Energetics of silicide interface formation.

The energetics of the early growth stages of epitaxial NiSi2 on Si have been investigated using local-density-functional theory. We find that a proposed diffusion region of interstitial Ni several atomic layers thick is highly unfavorable energetically. However, the energy difference between a single silicide overlayer and an interstitial monolayer is too small to rule out the existence of sub-monolayer concentrations of interstitials where kinetically favored.