EXTREME ULTRAVIOLET LIGHT SOURCE DEVICE AND CLEANING METHOD FOR EXTREME ULTRAVIOLET LIGHT CONVERGING MIRROR

PROBLEM TO BE SOLVED: To remove debris by enabling a cleaning means to act efficiently on a portion contaminated with the debris caused by a metal or a metal compound, in an extreme ultraviolet light converging mirror. SOLUTION: Power is supplied between a first electrode 11 and a second electrode 12 from a pulse power supply 15 to generate a high temperature plasma P in a discharge part 1. An EUV light is emitted thereby. The EUV light is emitted from an EUV light extracting part 7 via the converging mirror 2. At the same time as this, the debris containing tin, etc. is emitted from the discharge part 1, and a part of this reaches the converging mirror 2 and sticks to a reflecting surface. A cleaning gas supply unit 5 and a radical generating part 6 are installed at a light emitting side of the converging mirror 2, and a non-reflective surface 2b of the converging mirror 2 is covered with an insulating material. Even when a hydrogen radical is brought into contact with the non-reflective surface 2b, etc., therefore, it can react with the debris containing tin, etc. stuck and deposited on the converging mirror without deactivating, so that cleaning is performed efficiently. COPYRIGHT: (C)2009,JPO&INPIT