chamber having an opening through which a laser beam is introduced into the chamber;
a target supply unit for supplying a target material to be irradiated by the laser beam to a predetermined region inside the
chamber;

a laser beam focusing optical system for focusing the laser beam in the predetermined region inside the chamber to turn the
target material into plasma;

a collector mirror for collecting the extreme ultraviolet light emitted from the plasma; and
a reference member having a first surface and a second surface opposite to the first surface, the chamber and the collector
mirror being disposed on the first surface, the laser beam focusing optical system being disposed on the second surface, the
reference member positioning the chamber, the collector mirror, and the laser beam focusing optical system.

US Pat. No. 9,198,272

TARGET GENERATION DEVICE AND EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. A target supply device comprising:
a reservoir configured to hold a target material in its interior in liquid form;
a vibrating element configured to apply vibrations to the reservoir;
a target sensor configured to detect droplets of the target material outputted from the reservoir;
a control unit configured to set parameters based on a result of the detection performed by the target sensor;
a function generator configured to generate an electrical signal having a waveform based on the parameters; and
a power source configured to apply a driving voltage to the vibrating element in accordance with the electrical signal.

US Pat. No. 9,097,434

TARGET SUPPLY APPARATUS AND TARGET SUPPLY METHOD

GIGAPHOTON INC., Tochigi...

1. A target supply apparatus used in an extreme ultraviolet light apparatus that generates extreme ultraviolet light by irradiating
a target with a laser beam, the target supply apparatus comprising:
a tank;
a nozzle that includes a through-hole and is disposed so that the through-hole communicates with an interior of the tank;
a first heater disposed along a wall of the tank;
a second heater disposed along a wall of the tank in a position that is further from the nozzle than the first heater;
a third heater configured to heat the nozzle; and
a control unit configured to control the first heater, the second heater and the third heater so that a temperature of the
first heater is greater than a temperature of the second heater and a temperature of the third heater is greater than the
temperature of the first heater.

US Pat. No. 9,338,869

EUV LIGHT SOURCE APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light source apparatus comprising:
a target supply apparatus including:
a tank for storing a liquid target material;
a nozzle for outputting the liquid target material in the tank; and
a gas supply source for supplying gas into the tank, and the target supply apparatus controlling a gas pressure inside the
tank with a pressure of the gas supplied from the gas supply source provided with a pressure regulator;

a chamber in which an extreme ultraviolet light is generated, by irradiating the liquid target material outputted from the
nozzle with a laser beam;

a collector mirror provided in the chamber and configured to collect the generated extreme ultraviolet light;
a first gas passage connected to the tank, the gas from the tank being exhausted through the first gas passage;
a first valve provided on the first gas passage;
a second gas passage connected to the first gas passage between the tank and the first valve;
a second valve provided on the second gas passage; and
a controller configured to control open/close of the first valve and the second value, wherein the controller closes the first
valve and opens the second valve such that the gas from the tank flowing through the first gas passage is exhausted through
the second gas passage.

US Pat. No. 9,253,866

GAS LOCK DEVICE AND EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. A gas lock device for suppressing debris from reaching an optical element, the gas lock device comprising:
a chamber including a passage section and a connection hole that connects an interior surface of the chamber to a lateral
face of the passage section, the optical element is attached to the chamber and seals the passage section, and the intersection
of the connection hole to the lateral face is at an angle with respect to the lateral face;

a gas supply apparatus; and
a pipe, attached at one end to the gas supply apparatus and attached at the other end to the chamber, that defines a flow
channel communicating with the connection hole, such that a flow of gas is directed toward the optical element.

US Pat. No. 9,439,275

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

GIGAPHOTON INC., Tochigi...

1. A system for generating extreme ultraviolet light, comprising:
a chamber;
a target supply device configured to supply a target material to a specific region in the chamber;
a first laser apparatus configured to output a first laser beam to irradiate the target material;
an optical system configured to focus the first laser beam outputted from the first laser apparatus;
a detector configured to detect a backpropagating beam of the first laser beam reflected by the target material; and
a controller configured to control a focus position of the optical system based on the backpropagating beam detected by the
detector.

US Pat. No. 9,130,338

EXCIMER LASER AND LASER DEVICE

GIGAPHOTON INC., Tochigi...

1. An excimer laser comprising:
a frame;
a base plate on which said frame is disposed;
an excimer laser configured to oscillate and output laser light by discharge-pumping within a chamber containing a laser gas;
an optical element that is mounted upon said frame and that is disposed in the optical path of said outputted laser light;
a heat removal mechanism connected to both said frame and said base plate; and
a heat transfer mechanism having an interspace connected to both said frame and said base plate;
wherein said heat transfer mechanism is an attitude adjustment mechanism mounted upon said base plate,
said frame is mounted upon a mounting surface of said attitude adjustment mechanism,
said attitude adjustment mechanism includes a lower plate section disposed upon said base plate, an upper plate section positioned
above the lower plate section, a support section that supports the upper plate section relative to said lower plate section,
a first adjustment section that supports said upper plate section relative to said lower plate section at a different location
than the support section and that is configured to enable the distance between said lower plate section and said upper plate
section to be adjusted, said interspace is defined as surrounded by the lower plate, the upper plate and the support section,

said attitude adjustment mechanism is configured to adjust the tilt of said mounting surface relative to said base plate,
and

a first direction in which a bent area of said heat removal mechanism extends to be essentially parallel to a second direction
in which said support section extends.

US Pat. No. 9,497,841

EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation system comprising:
a chamber;
a target generation unit configured to output a target toward a plasma generation region in the chamber;
a laser system configured to generate a first pre-pulse laser beam, a second pre-pulse laser beam, and a main pulse laser
beam so that the target is irradiated with the first pre-pulse laser beam, the second pre-pulse laser beam, and the main pulse
laser beam in this order; and

a controller configured to control the laser system so that a fluence of the second pre-pulse laser beam is equal to or higher
than 1 J/cm2 and equal to or lower than a fluence of the main pulse laser beam.

US Pat. No. 9,331,450

LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A laser apparatus comprising:
a laser chamber including a laser gain medium, and a part of the laser chamber being constructed by an insulator;
a power source;
a first electrode to which a voltage is applied from the power source and a second electrode that is grounded, the first and
second electrodes being disposed in the laser chamber, and the first electrode being disposed at a side where the insulator
is disposed;

a connector connected to the power source, and supporting the first electrode in a way that allows the first electrode to
move toward a side where the second electrode is disposed; and

an electrode moving mechanism being installed in the insulator and being connected to the first electrode to move the first
electrode toward the side where the second electrode is disposed,

wherein the electrode moving mechanism comprises shims which are stacked and removed corresponding to a wear volume of the
first electrode.

US Pat. No. 9,265,136

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. A system comprising:
a laser beam apparatus configured to generate a laser beam; and
a target supply unit configured to supply a target material to be irradiated with the laser beam for generating extreme ultraviolet
light, wherein

the laser beam apparatus is configured to:
generate a first pre-pulse laser beam with which the target material is irradiated, the first pre-pulse laser beam having
a pulse duration of less than 1 ns, so as to make the target be diffused in a dome shape,

generate a second pre-pulse laser beam with which the target material irradiated with the first pre-pulse laser beam is irradiated,
and

generate a main pulse laser beam with which the target material irradiated with the second pre-pulse laser beam is irradiated.

US Pat. No. 9,332,625

EXTREME ULTRAVIOLET LIGHT SOURCE APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light source apparatus for generating plasma by applying a laser beam to a target material and entering
extreme ultraviolet light radiated from the plasma into projection optics of exposure equipment, said apparatus comprising:
a chamber in which the extreme ultraviolet light is generated;
a target supply unit for supplying the target material into said chamber;
a driver laser for applying the laser beam to the target material supplied by said target supply unit to generate the plasma;
a collector mirror for collecting the extreme ultraviolet light radiated from the plasma;
a positioning mechanism for positioning at least a part of said chamber in a predetermined location where an optical axis
of the collected extreme ultraviolet light and an optical axis of the projection optics of said exposure equipment are aligned
with each other;

a movement mechanism for moving at least the part of said chamber positioned in the predetermined location between said predetermined
location and a maintenance area; and

a magnetic field generating unit includes a pair of magnets placed opposite to each other for trapping charged particles radiated
from said plasma, said magnetic field generating unit being provided outside of a track on which at least the part of said
chamber moves between said predetermined location and said maintenance area.

US Pat. No. 9,198,273

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An apparatus for generating extreme ultraviolet light, the apparatus comprising:
a reference member;
a chamber fixed to the reference member, the chamber including at least one window;
a laser beam introduction optical system configured to introduce an externally supplied laser beam into the chamber through
the at least one window; and

a positioning mechanism configured to position the laser beam introduction optical system to the reference member, the positioning
member including:

three legs configured to support the laser beam introduction optical system;
three mounts fixed to the reference member, the three mounts being configured to respectively support the three legs so as
to position the laser beam introduction optical system on a predetermined plane; and

two stoppers fixed to the reference member, the two stoppers being configured to position the laser beam introduction optical
system in the predetermined plane while the three mounts respectively support the three legs.

US Pat. No. 9,497,842

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

GIGAPHOTON INC., Tochigi...

1. A system comprising:
a laser beam apparatus configured to generate a laser beam; and
a target supply unit configured to supply a target material to be irradiated with the laser beam for generating extreme ultraviolet
light, wherein

the laser beam apparatus is configured to:
generate a first pre-pulse laser beam with which the target material is irradiated so as to make the target be diffused in
a dome shape,

generate a second pre-pulse laser beam with which the target material irradiated with the first pre-pulse laser beam is irradiated,
and

generate a main pulse laser beam with which the target material irradiated with the second pre-pulse laser beam is irradiated.

US Pat. No. 9,192,037

CONTROL METHOD FOR TARGET SUPPLY DEVICE, AND TARGET SUPPLY DEVICE

Gigaphoton Inc., Tochigi...

1. A control method for a target supply device that is provided in an EUV light generation apparatus and that includes a target
generator having a nozzle and holding a target material, a pressure control unit configured to control a pressure within the
target generator, and a heating unit configured to heat the target material within the target generator, the method comprising:
melting the target material by heating the target material within the target generator using the heating unit;
pushing out the target material in the target generator from a nozzle hole in the nozzle by pressurizing the interior of the
target generator using the pressure control unit;

determining whether or not the size of an adhering area of the target material that forms when the target material is pushed
out from the nozzle hole and adheres to a leading end of the nozzle has reached a set size that covers the entire nozzle hole;

stopping the pressurization of the interior of the target generator by the pressure control unit when the size of the adhering
area has reached the set size; and

hardening the target material in the target generator and the adhering area by stopping the heating of the target material
by the heating unit.

US Pat. No. 9,125,285

TARGET SUPPLY DEVICE AND EUV LIGHT GENERATION CHAMBER

GIGAPHOTON INC., Tochigi...

1. A target supply device that supplies a droplet of a target material to a plasma generation region, the device comprising:
a target generator comprising:
a tank containing the target material;
a nozzle from which the droplet is supplied toward the plasma generation region;
a first electrode disposed within the tank;
a second electrode provided with a first through-hole and disposed so that a center axis of the nozzle is positioned within
the first through-hole;

a first potential setting unit configured to set a potential at the first electrode to a first potential; and
a second potential setting unit configured to set a potential at the second electrode to a second potential that is different
from the first potential, the droplet being charged and extracted from the nozzle due to a difference between the first potential
and the second potential, and passing through the first through-hole of the second electrode, wherein

the target generator further comprises a charge neutralization unit configured to neutralize the charged droplet at a first
region immediately before the droplet is outputted from the target generator to the plasma generation region.

US Pat. No. 9,046,651

MIRROR DEVICE

GIGAPHOTON INC., Tochigi...

1. A mirror device, comprising:
a mirror including
a base plate having a surface a second surface opposite to the first surface, and a side surface different from the first
and second surfaces, the side surface having a plurality of holes,

a reflective film on the first surface of the base plate, and
a plurality of first protrusions on the second surface of the base plate;
a plurality of support parts for respectively supporting the plurality of the first protrusions, each support part having
a groove for guiding the first protrusion; and

a plurality of clamps each having a first portion secured on corresponding one of the plurality of support parts and a second
portion positioned in corresponding one of the plurality of holes, the plurality of clamps being configured to press respectively
the plurality of the first protrusions against grooves in the plurality of the support parts.

US Pat. No. 9,225,139

DISCHARGE-PUMPED GAS LASER DEVICE

GIGAPHOTON INC., Tochigi...

1. A discharge-pumped gas laser device, comprising:
a laser chamber being independently replaceable;
a pair of discharge electrodes provided in the laser chamber;
a fan with a magnetic bearing being provided in the laser chamber and configured to be capable of circulating a gas in the
laser chamber;

a housing configured to contain the laser chamber;
a magnetic bearing controller connected to the magnetic bearing electrically, being capable of controlling the magnetic bearing,
separated from the laser chamber, provided in the housing, and including a digital circuit and a storage element or external
terminal connected the digital circuit; and

a laser controller configured to control generation of laser light, wherein
the digital circuit calculates an optimal value in order to provide a rotor included the fan with a target control value,
and

the laser controller causes the magnetic bearing controller to execute calculation and setting of a control parameter necessary
for a control of the magnetic bearing in a case where at least one of a predetermined time course, a predetermined number
of an output(s) of the laser light, a predetermined change of a predetermined gas pressure in the laser chamber, vibration
of the laser chamber, a predetermined change of a wavelength stability of the laser light, a predetermined change of an energy
stability of the laser light, touchdown of the magnetic bearing, and an error in the magnetic bearing controller, is detected
after replacement of the laser chamber.

US Pat. No. 9,402,297

EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. An apparatus used with a laser apparatus, the apparatus comprising:
a chamber;
a target supply configured to supply a target to a first region inside the chamber;
a laser beam focusing optical system configured to focus laser beams on the first region,
the laser beams including a pre-pulse laser beam with which the target is irradiated and a main pulse laser beam with which
the target is irradiated subsequent to the pre-pulse laser beam;

a laser apparatus configured to generate the pre-pulse laser beam having a pulse duration of less than 1 ns and to generate
the main pulse laser beam; and

an intensity distribution control optical system configured to control intensity distribution along a first cross section
of the pre-pulse laser beam,

the first cross section being located in the first region, the intensity distribution along the first cross section has a
second region in which a variation value C={(Imax?Imin)/(Imax+Imin)}×100(%) is equal to or less than 20%, where Imax is the
highest beam intensity in the second region and Imin is the lowest beam intensity in the second region, an area of the second
region being larger than an area of a second cross-section of the target, the second cross-section being a maximum cross-section
perpendicular to the traveling path of the pre-pulse laser beam.

US Pat. No. 9,310,686

TARGET SUPPLY DEVICE AND TARGET SUPPLY METHOD

GIGAPHOTON INC., Tochigi...

4. A target supply device comprising:
a target generation unit that has a nozzle and is configured to accommodate a target material in the interior of the target
generation unit;

a pressure control unit that has a pressure sensor configured to detect a pressure inside the target generation unit and has
an actuator configured to control the pressure inside the target generation unit;

an electrode configured to extract the target material through a nozzle hole of the nozzle with electrostatic force;
a potential application unit configured to apply a potential to the electrode and the target material inside the target generation
unit;

a timer; and
a controlling unit configured to:
control the actuator such that the pressure inside the target generation unit is raised to a setting pressure based on a detection
result of the pressure inside the target generation unit detected by the pressure sensor and a time of the timer;

control the potential application unit such that applying different potentials are applied to the electrode and the target
material from each other in the case where it is detected that the pressure inside the target generation unit is halfway raised
to the setting pressure based on the detection result of the pressure inside the target generation unit by the pressure sensor
and the time of the timer; and

control the potential application unit such that a constant first potential is applied to the target material and a first
pulse voltage is applied to the electrode in order to extract the target material with the electrostatic force in the case
where it is detected that the pressure inside the target generation unit has been raised to the setting pressure based on
the detection result of the pressure inside the target generation unit detected by the pressure sensor and the time of the
timer.

US Pat. No. 9,179,534

EXTREME ULTRAVIOLET LIGHT SOURCE APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light source apparatus for supplying extreme ultraviolet light to a processing unit for performing
processing by using the extreme ultraviolet light, said apparatus comprising:
a chamber in which the extreme ultraviolet light to be supplied to said processing unit is generated;
a collector mirror provided in said chamber, and configured to collect the extreme ultraviolet light generated in said chamber
and to output the extreme ultraviolet light from said chamber; and

an optical path connection module arranged at a position between said chamber and said processing unit, and configured to
be detachable from the position by detaching said chamber from said processing unit, to isolate a route of the extreme ultraviolet
light between said chamber and said processing unit from outside, and to form, in the optical path connection module, an intermediate
focusing point of the extreme ultraviolet light from said chamber, wherein

said optical path connection module includes a wave-shaped section formed on an inner wall of said optical path connection
module.

US Pat. No. 9,055,657

EXTREME ULTRAVIOLET LIGHT GENERATION BY POLARIZED LASER BEAM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation apparatus, comprising:
a droplet production device configured to produce a droplet of a target substance in a predetermined traveling direction;
a first laser device configured to generate a first laser beam and irradiate the droplet with the first laser beam to diffuse
the droplet;

a second laser device configured to generate a second laser beam and irradiate the target substance diffused by irradiation
of the first laser beam with the second laser beam to produce plasma of the diffused target substance and generate extreme
ultraviolet light from the plasma of the target substance;

a beam shaping unit configured to elongate a beam spot of the first laser beam in the traveling direction of the droplet produced
by the droplet production device; and

a polarization adjustment mechanism configured to adjust polarization of the first laser beam emitted from the first laser
device,

wherein the polarization of the first laser beam adjusted by the polarization adjustment mechanism is linear polarization
and a polarization direction of the linear polarization is generally parallel to the traveling direction of the droplet.

US Pat. No. 9,192,038

TARGET SUPPLY APPARATUS, CONTROL SYSTEM, CONTROL APPARATUS AND CONTROL CIRCUIT THEREOF

Gigaphoton Inc., Tochigi...

1. A target supply apparatus comprising:
a tank for storing a liquid target material;
a nozzle for outputting the liquid target material in the tank; and
a gas supply source for supplying gas into the tank,
the target supply apparatus controlling a gas pressure inside the tank with a pressure of the gas supplied from the gas supply
source provided with a pressure regulator, and further comprising:

a pressure-decrease gas passage of which one end is connected to the tank and the other end forms an exhaust port;
a pressure-decrease valve provided in the pressure-decrease gas passage;
a controller for controlling open/close of the pressure-decrease valve;
a pressure-increase gas passage connecting between the gas supply source and the tank, the pressure regulator being provided
in the pressure-increase gas passage;

a pressure-increase valve provided in the pressure-increase gas passage between the pressure regulator and the tank,
a first gas passage connected to the pressure-decrease gas passage on the side of the tank from the pressure-decrease valve;
a vacuum pump connected to the other end of the first gas passage; and
a first valve provided in the first gas passage, wherein
one end of the pressure-decrease gas passage is connected to the pressure-increase gas passage between the pressure-increase
valve and the tank,

the controller, when the target material is to be output from the nozzle, opens the pressure-increase valve and closes the
pressure-decrease valve, to thereby increase the pressure inside the tank, and decreases the pressure inside the tank, when
the target material is not to be output from the nozzle, by closing the pressure-increase valve and opening the pressure-decrease
valve, and

the controller, when the output of the target material from the nozzle is to be stopped, closes the first valve and opens
the pressure-decrease valve, to thereby decrease the pressure inside the tank, then closes the pressure-decrease valve, opens
the first valve, and further decreases the pressure inside the tank by using the vacuum pump.

US Pat. No. 9,386,675

LASER BEAM CONTROLLING DEVICE AND EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

GIGAPHOTON INC., Tochigi...

