Photomask blank, photomask and method of manufacture
US6733930B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 13, 2002 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | Jun 27, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/80
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a photomask blank comprising a light-shielding film and an antireflective film on a transparent substrate, the light-shielding film and the antireflective film are formed of a chromium base material containing oxygen, nitrogen and carbon such that the content of carbon decreases stepwise or continuously from a surface side toward the substrate. The photomask blank can be etched at a controlled rate to produce perpendicular walls. A photomask is manufactured by lithographically patterning the photomask blank. The photomask blank and photomask have uniform film properties and contribute to the microfabrication of semiconductor ICs of greater density and finer feature size.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.