Reactive-Environment Hollow Cathode Sputtering: Compound Film Production, and Application to Thin Film Photovoltaics

This paper reviews EPV's development of hardware and process technology to accomplish large area, high rate sputtering from metal targets in a reactive mode without target poisoning. The method is termed reactive-environment hollow cathode sputtering (RE-HCS) and makes use of the intense plasma confined in a hollow cathode. A linearly extended cathode is described, with one or more reactive gases delivered externally to the cathode. The basic operating characteristics of the cathode are described. The method is applied to the development of high performance transparent conducting oxides (TCOs) and other oxides and nitrides. The relevance of RE-HCS to the PV community is further demonstrated through the incorporation of TCOs and other materials produced by the method into thin film PV devices with competitive performance. Versions of the cathode suitable for large width industrial coating have been developed