Silicon Suboxides: The “Co-Deposition” of a-Si:H and SiO2

Abstract

ABSTRACTThe deposition mechanism of silicon suboxides (SiOx, x<2) prepared by remote plasma enhanced chemical vapor deposition (Remote PECVD) is investigated. These films were deposited in a Deposition/Analysis chamber designed to investigate the gas phase chemistry. In this technique, an O2/He mixture is plasma excited, and the silane reactant is injected into the deposition chamber down-stream from the plasma tube. We show that if the plasma after-glow is prevented from extending into the deposition region by an electrical grid placed between the plasma tube and the deposition region, silicon dioxide is then deposited for all O2/He mixtures investigated (0.1 to 1.0 %). In contrast, hydrogenated suboxides of silicon are deposited when the plasma after-glow is allowed to extend past the grid into the deposition region.