Illumination unit having a facility for preventing contamination of optical components, and photolithographic apparatus including such an illumination unit
US5508528A · kind A · utility
12Cited by
9References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1994 |
| Grant date | Apr 16, 1996 |
| Priority date | — |
| Expiry date | Nov 29, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70933
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging apparatus and an illumination unit for use in such an apparatus are described, which unit comprises an illumination housing (LH) accommodating a radiation source (LA) and at least a reflector (RL). To prevent a decrease of the radiation power supplied by the illumination housing, this housing is provided with means (LA, SH, L.sub.29) which prevent a diffuse deposit of silicon-containing particles present in the ambient air from being formed on optical components within the illumination housing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.