Coatings deposited by cathodic arc discharges

LEANDRO GIULIANI; ARIEL KLEIMAN; MÓNICA PIRRERA; DIANA GRONDONA; HÉCTOR KELLY; ADRIANA MÁRQUEZ

Buenos Aires

Workshop; Recent Developments in Complex Materials: Production and Characterization; 2005

Cathodic arcs are attractive devices for coating production due to their very high deposition rate as compared with other plasma techniques. In these devices a high-current electrical discharge is generated between electrodes immersed in a vacuum chamber, the current being conducted by a metallic plasma consisting of ionized vapour of the cathode material. The plasma is ejected in the form of a jet, which contains metallic ions flowing away from the cathode surface. By placing a substrate in a position where it intercepts the plasma jet, a metallic coating is generated. Furthermore, if a reactive gas such as N2 or O2 is also present in the discharge chamber, metal oxide or nitride films can be produced. The presence of microdroplets of melted cathode material (macroparticles) in the coatings is a drawback in optical and microelectronic applications. Several attempts have been made to separate the metallic plasma from these macroparticles by using straight and curved magnetic filters. They consist in a tube with a magnetic field generated by an external coil, with an  intensity high enough to drive the plasma to the substrate, while heavy macroparticles impinge on the filter wall.  At the INFIP three different cathodic arc systems have been developed. A brief description of these devices and characteristics of the films produced with them are presented.