| 摘要 |
This invention discloses a light-source device that minimizes decreases in the reflectance of a condensing mirror or the transmittance of a debris trap due to debris. In this device, a masking member (6) that has an opening (6a) is provided in front of a fixed foil trap (5) so as to limit the solid angle subtended by light emitted by a high-temperature plasma (P). Also, the fixed foil trap (5) is provided with a drive mechanism (7) and is rotated away from a position in which a section of the foil trap to which debris is attached faces the aforementioned opening (6a). This makes it possible to minimize (or reverse) decreases in transmittance due to attached debris, resulting in a longer usable life. The foil trap may also be a rotating foil trap (4) that traps debris from the plasma by rotating. An EUV condensing mirror (9) may also be rotated so as to minimize decreases in reflectance due to attached debris. |
