The reaction of N-2(+) ions with the Si(100) surface over the energy range of 0.25-5 keV has been studied by angle-resolved X-ray photoelectron spectroscopy (ARXPS) measurements of the Si 2p core levels. Position. width, and shape of the Si 2p band are explained in terms of a superposition of five components. Si-n (n = 0,..., 4), which correspond to different bonding configurations denoting a Si atom with it nitrogen neighbors. The depth distribution of the different components is dependent on the ion energy. For energies below I keV, the surface film can be modeled by a layered film in which the composition is Si-4, Si-3, Si-2. and Si-1 in going from the surface to the substrate. Above I keV, a nitride film composed of a mixture of Si-1, Si-2, Si-3, and Si-4 species, with reduced Si-0 species at the near surface, was found. The differences are attributed to the effect of the ion energy on the preferential sputtering of nitrogen and on the knock-on mechanism.