Scanning system for inspecting anomalies on surfaces
US5883710A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1995 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jul 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/956
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A high sensitivity and high throughput surface inspection system directs a focused beam of light at a grazing angle towards the surface to be inspected. Relative motion is caused between the beam and the surface so that the beam scans a scan path covering substantially the entire surface and light scattered along the path is collected for detecting anamolies. The scan path comprises a plurality of arrays of straight scan path segments. The focused beam of light illuminates an area of the surface between 5-15 microns in width and this system is capable of inspecting in excess of about 40 wafers per hour for 150 millimeter diameter wafers (6-inch wafers), in excess of about 20 wafers per hour for 200 millimeter diameter wafers (8-inch wafers) and in excess of about 10 wafers per hour for 300 millimeter diameter wafers (12-inch wafers).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.