Defect inspection method and apparatus therefor
US8885037B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 2010 |
| Grant date | Nov 11, 2014 |
| Priority date | — |
| Expiry date | Nov 20, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To effectively utilize the polarization property of an inspection subject for obtaining higher inspection sensitivity, for the polarization of lighting, it is necessary to observe differences in the reflection, diffraction, and scattered light from the inspection subject because of polarization by applying light having the same elevation angle and wavelength in the same direction but different polarization. According to conventional techniques, a plurality of measurements by changing polarizations is required to cause a prolonged inspection time period that is an important specification of inspection apparatuses. In this invention, a plurality of polarization states are modulated in micro areas in the lighting beam cross section, images under a plurality of polarized lighting conditions are collectively acquired by separately and simultaneously forming the scattered light from the individual micro areas in the individual pixels of a sensor, whereby inspection sensitivity and sorting and sizing accuracy are improved without reducing throughput.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.