The irradiation effects in Ni3N/Si bilayers induced by 100–700 keV Xe ions at fluences up to 4 × 1016ions/cm2 were investigated at 80 K and room temperature. The element depth profiles were measured via Rutherford backscattering (Ni, Si) and resonant nuclear reaction (N) analysis, the phase formation at the interface via x-ray diffraction, and the surface roughness by atomic force microscopy. The observed dissociation and preferential sputtering of Ni3N followed by nitrogen out-diffusion were related to the small binding energy of this compound. Mixing at the Ni3N/Si interface occurs via a combination of diffusion and reaction controlled transport processes and the interface broadening varies in second order with the ion fluence. At higher ion fluences, the formation of NiSi2 and Si3N4 phases at the interface was found. © 2001 The American Physical Society.