Simple repair method for phase shifting masks
US5795685A · kind A · utility
74Cited by
10References
47Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1997 |
| Grant date | Aug 18, 1998 |
| Priority date | — |
| Expiry date | Jan 14, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/72
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method and apparatus for correcting defects in a phase shift mask to be used in photolithography. More specifically, the method of the invention includes creating a second repair mask which contains phase shifters. Regions surrounding the defects on the first mask are made opaque. The design circuitry located in these defective regions is copied onto the second mask. During a second exposure the design circuitry is placed onto the semiconductor wafer. Therefore, this method and apparatus provides an inexpensive solution to a difficult problem.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.