INNOVATIVE SURFACE-WAVE PLASMA REACTOR TECHNIQUE FOR PFC ABATEMENT

Application of surface wave plasmas as an innovative technology for th e destruction and removal of perfluorocompounds (PFC) emanating from s emiconductor fabrication tools is demonstrated. The destruction of par ts per thousand (ppt) concentrations of hexafluoroethane, C2F6, in oxy gen and natural gas mixtures has been investigated as a function of mi crowave power in a low-pressure plasma reactor at 11.3 Torr. Effluent analysis included the determination of destruction and removal efficie ncies (DRE) and product distributions by Fourier transform infrared sp ectroscopy and mass spectrometry. Destruction and removal efficiencies of up to 99.6% for C2F6 were achieved using applied microwave powers from 500 to 2000 W, which corresponded to millisecond range residence times within the plasma. Product analysis indicated that hexafluoroeth ane conversion was limited to low molecular weight gases such as CO2, CO, COF2, H2O, and HF. CF4 was not produced as a plasma byproduct in a ny significant quantities. These investigations indicate that surface wave plasma destruction of perfluorocompounds at the point of use is a viable nonintrusive abatement technology for application to semicondu ctor manufacturing tools.