Phase shift mask blank, phase shift mask, and methods of manufacture
US6641958B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2001 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Jan 23, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/32
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A phase shift mask blank includes a transparent substrate and a phase shift film composed primarily of a metal and silicon. The substrate has an etch rate A and the phase shift film has an etch rate B when the blank is patterned by reactive ion etching, such that the etch selectivity B/A is at least 5.0. When a phase shift mask is manufactured from the blank, the substrate is less prone to overetching, providing good controllability and in-plane uniformity of the phase shift in patterned areas. The phase shift mask can be used to fabricate semiconductor integrated circuits to a smaller minimum feature size and a higher level of integration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.