Studies of the Ti‐W Metallization System on Si

MeV backscattering spectrometry and x‐ray diffraction are used to investigate the behavior of sputter‐deposited Ti‐W mixed films on Si substrates. During vacuum anneals at temperatures of 700°C for several hours, the metallization layer reacts with the substrate. Backscattering analysis shows that the resulting compound layer is uniform in composition and contains Ti, W, and Si. The Ti:W ratio in the compound corresponds to that of the deposited metal film. X‐ray analyses with Reed and Guinier cameras reveal the presence of the ternary compound. Its composition is unaffected by oxygen contamination during anneal, but the reaction rate is affected. The rate measured on samples with about 15% oxygen contamination is linear, of the order of 0.5 Å/sec at 725°C, and depends on the crystallographic orientation of the substrate and the d‐c bias during sputter deposition of the Ti‐W film.