Review of Cathodic Arc Deposition for Preparing Droplet-Free Thin Films

Cathodic arc plasma is one of the potential ion plating physical vapor deposition methods to prepare protective coatings on cutting tools, metal mold, etc. In particular, TiN, CrN, and TiAlN films are coated on industrial cutting tools using cathodic arc plasma. However, the cathode spot of the vacuum arc generates macrodroplets as coproducts of cathodic arc plasma containing high-energy ions. These macrodroplets may pose problems with smooth-surface films that are used for advanced high-precision applications. This paper reviews cathode phenomena particularly for a graphite cathode, the techniques for reduction of macrodroplet generation, and the techniques for macrodroplet removal from the processing plasma. The reduction technique includes steered arc, pulsed arcs, etc. The removal technique includes shielded arcs and filtered arcs. Recent filtered arc deposition systems are referred.