Wafer inspection apparatus
US11264256B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2020 |
| Grant date | Mar 1, 2022 |
| Priority date | — |
| Expiry date | Oct 14, 2040 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30148
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Provided is a wafer inspection apparatus including a monochromator that extracts monochromatic light, a collimator that outputs the monochromatic light as parallel light, a first polarization assembly that polarizes the parallel light and radiates the polarized light to a wafer, an imaging optical system that condenses light reflected from the wafer, a spectroscope that splits the condensed light into a plurality of spectrums, a first lens that condenses the plurality of spectrums, a second polarization assembly that outputs the plurality of spectrums as a plurality of polarized lights having different diffraction orders and a difference of 90°, a second lens that condenses the plurality of polarized lights, a third polarization assembly that outputs common polarized light based on the plurality of polarized interfering with each other, a camera that generates a phase difference image based on the common polarized light, and a signal processor that analyzes the phase difference image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.