Defect testing apparatus and defect testing method
US6563577B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 2001 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Apr 18, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/9501
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention aims of preventing a diffracted light, in testing to detect a foreign substance or a flaw on a tested substrate having a repeated pattern, from entering the eye of the observer or a light receiving optical system to be hindrance to the defect test, by providing a defect testing apparatus which comprising: a light source; an illumination optical system for applying a light flux from the light source onto a tested substrate having a repeated pattern at a predetermined angle of incidence; a light receiving optical system for receiving a scattered light from the tested substrate; an image pick-up device for picking up an image formed by the light receiving optical system; a display device for displaying the image obtained by the image pick-up device; and a test stage for mounting the tested substrate thereon at the time of testing, wherein the tested substrate and the illumination optical system are arranged to be rotatable relatively to each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.