Abstract: Plasma processing is accomplished with an improved single electrode reactor apparatus. High and low frequency power supplies are coupled to the single electrode to provide increased process flexibility, control and residue removal. A multi-stage passive filter network is disclosed which performs the functions of coupling both power supplies to the electrode, isolating the low frequency power supply from the high frequency power supply and attenuating the undesired frequencies produced by mixing of the two frequencies in the non-linear load represented by the reactor.