1. A laser beam controlling device, comprising:
a guide laser device configured to output a guide laser beam;
a guide laser beam wavefront adjuster provided in a beam path of the guide laser beam outputted from the guide laser device;
a beam combiner configured to adjust a travel direction of a laser beam outputted from a laser system and a travel direction
of the guide laser beam outputted from the guide laser beam wavefront adjuster to coincide with each other;

a both beam wavefront adjuster provided in a beam path of both the laser beam outputted from the beam combiner and the guide
laser beam outputted from the beam combiner;

a beam monitor provided in a beam path of both the laser beam outputted from the both beam wavefront adjuster and the guide
laser beam outputted from the both beam wavefront adjuster; and

a controller configured to control the guide laser beam wavefront adjuster and the both beam wavefront adjuster based on detection
results at the beam monitor with respect to both the laser beam outputted from the both beam wavefront adjuster and the guide
laser beam outputted from the both beam wavefront adjuster.

US Pat. No. 9,128,391

OPTICAL DEVICE INCLUDING WAVEFRONT CORRECTION PARTS AND BEAM DIRECTION PARTS, LASER APPARATUS INCLUDING THE OPTICAL DEVICE, AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM INCLUDING THE LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. An optical device, comprising:
a mirror configured:
to reflect part of a first laser beam incident on one principal surface thereof as a first reflected beam and transmit the
other part of the first laser beam through the mirror as a first transmitted beam, and

to transmit part of a second laser beam incident on the other principal surface thereof through the mirror as a second transmitted
beam and reflect the other part of the second laser beam as a second reflected beam;

an optical system disposed so that the first and second laser beams are incident on the mirror such that a beam path of the
first transmitted beam and a beam path of the second reflected beam are made to be parallel to each other or to substantially
coincide with each other, or such that a beam path of the first reflected beam and a beam path of the second transmitted beam
are made to be parallel to each other or to substantially coincide with each other;

a first measuring unit configured to measure a beam parameter of at least one of the first transmitted beam and the first
reflected beam; a second measuring unit configured to measure a beam parameter of at least one of the second reflected beam
and the second transmitted beam;

a first adjusting unit configured to adjust the first laser beam based on a measurement result by the first measuring unit;
and

a second adjusting unit configured to adjust the second laser beam based on a measurement result by the second measuring unit,
wherein:

the first adjusting unit includes a first wavefront correction part for correcting a wavefront of the first laser beam, and
a first beam direction correction part for correcting a direction in which the first laser beam travels,

the second adjusting unit includes a second wavefront correction part for correcting a wavefront of the second laser beam,
and a second beam direction correction part for correcting a direction in which the second laser beam travels, and

the correction is performed so that a difference between a measured value and a target value falls within a predetermined
acceptable range.

US Pat. No. 9,072,152

EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM UTILIZING A VARIATION VALUE FORMULA FOR THE INTENSITY

GIGAPHOTON INC., Tochigi...

1. An apparatus comprising:
a chamber;
a target supply for supplying a target material to a region inside the chamber;
a focusing optical system for focusing a laser beam on the region, the laser beams including (1) a pre-pulse laser beam with
which the target material is irradiated and (2) a main pulse laser beam with which the target material is irradiated subsequent
to the pre-pulse laser beam;

a laser apparatus configured to generate the pre-pulse laser beam having a pulse duration of less than 1 ns and to generate
the main pulse laser beam;

an intensity control optical system for controlling intensity distribution of the pre-pulse laser beam has a uniform intensity
distribution region in a first cross-section with which the target material is irradiated, the uniform intensity distribution
region in the first cross-section being perpendicular to a first traveling path of the pre-pulse laser beam, a variation value
C={(Imax?Imin)/(Imax+Imin)}×100(%) being equal to or less than 20%, where Imax is the highest beam intensity in the uniform
intensity distribution region and Imin is the lowest beam intensity in the uniform intensity distribution region;

a first detector configured to detect that the target material reaches a predetermined position along the first traveling
path;

a laser trigger generator configured to, responsive to the detection of the first detector, generate a trigger signal to control
generation of the pre-pulse laser beam and the main pulse laser beam;

a second detector configured to detect a second traveling path of the target material; and
a droplet controller configured to control the target supply to adjust the second traveling path when a deviation of the second
traveling path is out of a permissible range, wherein:

an area of the uniform intensity distribution region of the first cross-section the pre-pulse laser beam is larger than an
area of the maximum cross section of the target material, the maximum cross section of the target material being perpendicular
to the first traveling path of the pre-pulse laser beam, and

the main pulse laser beam does not have a uniform intensity distribution region in a second cross-section with which the target
material is irradiated, the uniform intensity distribution region in the second cross-section being perpendicular to a third
traveling path of the main pulse laser beam.

US Pat. No. 9,407,052

AMPLIFIER, LASER APPARATUS, AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. An amplifier, comprising:
a plurality of discharge tubes arranged between a first position and a second position in a path of a seed laser beam forming
a beam waist, the first position being an input position from which the seed laser beam enters the amplifier and the second
position being an output position from which the seed laser beam exists the amplifier; and

a reflective optical system arranged between the plurality of discharge tubes in the path such that a central position between
the first position and the reflective optical system in the path is transferred onto a central position between the reflective
optical system and the second position in the path.

US Pat. No. 9,538,629

CHAMBER FOR EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS, AND EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation apparatus, comprising:
a chamber into which droplets are sequentially outputted, the chamber including an image capturing unit configured to repeatedly
capture images of the droplets during an image capturing time set so that images of two adjacent droplets that have been outputted
do not overlap,

a target generation apparatus configured to hold a target that generates extreme ultraviolet light when irradiated with a
laser beam within the chamber and configured to output the target into the chamber as the droplets;

a droplet image measurement unit configured to measure image data captured by the image capturing unit of the droplets outputted
into the chamber;

a droplet diameter calculation unit configured to calculate a diameter of the droplets based on the image data,
a droplet output calculation control unit configured to calculate a total output amount of the droplets outputted into the
chamber based on the diameter;

a remaining target amount calculation unit configured to calculate a remaining amount of the target held in the target generation
apparatus based on an initial amount of the target held in the target generation apparatus before outputting the droplets
into the chamber and the total output amount; and

a droplet counter unit configured to count the number of the droplets outputted into the chamber,
wherein when a distance between the images of the two droplets in a travel direction of the droplets is represented by d and
a travel velocity of the droplets is represented by v, a single image capturing time ?t of the image capturing unit is expressed
by ?t
wherein when a length of an image capturing range of the image capturing unit in the travel direction of the droplets is represented
by A, the single image capturing time ?t of the image capturing unit is set so that a relationship ?t>(d?A)/v is fulfilled,
and

wherein the droplet output calculation control unit is configured to calculate the total output amount based on the number
and diameter of the droplets.

US Pat. No. 9,113,540

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. A system comprising:
a chamber;
a laser beam apparatus configured to generate a laser beam to be introduced into the chamber;
a laser controller for the laser beam apparatus to control at least a beam intensity and an output timing of the laser beam;
and

a target supply unit configured to supply a target material into the chamber, the target material being irradiated with the
laser beam for generating extreme ultraviolet light, wherein the laser beam apparatus includes a first laser apparatus configured
to output a first pre-pulse laser beam with which the target material is irradiated inside the chamber; and

the system further comprises a polarization converter provided in a beam path of the first pre-pulse laser beam for changing
a polarization state of the first pre-pulse laser beam so that the target material is irradiated with the first pre-pulse
laser beam having a degree of linear polarization P defined by an expression P=?Imax?Imin|/|Imax+Imin|×100(%) which is equal
to or greater than 0% and smaller than 30% in order for the target material to improve an absorptivity of an energy of a subsequently-emitted
pulse laser beam, here Imax and Imin are respectively beam intensities of first and second polarization components in the
first pre-pulse laser beam, the polarization components being perpendicular to each other.

US Pat. No. 9,052,615

EXTREME ULTRAVIOLET LIGHT SOURCE APPARATUS

GIGAPHOTON INC., Tokyo (...

1. An extreme ultraviolet (EUV) light source apparatus for generating plasma by irradiating a target material with a laser
beam and outputting EUV light from the plasma to exposure equipment, the apparatus comprising:
a chamber in which the plasma is generated;
a droplet generator disposed in the chamber to provide the target material to be irradiated with the laser beam for generating
the plasma;

a collector mirror disposed in the chamber and configured to collect the EUV light from the plasma to the exposure equipment;
a support configured to support the chamber to align the optical axis of the EUV light source apparatus with an optical axis
of the exposure equipment, the support being further configured to:

move the chamber in a first direction crossing the aligned optical axes of the EUV source apparatus and the exposure equipment:
move the chamber in a second direction to align the optical axis of the EUV light source apparatus with an optical axis of
the exposure equipment, the second direction being opposite to the first direction;

a positioning mechanism configured to position the chamber for aligning the optical axis of the EUV light source apparatus
with the optical axis of the exposure equipment and restrict movement of the chamber in the second direction;

a fixing member configured to restrict movement of the chamber in the first direction from the position where the optical
axis of the EUV light source apparatus is aligned with the optical axis of the exposure equipment;

a base fixed onto a floor;
a rail fixed onto the base and extending in the first and second directions;
a slide block fixed to an undersurface of the support and configured to engage with the rail;
a bearing disposed between the rail and the slide block; and
a gate valve disposed at an EUV outlet of the chamber.

US Pat. No. 9,509,115

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT, AND LASER APPARATUS

GIGAPHOTON INC., Tokyo (...

1. An extreme ultraviolet light generation system used with a laser apparatus, the extreme ultraviolet light generation system
comprising:
a chamber including at least one window for at least one laser beam and a target supply unit for supplying a target material
into the chamber;

at least one polarization control unit, provided on a laser beam path, for controlling a polarization state of the at least
one laser beam;

a magnetic field generation unit, provided to the chamber, for generating a magnetic field in which a charged particle emitted
from the target material that has been struck by the laser beam is trapped; and

a collection unit into which the trapped charged particle is collected,
wherein the at least one polarization control unit converts the laser beam into a linearly polarized laser beam.

US Pat. No. 9,233,782

TARGET SUPPLY DEVICE

GIGAPHOTON INC., Tochigi...

1. A target supply device, comprising:
a tank formed cylindrically with a first material;
a cylindrical portion for covering the tank, the cylindrical portion being formed of a second material having higher tensile
strength than the first material;

a first lid formed of the second material and having a through-hole, the first lid being provided at one end in an axial direction
of the cylindrical portion;

a second lid formed of the second material and provided at another end opposite the one end in the axial direction of the
cylindrical portion; and

a nozzle provided to be in fluid communication with the interior of the tank and to pass through the through-hole, the nozzle
being formed of the first material.

US Pat. No. 9,184,551

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser apparatus, comprising:
a master oscillator;
an optical unit provided in a beam path of a laser beam from the master oscillator;
a beam adjusting unit provided upstream from the optical unit in a beam path of the laser beam and configured for adjusting
at least a beam path of the laser beam;

a first detection unit provided between the beam adjusting unit and the optical unit in a beam path of the laser beam and
configured for detecting the laser beam and outputting a detection value pertaining to the beam path of the laser beam;

a second detection unit provided downstream from the optical unit in a beam path of the laser beam and configured for detecting
the laser beam; and

a controller configured for controlling the beam adjusting unit based on outputs from the first and second detection units.

US Pat. No. 9,072,153

EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM UTILIZING A PRE-PULSE TO CREATE A DIFFUSED DOME SHAPED TARGET

GIGAPHOTON INC., Tochigi...

1. A system for generating extreme ultraviolet light by irradiating a target with a pre-pulse laser beam and a main laser
beam to turn the target into plasma, the system comprising:
a chamber;
a target supply configured to supply the target to a region inside the chamber;
a first laser apparatus configured to output the pre-pulse laser beam having a pulse duration of smaller than 1 ns, the pre-pulse
laser beam having a fluence equal to or lower than a fluence of the main pulse laser beam, the fluence of the pre-pulse laser
beam being equal to or higher than 6.5 J/cm2 and equal to or lower than 52 J/cm2, where the target is to be irradiated with the pre-pulse laser beam;

a second laser apparatus configured to output the main pulse laser beam, where the target irradiated with the pre-pulse laser
beam is to be further irradiated with the main pulse laser beam; and

an intensity distribution control optical system for controlling intensity distribution of the pre-pulse laser beam so that
the pre-pulse laser beam has a uniform intensity distribution region in a first cross-section where the target is irradiated
with the pre-pulse laser beam, the first cross-section being perpendicular to a first traveling path of the pre-pulse laser
beam, wherein:

the first laser apparatus is configured to output the pre-pulse laser beam so as to make the target be diffused in a dome
shape,

the uniform intensity distribution region of the first cross-section of the pre-pulse laser beam has an area larger than an
area of a maximum cross section of the target, the maximum cross section of the target being perpendicular to the first traveling
path, and

the main pulse laser beam does not have a uniform intensity distribution region in a second cross-section where the target
is irradiated with the main pulse laser beam, the second cross-section being perpendicular to a second traveling path of the
main pulse laser beam.

US Pat. No. 9,647,415

LASER APPARATUS AND METHOD OF CONTROLLING LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:
a laser chamber filled with a laser gain medium;
a pair of electrodes disposed in the laser chamber;
a charger configured to apply a charge voltage for causing a discharge to occur between the pair of the electrodes;
a pulse power module configured to convert the charge voltage applied by the charger into a short pulsed voltage, and apply
the short pulsed voltage between the pair of the electrodes; and

a controller configured to calculate input energies Ein applied to the pair of the electrodes based on the charge voltage,
calculate an integration value Einsum of the input energies Ein by integrating the calculated input energies Ein, and determine
whether the integration value Einsum exceeds an integration lifetime value Einsumlife or not,

wherein the integration lifetime value Einsumlife is calculated from an electrode consumption amount Rdlife, an area S of
discharge surfaces of the pair of electrodes, and a consumption rate coefficient ? of the pair of the electrodes.

US Pat. No. 9,373,926

LASER CHAMBER AND DISCHARGE EXCITATION GAS LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A laser chamber housing a pair of discharge electrodes and a gas circulation fan, the laser chamber comprising:
a magnetic bearing configured to support a shaft of the gas circulation fan, with the shaft being in non-contact with the
magnetic bearing; and

a touchdown bearing configured to operate as a bearing when the magnetic bearing is uncontrollable, the touchdown bearing
being provided with solid lubricant configured of a Cu plating layer.

US Pat. No. 9,351,388

TARGET GENERATION DEVICE AND EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. A target supply device comprising:
a reservoir configured to hold a target material in a reservoir interior in a liquid form;
a target sensor configured to detect droplets of the target material outputted from the reservoir; and
a control unit configured to determine a standard deviation of an interval between the droplets, and to determine whether
the standard deviation is less than a redetermined threshold;

wherein the control unit permits laser radiation only if the standard deviation is less than the predetermined threshold.

US Pat. No. 9,439,276

EXTREME ULTRAVIOLET LIGHT GENERATING SYSTEM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generating system comprising:
a laser apparatus configured to provide pulsed laser light inside a chamber in which EUV light is generated;
an optical shutter disposed on an optical path of the pulsed laser light;
a controller configured to open or close the optical shutter, based on a generation signal supplied from an external unit,
the generation signal instructing generation of the EUV light;

a light emission trigger generator configured to generate a light emission trigger signal and to supply the light emission
trigger signal to the laser apparatus, the light emission trigger signal instructing output of the pulsed laser light;

a target feeder configured to feed a target inside the chamber, the target being to be irradiated with the pulsed laser light
outputted from the laser apparatus;

a detector configured to detect feed timing at which the target is fed from the target feeder and to provide the light emission
trigger generator with a first timing signal indicating the feed timing; and

a timer circuit configured to generate a second timing signal and to provide the light emission trigger generator with the
second timing signal, during absence of the first timing signal from the detector,

wherein the light emission trigger generator generates the light emission trigger signal, based on the first timing signal
and the second timing signal.

US Pat. No. 9,478,933

WAVELENGTH DETECTOR AND WAVELENGTH CALIBRATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. A wavelength detector that detects a wavelength of a laser beam outputted from an ultra violet laser device, the wavelength
detector comprising:
a discharge tube that includes a cylindrical anode and a cylindrical cathode that each have a through-hole formed therein,
and that is configured so that an electrical property between the anode and the cathode changes due to an opto-galvanic effect
when a laser beam having a predetermined first wavelength passes through the through-hole of the cathode in a state in which
a DC voltage is applied to the anode;

a high-voltage DC power source configured so as to apply the DC voltage to the anode;
an electrical signal processing unit including an electrical signal detection point for detecting a voltage change in a signal
level of the cathode; and

a dumper provided downstream from the discharge tube in an optical path of the laser beam and configured to absorb the laser
beam that has passed through the discharge tube,

wherein the electrical signal processing unit includes at least one of
an electrical low-pass filter connected to the electrical signal detection point for suppressing a voltage level of a photoelectric
effect signal produced when the cathode is irradiated with the laser beam and

an electrical delay circuit that delays an electrical signal detection timing of the voltage level in the electrical signal
detection point by a predetermined amount of time in order to start the electrical signal detection of the voltage level at
least after the voltage peak of the photoelectric effect signal in the electrical signal detection point, and

wherein the electrical signal processing unit detects the voltage change in the electrical property.

US Pat. No. 9,429,847

EXTREME ULTRAVIOLET LIGHT SOURCE APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light source apparatus configured to generate plasma by applying a laser beam to a target material
and entering extreme ultraviolet light radiated from the plasma into projection optics of exposure equipment, the apparatus
comprising:
a chamber in which the extreme ultraviolet light is generated;
a movement mechanism for moving at least a part of the chamber positioned in a predetermined location between the predetermined
location and a maintenance area, the predetermined location where an optical axis of collected extreme ultraviolet light and
an optical axis of the projection optics of the exposure equipment are aligned with each other; and

a laser beam introduction duct for introducing the laser beam from an outside of the chamber to an inside of the chamber,
the laser beam introduction duct being provided outside of a track on which at least the part of the chamber moves between
the predetermined location and the maintenance area.

US Pat. No. 9,425,576

EXCIMER LASER APPARATUS AND EXCIMER LASER SYSTEM

GIGAPHOTON INC., Tochigi...

1. An excimer laser system comprising:
a first excimer laser apparatus that includes a first laser chamber containing a gas, at least a pair of first electrodes
disposed within the first laser chamber, and a first resonator disposed sandwiching the first laser chamber;

a second excimer laser apparatus that includes a second laser chamber containing a gas, at least a pair of second electrodes
disposed within the second laser chamber, and a second resonator disposed sandwiching the second laser chamber, and that amplifies
laser light outputted from the first excimer laser apparatus;

at least one power source unit that supplies a voltage between the first electrodes and the second electrodes;
a gas supply unit, connected to a first receptacle that holds a first laser gas containing halogen gas and a second receptacle
that holds a second laser gas having a lower halogen gas concentration than the first laser gas, the gas supply unit including:

a first pipe connected to the first laser chamber;
a first valve provided in the first pipe;
a second pipe connected to the second laser chamber;
a second valve provided in the second pipe; and
a third pipe connected to both the first pipe and the second pipe, at least one of the first receptacle and the second receptacle
being connected to the third pipe, so that the gas supply unit supplies the first laser gas and the second laser gas to the
interiors of the first laser chamber and the second laser chamber;

a gas exhaust unit that partially exhausts gas from within the first laser chamber and the second laser chamber; and
a gas control unit that controls the gas supply unit and the gas exhaust unit,
wherein the gas control unit selectively performs:
a first gas pressure control in which the gas supply unit supplies the second laser gas to the interior of the first laser
chamber or the gas exhaust unit partially exhausts gas from within the first laser chamber, where the gas control unit controls
the first valve to open, while the second valve being closed;

a second gas pressure control in which the gas supply unit supplies the second laser gas to the interior of the second laser
chamber or the gas exhaust unit partially exhausts gas from within the second laser chamber, where the gas control unit controls
the second valve to open, while the first valve being closed;

a first partial gas replacement control in which the gas supply unit supplies the first laser gas and the second laser gas
to the interior of the first laser chamber and the gas exhaust unit partially exhausts gas from within the first laser chamber
sequentially, where the gas control unit controls the first valve to open, while the second valve being closed; and

a second partial gas replacement control in which the gas supply unit supplies the first laser gas and the second laser gas
to the interior of the second laser chamber and the gas exhaust unit partially exhausts gas from within the second laser chamber
sequentially, where the gas control unit controls the second valve to open, while the first valve being closed,

wherein the gas control unit is configured to:
measure a repetition rate of the laser light outputted from the first laser chamber or the second laser chamber;
calculate a first time interval based on the repetition rate, the first time interval having a first length when the repetition
rate has a first value, the first time interval having a second length shorter than the first length when the repetition rate
has a second value larger than the first value;

calculate a second time interval based on the repetition rate, the second time interval having a third length when the repetition
rate has a third value, the second time interval having a fourth length shorter than the third length when the repetition
rate has a fourth value larger than the third value;

perform a next first partial gas replacement control when the first time interval has passed since a former first partial
gas replacement control was performed; and

perform a next second partial gas replacement control when the second time interval has passed since a former second partial
gas replacement control was performed,

wherein, in the first partial gas replacement control, the gas supply unit supplies a first amount of laser gas including
the first laser gas and the second laser gas to the interior of the first laser chamber and the gas exhaust unit partially
exhausts the first amount of laser gas from within the first laser chamber when the repetition rate has the first value, and
the gas supply unit supplies a second amount of laser gas including the first laser gas and the second laser gas to the interior
of the first laser chamber, the second amount being smaller than the first amount, and the gas exhaust unit partially exhausts
the second amount of laser gas from within the first laser chamber when the repetition rate has the second value, and

wherein, in the second partial gas replacement control, the gas supply unit supplies a third amount of laser gas including
the first laser gas and the second laser gas to the interior of the second laser chamber and the gas exhaust unit partially
exhausts the third amount of laser gas from within the second laser chamber when the repetition rate has the third value,
and the gas supply unit supplies a fourth amount of laser gas including the first laser gas and the second laser gas to the
interior of the second laser chamber, the fourth amount being smaller than the third amount, and the gas exhaust unit partially
exhausts the fourth amount of laser gas from within the second laser chamber when the repetition rate has the fourth value.

