US Patent No. 10,172,225

EXTREME ULTRAVIOLET LIGHT GENERATION APPARATUS


Patent No. 10,172,225
Issue Date January 01, 2019
Title Extreme Ultraviolet Light Generation Apparatus
Inventorship Toru Suzuki, Oyama (JP)
Tamotsu Abe, Oyama (JP)
Osamu Wakabayashi, Oyama (JP)
Tatsuya Yanagida, Oyama (JP)
Assignee Gigaphoton Inc., Tochigi (JP)

Claim of US Patent No. 10,172,225

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.