Position detection method and apparatus
US4655598A · kind A · utility
31Cited by
2References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1985 |
| Grant date | Apr 7, 1987 |
| Priority date | — |
| Expiry date | Nov 18, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Position detecting method and a apparatus detect a position of substrate formed with a diffraction grating mark and a linearly extending stepped edge mark spaced from the diffraction grating. In the method and apparatus, those marks are relatively scanned by light beam, and position of the substrate is detected based on light information generated by both the marks and the scanning position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.