Pattern defect inspection apparatus

Image analysis – Histogram processing – For setting a threshold

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

250562, 356237, G06K 900

Patent

active

047318554

ABSTRACT:
A pattern defect inspection apparatus detects presence or absence of a defect in a pattern formed on a semiconductor wafer by scanning the pattern normally to the surface thereof by a coherent light beam of a predetermined spot size, detecting reflected diffraction lights generated thereby and processing the detected lights. It comprises an abnormal direction signal detector including photo-detectors having wide light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from a normal pattern do not normally reach, a normal pattern detector including photo-detectors having large light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from the normal pattern reach, and a defect discriminator for determining if the abnormal direction signals are due to a true defect or not in accordance with the signals from the abnormal direction signal detector and the normal pattern detector.

REFERENCES:
patent: 3790280 (1974-02-01), Heinz et al.
patent: 3879131 (1975-04-01), Cuthbert et al.
patent: 3905019 (1975-09-01), Aoki et al.
patent: 4360799 (1982-11-01), Leighty et al.
patent: 4377340 (1983-03-01), Green
patent: 4428672 (1984-01-01), Allard et al.
patent: 4578810 (1986-03-01), MacFarlane et al.
patent: 4598997 (1986-07-01), Steigmeier et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Pattern defect inspection apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

     

Profile ID: LFUS-PAI-O-1930924

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.