2001 年 67 巻 12 号 p. 2032-2036
High quality diamond films have been synthesized on substrates of high-temperature high-pressure synthesized diamond by means of arc discharge plasma jet chemical vapor deposition. Diamond films have been deposited on diamond substrate at high growth rates up to approximately 130 μm/h when methane concentration was 3%. Properties of the diamond films were determined by optical microscopy, SEM, Raman spectroscopy, X-ray diffraction analysis and FT-IR. Diamond films synthesized at methane concentration of 3% have homoepitaxially grown on diamond substrates and have shown superior crystallinity similar to type IIa natural diamond. Nitrogen contaminant in the diamond films was less than in diamond substrates. Moreover, quality of diamond films has been improved by pre-treatment of the surface of diamond substrates. As a result, hydrogen plasma treatment of substrate surface has led to fewer defects in diamond films as compared with ion beam irradiation and thermochemical polishing using a hot iron plate.