Phase-shifting photomask blank, phase-shifting photomask, method for producing them and apparatus for manufacturing the blank
US6228541A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 16, 1999 |
| Grant date | May 8, 2001 |
| Priority date | — |
| Expiry date | Apr 16, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/32
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A uniform thin phase-shifting photomask blank can be formed by depositing a thin film on a substrate by a reactive sputtering technique while passing, at least four times, the substrate over a sputtering target. In the formation of the blank, NO gas is used as the reactive gas, a target composed of a mixture of molybdenum and silicon is used as the sputtering target and a transparent substrate is used as the thin film-forming substrate to form, on the transparent substrate, a light-transmitting film capable of transmitting light rays having an intensity, which cannot substantially contribute to the exposure. In addition, the film is formed, on the substrate, through an opening having a sufficiently enlarged length along the substrate-conveying direction so that even regions whose deposition rate of the target component is not more than 90% of the maximum level thereof also contribute to the film-formation. The phase-shifting photomask blank thus prepared is subjected to a patterning treatment to form a phase-shifting photomask.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.