On-site tetrafluoroethylene gas generation from moderate-pressure pure tetrafluoromethane plasma reactor

Abstract On-site C2F4 gas production from CF4 feedstock gas was achieved using pure CF4 plasma at a moderate pressure (40–200 Torr) and a relatively low gas temperature. The decomposition of CF4 and the generation of perfluorocarbon gases with a larger number of carbon atoms were investigated by gas-phase Fourier-transform infrared spectroscopy. The generated perfluorocarbon gases were C2F6 and C2F4, and more C2F4 was generated than C2F6. The dependence of the CF4 decomposition efficiency and the C2F4 generation behavior on various plasma-generation parameters, such as the input power, gas flow rate, and process pressure, was investigated. It was found that contact of the graphite material with the CF4 plasma was important for efficient C2F4 generation. In addition, a moderately elevated graphite temperature was necessary to produce C2F4 gas efficiently. The surface reaction between graphite and fluorine-related species is important for C2F4 production from pure CF4 feedstock gas.