Ion-irradiation effect on the Ni/SiC interface reaction

The formation of nickel silicide induced by thermal annealing of Ni/SiC samples was studied by means of Rutherford backscattering spectrometry (RBS) and X-Ray diffraction (XRD). Nickel silicide (Ni2Si) could be observed already after 20 minutes annealing at 600¬?C, even RBS analysis showed a thin layer of non-reacted Ni on the top of the sample at this temperature. On the other hand, annealing at higher temperature (800¬?C) led to the complete reaction of the deposited film. Analytical transmission electron microscopy (EDX) showed that carbon was almost uniformly distributed inside the Ni2Si layer. RBS and Transmission Electron Microscopy (TEM) analysis showed a rough interface between the silicide and the underlying SiC. Ar+-irradiation of the as-deposited samples and subsequent annealing at 600 and 800¬?C resulted in the improvement of the silicide/SiC interface with respect to the non-irradiated samples. This effect can be ascribed to the radiation induced damage in the crystalline SiC substrate, which improves the adhesion of the deposited film and enhances the mobility of Ni atoms.