Foreign particle inspection apparatus
US5623340A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1995 |
| Grant date | Apr 22, 1997 |
| Priority date | — |
| Expiry date | Feb 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8806
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A foreign particle inspection apparatus, for detecting a foreign particle on a reticle or the like includes an illumination system for irradiating an inspection area on a specimen with inspecting light, and plural light-receiving systems adapted to condense the scattered light from a foreign particle in the inspection area and having respective light-receiving areas on the specimen, each smaller than the inspection area. Each of the light-receiving areas of the plural light-receiving systems overlaps partially with at least one of the other light-receiving areas. The plural light-receiving systems are so arranged that any point in the inspection area is covered by the light-receiving areas of at least two of the plural light-receiving systems. A foreign particle in the inspection area is detected by a detection system, based on the lights condensed by the plural light receiving systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.