Invention Grant
- Patent Title: Microlithography reduction objective and projection exposure apparatus
- Patent Title (中): 微光学削减物镜和投影曝光装置
-
Application No.: US10004674Application Date: 2001-12-03
-
Publication No.: US06600552B2Publication Date: 2003-07-29
- Inventor: Udo Dinger
- Applicant: Udo Dinger
- Priority: DE19906001 19990215; DE19948240 19991007
- Main IPC: G03B2754
- IPC: G03B2754

Abstract:
A microlithography reduction objective formed from six mirrors arranged in a light path between an object plane and an image plane is provided. The microlithography reduction objective is characterized by having an image-side numerical aperture NA≧0.15. In some embodiments, the mirror closest to the image plane, i.e., the fifth mirror is arranged such that an image-side optical free working distance is greater than or equal to a used diameter of a physical mirror surface of the fifth mirror, a physical mirror surface being the area of a mirror where light rays from the object impinge. The fifth mirror may be arranged such that an image-side optical free working distance is greater than or equal to the sum of one-third the used diameter of the physical mirror surface on the fifth mirror and a length between 20 mm and 30 mm. The fifth mirror may be arranged such that the image-side optical free working distance is at least 50 mm, as well. The image-side free working distance is the physical distance between the vertex of the surface of the fifth mirror and the image plane. Other embodiments are described.
Public/Granted literature
- US20020145718A1 Microlithography reduction objective and projection exposure apparatus Public/Granted day:2002-10-10
Information query