| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection optical system which enables adjustment of an image-formation performance affected by birefringence without varying aberrant conditions which are not caused by birefringence. SOLUTION: The projection optical system PL is provided, comprising a plurality of refraction members for substantially transmitting light having a wavelength of 200 nm or below, and projecting an image on a reticle R to a wafer W. The system is provided with: a powerless first refraction member A made of a crystal optical material, which is arranged the nearest to the wafer W in an optical path between the reticle R and the wafer W; and a second refraction member B made of crystal optical material with a face having no power over the first refraction member A, which is arranged adjacent to the first refraction member A, at a reticle side in the optical path. Positions of a crystal axis of the first refraction member A and a crystal axis of the second refraction member B are determined so as to form a predetermined relation. COPYRIGHT: (C)2004,JPO
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