Studies of steam-oxidized WSi2 by Auger sputter profiling

We have studied steam-oxidized WSi2 films sputter deposited upon Si and SiO2 substrates using Auger sputter profiling. As previously reported, steam oxidation produces an SiO2 surface layer. Silicon is supplied to the growing SiO2 layer by the conversion of the WSi2 to W5Si3, and additional Si is supplied by diffusion through the WSi2 layer only for the case of a Si substrate. The W5Si3 is distributed throughout the silicide layer, but with slightly higher concentration at the SiO2-silicide interface. This interface also contains an oxidized tungsten phase possibily is the form of a WxSiyOz compound.