Electrodeless microwave plasma torch at atmospheric pressure

Summary form only given, as follows. Environmental clean-up and energy efficiency enhancement utilize plasma generated from air at the atmospheric pressure. Perfluorocompounds (PFC´s), which have long lifetimes and large global warming potentials, are widely used during plasma etching and plasma-assisted chamber cleaning processes in metal and dielectric film chemical vapor deposition (CVD) systems. Electrodes of the arc plasma torches oxidize very quickly due to the oxygen molecules in air. That is why the conventional thermal plasma torch cannot be used in environmental applications. In order to solve this difficult problem and destruct all of the global warming gases including PFCs, we developed a thermal plasma source operating without electrodes. We can generate plasma at the atmospheric pressure by making use of magnetrons in microwave ovens. Most of the magnetrons are operated at the frequency of 2.45 GHz typical magnetron power of home-microwave oven is about 1 kW. Electromagnetic waves from magnetron propagate through a waveguide. Plasma is generated under resonant condition, by initiation of an auxiliary ignition system. The plasma is stabilized by vortex stabilization. The plasma abatement device is attached to the vacuum pump, which discharges the nitrogen gas with contaminants. The abatement was carried out using oxygen and air as an additive gases. The destruction and removal efficiency (DRE) of more than 98% was achieved for tetrafluoromethane(CF/sub 4/). The detailed characterization of CF/sub 4/ abatement using Fourier transform infrared (FT-IR) and quadrupole mass spectrometer (QMS) showed the major PFC by-products. Finally, electromagnetic waves in the waveguide were studied by a high frequency structure simulator (HFSS) and preliminary experiments were conducted.