Effect of continuous in situ cathode polishing on plasma yield and energy in filtered pulsed arc discharge system

The significance of the rotationally polished cathode system for the preparation of the diamond like carbon (DLC) coatings with the pulsed arc discharge method is presented. A continuous deposition rate of 5 μm/h of high quality DLC over a surface of 7 cm in diameter has been obtained with a system equipped with in situ cathode polishing. Depending on the cathode size, this yield can be maintained for weeks. Whole cathode material can be used without any change in the deposition rate or the quality of the resulting DLC coating. Without the polishing of the cathode the plasma yield decreases at least by a factor of five in a short time. Also, the plasma ion energy increases and the quality of the DLC coating changes. A detailed description of the equipment is given.