Abatement of Perfluorocompounds by Tandem Packed-Bed Plasmas for Semiconductor Manufacturing Processes

The technological feasibility and chemical kinetics of carbon tetrafluoride (CF 4 ) decomposition with tandem packed-bed plasmas (TPBPs) are investigated in this study. Relevant parameters including types of packing dielectric materials, applied voltage, discharge gap, and Ar additives are extensively investigated. Results demonstrate that the addition of Ar is beneficial to CF 4 abatement. Operating at a higher voltage results in higher removal efficiencies. The effect of packing dielectric materials on CF 4 abatement is in the order of BaTiO 3 > Al 2 O 3 > glass pellets, being correlative with their dielectric constants. An overall kinetic model is also developed. Experimental results and kinetic analysis indicate that the CF 4 removal efficiency achieved with a TPBP obeys a first-order rate law. The overall removal rate constant ( k, s -1 ) can be expressed in an Arrhenius form, k = 0.1313 P s 0.6887, where P s represents the specific power (W/cm 3 ). The requirement of 90% reduction of perfluorocompounds for a semiconductor manufacturing process can be accomplished by combining five TPBP reactors in series, being operated at a residence time of 3.2 s and a specific power of 1.2 W/cm 3 .