Attenuated embedded phase shift photomask blanks
US6682860B2 · kind B2 · utility
4Cited by
2References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 12, 2002 |
| Grant date | Jan 27, 2004 |
| Priority date | — |
| Expiry date | Apr 12, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC23C14/08
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An attenuating embedded phase shift photomask blank that produces a phase shift of the transmitted light is formed with an optically translucent film made of metal, silicon, nitrogen and oxygen. An etch stop layer is added to improve the etch selectivity of the phase shifting layer. A wide range of optical transmission (0.001% up to 15% at 157 nm) is obtained by this process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.