Nitrides (such as BN and TiN) are widely used in various industrial applications because of their excellent wear and corrosion resistance and their thermal and electronic properties. The structural and chemical features formed during plasma vapor deposition of Ti/TiN on BN substrates have been studied using synchrotron radiation near edge absorption spectroscopy (NEXAFS). Various phases of interest have been formed with different annealing temperatures. Diffusion of the nitridation and the interference from oxidation (e.g., TiO2) and boride formation are of particular concern. X-ray photoelectron spectroscopy and secondary ion mass spectroscopy measurements complement our NEXAFS data. Phase formation and chemical bonding between the coating and the substrate are shown to be determining factors for the microhardness.