Confocal line inspection optical system
US9927371B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 2015 |
| Grant date | Mar 27, 2018 |
| Priority date | — |
| Expiry date | Jun 15, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A line scan wafer inspection system includes a confocal slit aperture filter to remove sidelobes and enhance resolution in the scanning direction. A position detector associated with the slit aperture filter monitors and corrects illumination line image positions relative to the slit aperture to keep image position variations within tolerable limits. Each detector measures a line position and then uses the line position signal to adjust optical, mechanical, and electronic components in the collection path in a feedback loop. The feedback loop may be employed in a runtime calibration process or during inspection to enhance stability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.