System and method for multi-wavelength, narrow-bandwidth detection of surface defects
US6847443B1 · kind B1 · utility
8Cited by
10References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2002 |
| Grant date | Jan 25, 2005 |
| Priority date | — |
| Expiry date | Dec 18, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8806
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for detecting defects in surface structures, such as those formed on semiconductor wafers. A light source, preferably a strobe light, provides illumination that is separated by a filter into a plurality of selected bandwidths. The light then is transported through a fiber optic cable to a diffuser, and from there directed toward the surface. A camera captures a plurality of images, each image formed by a separate portion of the electromagnetic spectrum. The images may be formed by either reflected or diffracted light, or both. The images may be stored or compared to an image of a calibration wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.