Optics: measuring and testing – Inspection of flaws or impurities – Having predetermined light transmission regions
Patent
1993-04-16
1995-10-31
McGraw, Vincent P.
Optics: measuring and testing
Inspection of flaws or impurities
Having predetermined light transmission regions
437 8, 437939, G01N 2189, G02B 2746, G06F 1546
Patent
active
054634598
ABSTRACT:
A defect detecting apparatus including an illumination system for radiating a light of a plane wave linearly to a substrate having repetitive patterns of different pitches; a focusing optical system for focusing a light image reflected from the substrate thus illuminated by the illumination system; a spatial filter disposed intermediate the focusing optical system so as to shield a diffraction light from repetitive patterns of a small pitch on the substrate; a detector for detecting the light image formed by the focusing optical system; an erasing means for comparing and erasing signals which are generated on the basis of repetitive patterns of a large pitch and obtained through the spatial filter, out of signals detected by the detector; and a defect detecting means for detecting defects on the substrate in accordance with a signal detected by the detector, as well as a method applied to the said apparatus.
REFERENCES:
patent: 4448532 (1984-05-01), Joseph et al.
patent: 4571685 (1986-02-01), Kamoshida
patent: 5172000 (1992-12-01), Scheff et al.
patent: 5274434 (1993-12-01), Morioka et al.
patent: 5276498 (1994-01-01), Galbraith et al.
Kembo Yukio
Matsuoka Kazuhiko
Morioka Hiroshi
Nishiyama Hidetoshi
Noguchi Minori
Hitachi , Ltd.
McGraw Vincent P.
LandOfFree
Method and apparatus for analyzing the state of generation of fo does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for analyzing the state of generation of fo, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for analyzing the state of generation of fo will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1777496