Confocal inspection system having non-overlapping annular illumination and collection regions
US10551605B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 2017 |
| Grant date | Feb 4, 2020 |
| Priority date | — |
| Expiry date | Sep 27, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A confocal inspection system can optically characterize a sample. An objective lens, which can be a single lens or a combination of separate illumination and collection lenses, can have a pupil. The objective lens can deliver incident light to the sample through an annular illumination region of the pupil, and can collect scattered light returning from the sample to form collected light. Confocal optics can be positioned to receive the collected light. A detector can be configured with the confocal optics so that the detector generates signals from light received from a specified depth at or below a surface of the sample and rejects signals from light received from depths away from the specified depth. An optical element, such as a mask, a reconfigurable panel, or the detector, can define the annular collection region to be non-overlapping with the annular illumination region in the pupil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.