Characteristics of the cathodic arc discharge with a hot boron cathode

Recently, we have developed a cathodic arc plasma source with a heated boron cathode and successfully applied to the deposition of cubic boron nitride thin films. The cathode surface area under operation exhibits an extended red-hot area and it was therefore tentatively assumed that the arc operates in the distributed mode. However, high-speed photography has revealed that cathode spots exist which move randomly similar to cathode spots on metal. The discharge mode of the hot boron cathode has been characterized both in Ar and N/sub 2//Ar atmosphere. The properties of the ion component of the emitted plasma were investigated by energy-resolved mass spectroscopy. Conclusions are drawn on the potential of boron arc evaporation as a viable deposition process for c-BN films.