抄録
In order to prepare a large amount of powders, nono-size powders, highly pure powders of silicon carbide, many kind of trials have be done. The presentation is a summery of these trials in plasma CVD method.Synthetic conditions are summarized as follows. Frequency and power of RF generator: 4 MHz and 15 kW, respectively. Reactants: monosilane, and methane/ethane, plasma working gas: argon, sheath gas: argon, gaseous pressure and flow rate were controlled. Powders were characterized to be ultra fine powders (5~100nm, mean size: 30nm), ultra pure (each cation impurity: ppb level), and spherical shape with sharp particle size distribution.Observation of temperature and reaction during the formation of silicon carbide was performed in-situ by measuring the emission spectra from plasma flame using optical analyzer. The present experimental conditions established local thermodynamic equilibrium, (LTE). Temperature distribution in the plasma flame and near the flame showed as expected from plasma reactor design.
