Synthesis of B–C–N thin films by electron beam excited plasma CVD

Abstract

Boron–carbon–nitrogen (B–C–N) thin films were synthesized using an electron beam excited plasma (EBEP)-CVD method and their properties and structure investigated. By controlling the flow rate ratios of process gases, we obtained films with composition expressed as BxCyN, where x=0.9–4.7 and y=0.5–6.0. Hydrogen content is very small, of the order of 1 at.%. The hardness of the films increases monotonically with increasing boron content and reaches 29 GPa. Results of X-ray photoelectron spectroscopy, Fourier transform infrared transmission and X-ray diffraction measurements show that while the films consist of a sp2-bonded B–C–N structure in a boron poor region, a sp3-bonded structure exists as well as the sp2-bonded structure in a boron rich region.