Furnace purification and metal fluoride crystal grown in a purified furnace
US7306673B2 · kind B2 · utility
0Cited by
6References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2004 |
| Grant date | Dec 11, 2007 |
| Priority date | — |
| Expiry date | Nov 2, 2025 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B29/12
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention is directed to a method for growing metal fluoride crystals suitable for use in below 200 nm optical lithography systems, the method comprising including at least the step of heating a crystal growth furnace to a temperature in the range of 1400-2000° C. to purify the furnace by removal of sulfur and chlorine prior to using the furnace for growing metal fluoride single crystals.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.