Enhanced macroparticle filter and cathode arc source

摘要

A cathode arc source for depositing a coating on a substrate has an anode and a cathode station for a target, a first filter means comprising a filter duct having at least one bend, and first magnetic means for steering plasma through the filter duct for removal of macroparticles from the plasma. The apparatus comprises a second filter ( 10 ) for further removal of macroparticles from the plasma, made up of a baffle ( 11 ), an aperture ( 12 ) through which plasma can pass and second magnetic means ( 13 ) for steering plasma through the aperture. The aperture size may be less than 33% of the duct sectional area at that point. The source can also include an ion beam generator. Also described is a method of depositing coatings of ions using the second filter and closing the aperture in the filter when required.