Real dimensional simulation of SiO 2 etching in CF 4+H 2 plasma

Abstract

The reactive ion etching of silicon oxide in CF 4+H 2 plasma is considered. The profiles of etched grooves are calculated as a function of mask dimensions, fluxes of chemically active and non-active plasma components and parameters of ion bombardment. To achieve this goal the chemical composition of CF 4+H 2 plasma is calculated and the one-dimensional etching of SiO 2 in this plasma is considered. The values of phenomenological constants are found by extrapolation from the experimental results. Using the values of phenomenological constants, found by analysis of chemical composition of plasmas and one-dimensional etching, the etched groove profiles at real dimensions are calculated. The influence of hydrogen addition to fluorocarbon plasma on an etched groove profile is considered. Special attention is given to the selectivity of SiO 2 etching over Si. The conditions under which etching selectivity is high are found.