Evaluation of a two-mask resolution enhancement technique

We have evaluated the performance of an optical projection lithography came ra employing a two-mask resolution enhancement technique proposed by Matsum oto et al. [K Matsumoto et al., Proc. SPIE 2197, 844 (1994)] and Kamon et a l. [K. Kamon et al., Jpn. J. Appl. Phys., Part 1 33, 6848 (1994)] in 1994 t hat automatically provides a different illumination for every feature on th e reticle. Our simulations show that such a system can provide better imagi ng performance than a system that employs ordinary quadrupole illumination and can enhance the depth of focus by more than 50% in specific cases. (C) 1998 American Vacuum Society.