A review of SiO2 etching studies in inductively coupled fluorocarbon plasmas

A comprehensive overview of results from mechanistic studies on plasma-surface interactions in inductively coupled fluorocarbon plasmas, which are currently widely used for the SiO2 etching process in semiconductor device manufacturing industry, is presented. The plasma-surface interactions that are covered in this overview range from interactions at the plasma reactor wall and coupling window, which affect the plasma gas phase, to interactions at the substrate level, which determine the etching of both blanket surfaces and microscopic features. In particular, the effects of reactor wall temperature and parasitic capacitive coupling on the SiO2 etching process are addressed. Further, the mechanism of selective SiO2 to Si and Si3N4 etching on blanket and inclined surfaces is discussed. Finally, it is shown how the SiO2 etch process in high aspect ratio microstructures differs from the etch process on blanket surfaces. (C) 2001 The Electrochemical Society.