Physical properties of dual ion beam deposited (B0.5−xSix)N0.5 films

Abstract

( B 0.5−x Si x ) N 0.5 films (0⩽x⩽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/(B0.5−xSix)N0.5/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 ≈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