Optical member and method of producing the same, and projection aligner
US6850371B2 · kind B2 · utility
2Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 13, 2002 |
| Grant date | Feb 1, 2005 |
| Priority date | — |
| Expiry date | Aug 12, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70958
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical member of the invention is an optical member for photolithography used together with light having a wavelength of not more than 250 nm. The optical member is made of a fluoride crystal in which a maximum diameter dmax (cm) of scattering bodies existing internally and a quantity ns of the scattering bodies per 1 cm3 satisfy a condition represented by following formula (1):0<dmax2×ns<6.5×10−4 (cm−1) (1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.