燃焼炎法による炭素膜合成における基板回転とガス組成の影響

Abstract

The synthesis of diamond or DLC film in the atmosphere was investigated using an improved combustion flame apparatus equipped with a substrate revolution system. The films have been synthesized at conditions involving of substrate revolution at 0 to 900rpm, a gas composition of C2H2 fixed at 3.0SLM, O2 was 2.4 at 2.7SLM, and deposition time of 90 minutes at atmospheric pressure. The substrates used were cemented carbide (WC-6%Co).Using SEM observation of the surface morphology, deposits were covered with Diamond (111) surfaces with a grain size of 10μm in diameter at C2H2:O2=3.0:2.7gas composition without revolution. The deposits at C2H2:O2=3.0:2.4 consisted of fine grains and the surface appeared glass like. The qualities of the deposits have been estimated using Raman spectroscopy. The deposited film was found to be a diamond, because a Raman band was observed at 1333cm-1 at C2H2:O2=3.0:2.7 gas composition. On the other hand, the deposit at C2H2:O2=3.0:2.4 gas composition have bands at 1350cm-1 and 1600cm-1, and were identified as a mixture of amorphous carbon and graphite. The deposits changed from DLC to diamond with an increase in the oxygen content, and the deposit at C2H2:O2=3.0:2.7 was identified as high quality diamond in particular.The effects of substrate rotation were such that diamond was deposited without revolution, and that deposits changed to DLC consisting of small grains at higher revolutions. The deposit at C2H2:O2=3.0:2.5 gas composition and 600rpm substrate revolution were identified as DLC because Raman bands were displayed at a center band of 1550 cm-1 and at a 1400cm-1 shoulder band. Regarding the effects of revolution, diamond was formed at C2H2:O2=3.0:2.7 without revolution, but the deposited surface because finer with an increase in revolutions. Results of Raman spectra confirmed that the deposits changed from diamond to DLC with revolutions. Control of deposits of either diamond or DLC will be possible via selection of conditions such as gas component or substrate revolution.