Imaging system for deep ultraviolet lithography
US5650877A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1995 |
| Grant date | Jul 22, 1997 |
| Priority date | — |
| Expiry date | Aug 14, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70225
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A catadioptric reduction system operating in the deep ultraviolet range projects a reduced image of a mask on a substrate. A reducing optic made of a material transmissive to deep ultraviolet light has a concave front face covered by a partially reflective surface and a convex back face covered by a concave reflective surface surrounding a central aperture. The partially reflective surface transmits a portion of the light passing through the mask to the concave reflecting surface, which returns a portion of the transmitted light to the partially reflective surface. A portion of the returned light is reflected by the partially reflective surface on a converging path through said central aperture for producing a reduced image of the mask on the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.