Method and system for fast on-line electro-optical detection of wafer defects
US6693664B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 2002 |
| Grant date | Feb 17, 2004 |
| Priority date | — |
| Expiry date | Dec 16, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/95607
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and system for fast on-line electro-optical detection of wafer defects featuring illuminating with a short light pulse from a repetitively pulsed laser, a field of view of an electro-optical camera system having microscopy optics, and imaging a moving wafer, on to a focal plane assembly optically forming a surface of photo-detectors at the focal plane of the optical imaging system, formed from six detector ensembles, each ensemble including an array of four two-dimensional CCD matrix photo-detectors, whereby each two-dimensional CCD matrix photo-detector produces an electronic image of a large matrix of two million pixels, such that the simultaneously created images from the different CCD matrix detectors are processed in parallel using conventional image processing techniques, for comparing the imaged field of view with another field of view serving as a reference, in order to find differences in corresponding pixels, indicative of the presence of a wafer die defect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.