Abstract: The ion beam induced atomic mixing and interface reaction between a metalthin film (Ni, Nb, Mo, Ti, Cu) and its silicon substrate is investigated by RBSfor 300 keV Xe~(2+) ions, dose with 5×10~(15) cm~(-2) and an implantation temperaturefrom LNT to 400℃ Many Crystal silicide phases including one phase or two pha-ses are formed. The phase growth is layer by layer. The results are discussed interms of chemical driving force and radiation enhanced diffusion effect.