Change in the microstructure at W/Si interface and surface by swift heavy ions.

Metal/Si thin film interfaces and surfaces can be modified by swift heavy ions (SHI) in a controlled manner. The mixing induced by 120 MeV Au(+9) ions at W/Si interface are presented in the manuscript. Grazing Incident X-ray Diffraction (GIXRD) result shows the formation of two type of tungsten silicides t-W(5)Si(3) along with t-WSi(2) by atomic mixing at the interface on increasing the ion fluence. The diffusivity value calculated from the Rutherford Backscattering Spectroscopy (RBS) measurements, suggest a transient molten phase at the interface causing the atomic mixing following by Thermal spike model. Atomic Force Microscopy (AFM) results revealed increase in surface roughness and grain size formation, which increases with ion fluence showing the irradiation effect at the surface also.