Silica glass member and method of manufacturing the same
US10252933B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2017 |
| Grant date | Apr 9, 2019 |
| Priority date | — |
| Expiry date | May 30, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03C2203/54
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Provided is a silica glass member which exhibits high optical transparency to vacuum ultraviolet light and has a low thermal expansion coefficient of 4.0×10−7/K or less at near room temperature, particularly a silica glass member which is suitable as a photomask substrate to be used in a double patterning exposure process using an ArF excimer laser (193 nm) as a light source. The silica glass member is used in a photolithography process using a vacuum ultraviolet light source, in which the fluorine concentration is 1 wt % or more and 5 wt % or less, and the thermal expansion coefficient at from 20° C. to 50° C. is 4.0×10−7/K or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.