Optimized alternating phase shifted mask design
US6338922B1 · kind B1 · utility
76Cited by
12References
33Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 8, 2000 |
| Grant date | Jan 15, 2002 |
| Priority date | — |
| Expiry date | May 8, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/30
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for reducing lens aberrations sensitivity and proximity effects of alternating phase shifted masks is described. The critical features of a chip design layout are first identified. Multiple, narrow phase regions and auxiliary phase transitions, which provide additional opaque features, are then formed alongside the critical features such that a grating pattern of substantially uniform pitch is printed. Together with a complementary trim mask, the circuit pattern so delineated has reduced sensitivity to lens aberrations and proximity effects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.