Diffusion in intermetallic compounds with the CaF2 structure: A marker study of the formation of NiSi2 thin films

A xenon marker was implanted into a thin film of NiSi initially formed on its silicon substrate by the reaction of this substrate with a thin film of nickel. During the subsequent transformation of NiSi into NiSi2 at about 800 °C, the displacement of the xenon marker towards the free surface of the film indicates that nickel constitutes the main diffusive species for the growth of NiSi2. This is compared with the previously published knowledge about Ni2Si, NiSi, and the silicides of cobalt.