(B0.5Six)N-0.5 films (0 less than or equal to x less than or equal to 0.5) were prepared by dual ion beam deposition. Buffer layers were added to improve the film adhesion. The film structure was characterized by x-ray photoelectron spectroscopy, infrared absorption, and x-ray diffraction. The hardness and elastic modulus were measured by a nanoindenter. The I-V curves of the Ti/(B0.5Six)N-0.5/buffer/p-Si/Ti diodes were investigated. The films are composites of cubic-boron nitride (c-BN), h-BN, and Si-N. When x = 0, the film contains 70-75 vol % c-BN and has a hardness approximate to 38 GPa, but peels off quickly from the substrate after exposure to air. When x increases to 0.013, a small amount of Si-N phase is formed, which serves to release part of the internal stress without affecting the volume fraction of c-BN or the mechanical strength, and good adhesion is achieved. For higher Si content (0.013

Keywords:CUBIC BORON-NITRIDE;PULSED-LASER DEPOSITION;RAY PHOTOELECTRON-SPECTROSCOPY;ELECTRON-CYCLOTRON-RESONANCE;CHEMICAL-VAPOR-DEPOSITION;SILICON-NITRIDE;ASSISTED DEPOSITION;HIGH-PRESSURE;THIN-FILMS;NITROGEN