FORMATION OF CUBIC BORON-NITRIDE THIN-FILMS BY REACTIVE CATHODIC ARC EVAPORATION

A special cathodic are evaporation assembly including a heated cathode holder [Richter et al. Surf: Coat. Technol. (accepted)] makes it poss ible to operate the cathode at temperatures up to ca. 1000 degrees C. This device was utilized to demonstrate for the first time the feasibi lity of a cathodic are evaporation of a boron cathode. By means of a m agnetic coil (''arc filtering'') most of the macroparticles emitted fr om the cathode were kept from being incorporated into the film. Operat ing the novel boron are evaporation source in a nitrogen environment, practically 100% cubic boron nitride (c-BN) films have been deposited. In addition to proper substrate bias as well as gas composition and p ressure conditions the crucial measure to achieve cubic BN growth was the utilization of novel boron cathodes facilitating a sufficiently lo ng period of continuous operation of the are discharge. The c-BN films have been characterized with respect to their composition (elastic re coil detection analysis) and phase structure (Fourier transform infrar ed spectroscopy, transmission electron micrography). (C) 1997 Elsevier Science S.A.