Changes of chemical structure of hydrogenated amorphous silicon carbide films with the application of radio-frequency bias voltages during chemical vapor deposition

Hydrogenated amorphous silicon carbide films were fabricated using the decomposition of Si(CH3)(4) with the microwave discharge flow of Ar. The changes of the chemical structure and the mechanical hardness of films were investigated upon the application of the radio-frequency bias voltages (-V-RF) to the substrate. The analysis was based on a combination of Rutherford backscattering and elastic-recoil detection analysis, the X-ray photoelectron spectroscopy, the glow discharge optical emission spectroscopy, the nano-indentation measurements, and Fourier-transformed infrared spectroscopy. The fraction of the C-Si bonding state has a positive dependence on -V-RF, whereas that of the C-C bonds in the sp(3) hybridized state is negligible. In addition, hydrogen terminations were removed effectively under the low -V-RF conditions of 0-20 V. The films show the penetration of O atoms from the atmospheric origin into the bulk region. The mechanical hardness of the present flint is the result of the balance among these factors. (C) 2016 Elsevier B.V. All rights reserved.