Laser direct writing system and its lithography properties

Abstract

Laser Direct Writing System (LDWS) is a key equipment for manufacturing the binary optical masks. A polar coordinate laser direct writing system was developed and the maximum mask size which can be made is 4 inches. One of its main properties, namely lithography resolution, was analyzed based on the optical intensity distribution in the photoresist. Normally, 0.86 micrometer linewidth on masks can be achieved. In some special case, a super resolution of 0.5 micrometer linewidth can also be obtained, and it will require a more rigorous exposure latitude. The exposure experiment results on LDWS showed good agreement with the theoretical calculations. The approach by using the optical intensity distribution in the photoresist to predict the relations between linewidths and exposure latitude gives out a simple and clear image about the effects of photoresist on lithographic linewidths.