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Formation of vanadium silicides by the interactions of vanadium with bare and oxidized Si wafers has been studied by both x-ray diffraction and He ion backscattering techniques. X-ray diffraction was used to identify phases and ion backscattering to profile compositional changes. In the case of V on Si, the silicide VSi2, which is a silicon-rich phase, was found to form at temperatures from 600 to 1000 °C. In the case of V on SiO2, reactions took place only at temperatures above 800 °C, and the reaction products were identified to be V3Si, V5SI3, and V2O5. Both V3Si and V5Si3 are vandium-rich phases, and the V3Si that we found was a continuous layer between the substrate and the other two phases, and became superconducting at about 15 °K.

Backscattering of He ions and Seemann-Bohlin x-ray diffraction techniques have been used to investigate the composition and growth kinetics of hafnium silicide formed from thin films of hafnium sputter deposited on silicon. The stable-phase HfSi was formed in the temperature region 550–750°C. Zirconium and argon impurities were present in the Hf films at the level of 2.5 at.%. During the formation of the HfSi phase, these impurities served as markers which were used to determine the diffusing species. We conclude that Si is the diffusing species.

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