On the Etching Mechanisms of SiC Thin Films in CF4/CH2F2/N-2/Ar Inductively Coupled Plasma

Abstract

Etching mechanisms of SiC thin films in CF4/CH2F2/N-2/Ar inductively coupled plasmas were studied based on the correlations between measured SiC etching rates and model-predicted fluxes of plasma active species. Plasma chemistry was analyzed using Langmuir probe diagnostics, optical emission spectroscopy and 0-dimensional (global) plasma modeling. It was found that, under the given set of process conditions, the SiC etching kinetics is not affected by the thickness of the fluorocarbon polymer film and corresponds to the steady-state ion-assisted chemical reaction with the domination of the chemical etching pathway. It was proposed that the reaction probability between SiC and F atoms depends on both ion energy flux and the flux of polymerizing radicals through the balance active surface sites acceptable for the adsorption of F atoms.