Apparatus for detecting defects in patterns

Details Apparatus for detecting defects in patterns Apparatus for detecting defects in patterns

1978-07-05

1980-06-24

Corbin, John K.

Optics: measuring and testing

By configuration comparison

With comparison to master, desired shape, or reference voltage

356398, G01B 1100

Patent

active

042092574

ABSTRACT:
An apparatus for detecting defects in patterns, particularly defects in chip patterns of photomasks for use in manufacturing semiconductor integrated circuits comprising optically scanning means for scanning in a raster scan mode identical portions of the two patterns to be compared with each other by means of a pair of lens systems to produce a pair of picture signals each corresponding to a respective one of the scanned pattern portions and a defect signal producing means for receiving said pair of picture signals and producing a defect signal as a difference between the two picture signals. A variable delay circuit is provided between the optically scanning means and defect signal producing means to correct or compensate for deviations in the two picture signals due to differences in optical characteristics between the two lens system such as distortion and magnification. The variable delay circuit delays the picture signals for a delay time which is varied as a function of a position on the raster.

REFERENCES:
patent: 3546377 (1970-12-01), Troll
patent: 4123170 (1978-10-01), Uchiyama et al.

Affiliated with

Also associated with

Rating

Apparatus for detecting defects in patterns does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Apparatus for detecting defects in patterns, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for detecting defects in patterns will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1478884