A multilayer sample of amorphous SiC (α-SiC) and polycrystalline Ni was prepared by ionbeam sputtering, and was used as a model, prototype system to study the stability of metal contacts with SiC against interdiffusion reactions near the interface. The modulation wavelength is around 80 nm and with equal thickness of α-SiC and Ni layers. By use of XRD, TEM and energy dispersive spectroscopy (EDS), information on the structural evolution and composition distribution during heat treatment was obtained. The diffusion of Ni into the SiC layer, and Si and C into the Ni layer appears to take place concurrently during the annealing process. An amorphous reaction layer was formed during the heat treatment that is distinct from the α-SiC. The increase in thickness of the reaction layer followed a parabolic time dependence in the initial stage, until further reaction was limited by the precipitation of a graphite layer near the original α-SiC/Ni interface. A metastable intermediate phase and a NiSi phase were identified in the original Ni layer due to the diffusion of Si and C based on the decomposition of the α-SiC.