Photomask blank, photomask and fabrication method thereof
US7771893B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Jul 20, 2006 |
| Grant date | Aug 10, 2010 |
| Priority date | — |
| Expiry date | Jun 27, 2028 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31616
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A light-shielding film for exposure light is formed on one principal plane of a transparent substrate made of quartz or the like that serves as a photomask substrate. The light-shielding film can serve not only as the so-called “light-shielding film” but also as an anti-reflection film. In addition, the light-shielding film has a total thickness of 100 nm or less, 70% or more of which is accounted for by the thickness of a chromium compound that has an optical density (OD) per unit thickness of 0.025 nm−1 for light having a wavelength of 450 nm. In the case where the photomask blank is used for fabricating a mask designed for ArF exposure, the thickness and composition of the light-shielding film are selected in such a manner that the OD of the light-shielding film is 1.2 to 2.3 for 193 or 248 nm wavelength light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.