CHARACTERIZATION OF 3C-SIC FILMS GROWN ON MONOCRYSTALLINE SI BY REACTIVE HYDROGEN PLASMA SPUTTERING

Detailed characterization using x-ray diffractometry, scanning electro n microscopy, transmission electron microscopy, x-ray photoelectron sp ectroscopy, and Auger infrared and focused ion-beam spectroscopy, was carried out on cubic SiC films grown on single-crystal (100) Si substr ates by reactive hydrogen plasma sputtering over a range of growth tem peratures between 700 and 1000 degrees C. It was found that the first few deposited atomic layers were always amorphous. The subsequent SiC films showed well-defined (111) growth at the lowest temperatures, bec oming randomly oriented by 1000 degrees C. The measured C:Si ratio was always >1, and varied with depth inside a film and also with temperat ure. At higher temperatures, the presence of ''hollow voids'' was obse rved, our data being consistent with their formation by outdiffusion o f Si atoms from the substrate through the SiC layer. Associated with t he hollow voids we observed the presence of a porous, highly C-rich re gion at the Si-SiC interface. We propose that this was due to diffusio n of C from the SiC film into the voids themselves. (C) 1997 American Institute of Physics.