Projection exposure apparatus
US4977426A · kind A · utility
19Cited by
8References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 24, 1988 |
| Grant date | Dec 11, 1990 |
| Priority date | — |
| Expiry date | Jun 24, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70241
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A projection exposure apparatus for projecting, through a refracting optical system, a pattern formed on an original such as a mask or reticle onto a wafer. The projection exposure apparatus includes a light source for providing an excimer laser beam to illuminate the original. The refracting optical system includes a plurality of lenses each of which is made of fused silica (SiO.sub.2) or calcium fluoride (CaF.sub.2).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.