First principal simulation of CoSi2/Si and NiSi2/Si contacts

The CoSi₂/Si and NiSi₂/Si interfaces are examined by using the first principles calculation. metal-induced gap states (MIGS) exist at the interface, and the magnitude is large enough to pin the Fermi level. The MIGS decay exponentially with interface distance and penetrate about 6 ¿ into the Si layers. Schottky barrier height (SBH) for electrons can be increased by a B atom at substitutional site of a Si atom located in Si layers near the interface for a p-type doping, but it will be decreased by an N atom doping. The precise control of the dopants near the interface can reduce SBH and realize reduction in contact resistance. The SBH also depends on the crystallographic orientation of the silicide/silicon interface.