Characteristics of the cathodic arc discharge with a hot boron cathode

Recently, the authors developed a cathodic arc evaporation source with a heated boron cathode and successfully applied it to the deposition of cubic BN thin films. The cathode surface area under operation exhibits an extended red-hot area and therefore the so-called distributed arc mode was suspected first. Nevertheless, high-speed photography has revealed that cathode spots exist which move randomly in a similar manner as cathode spots on metal. The discharge mode of the hot boron cathode has been characterized both in Ar and a N₂/Ar atmosphere. The properties of the ion component of the emitted plasma were investigated by energy-resolved mass spectroscopy and conclusions are drawn on the potentials of the boron are evaporation as a deposition process for c-BN films