Surface analysis system and method
US4893932A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 21, 1988 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Oct 21, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9505
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A surface analysis system and method are disclosed for determining particle contamination and/or defects on or below a surface of material. Laser beams having different polarizations are directed to the surface to be analyzed and light scattered from particle contamination and/or defects on or below the surface is collected and detected to provide electrical signals representative thereof. The electrical signals are then processed to provide an output indicative of sensed contamination and/or defects. In the embodiment particularly shown and described, a pair of polarized laser beams, one of which is a "P" polarized laser beam and the other of which is a "S" polarized laser beam, are separately directed to a monitoring region so that the beams impinge at a common point on the surface to be analyzed. The scattered light is then collected and split into two components depending upon whether scattered from the "P" polarized laser beam or the "S" polarized laser beam and each component is separately detected, after which the electrical outputs are processed to provide the desired indication.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.