Characterization of proximity effects in optical lithography.

Proximity effects are studied for each stage of the projection optical lithogaphy process, with the aim of characterizing the individual contributions from various process parameters and mechanisms. The aerial images are studied with SAMPLE and SPLAT simulation programs in conjunction with an exposure threshold model. The exposure and development of resist are then simulated using the PROSIM program coupled with a Development Rate Monitor (DRM), followed by an experimental evaluation. Except for the aerial image study where results can be generalized to some extent, this work is directed to printing 0.6micron lines with a 0.40NA I-line lens. The results indicate the key role that resist processing plays in the proximity effects, and also demonstrate the capabilities and limitations of the lithographic simulation tools.