Thickness Reduction Effect in a Chemically Amplified Resit Simulator

Abstract

The chemical reaction is increased during post exposure bake and, consequently, the thickness of the resist in the exposed area is physically reduced in most deep UV and 193-nm chemically amplified resist. The thickness change of a 193-nm chemically amplified resist before and after post-exposure bake was measured, and the relationship between the concentration of the deprotected sites and the thickness reduction was extracted. This resist thickness reduction effect was included in our modified simulator, and more realistic resist profiles could be obtained. The simulation results showed enhancements in top rounding, sidewall angle, focus latitude, and dose reduction.