Catoptric projection optical system, exposure apparatus and device fabrication method
US7130018B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 24, 2003 |
| Grant date | Oct 31, 2006 |
| Priority date | — |
| Expiry date | Dec 24, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70275
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A catoptric projection optical system for projecting a reduced size of a pattern on an object surface onto an image surface includes eight mirrors and forms an intermediate image between the sixth mirror and the seventh mirror on an optical path, wherein a position in a height direction of a principal ray from an optical axis at each mirror displaces, and a displacement direction from the first mirror to the fourth mirror is reverse to that from the fifth mirror to the eight mirror, wherein the second mirror to the fifth mirror are a concave mirror, a convex mirror, a concave mirror and a concave mirror, and the seventh mirror to the eighth are a convex mirror and a concave mirror, and wherein the second mirror of the eight mirrors is located closest to the object surface side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.