Method for monitoring a characteristic of illumination from a metrology apparatus
US10317805B2 · kind B2 · utility
2Cited by
4References
19Claims
0Family size
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Key dates
| Filing date | Dec 15, 2017 |
| Grant date | Jun 11, 2019 |
| Priority date | — |
| Expiry date | Dec 15, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for monitoring a characteristic of illumination from a metrology apparatus includes using the metrology apparatus to acquire a pupil image at different focus settings of the metrology apparatus and calculating an asymmetry value for each acquired pupil image, where each pupil image is acquired on at least one edge of a target of a substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.