SiOx mediated epitaxial ternary silicide (Co1-xNix) Si2

A ternary epitaxial (Co1-xNix)Si2 thin film was grown by the solid state reaction of Co/Ni/SiOx/Si(100) system and characterized by various techniques, such as XRD, RBS and four-point probe. The results show that the oxide interlayer can act as a diffusion barrier. The (Co1-xNix)Si2 film formed from Co/Ni/SiOx/Si(100) system has the crystal orientation parallel to the substrate. In contrast, the film formed from Co/Ni/Si(100) system is polycrystalline, without any epitaxial relation with the substrate. The lattice constant of the ternary (Co1-xNix)Si2 film is between that of CoSi2 and NiSi2 so that the strain in a silicide film is lowered. The present film is about 110 nm in thickness and its minimum channel yield is 22%. The resistance of the epitaxial film is about 17 μΩ&middotcm, with the thermal stability as high as 1000°C. Thus, the epitaxial film is comparable with a high quality CoSi2 film.