Patent ID: 8197648

Claim:
Method for producing a low-conductivity layer on a workpiece by vacuum coating, the method comprising: operating an electrical arc discharge between an anode and a cathode of an arc source in an atmosphere containing a reactive gas, the cathode being electrically connected to a target; and supplying to the cathode, from a current source, an excitation current conducted by a magnet system comprising at least one essentially axially-polarized coil with a geometry similar in size to that of the target to apply an external magnetic field essentially perpendicular to a target surface of the target electrically connected to the cathode, said magnetic field comprising a vertical component B z and a relatively smaller component B r parallel to the target surface, wherein the excitation current is (i) a direct current and/or a pulsed current or (ii) an alternating current that is supplied to the cathode through the coil.