Phenomenological model for predicting CxHyFz+ ion etching yields of SiO2 and SiNx substrates

In this study, a novel phenomenological model is developed to predict the etching yields of SiO2 and SiNx substrates by fluorocarbon and hydrofluorocarbon ions. The CF layer thickness and reactive layer chemistry are described, which significantly affect the etching yields. The study focuses on the dependence of the atomic component of the ion and the incident ion energy of the ion on the etching yield. Some assumptions enable the calculation of ion etching yields in a short turn-around-time. The proposed model can predict the etching yields of other larger species at higher incident ion energies. The obtained simulation results are in good agreement with the experimental data. The optimal etching ions for high aspect ratio etching are comprehensively investigated using the proposed model, providing a better understanding of the differences in the underlying material and the atomic component of the ion.