Phase-shift photomask-blank, phase-shift photomask and fabrication method thereof
US7622227B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 2006 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | Sep 13, 2027 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31616
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
On a substrate that is transparent to exposure light, a phase-shift multilayer film including a stack of two layers of a metal silicide compound is formed. A stabilized oxide layer is formed on the surface of the metal silicide compound layer close to the top surface. The layer close to the substrate (the lower layer) of the phase-shift multilayer film is made of a relatively-metal-rich metal silicide compound, and the upper layer is made of a relatively-metal-poor metal silicide compound. The stabilized oxide layer has a metal-poor composition, and the metal content thereof is equal to or less than one third of the metal content of the lower layer. Thus, the stabilized oxide layer is highly chemically stable and has a high chemical resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.