Growth and characterization of boron-doped (111) CVD homoepitaxial diamond films

The CH4/H2 ratio (growth rate) dependence of B-doped (111) homoepitaxial diamond film quality was investigated in the region of CH4/H2 ratio ⩽1% and 10 ppm B2H6/H2 ratio in terms of surface morphology, crystallinity, incorporation of impurities and electrical and optical properties. It was found that there are two different growth regimes, which depend on CH4/H2 ratio, in B-doped (111) film growth. In the region of low CH4/H2 ratio growth ⩽0.25%, as CH4/H2 ratio increased, film quality was improved in spite of the same incorporation efficiency. This result is different from that of (001) diamond film growth. On the other hand, for high (⩾0.5%) CH4/H2 ratio growth, significant deterioration in the film quality was observed. Differences between (111) and (001) in B-doped film growth are discussed.