Patent ID: 7842937

Claim:
A laser produced plasma type extreme ultra violet light source apparatus for generating extreme ultra violet light by applying a laser beam to a target, said apparatus comprising: a chamber in which extreme ultra violet light is generated; a target supply unit which supplies a liquid or solid metal target to a predetermined position within said chamber; a laser beam generating unit which synthesizes pulse laser beams having delays different from one another to generate one of a single pulse laser beam and a pulse train laser beam having substantially homogeneous intensity, and applies the laser beam to the target supplied by said target supply unit to generate plasma; and a collector mirror which collects the extreme ultra violet light radiated from said plasma and outputs the extreme ultra violet light, wherein said laser beam generating unit includes a plurality of oscillation and amplification laser arrangements which respectively generate pulse laser beams having delays different from one another, and each of said oscillation and amplification laser arrangements has an oscillation laser device which outputs a pulse laser beam and an amplification device including at least one amplifier which amplifies the pulse laser beam outputted from said oscillation laser device.