Theoretical studies of metal disilicide–silicon interfaces

General trends of the chemical bonding and electronic structure for the interfaces between Si(111) and a series of metal disilicides (CaSi₂, ScSi₂, TiSi₂, VSi₂, CrSi₂, MnSi₂, FeSi₂, CoSi₂, and NiSi₂) have been studied using the empirical tight-binding method and the slab model. For all the disilicides the CaF₂ structure is adopted. With the increase of the atomic number Z from Ca to Ni, the occupancy of the nonbonding d state of the metal at the interface changes from empty to full. The positions of the Fermi level EF for various structures of the NiSi₂/Si(111) and CoSi₂/Si(111) interfaces have been compared. The 180^∘{} rotation of the orientation of the NiSi₂ film with respect to the substrate does not seem to affect the position of EF.