Method and apparatus for macro defect detection using scattered light
US5859698A · kind A · utility
86Cited by
8References
20Claims
0Family size
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Key dates
| Filing date | May 7, 1997 |
| Grant date | Jan 12, 1999 |
| Priority date | — |
| Expiry date | May 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/95607
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Macro defects in a processed or partly processed semiconductor wafer, liquid crystal display element, disk drive element or the like, are detected using scattered light. By use of automated image processing techniques, a reference image and a sample image are formed from the scattered light and edge enhanced. A difference image is formed by comparing the edge enhanced reference and sample images. The difference image is evaluated using one or more automated image processing techniques such as thresholding, morphological transformations and blob analysis to identify macro defects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.