Ion-beam-induced silicide formation

Abstract

Rutherford‐backscattering spectrometry and x‐ray‐diffraction analysis have been used to investigate intermixing between thin metal films (Pt, Ni, and Hf) and silicon substrates as a result of inert‐gas ion bombardment. Silicide phases (Pt₂Si, Ni₂Si, and HfSi) were observed near the interface as long as the ion range exceeds the film thickness. For a fixed dose, the silicide thickness increases with the atomic mass of both ion and metal and is greater for Pt₂Si than HfSi. The growth of Pt₂Si showed a square‐root dependence on ion dose for Ar, Kr, and Xe ions. The phenomenon of ion‐induced silicide formation is similar to formation resulting from thermal anneal until the whole metal film is consumed in the reaction, at which point a progressive intermixing to redistribute the metal into deeper regions of the sample occurred along with the disappearance of the structure diffraction patterns.