1 March 1974 Automated Inspection Of IC Photomasks
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The results of a nationwide review of automated IC photomask inspection methods are presented. Major photomask inspection problems of detection of visual defects and registration errors, and the determination of critical dimensions and photoplate quality are discussed. This review indicates that for high-volume, large-scale integrated circuits, the greatest concern is for the detection of visual defects. Next in order of importance are the detection of registration errors, and then the accurate determination of critical dimensions. Automated inspection systems and technologies currently available for this are discussed including: microdensitometer-digital computer systems, laser beam scanning systems, spatial filtering systems and microscope-television-digital computer systems. Suggested criteria for an ideal photomask inspection system are the simultaneous inspection for 2-μm visual defects, the determination of registration tolerances to within ±0.5 μm and the determination of the accuracy of the critical dimensions to tolerances of ±0.5 μm on a single photomask in ten minutes.
© (1974) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
D. R. Ciarlo, D. R. Ciarlo, P. A. Schultz, P. A. Schultz, D. B. Novotny, D. B. Novotny, } "Automated Inspection Of IC Photomasks", Proc. SPIE 0055, Technological Advances in Micro and Submicro Photofabrication Imagery, (1 March 1974); doi: 10.1117/12.954254; https://doi.org/10.1117/12.954254


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