CVD DEPOSITION OF DIAMOND ON NITRIDES AND OXIDES AS SUBSTRATES

Nucleation is an important step during the preparation of diamond thin films. The nature of the substrate composition, local structure and surface energy are important factors which govern such a step. In order to compare the influence of the substrate composition, diamond has been deposited on nitride- and oxide-based substrates. The nucleation density is increased in comparison with the corresponding metallic substrate. Crystal growth is also favored and particles well defined in morphology and size (about 10 mum) are observed. An interface made of carbide or a mixture of carbonitride and carbide has been found using XRD characterization. The higher density of nucleation is explained in terms of velocity exchange N/C or O/C near the substrate surface and diffusion of the carbon atoms into the bulk.