DIAMOND NUCLEATION ON SINGLECRYSTALLINE 6H-SIC SUBSTRATES BY BIAS-ENHANCED NUCLEATION IN HOT-FILAMENT CHEMICAL-VAPOR-DEPOSITION

A bias-enhanced nucleation (BEN) technique in hot-filament chemical va por deposition (HF-CVD) has been applied to singlecrystalline 6H-SiC s ubstrates for diamond nucleation. The oriented diamond film has been g rown on a 6H-SiC substrate. The experimental results have shown that t he 6H-SIC substrate surfaces are etched by the reactive hydrogen speci es during the BEN process, and many inclined-pyramid crystals with {<0 1(1)over bar 4>} type faces are formed on the substrate surface. The a rray direction of the inclined-pyramid crystals is determined by the d iffusion direction of the reactive hydrogen species existing in the pl asma sheath and the specific free surface energy of the substrate. Dia monds nucleate on the top of the inclined-pyramid crystals. Diamond nu cleation density is higher on the (0001) face than on the (<000(1)over bar>)face. The relationship between the inclined-pyramid crystals and the diamond nuclei is investigated using scanning electron microscopy .