US Patent No. 9,860,966


Patent No. 9,860,966
Issue Date January 02, 2018
Title Radiation Source
Inventorship Jan Bernard Plechelmus Van Schoot, Eindhoven (NL)
Antonius Theodorus Wilhelmus Kempen, Den Bosch (NL)
Hermanus Kreuwel, Veldhoven (NL)
Andrei Mikhailovich Yakunin, Veldhoven (NL)
Assignee ASML NETHERLANDS B.V., Veldhoven (NL)

Claim of US Patent No. 9,860,966

1. A method of generating EUV radiation in a radiation source for a lithographic apparatus, the method comprising:
supplying a stream of fuel droplets to a target area;
configuring a laser to emit pulses of laser radiation directed at said target area timed to strike and vaporize a fuel droplet
to generate EUV radiation; and

predicting a delay caused by the effect of vaporization of one fuel droplet on a subsequent fuel droplet in said stream; and
controlling the timing of said pulses to be dependent on the predicted delay caused by the effect of the vaporization.