Apparatus for detecting foreign matters on a planar substrate
US4568835A · kind A · utility
20Cited by
2References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 2, 1982 |
| Grant date | Feb 4, 1986 |
| Priority date | — |
| Expiry date | Nov 2, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/104
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for detecting foreign matter present on a planar substrate comprises apparatus for scanning the surface of the substrate with an oblique incident light beam, apparatus for photo-electrically detecting the scattered light generator in the trajectory of the light beam scanning on the substrate, and apparatus for eliminating stray light unnecessary for the foreign matter detection.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.