Oxidative conversion of pfc via plasma processing with dielectric barrier discharges

Perfluorocompounds (PFCs) have been extensively used as plasma etching and chemical vapor deposition (CVD) gases for semiconductor manufacturing processes. PFCs have significant effects on the global warming and have very long atmospheric lifetimes. Laboratory-scale experiments were performed to evaluate the effectiveness of CF₄ conversion by using dielectric barrier discharges (DBD). The results of this study revealed that the removal efficiency of CF₄ increased with application of higher voltage, gas residence time, oxygen content, and frequency. Combined plasma catalysis (CPC) is an innovative way for abatement of PFC and experimental results indicated that combining plasma with catalysts could effectively remove CF₄. Products were analyzed by Fourier transform-infrared spectroscopy (FT-IR) and the major products of the CF₄ processing with DBD were CO₂, COF₂, and CO, when O was included in the discharge process. Preliminary results indicated that as high as 65.9% of CF₄ was decomposed with CPC operated at 15 kV, 240 Hz for the gas stream containing 300 ppmv CF₄, 20% by volume O₂, and 40% by volume Ar, with N₂ as the carrier gas.