Ion source with plasma cathode for ion assisted deposition

Abstract An ion source with a plasma cathode has been developed to attain a long lifetime for oxygen ion production. In this ion source, a plasma of a nonreactive working gas serves as a cathode in place of a thermionic tungsten hot cathode used in the Kaufman ion source. This ion source consists of two compartments, i.e. a plasma generator provided with a metallic hot cathode and a plasma chamber interconnected by a narrow tapered duct. The pressure difference between the two parts made by differential pumping prevents the feed gas supplied to the plasma chamber from flowing into the plasma generator. Mass spectrometry results show that this ion source has the ability of generating a considerable amount of O + ions. This ion source is also eminently suitable for oxygen ion production.