INFLUENCE OF NUCLEATION DENSITY ON FILM QUALITY AND SURFACE MORPHOLOGY OF THIN CVD DIAMOND FILMS

High quality thin films can be produced reproducibly using H₂/CH₄ plasma with the optimum growth parameters of our 2kW microwave plasma CVD reactor.The thin films prepared in this system has very smooth crystalline facets free of second nucleation,the grain is a strong ＜111＞ fiber texture and the thin films are dense.The full width at half maximum（FWHM） of the diamond Raman peak is 7.5 cm-1,as narrow as that of the minimum value of heterogeneous epitaxial CVD diamond film.For this study,diamond films were grown on silicon substrates with different nucleation densities respectively.The effect of nucleation density on thin film quality,texture and surface morphology was studied.Our results suggest that under suitable growth conditions,nucleation density has little effect on film surface morphology and great influence on film quality.