ANALYSIS OF THE INTERMEDIATE LAYERS GENERATED AT THE FILM-SUBSTRATE INTERFACE DURING THE CVD PROCESS OF DIAMOND SYNTHESIS

In the present work the structural characteristics of diamond films, o btained by means of Hot Filament Chemical Vapour Deposition (HFCVD), o n various substrates (glassy carbon, soda-lime glass, and titanium) ar e correlated with the formation of different intermediate carbonaceous layers at the film/substrate interface. The surface morphology of the diamond was studied by electron microscopy, whereas the structural ch aracteristics of the intermediate layers were investigated by means of reflection high-energy electron diffraction (RHEED) and X-ray powder diffraction (XRPD) techniques. Graphite-like and amorphous structures, respectively, were identified at the interface with glassy carbon and soda-lime glass substrates. RHEED and Grazing Incidence X-ray Diffrac tion measurements allowed us to determine the stratification sequence of the intermediate carbonaceous layers grown on Ti. The XRPD techniqu e was used to study the growth kinetics of diamond, TiC and TiH2 layer s during the coating process. The features of diamond nucleation on th e various substrates are discussed with reference to the structure of carbonaceous transition layers formed at the substrate/film interface.