The present invention provides a magnetron sputtering system using a gas distribution system which also serves as a source of anodic charge to generate plasma field. The sputtering system is comprised of a vacuum chamber, a cathode target of sputterable material, a power source which supplies positive and negative charge, and a gas distribution system. The gas distribution system may comprise a simple perforated gas delivery member, or it may comprise a perforated gas delivery member with an attached conductive anodic surface. The gas delivery member may also contain an inner conduit with further perforations which serves to baffle flow of the sputtering gas. Gas flow may be regulated within discrete portions of the gas distribution system. The anodic surfaces of the gas distribution system are cleaned through the action of plasma and gas flow, creating a more stable plasma and reducing the need for maintenance.