GaN and related nitride semiconductors have attracted great attention in view of their wide applications in photonics and high temperature & high power electronic devices. Among other issues, reduction of defect densities by forming these interfaces at lower temperature and on novel substrates has been the motivation for several researchers. In the present study ion-induced conversion of Si (111) surface into silicon nitride at room temperature is optimized and used as substrate for the growth of Ga films. These Ga films are again nitrided by optimal N+ ion bombardment. Experiments have been performed in-situ in an ultra high vacuum chamber equipped with a Ga source and X-ray photoelectron spectrometer (XPS) at base pressure of 2×10-10 torr. The energy dependence of the nitridation is carefully performed at constant flux. The results clearly demonstrate the Si-N bond formation after a energy of 2 keV and the formation of GaN layer after 800eV of ion bombardment on Si (111) 7×7 surface and Ga adsorbed silicon nitride surface, respectively. The FWHM and chemical shifts in the core-level spectra of Si(2p), Ga(2p) and N(1s) have been analyzed to probe the interface reactions. The results demonstrate a possible novel and low temperature approach towards the integration of III-nitride & silicon technologies, since silicon nitride bonds can act as barriers to dislocation propagation.