Detecting defects on photomasks
US6701004B1 · kind B1 · utility
43Cited by
2References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1999 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Dec 22, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/84
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Defects on at least one photomask are detected by patterning alternating dice on a wafer with different process conditions. The different conditions, such as a length of exposure time and an optical focus condition, are configured to highlight and detect defect areas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.