Patent ID: 7923705
Filing Date: 2011-04-12
Classification: G03F,H05G

Abstract:
1. An extreme ultra violet light source apparatus for generating extreme ultra violet light by applying a laser beam to a target material to turn the target material into plasma, said apparatus comprising: an extreme ultra violet light generating chamber in which extreme ultra violet light is generated; a target material supply unit for injecting a target material into said extreme ultra violet light generating chamber when the extreme ultra violet light is generated; a driver laser for emitting a laser beam; a window provided to said extreme ultra violet light generating chamber, for passing the laser beam into said extreme ultra violet light generating chamber; laser beam focusing optics including at least one optical element, said laser beam focusing optics focusing the laser beam emitted from said driver laser onto a trajectory of the target material injected into said extreme ultra violet light generating chamber to generate plasma; extreme ultra violet light collecting optics for collecting and outputting extreme ultra violet light radiated from said plasma; a temperature sensor for detecting a temperature of said window; and a processing unit for determining deterioration of said window based on the temperature of said window detected by said temperature sensor when extreme ultra violet light is generated.