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

摘要

Boron-carbon-nitrogen (B-C-N) thin films were synthesized using an election 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 B_xC_yN, where x = 0.9-4.7 and y = 0.5-0.6. 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 sp~2-bonded B-C-N structure in a boron poor region, a sp~3-bonded structure exists as well as the sp~2-bonded structure in a boron rich region.