Design verification for asymmetric phase shift mask layouts
US6185727A · kind A · utility
73Cited by
2References
8Claims
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Key dates
| Filing date | Dec 12, 1995 |
| Grant date | Feb 6, 2001 |
| Priority date | — |
| Expiry date | Dec 12, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A checking routine verifies a phase shifted mask (PSM) design based on fundamental principles of PSM and utilizing only basic shape manipulation functions and Boolean operations found in most computer aided design (CAD) systems. The design verification system checks complete chip designs for the two possible design errors that can cause defective masks by eliminating the phase transition; namely, placing a 180.degree. phase region on both sides of a critical feature or completely omitting the phase region adjacent to certain critical features.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.