Microlithographic system
US4616908A · kind A · utility
64Cited by
11References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 19, 1984 |
| Grant date | Oct 14, 1986 |
| Priority date | — |
| Expiry date | Jul 19, 2004 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70883
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In the microlithographic system disclosed herein, the spaces between elements in a projection lens are filled with flowing helium gas which substantially reduces the refraction errors caused by barometric changes in the atmosphere, even though the portions of the optical path outside the lens are exposed to the atmosphere.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.