US Pat. No. 9,362,703

OPTICAL DEVICE, LASER APPARATUS, AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation system including a laser apparatus, an optical device included in the laser apparatus,
comprising:
first and second optical modules disposed in a beam delivery path of a laser beam outputted from the laser apparatus;
first and second beam adjusting units disposed in the beam delivery path for adjusting the beam delivery path of the laser
beam;

first and second measuring units disposed in the beam delivery path for detecting the beam delivery path of the laser beam
passed through the first and second optical modules, respectively;

a first control unit for controlling the first beam adjusting unit based on a detection result of the beam delivery path of
the laser beam detected by the first measuring unit;

a second control unit for controlling the second beam adjusting unit based on a detection result of the beam delivery path
of the laser beam detected by the second measuring unit;

a control system for controlling the first and second control units; and
a positioning mechanism for positioning at least the first and second optical modules, wherein
the first optical module is a first amplifier for amplifying the laser beam,
the second optical module is a second amplifier disposed at an output side of the first optical module for amplifying the
laser beam passed through the first optical module,

the first measuring unit is disposed between the first optical module and the second optical module,
the second measuring unit is disposed at an output side of the second optical module,
the first beam adjusting unit is disposed at an input side of the first measuring unit,
the second beam adjusting unit is disposed at an output side of the first measuring unit and at an input side of the second
measuring unit,

the positioning mechanism positions at least the first and second amplifiers, and
the positioning mechanism further positions the first and second measuring units and the first and second beam adjusting units.

US Pat. No. 9,510,434

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS, METHOD OF GENERATING EXTREME ULTRAVIOLET LIGHT, CONCENTRATED PULSED LASER LIGHT BEAM MEASURING APPARATUS, AND METHOD OF MEASURING CONCENTRATED PULSED LASER LIGHT BEAM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generating apparatus, comprising:
a chamber containing one or more kinds of gases selected from the group consisting of argon gas, helium gas, krypton gas,
and N2 gas;

a light concentration optical system provided in an optical path of pulsed laser light outputted from a laser unit, and configured
to concentrate the pulsed laser light into a concentrated beam;

an image pickup section provided at a position out of the optical path of the pulsed laser light, and configured to pick up
a plasma emission image that is an image of plasma emission in the chamber, the plasma emission being caused by application
of the concentrated beam to the one or more kinds of gases in the chamber; and

a measuring section configured to determine, based on the plasma emission image acquired from the image pickup section, a
concentration position of the concentrated beam, and determine, as a concentration width of the concentrated beam, a minimum
value of a full width of the plasma emission image acquired from the image pickup section.

US Pat. No. 9,350,133

METHOD OF CONTROLLING LASER APPARATUS AND LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A method of controlling a laser apparatus comprising:
exchanging a laser gain medium in a laser chamber configured to output a laser beam by exciting the laser gain medium;
first measuring, after the exchanging, pulse energy of a laser beam which is oscillated in the laser chamber under a specific
gas pressure and a specific charge voltage;

calculating an approximate expression indicating a relationship between the pulse energy of the laser beam and the gas pressure
in the laser chamber and the charge voltage, or a table representing a correlationship between the pulse energy, the gas pressure
and the charge voltage, based on the specific pressure, the specific charge voltage and the pulse energy in the first measuring;

storing the approximate expression or the table;
setting a lifetime of the laser chamber;
calculating a reference ?Ept of an energy reduction amount based on the lifetime of the laser chamber such that the reference
?Ept is smaller at longer lifetime of the laser chamber;

second measuring, after the first measuring, pulse energy Er of a laser beam oscillated in the laser chamber;
calculating pulse energy Eec which is supposed to be obtained directly after the exchanging under the gas pressure and the
charge voltage in the second measuring based on the approximate expression or the table;

calculating a reduction amount ?Ed of pulse energy based on the pulse energy Eec and the pulse energy Er using ?Ed=Eec?Er;
and

conducting, when the reduction amount ?Ed of pulse energy is equal to or greater than the reference ?Ept, partial gas exchange
of the laser gas in the laser chamber, wherein the reference ?Ept of an energy reduction amount is calculated by ?Ept=Em??Ent,

where Em is calculated by Em=Emax?Eex, Emax is a value of maximum pulse energy in the data collected by the first measuring,
and Eex is a value of maximum pulse energy instructed based on a request from an exposure apparatus, and

where ?Ent is calculated by ?Ent=?d×Bt, Ad is an energy reduction amount per unit of the number of discharges, and Bt is the
number of discharges representing the lifetime of the laser chamber.

US Pat. No. 9,257,809

LASER DEVICE FOR EXPOSURE APPARATUS

GIGAPHOTON INC., Tochigi...

1. A laser device for an exposure apparatus, the device comprising:
a MOPA-type or MOPO-type laser device including a seed laser and at least one gas discharge-pumped amplifier stage that receives
output light from the seed laser as an input, amplifies the light, and outputs the amplified light to the exposure apparatus;

an output energy detector configured to detect energy of the amplified light outputted from the gas discharge-pumped amplifier
stage;

a laser gas control device configured to control a pressure of a laser gas in the gas discharge-pumped amplifier stage;
a laser power source control device configured to control an excitation voltage to be applied to a discharge electrode in
the gas discharge-pumped amplifier stage; and

a laser controller configured to arrange an upper limit and a lower limit of the excitation voltage and execute a first process
for controlling the laser power source control device so that energy detected by the output energy detector comes close to
a target energy, the laser controller being configured to:

receive a request for changing the target energy from the exposure apparatus,
execute the first process, in response to the request for changing the target energy, to change the excitation voltage from
a first voltage within a range of the upper limit and the lower limit to a second voltage outside the range of the upper limit
and the lower limit,

begin to execute, while executing the first process in response to change in the energy detected by the output energy detector,
a second process for controlling the laser gas control device so that the excitation voltage comes within the range of the
upper limit and the lower limit from the second voltage,

execute, while executing the first process and the second process, a third process for determining whether the excitation
voltage has come within the range of the upper limit and the lower limit,

continue the second process if the excitation voltage has not come within the range of the upper limit and the lower limit,
and

stop the second process if the excitation voltage has come to a third voltage within the range of the upper limit and the
lower limit,

wherein, in the second process, when the excitation voltage is higher than the upper limit, the laser controller controls
the laser gas control device so as to inject the laser gas into the gas discharge-pumped amplifier stage, and when the excitation
voltage is lower than the lower limit, the laser controller controls the laser gas control device so as to vent the laser
gas from the gas discharge-pumped amplifier stage.

US Pat. No. 9,465,307

CLEANING METHOD FOR EUV LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. A cleaning method for an EUV light generation apparatus that includes a chamber in which EUV light is generated by introducing
a laser beam, a connection portion configured to allow an interior of the chamber and an interior of an exposure apparatus
to communicate, a target supply apparatus configured to supply a target material to a plasma generation site in the interior
of the chamber, an EUV collector mirror having a reflective surface that reflects and collects EUV light generated by irradiating
the target material with the laser beam at the plasma generation site and a through-hole that is formed at the center of the
EUV collector mirror, and an exhaust apparatus configured to exhaust the interior of the chamber, the laser beam traveling
through the through-hole toward the plasma generation site, the method comprising:
closing the connection portion so that the interior of the chamber and the interior of the exposure apparatus do not communicate
when the EUV light is not being generated;

supplying an etchant gas for etching debris that has accumulated on the reflective surface of the EUV collector mirror to
the interior of the chamber in a state where the connection portion is closed;

exhausting the interior of the chamber using the exhaust apparatus while supplying the etchant gas,
measuring an amount of the debris that has accumulated in a circumferential edge area of the through-hole on the reflective
surface that is closest to the plasma generation site when the EUV light is being generated,

when it is determined that the amount of the accumulated debris is greater than or equal to a threshold, sending an etching
mode signal requesting the start of etching;

in response to the etching mode signal, stopping an exposure operation performed by the exposure apparatus; and
sending an etching mode enabling signal when the exposure operation is stopped,
wherein, after stopping a generation of the EUV light when the etching mode enabling signal is received, the closing of the
connection portion, the supplying of the etchant gas, and the exhausting of the interior of the chamber are performed.

US Pat. No. 9,468,082

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS AND CONTROL METHOD FOR LASER APPARATUS IN EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation apparatus that generates extreme ultraviolet light by irradiating a target with
a pulse laser beam and producing plasma, the apparatus comprising,
a chamber containing a plasma generation region irradiated by a pulse laser beam from a laser apparatus;
a target supply device configured to supply a plurality of targets consecutively to the plasma generation region in the chamber;
a target detection unit configured to detect a target outputted from the target supply device that has passed a predetermined
position between the target supply device and the plasma generation region; and

laser control circuitry configured to control the laser apparatus,
the laser control circuitry including a light emission trigger generation circuit configured to generate a light emission
trigger instructing a laser device included in the laser apparatus to emit a pulse laser beam, and output the generated light
emission trigger to the laser apparatus,

the light emission trigger generation circuit including a first circuit configured to output a first signal that changes from
OFF to ON after a first time has passed from a detection signal indicating target detection from the target detection unit,
and a first AND circuit configured to output an AND signal of the first signal and the detection signal,

the light emission trigger generation circuit outputting the light emission trigger to the laser apparatus based on an output
from the first AND circuit, and

the laser control circuitry outputting the light emission trigger to the laser apparatus in response to a next detection signal
received immediately after the first time has passed following the detection signal.

US Pat. No. 9,271,382

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:
a master oscillator configured to output a pulse laser beam;
an amplifier disposed in a light path of the pulse laser beam;
a wavelength selection element disposed in the light path of the pulse laser beam and configured to be switched between (1)
a first state and (2) a second state to suppress spontaneous emission light from being amplified and entering the master oscillator,
to suppress spontaneous emission light from being amplified and striking the target, or to suppress reflection light of the
pulse laser beam reflected by the target from being amplified and entering the master oscillator,

(1) the wavelength selection element in the first state having (1-1) a first transmittance for light of a first wavelength
and (1-2) a second transmittance for light of a second wavelength, the second transmittance being lower than the first transmittance,

(2) the wavelength selection element in the second state having (2-1) a third transmittance for light of the first wavelength
for which the amplifier has a first amplification factor, the third transmittance being lower than the first transmittance,
and (2-2) a fourth transmittance for light of the second wavelength for which the amplifier has a second amplification factor
lower than the first amplification factor, the fourth transmittance being higher than the third transmittance; and

a controller configured to switch the wavelength selection element.

US Pat. No. 9,578,730

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation system comprising:
a first laser apparatus configured to output a first pulse laser beam;
a second laser apparatus configured to output a second pulse laser beam;
a chamber;
a target generation unit configured to output a target to a predetermined region in the chamber;
a laser controller configured to control the first laser apparatus and the second laser apparatus so that the target is irradiated
with the first pulse laser beam, the target being turned into a secondary target by being irradiated with the first pulse
laser beam, and so that the secondary target is irradiated with the second pulse laser beam;

a focusing optical system configured to concentrate the first pulse laser beam to the target and concentrate the second pulse
laser beam to the secondary target;

a plurality of scattered light detectors each configured to detect both scattered light from the target irradiated with the
first pulse laser beam and scattered light from the secondary target irradiated with the second pulse laser beam; and

an EUV light generation controller configured to control at least an optical path of the first pulse laser beam on a basis
of results of detection of the scattered light from the target irradiated with the first pulse laser beam and then control
an optical path of the second pulse laser beam on a basis of results of detection of the scattered light from the secondary
target irradiated with the second pulse laser beam.

US Pat. No. 9,277,635

METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT AND DEVICE FOR GENERATING EXTREME ULTRAVIOLET LIGHT

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation method for generating extreme ultraviolet light, comprising:
outputting a target from a target supply device toward a first predetermined region inside a chamber, the chamber being provided
with a through-hole;

detecting the target passing through a second predetermined region by irradiating the second predetermined region with light
and by detecting light incident on an optical sensor from the second predetermined region, the second predetermined region
including part of a trajectory of the target between the target supply device and the first predetermined region, and the
second predetermined region being a region that is longer along a direction perpendicular to a direction of movement of the
target and perpendicular to an optical path of the light with which the second predetermined region is irradiated than along
the direction of movement of the target; and

irradiating the target with a pulse laser beam introduced into the first predetermined region through the through-hole, on
a basis of a timing of detecting the target passing through the second predetermined region, to turn the target into plasma.

US Pat. No. 9,510,433

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An apparatus for generating extreme ultraviolet light comprising:
a chamber provided with at least one inlet through which a laser beam is introduced into the chamber;
a target supply unit provided on the chamber configured to supply a target material to a predetermined region inside the chamber;
at least one optical element provided inside the chamber;
at least one temperature control mechanism configured to control a temperature of the at least one optical element, each of
the temperature control mechanism including:

a chiller configured to cool a heat carrier;
a flow channel connecting the at least one optical element and the chiller and configured to let a temperature-controlled
heat carrier flow therethrough;

a first temperature sensor configured to detect a temperature of the heat carrier flowing through the flow channel; and
a temperature controller configured to control a flow rate of the heat carrier flowing through the flow channel based on a
detection result of the first temperature sensor.

US Pat. No. 9,507,248

TWO-BEAM INTERFERENCE APPARATUS AND TWO-BEAM INTERFERENCE EXPOSURE SYSTEM

Gigaphoton Inc., Tochigi...

1. A two-beam interference apparatus comprising:
a wafer stage configured to receive a wafer to be set on the wafer stage;
a beam splitter configured to split first laser light output from a laser device into second laser light and third laser light
having a beam intensity distribution elongated in a first direction within a surface of the wafer;

an optical system configured to guide the second laser light and the third laser light onto the wafer;
a phase error detector configured to detect a phase error between the second laser light and the third laser light; and
a controller configured to tune a wavelength of the first laser light output from the laser device based on the phase error
detected by the phase error detector,

wherein the wafer is irradiated with the second laser light from a second direction perpendicular to the first direction,
and the third laser light from a third direction perpendicular to the first direction but different from the second direction,
to thereby cause interference of the second and third laser light output from the optical system on the wafer.

US Pat. No. 9,363,878

DEVICE FOR CONTROLLING LASER BEAM AND APPARATUS FOR GENERATING EXTREME ULTRAVIOLET LIGHT UTILIZING WAVEFRONT ADJUSTERS

GIGAPHOTON INC., Tochigi...

1. A device for controlling a laser beam, comprising:
a first wavefront adjuster provided in a beam path of a laser beam outputted from a laser apparatus;
a beam delivery unit provided in a beam path of the laser beam from the first wavefront adjuster;
a second wavefront adjuster provided in a beam path of the laser beam from the beam delivery unit;
a beam monitor provided in a beam path of the laser beam from the second wavefront adjuster, the beam monitor configured to
output a detection result; and

a controller configured to control the first wavefront adjuster based on a beam width calculation and the second wavefront
adjuster based on a beam spot width calculation, with each calculation based on the detection result of the beam monitor.

US Pat. No. 9,622,332

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation apparatus that irradiates a target with a pulse laser beam at a plasma generation
region, the apparatus comprising:
a chamber provided with a through-hole;
a conducting optical system configured to conduct the pulse laser beam to the plasma generation region in the chamber via
the through-hole;

a target supply device configured to output the target toward the plasma generation region; and
a target detection section, the target detection section including:
a light source;
a transfer optical system disposed tilted relative to a plane orthogonal to the trajectory of the target;
an image sensor configured to output image data of an image that has been formed by irradiating the target outputted from
the target supply device with light outputted from the light source and that has then been formed on a light-receiving unit
of the image sensor transferred by the transfer optical system; and

a processing unit, connected to the image sensor, configured to:
receive the outputted image data,
obtain, based on the image data of the image, a first optical intensity distribution along a first line that intersects with
a trajectory of the target and a second optical intensity distribution along a second line that intersects with the trajectory,

calculate a center of gravity position in the first optical intensity distribution and a center of gravity position in the
second optical intensity distribution, and

calculate parameters of a regression line expressing an actual path of the target based on the calculated center of gravity
positions.

US Pat. No. 9,184,555

LASER SYSTEM AND LASER LIGHT GENERATION METHOD

Gigaphoton Inc., Tochigi...

1. A laser system comprising:
a master oscillator including a seed laser and an amplifier and configured to generate pulsed laser light;
an amplification device configured to amplify the pulsed laser light from the master oscillator;
a first timing detector configured to detect a first timing at which the pulsed laser light passes through a predetermined
position;

a second timing detector configured to detect a second timing at which the amplification device discharges; and
a controller configured to, based on results of detection by the first timing detector and the second timing detector, control
at least one of the first timing and the second timing so that the amplification device discharges when the pulsed laser light
passes through a discharge space of the amplification device,

wherein the master oscillator further includes at least one optical shutter disposed in an optical path between the seed laser
and the amplification device,

wherein the predetermined position is a position where the pulsed laser light passes through after the optical shutter, and
wherein the controller is configured to control at least one of a timing at which the optical shutter is put into an open
state and a timing at which the amplification device discharges based on the results of detection by the first timing detector
and the second timing detector.

US Pat. No. 9,743,503

LASER DEVICE AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:
an oscillator capable of outputting a laser beam;
a slab optical amplifier capable of amplifying the laser beam outputted by the oscillator by passing the laser beam through
an optical amplification region shaped like a slab and outputting the amplified laser beam; and

a mirror disposed on an optical path of the laser beam to enter the slab optical amplifier or the amplified laser beam outputted
from the slab optical amplifier, the mirror being movable in a direction parallel to a plane where the laser beam travels
in the slab optical amplifier.

US Pat. No. 9,490,603

LASER APPARATUS AND METHOD OF CONTROLLING LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A laser apparatus comprising:
a laser chamber configured to include a laser gain medium;
a pair of electrodes disposed in the laser chamber;
an energy detector configured to measure pulse energy of laser beams outputted by discharging between the pair of the electrodes;
an optical element disposed on a light path of the laser beams; and
a controller configured to, with respect to the optical element, calculate a lifetime shot number with respect to the laser
beams with the pulse energy based on the pulse energy of the laser beams, calculate a lifetime index value by integrating
inverses of the respective calculated lifetime shot numbers, and determine whether the lifetime index value exceeds 1 or not.

