Cathodic arc coater with an apparatus for driving the arc

An apparatus for applying material by cathodic arc vapor deposition to a substrate is provided which includes a vessel (14), apparatus (16) for maintaining a vacuum in the vessel, a disk-shaped cathode (18), apparatus (22) for selectively sustaining an arc of electrical energy between the cathode and an anode (14,24,112), and apparatus (74) for driving the arc around an axially extending evaporative surface of the cathode. The apparatus for driving the arc includes a magnetic field generator (84,86) attached to a ferromagnetic center piece (82). The magnetic field generator includes a plurality of side magnets (84) attached to the ferromagnetic center piece, and a center magnet (86) positioned radially inside of the side magnets. Each side magnet produces a magnetic field that permeates the cathode, and each magnetic field includes a portion that runs substantially parallel to the evaporative surface (36). The center magnet influences the axial position of the arc path (122) relative to the evaporative surface.