Method and apparatus for illumination adjustment
US11429029B2 · kind B2 · utility
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2References
20Claims
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Key dates
| Filing date | Oct 27, 2020 |
| Grant date | Aug 30, 2022 |
| Priority date | — |
| Expiry date | Oct 27, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/956
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method includes projecting an illumination beam of radiation onto a metrology target on a substrate, detecting radiation reflected from the metrology target on the substrate, and determining a characteristic of a feature on the substrate based on the detected radiation, wherein a polarization state of the detected radiation is controllably selected to optimize a quality of the detected radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.