US Pat. No. 9,888,555

TRANSMISSION SYSTEM FOR TRANSMITTING PULSE LASER BEAM TO EXTREME ULTRAVIOLET LIGHT CHAMBER, AND LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising:
a laser apparatus including:
a first pre-pulse laser apparatus configured to output a first pre-pulse laser beam to illuminate a target supplied to an
extreme ultraviolet light chamber;

a second pre-pulse laser apparatus configured to output a second pre-pulse laser beam to illuminate the target at a time different
from the first pre-pulse laser beam; and

a main pulse laser apparatus configured to output a main pulse laser beam to illuminate the target at a time different from
both of the first pre-pulse laser beam and the second pre-pulse laser beam; and

a transmission system configured to transmit pulse laser beams outputted by the laser apparatus to the extreme ultraviolet
light chamber, the transmission system including:

an optical path adjustment device configured to substantially unify an optical path of the first pre-pulse laser beam and
an optical path of the second pre-pulse laser beam;

an optical path separation device configured to separate the optical paths of the first pre-pulse laser beam and the second
pre-pulse laser beam substantially unified by the optical path adjustment device to an optical path for the first pre-pulse
laser beam and an optical path for the second pre-pulse laser beam;

a first beam adjustment device disposed on the optical path for the first pre-pulse laser beam separated by the optical path
separation device and configured to adjust a beam parameter of the first pre-pulse laser beam; and

a second beam adjustment device disposed on the optical path for the second pre-pulse laser beam separated by the optical
path separation device and configured to adjust a beam parameter of the second pre-pulse beam.

US Pat. No. 10,136,510

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:a chamber, in which extreme ultraviolet light is generated from plasma, the plasma having been generated by irradiation of a target supplied in a plasma generation region inside of the chamber with laser light;
a condenser mirror configured to collect the extreme ultraviolet light generated in the chamber and guide the extreme ultraviolet light to outside of the chamber;
a first etching gas supply unit configured to blow an etching gas to a reflective surface of the condenser mirror and the plasma generation region;
a magnet disposed outside of the chamber and configured to generate a magnetic field in the chamber;
a port that is disposed in a wall of the chamber, intersects a central axis of the magnetic field, and is configured to take in suspended substances generated in the chamber and a gas in the chamber, the wall residing between the magnet and the plasma generation region, the port including an opening in an inner wall of the chamber;
an ejection path that is formed along the wall of the chamber between the chamber and the magnet, is formed between the inner wall of the chamber and an outer wall of the chamber, is in communication with the port, and is configured to eject the suspended substances and the gas that are taken from the port to the outside of the chamber; and
an ejection device that is connected to the ejection path, and is configured to eject the suspended substances and the gas in the chamber.

US Pat. No. 10,117,317

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation system configured to irradiate a target with a first pulse laser beam and a second pulse laser beam to turn the target into plasma thereby generating extreme ultraviolet light, comprising:a chamber having at least one aperture configured to introduce the first pulse laser beam and the second pulse laser beam;
a target supply unit configured to supply the target to a predetermined region in the chamber;
a first laser apparatus configured to output the first pulse laser beam with which the target in the chamber is irradiated so as to make the target be diffused in a dome shape; and
a second laser apparatus configured to output the second pulse laser beam with which the target which has been irradiated with the first pulse laser beam is further irradiated.

US Pat. No. 9,601,893

LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A laser apparatus comprising:
an optical resonator including an output coupler;
a laser chamber containing a laser medium and disposed in an optical path inside the optical resonator;
a pair of discharge electrodes disposed inside the laser chamber;
an electrode gap varying section configured to vary a gap between the discharge electrodes;
a laser beam measurement section disposed in an optical path of a laser beam outputted from the output coupler, the laser
beam resulting from electric discharge between the discharge electrodes; and

a controller configured to control the gap between the discharge electrodes through activating the electrode gap varying section,
based on a beam parameter of the laser beam measured by the laser beam measurement section.

US Pat. No. 10,057,972

EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM AND METHOD OF GENERATING EXTREME ULTRAVIOLET LIGHT

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation system configured to generate extreme ultraviolet light by irradiating a target with a pulse laser beam three times, the extreme ultraviolet light generation system comprising:a target supply device configured to supply a first primary target and supply a second primary target after the first primary target;
a laser system configured to provide a pulse laser beam to each primary target supplied from the target supply device; and
a controller,
wherein the laser system is configured to:
irradiate the first primary target with a first pulse laser beam to break and disperse the first primary target and produce a secondary target being a mist target;
irradiate the secondary target with a second pulse laser beam to produce a tertiary target including at least vapor or pre-plasma; and
irradiate the tertiary target with a third pulse laser beam to generate extreme ultraviolet light, and
wherein the controller is configured to:
measure a mist diameter of the secondary target; and
control energy of a first pulse laser beam to be used to irradiate the second primary target based on the mist diameter.

US Pat. No. 9,883,574

TARGET PRODUCING APPARATUS

GIGAPHOTON INC., Tochigi...

1. A target producing apparatus, to be used in an extreme ultraviolet light generation apparatus capable of generating extreme
ultraviolet light by irradiating droplets in a plasma generation region with a laser beam, the target producing apparatus
comprising:
a tank capable of containing a melted droplet material;
a nozzle provided at a distal end of the tank and being capable of outputting droplets toward the plasma generation region;
a nozzle holder holding the nozzle on the tank;
a gas supply unit capable of supplying a gas;
a gas lock cover secured to the nozzle holder and provided downstream of the nozzle, the gas lock cover being structured to
guide the gas supplied from the gas supply unit,

wherein the gas lock cover includes:
a hollow cylindrical part provided downstream of the nozzle and having an exit opening for outputting droplets that are outputted
from the nozzle and pass through an internal cavity of the cylindrical part; and

a channel for transmitting the gas supplied from the gas supply unit, the channel being structured to orient a flow of the
transmitted gas so as to flow to the exit opening of the cylindrical part through the internal cavity of the cylindrical part,

wherein the channel includes a buffer space that joins the internal cavity of the cylindrical part and is structured to diffuse
the gas flow entering the buffer space into different directions to guide the gas into the internal cavity of the cylindrical
part,

wherein the cylindrical part has a reverse-tapered wall expanding outward at an output end, and
wherein the reverse-tapered wall has a plurality of ejection outlets structured to join the buffer space and to eject the
gas.

US Pat. No. 9,647,411

METHOD OF CONTROLLING WAVELENGTH OF LASER BEAM AND LASER APPARATUS

GIGAPHOTON INC., Tochigi...

1. A method of controlling a wavelength of a laser beam, comprising:
measuring a relative wavelength of the laser beam with respect to a reference wavelength by using a spectroscope;
controlling a line narrowing module based on a difference between a target wavelength and a sum of the relative wavelength
and the reference wavelength, so as to change the wavelength of the laser beam by the difference;

measuring an absolute wavelength of the laser beam at a first interval by using an absolute wavelength detector; and
adjusting the reference wavelength of the laser beam at a second interval that is shorter than the first interval;
wherein the adjusting the reference wavelength of the laser beam includes obtaining a gradient by calculating a difference
between the reference wavelength and the absolute wavelength of the laser beam for the first interval, and adjusting the reference
wavelength of the laser beam based on a value obtained by multiplying the gradient by the second interval.

US Pat. No. 9,986,629

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:a chamber including a plasma generation region to which a target is supplied, the target being turned into plasma so that extreme ultraviolet light is generated in the chamber;
a target supply part configured to supply the target to the plasma generation region by outputting the target as a droplet into the chamber;
a droplet detector configured to detect the droplet traveling from the target supply part to the plasma generation region;
an imaging part configured to capture an image of an imaging region containing the plasma generation region in the chamber; and
a controller configured to control an imaging timing at which the imaging part captures the image of the imaging region, based on a detection timing at which the droplet detector detects the droplet, wherein
the droplet is turned into plasma upon being irradiated with a laser beam in the plasma generation region, and emits plasma light containing the extreme ultraviolet light;
the controller controls an irradiation timing at which the droplet is irradiated with the laser beam in the plasma generation region, based on the detection timing;
the controller sets a first imaging timing to a timing just after the irradiation timing;
and
the imaging part captures an image of the plasma light generated in the imaging region at the first imaging timing.

US Pat. No. 10,136,509

TARGET SUPPLY DEVICE, PROCESSING DEVICE AND PROCESSING METHOD THEFEFOR

Gigaphoton Inc., Tochigi...

1. A target supply device configured to supply a metal target in a plasma generation region, the target supply device comprising:a tank configured to store the metal target material;
an ingot of the metal target material shaped to form a groove as a passage for gases between the ingot and an inner wall of the tank in a state where the ingot is stored in the tank;
a filter having been subjected to a dehydration process, the filter being configured to suppress passage of particles in the metal target material stored in the tank; and
a nozzle provided with a nozzle hole, the nozzle being configured to eject, from the nozzle hole, the metal target that has passed through the filter.

US Pat. No. 9,853,410

GAS LASER DEVICE AND CONTROL METHOD THEREFOR

Gigaphoton Inc., Tochigi...

1. A gas laser apparatus comprising:
a chamber containing a laser gas;
a pair of electrodes disposed within the chamber;
a fan disposed within the chamber;
a motor connected to a rotating shaft of the fan; and
a rotating speed control unit configured to control a rotating speed of the fan based on a wear-out parameter of the pair
of electrodes to increase the rotating speed as the pair of electrodes wear out.

US Pat. No. 9,570,884

LASER APPARATUS, EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM, METHOD FOR CONTROLLING THE LASER APPARATUS, AND METHOD FOR GENERATING THE EXTREME ULTRAVIOLET LIGHT

GIGAPHOTON INC., Tochigi...

1. A laser apparatus, comprising:
a master oscillator configured to output a pulsed laser beam at a repetition rate, each pulse of the pulsed laser beam being
chirped, the master oscillator including a plurality of semiconductor laser apparatuses;

at least one amplifier configured to amplify the pulsed laser beam from the master oscillator, the at least one amplifier
being configured to include a plurality of gain bandwidths; and

a controller for controlling a temperature of each of the plurality of semiconductor laser apparatuses, as a parameter affecting
an output wavelength of the pulsed laser beam such that a wavelength chirping range of the pulsed laser beam overlaps at least
a part of at least one of the plurality of gain bandwidths, wherein:

at least two of the plurality of semiconductor laser apparatuses output pulsed laser beams having wavelength chirping ranges
different from each other,

the controller controls such that the temperature of each of the plurality of semiconductor laser apparatuses is placed between
a first temperature at which a temporally initial wavelength in a single pulse of the pulsed laser beam becomes a longest
wavelength of the at least one of the plurality of gain bandwidths and a second temperature at which a temporally final wavelength
in a single pulse of the pulsed laser beam becomes a shortest wavelength of the at least one of the plurality of gain bandwidths;
and

the wavelength chirping range of each pulse of the pulsed laser beam has the temporally initial wavelength, the temporally
final wavelength, and a plurality of wavelengths extending from the temporally initial wavelength to the temporally final
wavelength, with at least one of the temporally initial wavelength and the temporally final wavelength being outside the at
least one of the plurality of gain bandwidths, and at least one of the plurality of wavelengths being inside the at least
one of the plurality of gain bandwidths.

US Pat. No. 9,877,378

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. A system comprising:
a laser system configured to generate a pre-pulse laser beam with a pulse duration of less than 1 ns, and a main pulse laser
beam;

a target supply unit configured to supply a target material to be irradiated with the pre-pulse laser beam and the main pulse
laser beam for generating extreme ultraviolet light; and

a laser controller configured to control the laser system such that a fluence of the pre-pulse laser beam is lower than a
fluence of the main pulse laser beam and a beam intensity of the pre-pulse laser beam is higher than a beam intensity of the
main pulse laser beam.

US Pat. No. 9,854,658

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:
a chamber in which extreme ultraviolet light is generated when a target is irradiated with a laser beam inside the chamber;
a target supply part configured to supply the target into the chamber; and
a target collector having an opening that faces the target supply part, and including a receiving surface having a contact
angle of equal to or smaller than 90 degrees with the target, a liquid film of the target being formed on the receiving surface.

US Pat. No. 10,375,809

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE AND METHOD FOR CONTROLLING EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus comprising:a laser device configured to emit a pulsed laser beam;
a target detector configured to detect a target substance supplied as an application target for the laser beam to an inside of a chamber; and
a controller configured to control the laser device based on a burst signal in which are repeated a burst period for which to generate an extreme ultraviolet light beam and an idle period for which to pause the generation of the extreme ultraviolet light beam,
the controller reducing an intensity of a laser beam entering the inside of the chamber from the laser device, when a size of a target substance detected at the target detector in the idle period is greater than a predetermined size.

US Pat. No. 10,143,074

FILTER AND TARGET SUPPLY APPARATUS

Gigaphoton Inc., Tochigi...

1. A filter comprising:a first member having a first surface provided with a plurality of grooves; and
a second member set with a second surface thereof covering the plurality of grooves,
the first member including a first passable portion that allows a fluid to pass between the first surface and a first space, which is defined beside a surface of the first member opposite to the first surface, through a first area of the plurality of grooves,
the second member including a second passable portion that allows the fluid to pass between the second surface and a second space, which is defined beside a surface of the second member opposite to the second surface, through a second area of the plurality of grooves distanced from the first area,
wherein the first member is made of a material selected from molybdenum, tungsten, aluminum oxide, silicon dioxide glass, silicon carbide, tungsten carbide, aluminum nitride, zirconium boride, and boron carbide, and
wherein the second member exposes a part of the plurality of grooves therethrough to the second space.

US Pat. No. 10,103,509

EXCIMER LASER DEVICE

Gigaphoton Inc., Tochigi...

1. An excimer laser device configured to receive data on a target value of pulse energy from an external device and output a pulse laser beam, comprising:a master oscillator;
at least one power amplifier including a chamber provided in an optical path of the pulse laser beam outputted from the master oscillator, a pair of electrodes provided in the chamber, and an electric power source configured to apply voltage to the pair of electrodes; and
a controller configured to control the electric power source of one power amplifier of the at least one power amplifier to stop applying the voltage to the pair of electrodes based on the target value of the pulse energy.

US Pat. No. 9,574,935

SYSTEM FOR GENERATING EXTREME ULTRA VIOLET LIGHT

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet (EUV) light generation system configured to irradiate a target material with a laser beam to generate
EUV light and to output the EUV light to an exposure apparatus, the EUV light generation system comprising:
a laser apparatus configured to output the laser beam to irradiate the target material;
a focusing optical system configured to focus the laser beam outputted from the laser apparatus;
a target generator configured to output the target material;
an EUV light monitor configured to detect a generation position at which the EUV light is generated; and
a controller configured to control generation of the EUV light, wherein:
when the controller receives an EUV light generation position specification signal specifying a predetermined position as
the generation position, the controller adjusts the focusing optical system such that a focus position of the laser beam coincides
with the predetermined position and adjusts a position of the target generator to allow the target material to pass through
the predetermined position; and

upon receiving the generation position detected by the EUV light monitor, the controller determines whether or not the received
generation position falls within a permissible range, and, when the received generation position does not fall within the
permissible range, the controller adjusts at least one of the position of the target generator and the focusing optical system
such that the received generation position falls within the permissible range.

US Pat. No. 9,835,495

LIGHT BEAM MEASUREMENT DEVICE, LASER APPARATUS, AND LIGHT BEAM SEPARATOR

Gigaphoton Inc., Tochigi...

1. A light beam separator comprising:
a first separator substrate formed by a wedged substrate and provided on an optical path of a laser beam; and
a second separator substrate formed by a wedged substrate and provided on the optical path of the laser beam, wherein:
the first separator substrate is configured such that the laser beam having entered a first surface of the first separator
substrate is partially reflected by the first surface to separate part of the laser beam;

the second separator substrate is configured such that the laser beam having entered the first surface of the first separator
substrate and transmitted through the first separator substrate exits a second surface of the first separator substrate, enters
a first surface of the second separator substrate, and exits a second surface of the second separator substrate;

the first surface of the first separator substrate and the second surface of the second separator substrate are approximately
parallel to one another;

the second surface of the first separator substrate and the first surface of the second separator substrate are approximately
parallel to one another;

a thickness of the first separator substrate and a thickness of the second separator substrate are approximately the same
on the optical path of the laser beam; and

an optical axis of the laser beam entering the first separator substrate and an optical axis of the laser beam exiting the
second separator substrate approximately align in a straight line.

US Pat. No. 9,961,755

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:a chamber earthed to a ground, in which extreme ultraviolet light is generated by irradiating a metal target supplied inside with laser light;
a target supply unit earthed to the ground, fixed to the chamber and configured to output the target to be supplied into the chamber from a nozzle;
an extraction electrode disposed on a target output side of the nozzle and configured to exert electrostatic force on the target by applying a negative first potential to the extraction electrode;
a first power supply configured to apply the first potential to the extraction electrode;
an acceleration electrode unit disposed at a position through which the target extracted by the extraction electrode passes, and configured to accelerate the target by applying a negative second potential lower than the first potential to the acceleration electrode unit;
a second power supply configured to apply the second potential to the acceleration electrode unit; and
a charge neutralizer disposed inside the acceleration electrode unit and configured to emit electrons onto the target.

US Pat. No. 9,722,384

GAS LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A gas laser apparatus comprising:
a laser chamber connected through a first control valve to a first laser gas supply source that supplies a first laser gas
containing a halogen gas and connected through a second control valve to a second laser gas supply source that supplies a
second laser gas having a lower halogen gas concentration than the first laser gas;

a fourth control valve disposed between the second laser gas supply source and the second control valve;
a purification column that removes at least a part of the halogen gas and a halogen compound from at least a part of a gas
exhausted from the laser chamber;

a booster pump, connected through a third control valve to a pipe between the fourth control valve and the second control
valve, which raises a pressure of a gas having passed through the purification column to a gas pressure that is higher than
an operating gas pressure of the laser chamber; and

a controller that selectively executes a first control mode in which the third control valve is closed and the fourth control
valve is opened and a second control mode in which the fourth control valve is closed and the third control valve is opened.

US Pat. No. 9,966,721

LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising first and second laser apparatuses, a beam delivery device, and a moving mechanism, wherein:the first laser apparatus is provided so as to emit a first laser beam to the beam delivery device in a first direction;
the second laser apparatus is provided so as to emit a second laser beam to the beam delivery device in a direction substantially parallel to the first direction;
the beam delivery device includes first and second mirrors provided substantially parallel to each other;
the first mirror is provided so as to reflect the first laser beam to a beam delivery direction different from the first direction;
the second mirror is provided so as to reflect the second laser beam to the beam delivery direction;
the beam delivery device is configured to bundle the first and second laser beams and to emit the first and second laser beams to the beam delivery direction; and
the moving mechanism is configured to move the second mirror along an optical path of the second laser beam in a direction substantially parallel to the first direction.

US Pat. No. 9,949,354

EXTREME UV LIGHT GENERATION APPARATUS AND METHOD

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:a target supplier configured to sequentially supply targets to a plasma generation region in a chamber as a plurality of droplets at a predetermined generation frequency, the targets generating extreme ultraviolet light when being irradiated with a laser beam in the chamber;
a pressure regulator configured to regulate a pressure in the target supplier in which the targets are accommodated to make the pressure in the target supplier be a set pressure value;
an imaging part configured to image two adjacent droplets sequentially supplied into the chamber to output a piece of image data of the two adjacent droplets; and
a controller configured to calculate a distance between the two adjacent droplets by using the piece of image data, calculate a traveling speed of the droplets based on the distance between the two adjacent droplets and the predetermined generation frequency, and update the set pressure value according to a difference between the traveling speed of the droplets and a targeted traveling speed.

US Pat. No. 10,111,312

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:a chamber in which plasma is generated to generate extreme ultraviolet light;
a window provided in the chamber;
an optical path pipe connected to the chamber;
a light source disposed in the optical path pipe, the light source being configured to output light into the chamber via the window;
a gas supply unit configured to supply gas into the optical path pipe; and
an exhaust port configured to discharge the gas in the optical path pipe to an outside of the optical path pipe.

