Translator Disclaimer
12 February 1997 Evaluation of resist models for fast optical proximity correction
Author Affiliations +
One of the most prominent process non-linearities, which are summarized under 'proximity effects' is line-shortening. Line- shortening is poorly modeled by phenomenological lithography simulation -- even when resist models are used, which deliver reasonable results for process windows and resist edge profiles. So the challenge for a simulation-based OPC tool is not only the required speed, but also a lack in thoroughly understanding the processes involved. The OPC tool OPTISSIMO describes optical pattern transfer primarily by simulation of the aerial image according to a phenomenological model. Differences from the actual measured dimensions (either after resist processing or after etching) are described as corrections to the aerial image simulation results. These corrections are fitted by an empirical model. We show in this paper, that this model is not only able to explain the linewidth changes due to proximity effects, but also to describe line-shortening effects with reasonable accuracy. Further we show, that using a 'hammerhead design approach' (a rectangle placed over the end of each line) is a very effective way to compensate line-shortening This technique does not require an increase of resolution at mask fabrication and increases the data volume of the corrected design only moderately. Therefore, the addition of hammerheads to the line-mode of OPTISSIMO is a very promising method to perform OPC at full-chip designs and with available mask manufacturing techniques.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Christoph Dolainsky, Wilhelm Maurer, and Thomas Waas "Evaluation of resist models for fast optical proximity correction", Proc. SPIE 3236, 17th Annual BACUS Symposium on Photomask Technology and Management, (12 February 1997);

Back to Top