ARC source

An ARC evaporator comprising:

• a cathode assembly comprising a cooling plate, a target as cathode element, the target having a thickness in a cross direction, a front surface disposed to be evaporated, and a back surface, the front surface being parallel to the back surface, the front surface and the back surface being separated from each other by a thickness of the target, the cathode assembly having a total height in a transversal direction and borders delimiting a total amplitude in a longitudinal direction, and the target defining a central region of the cathode assembly in the longitudinal direction, with a peripherical region of the cathode assembly extending beyond the target in the longitudinal direction,
• an electrode arranged for enabling an arc to be established between the electrode and the front surface of the target for causing evaporation of at least part of the front surface of the target, and
• a magnetic guidance system placed in front of the back surface of the target comprising means for generating one or more magnetic fields resulting in a total magnetic field comprising magnetic field lines which extend through a cross section of the target and along a space in front of the front surface of the target for guiding a cathode spot that results from contact of an arc to the target, when the arc is established between the electrode and the front surface of the target,
• wherein the magnetic guidance system in the ARC evaporator comprises means placed in the central region for generating at least one magnetic field and means in the peripherical region for generating at least one further magnetic field, wherein the magnetic fields generated in this manner result in a total magnetic field for guiding the arc and controlling the cathode spot path at the front surface of the target, wherein the means placed in the central region comprises one electromagnetic coil for generating a magnetic field and the means placed in the peripherical region comprises two electromagnetic coils for generating two further magnetic fields.