Patent Number: 6,169,627

Title: Catadioptric microlithographic reduction objective

Abstract: The invention is directed to a catadioptric microlithographic reduction objective having two concave mirrors (21, 23) facing toward each other. The concave mirrors have a symmetrical configuration and a central bore. Lenses (24 to 60) are mounted downstream of the mirrors (21, 23) on the light path toward the image plane (61). Preferably, lenses (15 to 20) are moved at the object end forward into the intermediate space between the mirrors (21, 23) in the region of the central bore. The light path between the concave mirrors can then preferably be free of lenses. The formation of an intermediate image (Z) downstream of the mirrors (21, 23) affords especially good correction possibilities.

Inventors: Schuster; Karl Heinz (Konigsbronn, DE)

Assignee: Carl-Zeiss-Stiftung

International Classification: G02B 17/08 (20060101); G03F 7/20 (20060101); G02B 013/14 (); G02B 017/00 ()

Expiration Date: 01/02/2018