Simple compact 3D structures such as posts and contact holes may not be accurately described by simulations that do adequately predict the performance of 2D structures such as long lines. The purpose of the present work is to study the utility of a commercially available 3D simulation tool, PROLITH/3D, in addressing this problem. The results show that 3D diffusion can significantly impact sizing energies and exposure latitude for these compact structures and give a better much match with experimental results. Major emphasis is applied to a conventional i-line photoresist process though a chemically amplified process is also briefly examined.
Steven G. Hansen,
"Effect of 3D diffusion on photolithographic simulation results", Proc. SPIE 3679, Optical Microlithography XII, (26 July 1999); doi: 10.1117/12.354317; https://doi.org/10.1117/12.354317