Method for inspecting pattern defect and device for realizing the same
US7465935B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2006 |
| Grant date | Dec 16, 2008 |
| Priority date | — |
| Expiry date | Jan 5, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/4788
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
When using a CCD sensor as a photo-detector in a device for inspecting foreign matters and defects, it has a problem of causing electric noise while converting the signal charge, produced inside by photoelectric conversion, into voltage and reading it. Therefore, the weak detected signal obtained by detecting reflected and scattered light from small foreign matters and defects is buried in the electric noise, which has been an obstacle in detecting small foreign matters and defects. In order to solve the above problem, according to the present invention, an electron multiplying CCD sensor is used as a photo-detector. The electron multiplying CCD sensor is capable of enlarging signals brought about by inputted light relatively to the electric noise by multiplying the electrons produced through photoelectric conversion and reading them. Accordingly, compared to a conventional CCD sensor, it can detect weaker light and, therefore, smaller foreign matters and defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.