This paper describes how a technique was developed to make precise and accurate submicron linewidth measurements on photomasks which takes advantage of the inherent benefits of both optical and electrical measurement techniques. We present the theory of operation for both the optical and electrical equipment used, and the theory behind the electrical test structure design. Test mask development includes the materials (types of chrome and glass), processing, and test structure design. The optical and electrical test procedures are discussed, with emphasis placed on set-up and sample preparation. Test results are summarized and conclusions are drawn based on data analysis. Finally, we show how this integrated technique of submicron measurement of photomasks is applied in a production environment.

Date Published: 19 July 1989
PDF: 14 pages
Proc. SPIE 1087, Integrated Circuit Metrology, Inspection, and Process Control III, (19 July 1989); doi: 10.1117/12.953084

Published in SPIE Proceedings Vol. 1087:
Integrated Circuit Metrology, Inspection, and Process Control III
Kevin M. Monahan, Editor(s)