Patent ID: RE39296

Claim:
A catadioptric projection system for receiving light from a reticle and projecting a pattern from the reticle onto a substrate, the catadioptric projection system comprising: a first imaging system that forms an intermediate image of an illuminated region of the reticle, the first imaging system comprising in order from the reticle and along an optical axis of the first imaging system, (a) a single-pass lens group comprising a first negative subgroup, a positive subgroup, and a second negative subgroup, and (b) a double-pass lens group comprising a concave mirror, wherein light from the illuminated region of the reticle passes through the single-pass lens group and the double-pass lens group, reflects from the concave mirror, and returns through the double-pass optical group; a first turning mirror placed near the intermediate image that receives the light reflected by the concave mirror to and returned through the double-pass optical group; and a second imaging system that receives the light reflected by the first turning mirror and that re-images the intermediate image to form a final image of the illuminated region of the reticle on the substrate.