Defect inspection apparatus
US5473426A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1995 |
| Grant date | Dec 5, 1995 |
| Priority date | — |
| Expiry date | Apr 24, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/8901
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus includes a light source for emitting a light beam, a light beam expander for expanding the light beam in a predetermined direction, and radiating the expanded light beam onto an object to be inspected, a scanning device for moving the object to be inspected relative to the light beam to be radiated onto the object to be inspected, and a photodetector for photoelectrically converting scattered light generated from a defect (including foreign matter) on the object to be inspected, and inspects the defect on the basis of a photoelectric conversion signal obtained from the photodetector. A light-shielding plate having a plurality of edges for limiting the light beam expanded by the light beam expander at the two end portions, in the expansion direction, of the light beam is arranged, and at least one of the plurality of edges is formed to be transverse to the relative scanning direction (Y direction).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.