US Pat. No. 9,686,845

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation apparatus configured to generate extreme ultraviolet light by irradiating a target
with a pulse laser beam outputted from a laser apparatus to generate plasma, the extreme ultraviolet light generation apparatus
comprising:
a target supply device configured to supply a target;
a timing sensor configured to detect a target supplied from the target supply device and passing through a predetermined region;
and

a controller configured to control the laser apparatus in accordance with a signal indicating detection of the target and
received from the timing sensor,

wherein the timing sensor includes:
a light-emitting unit configured to illuminate the predetermined region with illumination light; and
a target sensor configured to receive the illumination light from the light-emitting unit,
wherein the target sensor includes:
a plurality of sensor elements, each of the plurality of sensor elements being configured to output a sensor signal that varies
in accordance with an amount of light received on a light-receiving surface; and

a signal generator configured to process the sensor signals from the plurality of sensor elements,
wherein the light-receiving surfaces of the plurality of sensor elements are disposed at different positions in a second direction
different from a first direction along which an image of the target illuminated by the illumination light moves, and

wherein the signal generator is configured to compare each of the sensor signals from the plurality of sensor elements with
a threshold and output the signal indicating detection of a target to the controller in a case where at least one of the sensor
signals from the plurality of sensor elements exceeds the threshold.

US Pat. No. 10,085,334

EXTREME ULTRAVIOLET LIGHT GENERATING SYSTEM

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating system that repetitively outputs extreme ultraviolet light which is generated by a target turning into plasma by being irradiated with a pulsed laser beam, comprising:a chamber;
a target supply unit configured to sequentially supply the target into a plasma generating region which is set within the chamber;
a laser apparatus configured to output a pulsed laser beam;
a laser beam focusing system configured to focus the pulsed laser beam which is output from the laser apparatus;
an actuator connected to the laser beam focusing system, configured to adjust the focusing position of the pulsed laser beam;
an extreme ultraviolet light generation controller configured to control the extreme ultraviolet light generating system to output extreme ultraviolet light based on a burst pattern; and
an actuator controller configured to control the actuator by feedforward control to compensate for a shift of the focusing position of the pulsed laser beam with respect to the target which is supplied to the plasma generating region that occurs during output of extreme ultraviolet light based on the burst pattern.

US Pat. No. 9,722,385

LASER CHAMBER

Gigaphoton Inc., Tochigi...

1. A laser chamber for a discharge excited gas laser apparatus, comprising:
a first discharge electrode disposed in the laser chamber;
a second discharge electrode disposed to face the first discharge electrode in the laser chamber;
a fan configured to flow laser gas between the first discharge electrode and the second discharge electrode;
a first insulating member disposed upstream and downstream of a laser gas flow from the first discharge electrode;
a first metallic damper member disposed upstream of the laser gas flow from the second discharge electrode;
a second metallic damper member disposed downstream of the laser gas flow from the second discharge electrode; and
a second insulating member disposed downstream of the laser gas flow from the second discharge electrode, and having a base
end that contacts to a downstream side surface of the second discharge electrode, the second insulating member extending from
the base end toward the downstream of the laser gas flow,

wherein the second metallic damper member has a tapered surface which tapers from the upstream to the downstream, and
the second insulating member is disposed on the tapered surface of the second metallic damper member, along the slope of the
tapered surface.

US Pat. No. 9,647,406

LASER UNIT AND EXTREME ULTRAVIOLET LIGHT GENERATING SYSTEM

GIGAPHOTON INC., Tochigi...

1. A laser unit, comprising:
a master oscillator configured to output a laser light beam;
a laser amplifier disposed in a light path of the laser light beam outputted from the master oscillator;
an adjuster disposed in the light path of the laser light beam, and configured to adjust a beam cross-sectional shape of the
laser light beam amplified by the laser amplifier to be a substantially circular shape, the beam cross-sectional shape being
at a beam waist of the laser light beam or in the vicinity of the beam waist of the laser light beam, and being in a plane
orthogonal to a light path axis;

a detecting section disposed at a downstream of the adjuster in the light path of the laser light beam, and configured to
detect the beam cross-sectional shape at the beam waist or in the vicinity of the beam waist; and

a controller configured to control the adjuster, based on a result of the detection by the detecting section, wherein
the adjuster includes a movable optical member and a rotary mechanism, the movable optical member being configured to vary
a beam diameter of the laser light beam in one direction that is orthogonal to the light path axis, the rotary mechanism being
configured to rotate the movable optical member around the light path axis of the laser light beam,

the controller measures, based on the result of the detection by the detecting section, a first direction in which the beam
diameter is maximized in the plane orthogonal to the light path axis and a second direction in which the beam diameter is
minimized in the plane orthogonal to the light path axis, and

the controller controls the rotary mechanism to allow the direction in which the beam diameter of the laser light beam is
varied by the adjuster to be substantially the same as one of the first direction and the second direction.

US Pat. No. 9,748,727

PRELIMINARY IONIZATION DISCHARGE DEVICE AND LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A preliminary ionization discharge device used in a laser chamber of a laser apparatus using preliminary ionization, comprising:
a dielectric pipe;
a preliminary ionization inner electrode provided inside the dielectric pipe; and
a preliminary ionization outer electrode provided outside the dielectric pipe, the preliminary ionization outer electrode
including:

a contact plate part configured to contact the dielectric pipe;
an elastic part configured to exert a force in a direction in which the contact plate part pushes the dielectric pipe, a first
end of the elastic part being connected to the contact plate part;

an additional elastic part configured to exert a force in the direction in which the contact plate part pushes the dielectric
pipe; and

a fixed plate part connected to a second end of the elastic part that is opposite to the first end,
wherein the additional elastic part is fixed to the fixed plate part.

US Pat. No. 10,095,084

SOLID-STATE LASER SYSTEM AND EXCIMER LASER SYSTEM

The University of Tokyo, ...

1. A solid-state laser system, comprising:a solid-state laser unit configured to output first pulsed laser light with a first wavelength and second pulsed laser light with a second wavelength;
a first solid-state amplifier configured to receive the first pulsed laser light, and output third pulsed laser light with the first wavelength;
a wavelength converter configured to receive the third pulsed laser light, and output harmonic light with a third wavelength;
a second solid-state amplifier configured to receive the second pulsed laser light, and output fourth pulsed laser light with the second wavelength;
a Raman laser unit configured to receive the fourth pulsed laser light, and output Stokes light with a fourth wavelength; and
a wavelength conversion system configured to receive the harmonic light and the Stokes light, and output fifth pulsed laser light with a fifth wavelength converted in wavelength from the third wavelength and the fourth wavelength.

US Pat. No. 9,954,339

LASER UNIT AND EXTREME ULTRAVIOLET LIGHT GENERATING SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser unit, comprising:a master oscillator configured to output a linear-polarized laser light beam;
a first polarization device disposed in a light path of the linear-polarized laser light beam from the master oscillator and provided with a polarization axis that is substantially aligned with a polarization direction of the linearly-polarized incident laser light beam;
a second polarization device disposed in the light path of the linear-polarized laser light beam and provided with a polarization axis that is substantially aligned with a direction of the polarization axis of the first polarization device; and
a laser amplifier disposed between the first polarization device and the second polarization device in the light path of the linear-polarized laser light beam and including a pair of discharge electrodes disposed to oppose each other, an opposing direction of the pair of discharge electrodes being substantially aligned with the direction of the polarization axis of the first polarization device.

US Pat. No. 10,009,991

TARGET SUPPLY APPARATUS AND EUV LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. A target supply device comprising:a tank including a cylindrical main body, a first end portion blocking an axial first end of the main body, and a second end portion blocking an axial second end of the main body;
a nozzle provided to the first end portion of the tank and configured to output a target material contained inside the tank; and
an inert gas supply unit configured to supply inert gas into the tank and including a gas flow path in a form of a hole penetrating the second end portion of the tank to guide the inert gas in an inclined direction toward an inner wall of the main body,
wherein the inner wall of the main body of the tank partially contacts with the target material, and
wherein the second end portion closes the axial second end of the main body except for an opening of the hole, the hole having an inclined portion extending at an angle with respect to the inner wall of the main body to guide the inert gas in the inclined direction towards the inner wall to cause the inert gas to collide against the inner wall.

US Pat. No. 9,667,019

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:
a master oscillator configured to output pulsed laser light;
two or more power amplifiers disposed in an optical path of the pulsed laser light to amplify the pulsed laser light; and
a plurality of optical isolators, each provided between adjacent two of the power amplifiers in the optical path of the pulsed
laser light, and each configured to suppress transmission of light traveling from the power amplifiers to a side where the
master oscillator is provided,

at least one of the optical isolators including a first retarder, wavelength filter configured to allow light with a wavelength
of the pulsed laser light to pass therethrough, and suppress transmission of light with a wavelength other than the wavelength
of the pulsed laser light, a first polarizer configured to provide a phase difference of ¼ wavelength, an EO Pockels cell,
a second retarder, a third retarder configured to provide a phase difference of ½ wavelength, and a second polarizer, and

the wavelength filter including a substrate and a multilayer film, the substrate containing ZnSe, and the multilayer film
being provided on a surface of the substrate and containing ZnSe and ThF4.

US Pat. No. 9,860,967

TARGET SUPPLY APPARATUS, EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS, AND TARGET SUPPLY METHOD

Gigaphoton Inc., Tochigi...

16. A target supply apparatus configured to melt a target and supply a molten target into a chamber, the target generating
extreme ultraviolet light when the target is irradiated with a laser beam in the chamber, the target supply apparatus comprising:
a pair of electrodes spaced from one another and configured to sandwich the target; and
a power source configured to supply a current to a solid target sandwiched between the pair of electrodes via the pair of
electrodes to melt the solid target to a core of the solid target, wherein

the pair of electrodes rotate to eject the molten target sandwiched between the pair of electrodes from between the pair of
electrodes.

US Pat. No. 9,742,141

LASER CHAMBER

Gigaphoton Inc., Tochigi...

1. A laser chamber including a first space and a second space in communication with the first space, the laser chamber comprising:
a first discharge electrode disposed in the first space;
a second discharge electrode disposed in the first space to face the first discharge electrode;
a fan disposed in the first space and configured to flow laser gas between the first discharge electrode and the second discharge
electrode;

a peaking condenser disposed in the second space; and
an electrical insulating member configured to partition the first space and the second space from one another, and disposed
to allow the laser gas to pass through between the first space and the second space.

US Pat. No. 10,256,594

SOLID-STATE LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A solid-state laser system, comprising:a first solid-state laser unit configured to output first pulsed laser light with a first wavelength;
a second solid-state laser unit including a semiconductor optical amplifier and configured to output second pulsed laser light with a second wavelength;
a wavelength conversion system where the first pulsed laser light and the second pulsed laser light enter; and
a controller coupled to the first solid-state laser unit and the semiconductor optical amplifier, and configured to control the first solid-state laser unit and the semiconductor optical amplifier to cause the first pulsed laser light and the second pulsed laser light to be continuously outputted from the first solid-state laser unit and the second solid-state laser unit, respectively, the controller being configured to control the first solid-state laser unit and the semiconductor optical amplifier to cause, while a burst signal from an external unit is on, the first pulsed laser light and the second pulsed laser light to enter the wavelength conversion system at a coincidental timing, thereby causing the wavelength conversion system to output third pulsed laser light with a third wavelength that is converted from the first wavelength and the second wavelength, and being configured to control the first solid-state laser unit and the semiconductor optical amplifier to cause, while the burst signal is off, the first pulsed laser light and the second pulsed laser light to enter the wavelength conversion system at different timings from each other, thereby preventing the wavelength conversion system from outputting the third pulsed laser light, a difference between the different timings being equal to or greater than sum of a pulse width of the first pulsed laser light and a pulse width of the second pulsed laser light.

US Pat. No. 9,891,012

DEVICE FOR CONTROLLING TEMPERATURE OF COOLING WATER

Gigaphoton Inc., Tochigi...

11. A device for supplying cooling water and controlling a temperature of the cooling water that flows through a portion of
a laser apparatus, the device comprising:
a three-way valve having a first inlet, a second inlet, and an outlet, the three-way valve being configured to adjust a ratio
of a flow rate of the cooling water flowing into the first inlet to a flow rate of the cooling water flowing into the second
inlet and to output the cooling water from the outlet;

a first feed pipe for connecting an outlet of a cooling water supply unit and the first inlet of the three-way valve;
a second feed pipe for connecting the outlet of the three-way valve and an inlet of the portion of the laser apparatus;
a return pipe for connecting an outlet of the portion of the laser apparatus and an inlet of the cooling water supply unit;
a return-side bypass pipe for connecting the return pipe and the second inlet of the three-way valve;
a pump provided on the second feed pipe for sending the cooling water to the portion of the laser apparatus from the three-way
valve;

a temperature sensor for measuring a temperature of the cooling water flowing in the second feed pipe;
a heater provided on the second feed pipe; and
a control unit configured to control the three-way valve and the heater to heat the cooling water, and to control the pump,
the temperature sensor, and the three-way valve to maintain the temperature of the cooling water to be within a predetermined
temperature range.

US Pat. No. 9,711,934

LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser apparatus, comprising:
a first laser resonator configured to generate a laser beam;
a first optical element configured to adjust a divergence in a first direction of the laser beam;
a second optical element configured to adjust a divergence in a second direction of the laser beam, the second direction being
perpendicular to the first direction;

a measuring unit configured to measure the divergence in the first direction and the divergence in the second direction of
the laser beam; and

a controller configured to control both of the first optical element and the second optical element, based on the divergence
in the first direction and the divergence in the second direction of the laser beam both measured by the measuring unit.

US Pat. No. 9,648,715

TARGET SUPPLY DEVICE

GIGAPHOTON INC., Tochigi...

1. A target supply device comprising:
a target generator configured to accommodate a liquid target material and having a nozzle with a nozzle hole from which the
liquid target material is outputted; and

a filter disposed in the target generator and made of glass, the glass reacting with the liquid target material, so that a
solid reaction product is generated, wherein:

the filter includes a first through-hole configured to allow the liquid target material to pass therethrough; and
an inner surface of the first through-hole is coated with a material which is not easy to react with the liquid target material.

US Pat. No. 10,102,938

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus comprising:a chamber including a window configured to allow a first pulse laser beam with which a target is irradiated at a predetermined region to generate a secondary target and a second pulse laser beam with which the secondary target is irradiated at the predetermined region to generate plasma to enter;
a mirror configured to reflect the first pulse laser beam;
a first actuator configured to control at least one of a position and a posture of the mirror;
a beam combiner configured to cause optical paths of the first pulse laser beam reflected by the mirror and the second pulse laser beam to substantially coincide with each other to output the first pulse laser beam and the second pulse laser beam;
a reflective optical system configured to reflect the first pulse laser beam and the second pulse laser beam outputted from the beam combiner toward the predetermined region;
a second actuator configured to control at least one of a position and a posture of the reflective optical system;
sensors each configured to output data for detecting a position of an optical path of the first pulse laser beam in the vicinity of the predetermined region; and
a controller configured to control the first actuator based on the data and control the second actuator based on a value related to control of the first actuator.

US Pat. No. 9,991,665

LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising:laser apparatuses configured to emit respective pulse laser beams;
a beam bundling device configured to bundle the pulse laser beams each emitted from a corresponding laser apparatus of the laser apparatuses and to emit a bundled laser beam to an exposure apparatus; and
a laser system controller configured to
receive target energy of the bundled laser beam and target pulse waveform of the bundled laser beam from the exposure apparatus,
calculate target pulse energy for each of the pulse laser beams emitted from the corresponding laser apparatus based on the target energy of the bundled laser beam,
calculate target delay time for each of the pulse laser beams emitted from the corresponding laser apparatus based on the target pulse waveform of the bundled laser beam, and
send, to the corresponding laser apparatus, the target pulse energy for a corresponding pulse laser beam of the pulse laser beams emitted from the corresponding laser apparatus and the target delay time for the corresponding pulse laser beam emitted from the corresponding laser apparatus.

US Pat. No. 9,825,417

LASER UNIT AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM

Gigaphoton Inc., Tochigi...

1. A non-transitory computer-readable storage medium holding a program that is configured to cause a computer to display,
on a display, one or both of electric power consumed by a laser unit and electric energy consumed by the laser unit, wherein
the electric power consumed by the laser unit includes a sum of electric power consumed by a charger included in the laser
unit, electric power consumed by a motor included in the laser unit, and electric power consumed by a standby-power supply
included in the laser unit, and

the electric energy consumed by the laser unit includes a sum of electric energy consumed by the charger included in the laser
unit, electric energy consumed by the motor included in the laser unit, and electric energy consumed by the standby-power
supply included in the laser unit.

US Pat. No. 9,812,841

LASERSYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system, comprising:
a Raman cell;
a pumping light generator including one optical parametric amplifier (OPA), a first OPA laser device, and a second OPA laser
device, and configured to output first Raman-cell pumping light and second Raman-cell pumping light to the Raman cell, the
first OPA laser device being configured to output OPA pumping light to the OPA, the second OPA laser device being configured
to output OPA signal light to the OPA;

a Raman cell laser unit configured to output probing light as a target of wavelength conversion to the Raman cell;
a pumping light monitor section configured to measure a state of the OPA pumping light;
a signal light monitor section configured to measure a state of the OPA signal light; and
a timing controller configured to control the first OPA laser device and the second OPA laser device to allow both the OPA
pumping light and the OPA signal light to be inputted to the OPA substantially simultaneously, based on measurement results
by the pumping light monitor section and the signal light monitor section.

US Pat. No. 9,806,490

LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising:
a delay circuit unit configured to receive a trigger signal, output a first delay signal representing that a first delay time
has passed since the delay circuit unit received the trigger signal, and output a second delay signal representing that a
second delay time has passed since the delay circuit unit received the trigger signal;

a first trigger-correction unit configured to receive the first delay signal and output a first switch signal representing
that a first correction time has passed since the first trigger-correction unit received the first delay signal;

a second trigger-correction unit configured to receive the second delay signal and output a second switch signal representing
that a second correction time has passed since the second trigger-correction unit received the second delay signal;

a first laser apparatus including
a first capacitor,
a first charger configured to apply voltage to the first capacitor,
a first switch configured to receive the first switch signal and allow the first capacitor to output a pulse current,
a first magnetic compression circuit configured to compress the pulse current outputted from the first capacitor,
a first chamber containing laser gas,
a first pair of discharge electrodes provided in the first chamber and connected to the first magnetic compression circuit,
and

a first discharge timing detector configured to detect discharge between the first pair of discharge electrodes and output
a first discharge detection signal;

a second laser apparatus including
a second capacitor,
a second charger configured to apply voltage to the second capacitor,
a second switch configured to receive the second switch signal and allow the second capacitor to output a pulse current,
a second magnetic compression circuit configured to compress the pulse current outputted from the second capacitor,
a second chamber containing laser gas,
a second pair of discharge electrodes provided in the second chamber and connected to the second magnetic compression circuit,
and

a second discharge timing detector configured to detect discharge between the second pair of discharge electrodes and output
a second discharge detection signal; and

a clock generator configured to generate a clock signal that is common to the delay circuit unit, the first trigger-correction
unit and the second trigger-correction unit, wherein

the first trigger-correction unit receives the first discharge detection signal and sets the first correction time so that
a first elapsed time between a timing of receiving the first delay signal and a timing of receiving the first discharge detection
signal approaches a first target value, and

the second trigger-correction unit receives the second discharge detection signal and sets the second correction time so that
a second elapsed time between a timing of receiving the second delay signal and a timing of receiving the second discharge
detection signal approaches a second target value.

US Pat. No. 9,791,780

EXPOSURE APPARATUS

Gigaphoton Inc., Tochigi...

1. An exposure apparatus configured to perform proximity exposure on a surface of a substrate, the exposure apparatus comprising:
a laser light source capable of varying a wavelength of a laser beam that is emitted from the laser light source;
a mask on which a pattern is formed, the pattern having a periodic structure and being configured to generate diffracted light
by being irradiated with the laser beam, the mask being irradiated with the laser beam emitted from the laser light source;
and

a controller configured to control, in accordance with a distance between the mask and the substrate, the wavelength of the
laser beam that is emitted from the laser light source, wherein

the exposure is performed with light generated by interference caused by the Talbot effect; and
the controller is configured to control the wavelength of the laser beam that is emitted from the laser light source so that
the distance between the mask and the substrate is equal to an integer multiple of a Talbot distance under the Talbot effect.

