| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for preprocessing and cleaning a condensing reflecting mirror that can completely remove the contaminants deposited on a light-reflecting surface of the condensing reflecting mirror, and to provide an extreme ultraviolet light source. <P>SOLUTION: The discharge gas is supplied to a plasma-generating part 2, and the high-voltage pulse voltage is applied between first and second main discharge electrodes 2a and 2b from a high-voltage pulse generator part 11. This generates a high-temperature plasma that emits extreme ultraviolet light of wavelength of 13.5 nm. This extreme ultraviolet light is condensed by a condensing reflecting mirror 4 to be emitted from an EUV light extracting part 5. Although debris arising from generation of the high-temperature plasma forms a contaminant layer on the light-reflecting surface of the condensing reflecting mirror 4, in order to completely remove this, a cleaning gas constituent material is attached to the top surface of the condensing reflecting mirror, before the contaminant layer is formed. As a result, by making the cleaning gas circulate from a cleaning gas supply nozzle 25, the contaminants can be removed substantially completely. <P>COPYRIGHT: (C)2009,JPO&INPIT |
