Method and system for defect detection
US7539583B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2005 |
| Grant date | May 26, 2009 |
| Priority date | — |
| Expiry date | May 18, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for inspecting objects such as semiconductor wafers. A staging platform and an optical platform are arranged so that the object may be staged and its surface scanned by optical equipment situated on the optical platform. During the scanning process, the surface is illuminated with light of a plurality of wavelengths, each strobed at a predetermined rate so that multiple images may be collected using time and frequency multiplexing. The multiple images are stored in a database for analysis, which includes processing selected ones of the multiple images according to one or more algorithms. The defect-detection algorithms used for each object are determined by referenced to a predetermined or calculated defect detection protocol, then a defect mask is created for each pixel in the images that is suspected to be defective. The defect mask is then compared to threshold parameters to determine which if any of the suspected defects should be reported.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.