Modeling of photoresist erosion in plasma etching processes

A set of surface reaction mechanisms has been developed to predict photoresist (PR) erosion in a high density Ar-c-C/sub 4/F/sub 8/ plasma. The mechanisms include angle and energy dependent ion sputtering, ion activation, and atomic F etching of activated surface species. An integrated plasma equipment and feature profile model was used to simulate these mechanisms. The simulation results show faceted profile evolution for the PR due to preferential ion sputtering at the incident angle to the facet. The faceting also occurs on small defective surface pits, leading to expansion of the defect size. Comparison between simulated and experimental profiles shows good agreement.