Preparation of cubic boron nitride film by activated reactive evaporation with a gas activation nozzle

The preparation of a cubic boron nitride film by physical vapor deposition processes has been investigated. The electron beam guns of a hollow cathode discharge type and a conventional high‐voltage type were used for the boron evaporation source. The stoichiometric boron nitride film could be obtained by using a gas activation nozzle. It was necessary to apply the rf bias potential to the substrate to accelerate the formation of the cubic BN phase. It was found that mixing argon gas to the reactant gas N2 assists the formation of cubic phase. The film structure was characterized by the infrared absorption spectrum and transmission electron diffraction observation. The microhardness of the cubic boron nitride film obtained was estimated to be about 4000 kg/mm².