Deposition and Characterization of Thin Si-B-C-N Films by DC Reactive Magnetron Sputtering of Composed Si/B4C Target

Abstract

The effect of the gas mixture composition on the structure, chemical bond character and hardness of Si-B-C-N films was systematically studied. A series of Si-B-C-N films was deposited by reactive dc magnetron sputtering of the target composed of Si disc with B₄C chips placed in the sputtering zone of disc. The films were deposited with nitrogen fractions 30-to-70% in Ar/N₂ gas mixture and annealed in a vacuum at temperatures up to 1200°C. The films were characterized by X-ray diffraction, X-ray photo-electron spectroscopy, Fourier transform infrared spectroscopy, indentation tests. Addition of nitrogen in the gas mixture up to 60% led to an increase of hardness from 13.4 up to 17.8 GPa. With further increase in nitrogen content in gas mixture the film hardness decreased. The latter is caused by formation of the weak B-N bonds as well as C-C and C-C bonds that are characteristic of h-BN-like phase and graphite phase, respectively.