| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection aligner that can readily reduce fluctuation in aberration generated by change in temperature due to the irradiation of exposure light. SOLUTION: Light from the pattern of a mask 3 forms a primary image I of a mask pattern via a first image-forming optical system K1. Light from the primary image I is reflected by a submirror M2 via the center opening of the main mirror M1 and a lens component L2, and the light reflected by the submirror M2 is reflected by the main mirror M1 via the lens component L2. The light reflected by the main mirror M1 forms the secondary image of the mask pattern with reduced magnification on the surface of a wafer 9 via the lens component L2 and the center opening of the submirror M2. At this time, a reflecting surface R2 of the submirror M2 is lined with a heat sink 81, having thermal conductivity larger than that of the lens component L2, thus allowing heat generated on the reflecting surface R12 that is a back- reflecting surface, having relatively large heat generation tending to allow escape to the heat sink 81 as compared with the lens component L2, and hence forming an image accurately. |
