Reduced capacitance electrode assembly

摘要

A reduced capacitance electrode assembly for use in an alternating current plasma system provides reduced input capacitance to an associated tuning network. The assembly includes an electrode adapted to receive alternating current power for maintaining a plasma region and a plurality of electrically conductive plates. The plates are closely spaced apart by less than a predetermined distance on one side of the electrode for precluding the formation of a plasma region on the one side of the electrode and for providing a plurality of series capacitances to present a substantially reduced capacitance to the alternating current power. The reduced capacitance electrode assembly is particularly useful in a system for making photovoltaic devices wherein a plurality of amorphous semiconductor materials is deposited onto a continuous conductive substrate moving through a corresponding plurality of deposition chambers. At least one of the chambers includes a reduced capacitance electrode assembly comprising an electrode spaced from the substrate adapted to receive alternating current power for establishing a plasma between the electrode and the substrate, and a plurality of electrically conductive plates being closely spaced apart on the side of the electrode opposite the substrate for confining the plasma between the electrode and the substrate and for providing a plurality of series coupled capacitances to present a substantially reduced capacitance to the alternating current power.