The effect of amorphous Si on the epitaxial growth of CoSi₂ by Co/Si/Ti/Si solid state epitaxy

An amorphous Si layer was added for the reduction of Si consumption in the ultra-shallow junctions during silicide formation. The present experiments show an epitaxial CoSi₂ layer with good single-crystalline quality was grown by Co/Si/Ti/Si(100) reaction. By varying the thickness of interposed amorphous Si, its effect on the epitaxial CoSi₂ growth and self-aligned process was investigated. The film structure and crystallinity were characterized by X-ray diffraction (XRD). Rutherford backscattering (RBS)/channeling and transmission electron microscopy (TEM). RBS/C shows that the channeling yield minimum of CoSi₂ formed by Co(15 nm)/Si(4 nm)/Ti(3 nm)/Si(100) reaction is 5.2%. It was also demonstrated that within a certain thickness range for the deposited Si, the self-aligned silicide (SALICIDE) contact structure can be formed by such a multilayer.