US Pat. No. 9,762,024

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

GIGAPHOTON INC., Tochigi...

1. A laser apparatus comprising:
a master oscillator capable of outputting a pulse laser beam;
a plurality of optical amplifiers disposed on an optical path of the pulse laser beam outputted from the master oscillator,
the plurality of optical amplifiers being configured to sequentially amplify the pulse laser beam;

an optical reflector disposed off an optical path of the pulse laser beam, capable of passing the pulse laser beam therethrough
and reflecting a self-oscillation beam generated in one of the plurality of optical amplifiers; and

an optical absorber capable of receiving and absorbing the self-oscillation beam reflected by the optical reflector.

US Pat. No. 9,699,877

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS INCLUDING TARGET DROPLET JOINING APPARATUS

GIGAPHOTON INC., Tochigi...

1. An extreme ultraviolet light generation apparatus configured to create a target droplet by joining successive droplets
and irradiate the target droplet with a pulse laser beam in a plasma generation region to generate extreme ultraviolet light,
the extreme ultraviolet light generation apparatus comprising:
a droplet supply device configured to contain a droplet material and successively supply droplets;
a charging electrode disposed between the droplet supply device and the plasma generation region, the charging electrode being
configured to control charging of droplets supplied from the droplet supply unit; and

a target controller configured to control electric polarities of the droplets supplied from the droplet supply unit by controlling
potential of the charging electrode in such a way that successive droplets join together to become a target droplet,

wherein the droplets controlled in charging by the charging electrode include a plurality of groups each composed of successive
droplets, and, in each of the groups, a droplet at one end is charged positively or negatively, a droplet at the other end
is uncharged or charged in a polarity being the same as a polarity of an adjacent droplet in a group adjacent to the droplet
at the other end, and the successive droplets join together utilizing a change in speed caused by Coulomb force of the droplet
at the one end to become a target droplet, and

wherein, in each of the groups, only the droplet at the one end is charged and the other droplets are uncharged.

US Pat. No. 9,882,334

MIRROR DEVICE

Gigaphoton Inc., Tochigi...

1. A mirror device comprising:
an optical element configured to reflect part of a laser beam and transmit the other part of the laser beam therethrough;
and

a holder in surface contact with the optical element to hold the optical element,
wherein a flatness of a contact surface of the holder in contact with a first surface of the optical element is equal to or
smaller than a flatness of the first surface of the optical element, and

wherein the holder includes:
a support member having the contact surface in surface contact with the first surface of the optical element to support the
optical element; and

a pushing member configured to push the optical element against the support member by pushing a second surface of the optical
element.

US Pat. No. 10,054,861

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus, comprising:a chamber, in which a target supplied into a plasma generating region therein turns into plasma by being irradiated with a laser beam and extreme ultraviolet light is generated;
a target supply unit configured to output the target into the chamber as droplets so as to supply the target into the plasma generating region;
a stage that moves the target supply unit in a direction substantially perpendicular to a trajectory of the droplets which are output from the target supply unit based on commands from an external apparatus;
a droplet detector, equipped with a light source unit and a light receiving unit arranged to face the light source unit, provided between the target supply unit and the plasma generating region such that a direction along which the light source unit and the light receiving unit face each other is at an inclination of a predetermined angle with respect to the direction substantially perpendicular to the trajectory of the droplets, the droplet detector configured to detect the droplets from the direction inclined at the predetermined angle; and
a calculation control unit configured to control the irradiation timings of the laser beam at which the laser beam is irradiated onto the droplets within the plasm generating region, by adding delay times to the timings at which the droplets are detected by the droplet detector;
the calculation control unit updating the delay time based on data regarding a distance of movement of the target supply unit based on the commands from the external apparatus and data regarding the predetermined angle.

US Pat. No. 9,980,360

EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation system comprising:a chamber;
a target generation unit configured to output a target toward a plasma generation region in the chamber; and
a laser system including
a first pre-pulse laser apparatus configured to generate a first pre-pulse laser beam with which the target is irradiated,
a second pre-pulse laser apparatus configured to generate a second pre-pulse laser beam after the first pre-pulse laser beam is generated, the second pre-pulse laser beam having a pulse duration longer than a pulse duration of the first pre-pulse laser beam, and
a main pulse laser apparatus configured to generate a main pulse laser beam after the second pre-pulse laser beam is generated.

US Pat. No. 9,954,340

EXCIMER LASER APPARATUS AND EXCIMER LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. An excimer laser apparatus comprising:a laser chamber containing a gas;
at least a pair of electrodes disposed within the laser chamber;
a power source unit that supplies a voltage between the electrodes;
a gas supply unit, connected to a first receptacle that holds a first laser gas containing halogen gas and a second receptacle that holds a second laser gas having a lower halogen gas concentration than the first laser gas, that supplies the first laser gas and the second laser gas to the interior of the laser chamber;
a gas exhaust unit that partially exhausts gas from within the laser chamber; and
a gas control unit that controls the gas supply unit and the gas exhaust unit,
wherein the gas control unit:
performs partial gas replacement control in which the gas supply unit supplies the first laser gas and the second laser gas to the interior of the laser chamber and the gas exhaust unit partially exhausts gas from within the laser chamber sequentially;
measures a repetition rate of laser light outputted from the laser chamber;
calculates a correction time by performing a correction computation on a predetermined period of time based on the repetition rate such that the correction time has a first length in the case where the repetition rate is a first value and the correction time has a second length shorter than the first length in the case where the repetition rate is a second value greater than the first value; and
performs the next partial gas replacement control when the correction time has elapsed following the performance of the previous partial gas replacement control.

US Pat. No. 9,872,372

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device for generating extreme ultraviolet light by irradiating a target with a
pulse laser beam and thereby turning the target into plasma, comprising:
a chamber;
a magnet configured to form a magnetic field in the chamber; and
an ion catcher including a collision unit disposed so that ions guided by the magnetic field collide with the collision unit,
wherein

the collision unit includes a plurality of collision surfaces disposed to be inclined with respect to the magnetic field.

US Pat. No. 9,841,684

LIGHT SOURCE APPARATUS AND DATA PROCESSING METHOD

Gigaphoton Inc., Tochigi...

1. A light source apparatus configured for an exposure apparatus which exposes a plurality of wafers by repeating a wafer
exposure for exposing a total exposure area of each wafer, the wafer exposure including a sequential execution of scanning
exposures in which each divided area defined by dividing the total exposure area of each wafer is scanned by pulsed light,
the apparatus comprising:
a light source controller configured to execute a control for outputting the pulsed light based on a luminescence trigger
signal received from the exposure apparatus;

a detector configured to detect a characteristic of the pulsed light; and
a data collection processor configured to collect at least a piece of data in data included in a pulse light data group related
to the pulsed light detected by the detector and a control data group related to the control, and to execute a mapping process
of mapping the data collected for each pulse of the pulsed light of each scanning exposure for at least one wafer, each pulse
of the pulsed light of a particular scanning exposure exposing a same area of the divided area, the mapping process mapping
the data collected for each pulse of the pulsed light with respect to each pulse of a total number of pulses of the pulsed
light for exposure of the at least one wafer,

the data collection processor being configured to execute a process of collecting the mapped data by each item and transmit
the data collected by each item to a monitor device, the item being for the particular scanning exposure for the at least
one wafer, the monitor device being configured to monitor a state of a semiconductor production equipment that includes the
exposure apparatus by providing an ability to analyze the mapped data.

US Pat. No. 10,165,665

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser apparatus for use with an extreme ultraviolet light generating apparatus that generates extreme ultraviolet light at a repetition frequency which is set in advance, comprising:a semiconductor laser that outputs a laser beam when a trigger signal is input thereto;
an optical switch that switches between a state in which the laser beam passes therethrough and a state in which the laser beam does not pass therethrough, provided along the optical path of the laser beam; and
a control unit having a storage/calculation unit, the control unit configured to change output timing of the trigger signal which is output to the semiconductor laser based on the repetition frequency in synchronization with the repetition frequency, and to control the optical switch such that the laser beam passes therethrough at the repetition frequency, wherein
the storage/calculation unit is configured to store, in advance, measurement results related to a relationship between time lags from output timings of the trigger signals to timings at which the laser beam is output from the semiconductor laser and the repetition frequency,
the storage/calculation unit is configured to refer to the measurement results to calculate the output timing of the trigger signal,
the control unit determines the output timing calculated by the storage/calculation unit as an updated output timing of the trigger signal,
the control unit determines the updated output timing of the trigger signal according to a change in the load state of the semiconductor laser; and
the semiconductor laser outputs the laser beam in synchronization with the repetition frequency, based on the output timing which is determined by the control unit.

US Pat. No. 9,685,756

LASER AMPLIFIER, LASER APPARATUS, AND EXTREME ULTRAVIOLET LIGHT GENERATING SYSTEM

GIGAPHOTON INC., Tochigi...

1. A laser amplifier, comprising:
a chamber containing a laser medium;
a first window provided on the chamber, and tilted to allow a laser light beam of a desired wavelength inputted from outside
of the chamber to enter the chamber and to allow light beams of one or more suppression target wavelengths different from
the desired wavelength to be off a light path of the laser light beam of the desired wavelength;

an excitation unit configured to amplify, by exciting the laser medium, the laser light beam that has entered the chamber;
a second window provided on the chamber, and tilted to allow the laser light beam that has been amplified by the excitation
unit to exit from the chamber to the outside and to allow the light beams of the one or more suppression target wavelengths
to be off the light path of the laser light beam of the desired wavelength;

a mirror provided on a laser light path between the first window and the second window; and
a wavelength selection film provided on one or more of the first window, the second window, and the mirror, and configured
to suppress propagation of the light beams of the one or more suppression target wavelengths.

US Pat. No. 10,349,508

TARGET STORAGE DEVICE

Gigaphoton Inc., Tochigi...

1. A target storage device comprising:a target receiving member;
a tank configured to store a target received by the target receiving member, the target having been output as a droplet, the target generating extreme ultraviolet light when being irradiated with laser light;
a heater connected with the tank, the heater being configured to heat the tank; and
a radiation member disposed to cover at least a part of the tank connected with the heater, the radiation member being configured to reflect heat radiation from the tank and the heater toward the tank,
the target receiving member including an inclined portion that is disposed at a position crossing a trajectory of the target output into the chamber, and allows the target not irradiated with the laser light to collide with it and receives the target, and
the tank storing the target received with the inclined portion.

US Pat. No. 9,837,780

EXCIMER LASER APPARATUS AND EXCIMER LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. An excimer laser apparatus comprising:
a laser chamber configured to contain gas;
a pair of electrodes provided in the laser chamber;
a power source unit configured to supply a pulse voltage between the pair of electrodes;
a gas supply unit configured to supply gas into the laser chamber;
a gas exhaust unit configured to partially exhaust gas from within the laser chamber;
a gas control unit configured to control the gas supply unit and the gas exhaust unit, where a replacement ratio of gas to
be replaced from within the laser chamber increases as deterioration of the pair of electrodes progresses, the deterioration
being represented by a deterioration parameter of the pair of electrodes, the deterioration parameter being an integrated
value of input energy having been inputted to the pair of electrodes since the pair of electrodes was installed in the laser
chamber;

an input unit configured to input an initial value of the integrated value of input energy; and
a laser control unit configured to add, to the initial value, a value of input energy additionally inputted to the pair of
electrodes.

US Pat. No. 10,512,148

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT EMPLOYING LASER PULSE INCLUDING PEDESTAL

Gigaphoton Inc., Tochigi...

1. A system for generating extreme ultraviolet light, the system comprising:a master oscillator configured to output a laser beam pulse, the laser beam pulse having a waveform including a first portion and a second portion following the first portion;
an optical element positioned in a beam path of the laser beam pulse, the optical element configured to transform the waveform of the laser beam pulse to a second waveform, the second waveform including a pedestal and a peak, the pedestal being formed by transformation of the first portion to the pedestal by the optical element, and the peak being the second portion;
an amplifier including a gain medium, the amplifier configured to amplify the pedestal and the peak to form an amplified pedestal and an amplified peak; and
the amplified pedestal and the amplified peak containing sufficient energy to turn a target material into a plasma that emits EUV light.

US Pat. No. 10,050,408

LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising:a plurality of laser apparatuses;
a beam delivery device configured to bundle pulse laser beams emitted from respective laser apparatuses of the plurality of laser apparatuses to emit a bundled laser beam; and
a controller configured to control operated laser apparatuses of the plurality of laser apparatuses such that, at a change in a number representing how many laser apparatuses are operated, a beam parameter of the bundled laser beam emitted from the beam delivery device approaches a beam parameter of the bundled laser beam emitted before the change.

US Pat. No. 9,942,973

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus configured to generate extreme ultraviolet light by irradiating a target with a pulse laser beam outputted from a laser apparatus to generate plasma, the extreme ultraviolet light generation apparatus comprising:a chamber;
a target supply device configured to supply a target to a plasma generation region inside the chamber;
a target sensor located between the target supply device and the plasma generation region and configured to detect the target passing through a detection region;
a shield cover disposed between the detection region and the target supply device, having a through-hole that allows the target to pass through, and configured to reduce pressure waves that reach the target supply device from the plasma generation region;
a heat shield disposed between the plasma generation region and the shield cover, structured to accommodate the plasma generation region, having a through hole that allows the target to pass through, and configured to reduce heat conducted to the chamber from the plasma generation region; and
a first damper between the heat shield and an inner wall of the chamber.

US Pat. No. 9,837,779

LASER APPARATUS AND LASER APPARATUS MANUFACTURING METHOD

GIGAPHOTON INC., Tochigi...

1. A laser apparatus comprising:
a laser system;
a pair of frames, one frame being provided with a sleeve through-hole and the other fame being provided with a sleeve insertion
portion;

a bolt;
a positioning sleeve, formed in an approximately cylindrical shape into the interior of which the bolt can be inserted, configured
to position the pair of frames by passing through the sleeve through-hole and being inserted into the sleeve insertion portion;

a female screw portion, provided in the other frame, into which the bolt is screwed; and
a fall prevention unit, provided in the one frame, configured to prevent the bolt and the positioning sleeve from falling,
wherein the laser system includes a plurality of laser system modules, at least one of the laser system modules are mounted
in the one frame; and at least one other of the laser system modules are mounted in the other frame,

wherein the fall prevention unit includes:
a sleeve loss prevention portion configured to prevent the positioning sleeve from coming out of the sleeve through-hole in
a state in which the positioning sleeve does not project from the one frame; and

a bolt loss prevention portion configured to prevent the bolt from coming out of the sleeve through-hole in a state in which
the bolt does not project from the one frame.

US Pat. No. 9,847,618

LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser apparatus, comprising:
a beam splitter configured to split a pulse laser beam into a first beam path and a second beam path;
an optical sensor provided in the first beam path;
an amplifier including an amplification region provided in the second beam path and being configured to amplify and emit the
pulse laser beam incident thereon along the second beam path;

a wavefront controller provided in the second beam path between the beam splitter and the amplifier; and
a processor configured to receive an output signal from the optical sensor and transmit a control signal to the wavefront
controller,

wherein the processor transmits the control signal to the wavefront controller to reduce a maximum value of a beam diameter
of the pulse laser beam between first and second positions positioned in the second optical path, the amplification region
being interposed between the first and second positions.

US Pat. No. 10,172,225

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:a chamber including a plasma generation region to which a target is supplied, the target being turned into plasma so that extreme ultraviolet light is generated in the chamber;
a target supply part configured to supply the target to the plasma generation region by outputting the target as a droplet into the chamber;
a droplet detector configured to detect the droplet traveling from the target supply part to the plasma generation region;
a light source part configured to emit light to the plasma generation region in the chamber;
an imaging part configured to capture an image of an imaging region containing the plasma generation region in the chamber; and
a controller configured to control an imaging timing at which the imaging part captures the image of the imaging region, based on a detection timing at which the droplet detector detects the droplet, wherein:
the droplet is turned into an aggregation of a plurality of fine particles of the target upon being irradiated with a prepulse laser beam in the plasma generation region;
the aggregation of a plurality of fine particles of the target is turned into plasma upon being irradiated with a main pulse laser beam in the plasma generation region, and the plasma emits plasma light containing the extreme ultraviolet light;
the controller controls an irradiation timing at which the droplet is irradiated with the prepulse laser beam in the plasma generation region, based on the detection timing;
the controller sets a first imaging timing to a timing just after the irradiation timing; and
the imaging part captures an image of the aggregation of a plurality of fine particles of the target generated in the imaging region at the first imaging timing.

US Pat. No. 10,050,403

EXCIMER LASER CHAMBER DEVICE

Gigaphoton Inc., Tochigi...

1. An excimer laser chamber device comprising:a laser chamber having an opening;
an electrical insulator configured to seal the opening;
a first electrode provided in the laser chamber;
a second electrode provided in the laser chamber to face the first electrode and to be connected to a ground potential;
an electrode holder provided in the laser chamber to be connected to a high voltage via a conductive element penetrating the electrical insulator;
at least one connecting terminal including a first anchored portion anchored to the first electrode and a second anchored portion anchored to the electrode holder, the at least one connecting terminal being configured to electrically connect the first electrode and the electrode holder;
a guide member held by the electrode holder, the guide member being configured to position the first electrode in a direction substantially perpendicular to both a direction of electric discharge between the first electrode and the second electrode and a longitudinal direction of the first electrode; and
an electrode-gap-varying unit penetrating the electrical insulator and configured to move the first electrode in a direction substantially parallel to the direction of electric discharge.

US Pat. No. 9,929,529

SOLID-STATE LASER SYSTEM AND LASER APPARATUS USED FOR EXPOSURE APPARATUS

Gigaphoton Inc., Tochigi...

1. A solid-state laser system, comprising:a first solid-state laser unit configured to output a first pulsed laser light beam with a first wavelength generated on a basis of first seed light;
a second solid-state laser unit configured to output a second pulsed laser light beam with a second wavelength generated on a basis of second seed light;
a wavelength conversion system configured to receive the first pulsed laser light beam and the second pulsed laser light beam, and output a third pulsed laser light beam with a third wavelength that is converted from the first wavelength and the second wavelength;
a wavelength detector configured to detect a value of the third wavelength; and
a wavelength controller configured to control the first solid-state laser unit to vary the first wavelength on a condition that an absolute value of a difference between a value of a target wavelength and the value of the third wavelength detected by the wavelength detector is equal to or less than a predetermined value, and control the second solid-state laser unit to vary the second wavelength on a condition that the absolute value of the difference exceeds the predetermined value.

US Pat. No. 10,073,353

TARGET SUPPLY DEVICE AND EUV LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. A target supply device configured to supply a target material comprising:a tank configured to store the target material;
a nozzle connected to the tank and configured to output the target material; and
a gas supply section configured to supply the tank with gas, the gas supply section comprising:
a pipe having a first end connected to the tank;
a booster connected between a gas line and a second end of the pipe and configured to boost gas supplied from the gas line and supply the pipe with the boosted gas;
a pressure sensor configured to measure pressure inside the tank; and
a pressure controller configured to adjust pressure of the boosted gas in the pipe based on a measurement result from the pressure sensor.

US Pat. No. 10,074,956

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT, AND LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation system used with a laser apparatus, the extreme ultraviolet light generation system comprising:a chamber including at least one window for at least one laser beam and a target supply unit for supplying a target material into the chamber;
at least one polarization control unit, provided on a laser beam path, for controlling a polarization state of the at least one laser beam;
a magnetic field generation unit, provided to the chamber, for generating a magnetic field in which a charged particle emitted from the target material that has been struck by the laser beam is trapped; and
a collection unit into which the trapped charged particle is collected,
wherein the at least one laser beam includes a first laser beam that strikes an unirradiated target material supplied into the chamber and a second laser beam that strikes the target material which the first laser beam has struck, and
wherein the at least one polarization control unit includes a first polarization control unit that controls a polarization state of the first laser beam into a linearly polarized laser beam and a second polarization control unit that controls a polarization state of the second laser beam into a circularly polarized laser beam.

