Photomask inspection apparatus and method using corner comparato

Details Photomask inspection apparatus and method using corner comparato Photomask inspection apparatus and method using corner comparato

1983-05-12

1985-07-30

Boudreau, Leo H.

Image analysis

Histogram processing

For setting a threshold

356237, 358101, 358106, G06K 900

Patent

active

045326509

ABSTRACT:
Defect detection apparatus including a mechanical and optical system for scanning duplicate areas of a photomask to be inspected, electronic means for converting the optically scanned information to digitized form, memory for storing such information, and means for comparing information obtained from one inspected area to the other inspected area to determine differences therebetween, such differences being classified as defects. The detection is accomplished using a vector gradient within a matrix technique to develop candidate and cancellor information which is then logically manipulated to qualify the data obtained from each pixel matrix and then, after qualification, is used to determine whether or not a defect has been detected. The subject invention has particular application to the detection of defects occurring at pattern corners within the inspected photomask and is specifically directed to overcoming difficulties previously encountered in detecting such defects.

REFERENCES:
patent: 4148065 (1979-04-01), Nakagawa et al.
patent: 4282510 (1981-08-01), Southgate
patent: 4282511 (1981-08-01), Southgate et al.
patent: 4403294 (1983-09-01), Hamada et al.
patent: 4454542 (1984-06-01), Miyazawa
patent: 4472738 (1984-09-01), Hada et al.

Affiliated with

Also associated with

Rating

Photomask inspection apparatus and method using corner comparato does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Photomask inspection apparatus and method using corner comparato, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photomask inspection apparatus and method using corner comparato will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2377352