Double inspection of reticle or wafer
US7355690B2 · kind B2 · utility
18Cited by
0References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 17, 2004 |
| Grant date | Apr 8, 2008 |
| Priority date | — |
| Expiry date | Apr 27, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30148
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
During mask or reticle inspection, each region is scanned at least twice, using an overlap between each pair of consecutive frames. System contamination and camera blemishes have approximately constant frame coordinates, while mask defects have constant reticle coordinates, but inconstant scan frame coordinates. True defects are detected at different coordinates in consecutive frames with a known displacement therebetween.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.