US Pat. No. 9,894,744

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:
a chamber in which extreme ultraviolet light is generated when a target is irradiated with a laser beam inside the chamber;
a target supply part configured to supply the target into the chamber; and
a target collector configured to collect the target which is supplied by the target supply part but is not irradiated with
the laser beam in a collection container, by receiving the target on a first receiving surface having a contact angle of greater
than 90 degrees with the target, the target collector including:

a prevention part including an opening to introduce the target into the collection container and configured to prevent the
target reflected by the first receiving surface from dispersing to an outside of the target collector;

a guide part configured to introduce the target into the opening of the prevention part, a diameter of an opening formed in
an upper end of the guide part being greater than a diameter of the opening of the prevention part;

a peripherally extending collection container wall; and
at least one second receiving surface positioned a first spaced distance from the first receiving surface and a second spaced
distance from the collection container wall.

US Pat. No. 10,237,961

TARGET SUPPLY DEVICE, PROCESSING DEVICE AND PROCESSING METHOD THEREFOR

Gigaphoton Inc., Tochigi...

1. A target supply device configured to supply a metal target in a plasma generation region, the target supply device comprising:a tank provided with an exhaust port, the tank being configured to store an ingot of a metal target material;
an exhaust device connected to the tank through the exhaust port, the exhaust device being configured to exhaust gases from the tank;
a heater configured to apply heat to the tank;
a nozzle provided with a nozzle hole, the nozzle being configured to eject, from the nozzle hole, the metal target formed from the ingot melted by the heat applied through the tank; and
a controller connected to the exhaust device and the heater, wherein:
the ingot is shaped to form a passage for the gases in a state where the ingot is stored in the tank, the passage being configured to connect the exhaust port and the nozzle hole; and
the controller is configured to cause the heater to apply the heat to the ingot through the tank while causing the exhaust device to exhaust the gases from the tank.

US Pat. No. 10,074,958

LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising:a plurality of laser apparatuses;
a beam delivery device configured to bundle pulse laser beams emitted from respective laser apparatuses of the plurality of laser apparatuses to emit a bundled pulse laser beam;
a beam parameter measuring device provided in an optical path of the bundled pulse laser beam to measure a beam parameter of each one of the pulse laser beams and a beam parameter of the bundled pulse laser beam;
beam steering devices provided in respective optical paths between the respective laser apparatuses and the beam parameter measuring device;
a controller configured to control the beam steering devices based on measurement result of the beam parameter measuring device; and
beam divergence adjusters provided in the respective optical paths between the respective laser apparatuses and the respective beam steering devices, wherein
the controller controls the beam steering devices and the beam divergence adjusters based on the measurement result of the beam parameter measuring device.

US Pat. No. 9,894,743

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

GIGAPHOTON INC., Tochigi...

1. An apparatus for generating extreme ultraviolet light by irradiating a target material with a laser beam to turn the target
material into a plasma, the apparatus comprising:
a reference member;
a chamber mounted on the reference member;
a target supply unit mounted on the chamber and configured to supply the target material into the chamber;
a laser beam introduction optical system mounted on the reference member and configured to introduce the laser beam into the
chamber;

a laser beam focusing optical system mounted on a first holder and configured to focus the laser beam onto the target material,
the first holder being mounted on the reference member; and

a collector mirror mounted on a second holder and configured to collect the extreme ultraviolet light emitted from the target
material, the second holder being mounted on the reference member, wherein

the chamber has a first opening, the chamber is mounted on an upper surface of the reference member, a seal is provided between
a periphery of the first opening of the chamber and the upper surface of the reference member, and

the second holder is mounted on the upper surface of the reference member, thereby connecting the collector mirror and the
reference member through the first opening.

US Pat. No. 9,882,343

NARROW BAND LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A narrow band laser apparatus, comprising:
a laser resonator including an optical element to narrow a spectral width;
a pair of discharge electrodes disposed with an optical path of a pulse laser beam of the laser resonator interposed therebetween;
a power supply configured to apply a pulsed voltage to the pair of discharge electrodes;
a first wavelength measurement device configured to measure a wavelength of the pulse laser beam outputted from the laser
resonator and output a first measurement result;

a second wavelength measurement device configured to measure the wavelength of the pulse laser beam outputted from the laser
resonator and output a second measurement result; and

a control unit configured to calibrate the first measurement result, based on the second measurement result, wherein
the control unit calibrates the first measurement result, based on a difference between the second measurement result derived
when the control unit controls the power supply to apply the pulsed voltage to the pair of discharge electrodes with a first
repetition frequency and the second measurement result derived when the control unit controls the power supply to apply the
pulsed voltage to the pair of discharge electrodes with a second repetition frequency, the second repetition frequency being
higher than the first repetition frequency.

US Pat. No. 10,251,254

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS AND CONTROL METHOD FOR CENTROID OF EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus comprising:a plurality of EUV light sensors configured to measure energy of extreme ultraviolet light from mutually different directions, the extreme ultraviolet light being generated by applying laser light to a target supplied to a predetermined region in a chamber;
an application position adjusting unit configured to adjust an application position of the laser light to the target supplied to the predetermined region; and
a controller configured to control the application position adjusting unit such that a centroid of the extreme ultraviolet light becomes a targeted centroid, the centroid of the extreme ultraviolet light being specified from measurement results of the EUV light sensors,
the controller
controlling the application position adjusting unit such that the application position is scanned in accordance with a plurality of reference scan points that are mutually different in position, and
calibrating the targeted centroid based on the measurement results acquired for the reference scan points.

US Pat. No. 10,126,657

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus, comprising:a chamber, in which extreme ultraviolet light is generated by plasma being generated in the interior thereof;
a window provided in a wall of the chamber;
a light source provided at the exterior of the chamber, configured to output illuminating light to the interior of the chamber via the window;
a light sensor provided at the exterior of the chamber, configured to detect the illuminating light which is output to the interior of the chamber via the window;
a shielding member having an opening that the illuminating light may pass through, that shields the window from emissions from the plasma, and is provided in the interior of the chamber; and
a mirror provided along an optical path of the illuminating light in the interior of the chamber between the window and the shielding member, having a reflective surface that reflects the illuminating light, the reflective surface being constituted by a surface of a metal layer.

US Pat. No. 10,038,295

GAS LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A gas laser apparatus comprising:a first laser chamber connected through a first control valve to a first laser gas supply source that supplies a first laser gas containing a halogen gas and connected through a second control valve to a second laser gas supply source that supplies a second laser gas having a lower halogen gas concentration than the first laser gas;
a second laser chamber connected through a sixth control valve to the first laser gas supply source and connected through a seventh control valve to the second laser gas supply source;
a common pipe connected to the second laser gas supply source and divided into a first branch pipe in which the second control valve is disposed and a second branch pipe in which the seventh control valve is disposed;
a fourth control valve disposed in the common pipe;
a purification column that removes at least a part of the halogen gas and a halogen compound from at least a part of a gas exhausted from the first laser chamber and at least a part of a gas exhausted from the second laser chamber; and
a booster pump, connected through a third control valve to the common pipe between the fourth control valve and a place where the common pipe is divided into the first and second branch pipes, the booster pump being configured to raise a pressure of a gas having passed through the purification column to a gas pressure that is higher than an operating gas pressure of the first laser chamber and an operating gas pressure of the second laser chamber.

US Pat. No. 10,028,365

CHAMBER DEVICE, TARGET GENERATION METHOD, AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A chamber device comprising:a chamber;
a target generation device assembled into the chamber, the target generation device being configured to supply a target material to a predetermined region in the chamber, the target generation device including:
a tank configured to store the target material;
a temperature variable device configured to vary temperature of the target material in the tank, the temperature variable device including a heater configured to heat the target material in the tank and a heater power source configured to supply electric current to the heater; and
a nozzle section in which a nozzle hole configured to output the target material in a liquid state is formed;
a gas nozzle having an inlet port facing the nozzle section, the inlet port of the gas nozzle being configured to introduce gas into the chamber;
a gas supply source configured to supply gas containing hydrogen to the gas nozzle such that the gas containing the hydrogen is supplied to at least periphery of the nozzle section; and
a moisture remover configured to remove moisture at least in the periphery of the nozzle section in the chamber.

US Pat. No. 10,582,600

DROPLET COLLECTION DEVICE

Gigaphoton Inc., Tochigi...

1. A droplet collection device comprising:a collecting container arranged on an outer wall surface side of a wall of a chamber and configured to communicate with an inside of the chamber through an opening provided at the wall of the chamber;
a collision plate arranged in the collecting container and configured such that a droplet supplied from the opening to the collecting container is to collide with the collision plate; and
a buffer member arranged on an opening side with respect to the collision plate and configured to mitigate impact of the droplet colliding with the collision plate,
the buffer member having a wire rod bundle configured such that multiple wire rods are bundled and fixed to a plate member,
the wire rods being made of carbon, and the plate member being made of graphite,
the wire rods being fixed to the plate member with a graphitized adhesive with the wire rods arranged in one direction,
a space having a greater width than a width between wire rods closest to each other is provided between wire rods positioned at both ends in a direction in which the wire rods are arranged,
the wire rods include first wire rods and second wire rods shorter than the first wire rods,
each second wire rod is arranged between the first wire rods, and
the space is between adjacent ones of the first wire rods.

US Pat. No. 10,122,145

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:a master oscillator configured to output a laser beam to travel along a laser beam path;
a plurality of amplifiers configured to amplify the laser beam outputted by the master oscillator on the laser beam path;
a photodetector including a first photodetector configured to detect energy of a light beam traveling back along the laser beam path and a second photodetector configured to detect power of the light beam traveling back along the laser beam path; and
a controller configured to receive an energy detection signal from the first photodetector and a power detection signal from the second photodetector, monitor intensities of the energy detection signal and the power detection signal, determine that a return beam is generated when the intensity of the energy detection signal exceeds a first threshold, determine that a self-oscillation beam is generated when the intensity of the power detection signal exceeds a second threshold, store determination results about the return beam and the self-oscillation beam to a memory, keep operation of the plurality of amplifiers and stop the master oscillator in a case of determining that a return beam is generated, and stop the master oscillator and the plurality of amplifiers in a case of determining that a self-oscillation beam is generated.

US Pat. No. 10,172,224

EXTREME UV LIGHT GENERATOR

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:a chamber in which extreme ultraviolet light is generated from plasma, the plasma being generated by irradiating a target supplied into the chamber with a laser beam;
a target generator configured to supply the target into the chamber as a droplet;
a droplet measurement unit configured to measure the droplet supplied from the target generator into the chamber; and
a shielding member configured to shield the droplet measurement unit from electromagnetic waves emitted from the plasma,
the droplet measurement unit including:
a light source configured to emit continuous light to the droplet;
a window provided in the chamber and configured to allow the continuous light to transmit therethrough; and
an optical sensor configured to receive the continuous light via the window, and
the shielding member including a shielding body provided on the chamber side with respect to the window configured to cover an optical path of the continuous light and having a light passing opening for passing the continuous light therethrough, and the shielding member is provided within the interior of the chamber, configured separately from a wall that constitutes the chamber.

US Pat. No. 10,001,706

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS AND METHOD OF DESIGNING THE SAME

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation apparatus comprising:a chamber;
a target supply device configured to successively supply targets into the chamber;
an extreme ultraviolet light collector mirror including a reflective surface having a through-hole at the center thereof, the reflective surface being configured to reflect and collect extreme ultraviolet light generated at a predetermined emission cycle because of irradiation of the successively supplied targets with a laser beam; and
a gas ejection device disposed in the through-hole to jut out from the reflective surface and having a gas ejection opening to eject etching gas for debris onto the reflective surface, the gas ejection device being configured so that the etching gas takes a longer time than the predetermined emission cycle to reach the through-hole-side end of effective reflective area of the reflective surface after being ejected from the gas ejection opening.

US Pat. No. 10,485,085

EXTREME ULTRAVIOLET LIGHT SENSOR UNIT AND EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light sensor unit comprising:a mirror configured to reflect extreme ultraviolet light;
a filter configured to transmit the extreme ultraviolet light reflected by the mirror;
an optical sensor configured to detect the extreme ultraviolet light having passed through the filter;
a purge gas supply unit disposed to supply purge gas to a space between the mirror and the filter; and
a pipe part configured to allow plasma light and the purge gas to pass therethrough, the plasma light including the extreme ultraviolet light to be made incident on the mirror, the purge gas supplied from the purge gas supply unit, the pipe part having an opening serving as a light entry port of the plasma light, the pipe part allowing the plasma light entering from the opening to pass therethrough toward the mirror and allowing the purge gas flowing to the space between the mirror and the filter to flow out of the opening,
wherein the gas outflow port of the purge gas supply unit is provided at a position not facing the filter.

US Pat. No. 10,027,084

ALIGNMENT SYSTEM AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. An alignment system for use with a laser apparatus, comprising:a guide laser device configured to output a guide laser beam, the guide laser device being configured such that average output power of the guide laser beam is smaller than average output power of a laser beam from the laser apparatus;
an adjusting mechanism configured to adjust a travel direction of the laser beam;
a beam path combiner configured to adjust a travel direction of the laser beam, and a travel direction of the guide laser beam to substantially coincide with each other;
an optical detection unit configured to detect the laser beam and the guide laser beam;
a controller configured to control the adjusting mechanism based on a detection result of the optical detection unit, wherein
the adjusting mechanism is provided upstream from the beam path combiner in a beam path of the laser beam.

US Pat. No. 10,314,152

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. An apparatus for generating extreme ultraviolet light, comprising:a chamber provided with an inlet through which a laser beam is introduced into the chamber;
a target supply unit configured to supply a target material to a predetermined region in the chamber;
an optical element provided in the chamber;
a supply pipe configured to supply a heat carrier to the optical element;
a heat carrier flow channel configured to allow the heat carrier to circulate in the optical element;
a discharge pipe configured to discharge the heat carrier from the optical element;
a temperature sensor configured to detect a temperature of the heat carrier; and
a temperature control mechanism configured to control a temperature of the optical element.

US Pat. No. 10,151,640

LIGHT BEAM MEASUREMENT DEVICE, LASER APPARATUS, AND LIGHT BEAM SEPARATOR

Gigaphoton Inc., Tochigi...

1. A light beam measurement device comprising:a polarization measurement device including a first measurement beam splitter provided on an optical path of a laser beam and configured to measure a polarization state of the laser beam having been partially reflected by the first measurement beam splitter;
a beam profile measurement device including a second measurement beam splitter provided on the optical path of the laser beam and configured to measure a beam profile of the laser beam having been partially reflected by the second measurement beam splitter; and
a laser beam-directional stability measurement device configured to measure a stability in a traveling direction of the laser beam,
the first measurement beam splitter and the second measurement beam splitter being made of a material containing CaF2.

US Pat. No. 10,028,366

EXTREME UV LIGHT GENERATION DEVICE AND TARGET RECOVERY APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:a chamber in which extreme ultraviolet light is generated when a target is irradiated with laser light in a predetermined region inside the chamber;
a target supply device configured to output the target to the predetermined region in the chamber to thereby supply the target to the predetermined region; and
a target recovery apparatus configured to recover the target output from the target supply device and not irradiated with the laser light,
the target recovery apparatus including:
a receiver disposed to be inclined with respect to a trajectory of the target output from the target supply device, the receiver being configured to receive the target by allowing the target not irradiated with the laser light to collide with the receiver; and
an excitation device configured to vibrate the receiver.

US Pat. No. 10,306,743

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation system configured to irradiate a target with a first pre-pulse laser beam, a second pre-pulse laser beam, and a main pulse laser beam to turn the target into plasma thereby generating extreme ultraviolet light, comprising:a chamber;
a target supply unit configured to supply the target to a predetermined region in the chamber;
a first laser apparatus configured to output the first pre-pulse laser beam with which the target in the chamber is irradiated; and
a second laser apparatus including a first oscillator, a second oscillator, and an amplifier, the first oscillator being configured to output a first seed beam, the second oscillator being configured to output a second seed beam, the amplifier being configured to amplify the first seed beam to output the second pre-pulse laser beam and amplify the second seed beam to output the main pulse laser beam, wherein the target which has been irradiated with the first pre-pulse laser beam is further irradiated with the second pre-pulse laser beam, and the target which has been irradiated with the second pre-pulse laser beam is further irradiated with the main pulse laser beam.

US Pat. No. 10,251,255

SYSTEM AND METHOD FOR GENERATING EXTREME ULTRAVIOLET LIGHT

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation system configured to irradiate a target with a first pulse laser beam and a second pulse laser beam to turn the target into plasma thereby generating extreme ultraviolet light, comprising:a chamber having at least one aperture configured to introduce the first pulse laser beam and the second pulse laser beam;
a target supply unit configured to supply the target to a predetermined region in the chamber;
a first laser apparatus configured to output the first pulse laser beam with which the target in the chamber is irradiated so as to make the target be diffused in a shape having a first length in a direction in which the first pulse laser beam travels and a second length in a direction perpendicular to the direction in which the first pulse laser beam travels, the first length being shorter than the second length; and
a second laser apparatus configured to output the second pulse laser beam with which the target which has been irradiated with the first pulse laser beam is further irradiated.

US Pat. No. 10,205,297

NARROW BAND EXCIMER LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A narrow band excimer laser apparatus, comprising:an optical resonator;
a laser chamber that contains an excimer laser gas and is disposed along an optical path of the optical resonator;
a line narrowing module including a casing and a line narrowing optical element housed in the casing, the line narrowing module being provided in the optical resonator and being configured to narrow a spectral line width of laser light which is output from the laser chamber;
a nitrogen gas supply apparatus;
a nitrogen gas introducing unit configured to cause nitrogen gas supplied from the nitrogen gas supply apparatus to flow into the casing;
a first valve configured to control inflow of nitrogen gas from the nitrogen gas introducing unit into the casing;
an exhaust unit configured to cause gas within the casing to flow outside the casing;
an exhaust pump configured to cause gas within the casing to be exhausted outside the casing through the exhaust unit;
a second valve configured to control exhausting of gas from the exhaust unit;
an atmosphere discharging unit configured to discharge gas within the casing to the atmosphere;
a third valve configured to control discharging of gas by the atmosphere discharging unit;
a control unit configured to close the second valve while opening the first valve and the third valve to supply nitrogen gas into the casing for a predetermined amount of time, then to close the first valve and the third valve while opening the second valve and driving the exhaust pump to exhaust the interior of the casing, and to cause laser oscillation thereafter; and
a detecting unit configured to detect that one of the line narrowing module and the laser chamber has been installed in the narrow band excimer laser apparatus and to output a detection signal,
wherein the control unit initiates control with respect to the first valve, the second valve, the third valve, and the exhaust pump after the detection signal is received.

US Pat. No. 10,194,515

BEAM DELIVERY SYSTEM AND CONTROL METHOD THEREFOR

Gigaphoton Inc., Tochigi...

1. A beam delivery system configured to deliver a pulse laser beam outputted from a laser apparatus to a target in an extreme ultraviolet light generation apparatus configured to generate extreme ultraviolet light by irradiating the target with the pulse laser beam, the beam delivery system comprising:a plurality of beam adjusters configured to adjust a divergence angle of a pulse laser beam outputted from the laser apparatus;
a beam sampler configured to separate a part of the pulse laser beam outputted from a first beam adjuster provided at the most downstream among the plurality of beam adjusters to acquire a sample beam;
a beam monitor configured to receive the sample beam and output a monitored diameter; and
a beam delivery controller configured to control the plurality of beam adjusters based on the monitored diameter,
wherein the beam delivery controller is configured to:
adjust each of beam adjusters other than the first beam adjuster selected one after another from the most upstream so that the monitored diameter at the beam monitor becomes a predetermined value specific to the beam adjuster; and
adjust the first beam adjuster so that the pulse laser beam becomes focused at a position downstream of a target position, and
wherein the first beam adjuster is a final-stage beam adjuster in the beam delivery system.

US Pat. No. 10,251,253

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:a chamber in which a target is irradiated with laser light and extreme ultraviolet light is generated; and
a target supply unit configured to eject a target into the chamber, the target supply unit including a nozzle member that includes an ejection face having an ejection port configured to eject the target into the chamber,
an angle ?1 defined by the ejection face and a gravity axis satisfying a condition of “0 degrees the nozzle member includes:
a substrate portion having a base face exposed to an inside of the chamber; and
a protruding portion having the ejection face at a tip of the protruding portion, the protruding portion being formed to protrude from the base face,
a diameter of the ejection port for the target, formed on the ejection face, is 2 micrometers or larger but 3 micrometers or smaller, and
a diameter of the ejection face is 10 micrometers or larger but 20 micrometers or smaller.

