The effect of adding gas ions to a beam for deposition of boron nitride films by the ion beam and vapor deposition method

Deposition of boron nitride films was studied by the simultaneous use of ion beam irradiation and vapor deposition. Inert gas (helium, argon) ions were added to a nitrogen ion beam, and the effect on the hardness and the crystallization was studied as a function of gas species, the ratio of inert gas ions/nitrogen ions, and ion energy. Irradiation of mixed ion beams, especially argon plus nitrogen, was effective for crystallization of boron nitride films at an ion energy of 2 keV. The X-ray diffraction pattern from these films was sharp, and its scattering angle agreed with the cubic phase. It became clear that electronic excitation was important in forming the metastable phase, as a result of the relation between the electronic stopping cross section and IR absorption spectroscopy from the cubic phase. The highest value of Knoop hardness of the film was about 4900 kg/mm2. The cubic phase dominates the hardness of the films. (orig.)