Plasma Etching and Surface Analysis of a-SiC:H Films Deposited by Low Temperature Plasma Enhanced Chemical Vapor Deposition

Abstract

AbstractOrganosilicon precursors were used to deposit thin films of highly stable amorphous hydrogenated silicon carbide at low temperatures by plasma enhanced chemical vapor deposition. X-ray photoemission and Auger electron spectroscopy were employed to characterize the surface chemistry of air exposed and plasma etched films. Auger analysis of the as-deposited material shows its composition to be constant throughout its depth. RF plasma etching was performed in CF4/O2 and SF6/O2 gas mixtures. Etch rates in these atmospheres are similar to those reported in the literature. After plasma etching, the surface was converted to a highly fluorinated state. In addition to the expected SiC bond, Si-OF bonds were found after plasma etching. Fluorocarbon residue was not produced in this process. Chlorine etching of this low temperature PECVD film is described and is shown to be compatible with standard integrated circuit manufacture processing as an hermetic-like sealant.