Abstract: An improved method is described for coating a substrate in a system in which an insulating layer is also formed on one portion of a conductive target plate which is bombarded with ions. One such system is a reactive sputtering system in which a predetermined partial pressure of a reactive gas is established between a reactive metal target plate and the substrate. The bombarding ions are formed in a glow discharge plasma which may be magnetically confined. In accordance with the invention, an ac potential is applied to the target plate in order to prevent arcing which is believed due to the dielectric breakdown of the insulating layer.

Abstract: A method and apparatus for coating a substrate with a layer of polymerized material by simultaneous glow discharge polymerization and sputtering is disclosed. A substrate and two electrodes are placed in a chamber which can be evacuated. An appropriate pressure of a gas which can form a polymer is introduced into the chamber. A glow discharge is established in the gas. Molecules of starting gas and reactive species created in the glow discharge deposit on the electrodes and on the substrate. Material deposited on at least one of the electrodes is sputtered onto the substrate by applying an electric potential, preferably an AC potential, across the electrodes. The glow discharge is preferably confined to a region adjacent to the sputtered electrode. This confinement may be accomplished by the use of a planar magnetron sputtering cathode. The method and apparatus disclosed allow the rapid deposition of high quality polymeric coatings at low gas pressures.