US Pat. No. 10,191,381

EXTREME ULTRAVIOLET LIGHT GENERATING DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating device comprising:a chamber in which extreme ultraviolet light is generated from a target supplied to a generation region;
a focusing mirror configured to reflect the extreme ultraviolet light, generated in the generation region, by a reflection surface, and focus the extreme ultraviolet light at a predetermined focal point, the predetermined focal point being located farther from the reflection surface than the generation region;
a light source unit connected with the chamber, the light source unit being configured to output illumination light toward the target to be supplied to the generation region; and
a light receiving unit connected with the chamber, the light receiving unit being configured to receive reflected light from the target, of the illumination light output toward the target, and capture an image of the target,
the reflection surface of the focusing mirror having a spheroidal face that defines a first focus at the generation region and a second focus at the predetermined focal point, and the light source unit and the light receiving unit being disposed such that at least one of an optical path of the illumination light and an optical path of the reflected light is included in an internal space of the chamber located between a first limit surface and a second limit surface; assuming that a surface formed when an extended line, on the first focus side, of a line segment linking an outer peripheral edge of the reflection surface and the first focus is rotated about an axis passing through the first focus and the second focus, is the first limit surface, and assuming that a surface formed when the line segment linking the outer peripheral edge of the reflection surface and the first focus, and an extended line, on the outer peripheral side, of the line segment, are rotated about the axis passing through the first focus and the second focus, is the second limit surface.

US Pat. No. 10,209,625

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus, comprising:a chamber, within which extreme ultraviolet light is generated from a droplet which is supplied to a predetermined region therein;
an image forming optical system provided in the chamber, configured to form an image of the droplet which is supplied to the predetermined region;
an imaging element configured to capture the formed image;
a stage configured to move at least a portion of the image forming optical system and/or the imaging element in an optical axis direction of the image forming optical system;
a light energy measuring unit configured to measure light energy which is generated when the extreme ultraviolet light is generated; and
a control unit configured to control the stage based on a measured value of the light energy measured by the light energy measuring unit such that an image formation plane of the image of the droplet formed by the image forming optical system matches an imaging surface of the imaging element.

US Pat. No. 10,096,966

GAS LASER DEVICE AND CONDENSER

Gigaphoton Inc., Tochigi...

1. A gas laser device comprising:a laser chamber containing laser gas;
a first discharge electrode disposed in the laser chamber;
a second discharge electrode disposed to face the first discharge electrode in the laser chamber; and
a condenser including a polyimide dielectric and configured to supply power to between the first discharge electrode and the second discharge electrode, wherein:
the condenser includes a condenser layer composed of a polyimide film constituting the polyimide dielectric and a pair of electrode films disposed on the polyimide film such that part of each of the pair of electrode films faces one another via the polyimide film;
surfaces of the pair of electrode films are covered with electrical insulating layers;
the condenser is formed by laminating a plurality of the condenser layers;
the condenser includes a plurality of heat sink layers disposed between the plurality of condenser layers which are laminated;
each of the plurality of electrical insulating layers includes at least a first insulating member and a second insulating member whose dielectric breakdown voltage is higher than that of the first insulating member;
the second insulating member is provided in contact with an electrode film of the pair of electrode films and the polyimide film; and
the first insulating member is provided in contact with the second insulating member and one of the plurality of heat sink layers.

US Pat. No. 10,271,414

DROPLET DETECTOR AND EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. A droplet detector, comprising:a light source unit configured to emit illuminating light onto a droplet, which is output into a chamber, and to generate extreme ultraviolet light when irradiated with a laser beam;
a light receiving unit configured to receive the illuminating light and to detect changes in light intensities; and
a timing determining circuit configured to output a droplet detection signal that indicates that the droplet has been detected at a predetermined position within the chamber, based on a first timing at which the light intensity of the illuminating light decreases due to the droplet being irradiated therewith and a second timing at which the light intensity of the illuminating light increases due to the droplet being not irradiated therewith, wherein:
the timing determining circuit:
specifies the first timing by detecting a timing at which the light intensity becomes less than a predetermined threshold value and specifies the second timing by detecting a timing at which the light intensity becomes greater than the threshold value;
determines a midpoint between the first timing and the second timing; and
outputs the droplet detection signal at a timing which is delayed for a predetermined amount of time from the midpoint between the first timing and the second timing.

US Pat. No. 10,250,007

LASER APPARATUS AND METHOD FOR ADDING CHAMBER TO LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:a frame;
a first amplifier positioned to the frame;
a first input optical system positioned to the frame and configured to cause a pulse laser beam generated by an external device to enter the first amplifier;
a first output optical system positioned to the frame and configured to cause a pulse laser beam having exited from the first amplifier in a first direction to exit in a second direction that is different from the first direction;
a second amplifier positioned to the frame;
a second input optical system positioned to the frame and configured to cause a pulse laser beam having exited from the first output optical system in the second direction to travel in a third direction and enter the second amplifier, the third direction being substantially opposite to the first direction and being different from the second direction; and
a second output optical system positioned to the frame and configured to cause a pulse laser beam having exited from the second amplifier in the third direction to exit in the third direction.

US Pat. No. 10,177,520

EXCIMER LASER APPARATUS AND EXCIMER LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. An excimer laser apparatus comprising:a laser chamber configured to contain gas;
a pair of electrodes provided in the laser chamber;
a power source unit configured to supply a pulse voltage between the pair of electrodes;
a gas supply unit configured to supply gas into the laser chamber;
a gas exhaust unit configured to partially exhaust gas from within the laser chamber; and
a gas control unit configured to, based on a deterioration parameter of the pair of electrodes,
control the gas supply unit and the gas exhaust unit to increase a replacement amount of gas to be replaced from within the laser chamber as the deterioration parameter changes to show that deterioration of the pair of electrodes progresses,
output a life expiration signal when the deterioration parameter shows a life expiration of the pair of electrodes, and
further increase the replacement amount of gas to be replaced from within the laser chamber upon receiving a life prolonging command after outputting the life expiration signal.

US Pat. No. 10,141,186

TARGET IMAGE-CAPTURE DEVICE, EXTREME-ULTRAVIOLET-LIGHT GENERATION DEVICE, AND EXTREME-ULTRAVIOLET-LIGHT GENERATION SYSTEM

Gigaphoton Inc., Tochigi...

1. A target image-capture device configured to capture an image of a target, the target being made into plasma when irradiated with laser light and generating extreme-ultraviolet-light, the target image-capture device comprising:a droplet detector configured to detect passage of a droplet output, as the target, from a target supply unit to a predetermined region in which the extreme-ultraviolet-light is generated, and output a detection signal each time the passage of the droplet is detected;
an illumination light source configured to radiate illumination light to the droplet detected by the droplet detector;
an image capturing element configured to receive reflected light from the droplet, the reflected light being caused by the droplet being irradiated with the illumination light, and capture an image of the droplet;
a shutter device including a shutter configured to switch between propagation and cutoff of light including the reflected light to the image capturing element; and
a controller configured to output, to the image capturing element, an exposure signal allowing the image capturing element to perform image capturing, and output, to the shutter device, a shutter open/close signal allowing the shutter to perform an open and close operation upon input of the detection signal, to thereby allow the reflected light to be exposed to the image capturing element,
the controller outputting the shutter open/close signal to the shutter device to make the shutter closed during when the droplet is irradiated with the laser light in the predetermined region so that the plasma is generated, wherein
the controller controls the shutter device such that the shutter is opened and closed by the shutter open/close signal until a time when the droplet reaches the predetermined region after input of the detection signal,
the controller outputs the exposure signal to the image capturing element after the detection signal is input and before the shutter open/close signal is output to the shutter device, and
an image capturing region of the image capturing element includes the predetermined region in which the extreme-ultraviolet-light is generated.

US Pat. No. 10,092,979

LASER IRRADIATION APPARATUS

Gigaphoton Inc., Tochigi...

1. A laser irradiation apparatus, comprising:an irradiation head section including a first irradiation head and a second irradiation head each configured to perform laser light irradiation on a workpiece;
a laser unit section including a first laser unit configured to output first laser light and a second laser unit configured to output second laser light;
a beam delivery section provided in an optical path between the laser unit section and the irradiation head section, and configured to perform switching of optical paths between an optical path of the first laser light and an optical path of the second laser light to cause one of the first laser light and the second laser light to enter one of the first irradiation head and the second irradiation head;
a first beam property varying section provided in an optical path between the first laser unit and the irradiation head section, and configured to vary a beam property of one of the first laser light and the second laser light in response to the switching of the optical paths by the beam delivery section; and
a second beam property varying section provided in an optical path between the second laser unit and the irradiation head section, and configured to vary a beam property of one of the first laser light and the second laser light in response to the switching of the optical paths by the beam delivery section.

US Pat. No. 10,925,143

LASER APPARATUS AND EUV LIGHT GENERATING SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:an optical element disposed on a laser beam axis;
an actuator configured to displace the optical element to displace the laser beam axis;
a driving amount monitor configured to monitor a driving amount of the actuator;
an optical axis monitor disposed along the laser beam axis and configured to monitor the laser beam axis; and
a control unit configured to control the actuator based on a monitoring result of the optical axis monitor, and determine abnormality of the optical element based on a monitoring result of the driving amount monitor.

US Pat. No. 10,455,679

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:a chamber having a first through-hole that allows a pulse laser beam to enter the chamber;
a target supply unit held by the chamber and configured to output a droplet target toward a predetermined region in the chamber;
a collector mirror configured to reflect and collect the extreme ultraviolet light generated in the predetermined region;
a shield member surrounding the predetermined region in the chamber, the shield member surrounding an optical path of the extreme ultraviolet light reflected by the collector mirror and having a target path that allows the droplet target outputted from the target supply unit to pass toward the predetermined region; and
a tubular member surrounding at least a part of an upstream portion of the trajectory of the droplet target outputted from the target supply unit toward the predetermined region, the upstream portion being upstream from the target path of the shield member.

US Pat. No. 10,582,601

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS USING DIFFERING LASER BEAM DIAMETERS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus comprising:a target supply unit configured to output a target toward a predetermined region;
a laser system configured to output a first laser beam with which the target is irradiated, a second laser beam with which the target is irradiated after being irradiated with the first laser beam, and a third laser beam with which the target is irradiated after being irradiated with the second laser beam; and
an optical system configured to cause an irradiation beam diameter of the second laser beam at the target to be larger than an irradiation beam diameter of the third laser beam at the target, wherein
the target supply unit is configured to sequentially output a plurality of targets including the target, and
the irradiation beam diameter of the second laser beam at the target is equal to or smaller than two times of a distance between two adjacent targets in the plurality of targets.

US Pat. No. 10,420,198

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus, comprising:a chamber having a window through which a pulse laser beam enters;
a target supply unit configured to output at least one target toward a predetermined region in the chamber along a predetermined trajectory;
a target image capturing device configured to capture an image of the at least one target moving along the predetermined trajectory, the target image capturing device being configured to capture the image in a direction inclined relative to a direction perpendicular to the predetermined trajectory;
a first actuator configured to move a focused area focused by the target image capturing device; and
a controller configured to control the first actuator based on a signal from an external device, wherein
the target image capturing device includes an image conveying fiber, a transfer optical system configured to transfer an image of an object in the focused area to a first end of the image conveying fiber, and an image sensor configured to receive light outputted from a second end of the image conveying fiber, and
the first actuator moves a part of the image conveying fiber including the first end and the transfer optical system to move the focused area.

US Pat. No. 10,303,061

EXTREME ULTRAVIOLET LIGHT GENERATION DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generation device comprising:an EUV sensor configured to measure energy of extreme ultraviolet light generated when a target is irradiated with a plurality of laser beams in a predetermined region in a chamber;
an irradiation position adjustment unit configured to adjust at least one of irradiation positions of the laser beams with which the target is irradiated in the predetermined region;
an irradiation timing adjustment unit configured to adjust at least one of irradiation timings of the laser beams with which the target is irradiated in the predetermined region; and
a control unit configured to control the irradiation position adjustment unit and the irradiation timing adjustment unit,
the control unit controlling the irradiation position adjustment unit and then controlling the irradiation timing adjustment unit based on a measurement result of the EUV sensor,
wherein the control unit controls the irradiation position adjustment unit so that the irradiation position is scanned on a plane that is substantially perpendicular to a traveling direction of the laser beams traveling toward the predetermined region and that intersects the predetermined region.

US Pat. No. 10,164,396

LASER UNIT AND NON-TRANSITORY COMPUTER-READABLE STORAGE MEDIUM

Gigaphoton Inc., Tochigi...

1. A laser unit comprising:a pair of electrodes;
a fan configured to make flow of gas fed to a clearance between the electrodes;
a motor configured to rotate the fan;
a display configured to display one or both of electric power consumed by the laser unit and electric energy consumed by the laser unit; and
a charger configured to apply a voltage between the electrodes,
the electric power consumed by the laser unit including one or more of electric power consumed by the charger, electric power consumed by the motor, and a sum of the electric power consumed by the charger and the electric power consumed by the motor,
the electric energy consumed by the laser unit including one or more of electric energy consumed by the charger, electric energy consumed by the motor, and a sum of the electric energy consumed by the charger and the electric energy consumed by the motor,
the electric power consumed by the motor being calculated based on pressure of the gas fed to the clearance between the electrodes, and
the electric energy consumed by the motor being calculated based on the pressure of the gas fed to the clearance between the electrodes.

US Pat. No. 10,268,118

EXTREME ULTRAVIOLET LIGHT GENERATING APPARATUS

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating apparatus, comprising:a light collecting mirror that reflects and focuses extreme ultraviolet light; and
a magnet that generates a magnetic field;
the light collecting mirror including:
a first mirror portion that includes a first reflective surface which is formed by a portion of a spheroidal surface; and
a second mirror portion that includes a second reflective surface having a focal point at substantially the same position as a focal point of the first reflective surface, and is formed by a portion of a spheroid surface different from that of the first reflective surface, the second reflective surface being provided at a position at which a magnetic flux density caused by the magnetic field is lower than that of the first reflective surface.

US Pat. No. 10,268,119

EXTREME ULTRAVIOLET LIGHT GENERATING DEVICE

Gigaphoton Inc., Tochigi...

1. An extreme ultraviolet light generating device comprising:a chamber;
an EUV light focusing mirror provided in the chamber, the EUV light focusing mirror including a reflection surface having a concave curved shape and an outer peripheral portion around an outer edge of the reflection surface, the EUV light focusing mirror being configured to focus EUV light radiated from plasma that is generated when a target is irradiated with laser light;
a gas supplying device including a peripheral head provided on the outer peripheral portion or along the outer peripheral portion, the gas supplying device being configured to blow out a gas flow; and
a discharge device including a discharge path forming a discharge port near the outer peripheral portion, the discharge device being configured to discharge an ion or a particle, generated together with the plasma, from the discharge port along with the gas flow,
the peripheral head including a plurality of peripheral outlets from each of which a peripheral gas flow is blown out, the peripheral gas flow flowing from the outer peripheral portion or a vicinity of the outer peripheral portion along the reflection surface, and
the peripheral head allowing a plurality of blown-out peripheral gas flows to join on the reflection surface having the concave curved shape to thereby form a gas flow flowing along the reflection surface toward the discharge port.

US Pat. No. 10,340,654

LASER APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATING SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser apparatus comprising:a light source configured to output excitation light;
an optical resonator in which laser medium is excited by the excitation light, the optical resonator being configured to output laser beam;
a temperature regulator configured to adjust temperature of the light source to a standard temperature;
an attenuator configured to limit output power of the laser beam transmitted by the attenuator;
an optical detector configured to detect the output power of the laser beam transmitted by the attenuator; and
a controller configured to
calculate output power of the laser beam outputted from the optical resonator based on both the detected output power of the laser beam transmitted by the attenuator and transmittance of the attenuator for the laser beam,
change the standard temperature based on a relationship between the calculated output power of the laser beam and the temperature of the light source when the calculated output power of the laser beam is equal to or lower than a threshold output power, and
change the transmittance of the attenuator for the laser beam when the calculated output power of the laser beam is equal to or lower than a second threshold output power, the second threshold output power being higher than the threshold output power.

US Pat. No. 10,290,992

LASER SYSTEM

Gigaphoton Inc., Tochigi...

1. A laser system comprising:a first laser apparatus including a first laser chamber, a first pair of electrodes provided in the first laser chamber, a first pulse generator including a first storage capacitor, the first pulse generator being configured to generate a pulsed voltage using electric energy stored in the first storage capacitor and configured to apply the pulsed voltage to the first pair of electrodes, and a first charger configured to supply electric energy to charge the first storage capacitor;
a second laser apparatus including a second laser chamber, a second pair of electrodes provided in the second laser chamber, a second pulse generator including a second storage capacitor, the second pulse generator being configured to generate a pulsed voltage using electric energy stored in the second storage capacitor and configured to apply the pulsed voltage to the second pair of electrodes, and a second charger configured to supply electric energy to charge the second storage capacitor;
a charging voltage measuring unit configured to be commonly used to measure the charging voltage of the first storage capacitor and the charging voltage of the second storage capacitor;
at least one bleeding circuit configured to reduce the charging voltage of the storage capacitor and the charging voltage of the second storage capacitor; and
a bleeding circuit controller configured to control the at least one bleeding circuit based on the voltage measured by the charging voltage measuring unit.

US Pat. No. 10,250,008

DISCHARGE EXCITATION GAS LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A discharge excitation gas laser apparatus comprising:a laser chamber in which a laser gas containing a halogen gas is encapsulated;
a pair of discharge electrodes disposed to face each other in the laser chamber;
a fan disposed in the laser chamber to make the laser gas flow between the pair of discharge electrodes;
a motor configured to rotate the fan;
a motor power supply for supplying power to the motor;
a magnetic bearing including a sensor target and a disk, which are fixed on a rotary shaft of the fan, and configured to magnetically levitate the rotary shaft;
displacement sensors including a radial displacement sensor configured to detect the position of a smooth surface of the sensor target in the radial direction of the rotary shaft and an axial displacement sensor configured to detect the position of a smooth surface of the disk in the axial direction of the rotary shaft, and configured to detect the position of the rotary shaft through a can; and
a controller configured to
control the magnetic bearing on the basis of detection signals from the displacement sensors so as to rotate the fan about a center of inertia thereof,
select one displacement sensor from the radial displacement sensor and the axial displacement sensor, the selected displacement sensor providing a detection signal having the largest difference between maximum and minimum values, and
measure the rotational speed of the fan on the basis of the detection signal from the selected displacement sensor and control the motor power supply in such a manner that the measured rotational speed becomes equal to a target rotational speed.

US Pat. No. 10,869,378

TARGET MEASURING APPARATUS AND EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS

Gigaphoton Inc., Tochigi...

1. A target measuring apparatus comprising:an image capturing unit configured to capture a picture image of a target output from a target supply unit;
a moving unit configured to move at least a part of the image capturing unit; and
a control unit configured to perform a first process of updating information on a coordinate system in the picture image based on an amount of movement of the image capturing unit by the moving unit, and a second process of measuring a parameter of the target based on the picture image captured by the image capturing unit and the information on the coordinate system.

US Pat. No. 10,283,927

LINE NARROWED LASER APPARATUS

Gigaphoton Inc., Tochigi...

1. A line narrowed laser apparatus configured to perform a plurality of burst oscillations including a first burst oscillation and a second burst oscillation next to the first burst oscillation to output a pulse laser beam, comprising:a laser resonator;
a chamber provided in the laser resonator;
a pair of electrodes provided in the chamber;
an electric power source configured to apply a pulsed voltage to the pair of electrodes;
a wavelength-selecting element provided in the laser resonator;
a spectral width varying unit provided in the laser resonator;
a wavelength variable unit configured to change a selected wavelength selected by the wavelength-selecting element; and
a controller configured to control the wavelength variable unit based on an amount of control of the spectral width varying unit in a period from a time of ending the first burst oscillation to a time of starting the second burst oscillation.