Position sensor
US11333985B2 · kind B2 · utility
0Cited by
2References
22Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2019 |
| Grant date | May 17, 2022 |
| Priority date | — |
| Expiry date | Jun 5, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7092
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention provides a position sensor (300) which comprises an optical system (305,306) configured to provide measurement radiation (304) to a substrate (307). The optical system is arranged to receive at least a portion of radiation (309) diffracted by a mark (308) provided on the substrate. A processor (313) is applied to derive at least one position-sensitive signal (312) from the received radiation. The measurement radiation comprises at least a first and a second selected radiation wavelength. The selection of the at least first and second radiation wavelengths is based on a position error swing-curve model.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.