Ab Initio Investigations of Textured Ni2Si Films on Silicon

Transition metal silicides grown on Si substrates show peculiar structural behavior, due to their rich variety of phases with different stoichiometric compositions. Phases with low electrical resistivity and high thermal stability are needed as contact materials in advanced integrated circuits while nickel silicide is the main candidate as future material for interconnects. Recently, structural investigations on thin silicide films on Si(100) have characterized novel forms of silicide texturing: alignment of planes across the interface seems to be preferred over standard in-plane epitaxial alignment. We investigate by first-principle total energy calculations the role of interface and elastic energies in the stabilization of textured silicide film structures on Si(001). From the comparison of calculated interface energy values we address the role of energetics in texture selection.