Modeling and Simulation of Plasma-Induced Damage Distribution during Hole Etching of SiO2 over Si Substrate by Fluorocarbon Plasma

We developed a plasma etching simulation with our new concept in order to predict the distribution of plasma-induced damage during contact hole etching of SiO2 over Si substrate using fluorocarbon plasma (C4F8/O2/Ar). Our model included plasma database, gas transport (direct and indirect fluxes of ions and radicals), surface reaction considering depth effect, and damage distribution. We could demonstrate how to evolve the Si damage in main and overetching steps, which is realistically difficult to measure. Our results show that polymer thickness, overetching time, and etched profile should be carefully controlled to reduce physical damage.