Projection optical system and projection exposure apparatus
US7092168B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 2005 |
| Grant date | Aug 15, 2006 |
| Priority date | — |
| Expiry date | Nov 8, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70275
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A catadioptric projection optical system for projecting an image of an object onto an image plane through two intermediate image formations. The catadioptric projection optical system includes a first optical system, for receiving light from the object, including a plurality of lenses, a second optical system, for forming the image of the object on the image plane, including a plurality of lenses, and a third optical system disposed optically between the first optical system and the second optical system. The third optical system includes a first concave mirror and a second concave mirror. The light is reflected by the first concave mirror then by the second concave mirror to be directed to the second optical system along a z-shaped optical path, and the first, second and third optical systems have a common straight optical axis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.