Catadioptric lens used as a projection lens in semiconductor lithography comprises a beam divider partially surrounded by a holder, a mirror, lenses, a plate and an absorption unit arranged between the beam divider and the holder

摘要

Catadioptric lens comprises a beam divider (4) partially surrounded by a holder (12); a mirror (8); lenses (1-3); an lambda /4 plate (7); and an absorption unit (13) arranged between the beam divider and the holder on the side on which the stray light leaves the beam divider. The absorption unit absorbs the stray light. Preferred Features: The absorption unit is a glass substrate and is arranged on the side opposite the light bundle entering the beam divider and the holder. The glass substrate has an antireflection coating.