Patent ID: 9167678
Filing Date: 2015-10-20
Classification: H01S,H05G

Abstract:
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.