Effects of working pressure and substrate temperature on the structure and mechanical properties of nanocrystalline SiC thin films deposited by bias-enhanced hot filament chemical vapor deposition

•Excellent SiC films were deposited using Si(CH3)4/H2 as precursor gases.•Systematically studied the effect of working pressure on properties of SiC films.•Studied the effect of substrate temperature on properties of SiC films.•Better parameters were obtained for SiC deposition among the tested conditions.

The effects of working pressure and substrate temperature on the structure and mechanical properties of nanocrystalline SiC films deposited by bias-enhanced, hot-filament chemical vapor deposition using tetramethylsilane/H2 gas mixtures were investigated. Experiments were performed at over a working pressure range of 0.5 kPa to 1.5 kPa, and the substrate temperature was varied from 520 °C to 720 °C. Field emission scanning electron microscopy, X-ray diffraction (XRD), Raman scattering analyses, and nanoindentation experiments were performed to characterize the morphology, phases, and mechanical properties of the deposited films. These experimental results indicate that the working pressure and substrate temperature had a great influence on the morphology, phases, and mechanical properties of the deposited films. XRD analyses of all thin films fabricated revealed (111) and (220) peaks, but peaks associated with the (200), (311), and (222) planes gradually disappeared with increasing gas pressure. Raman spectroscopy demonstrated the presence of the Raman peaks corresponding to the TO and LO phonon modes of SiC, as well as the D and G peaks of graphite. By adjusting the working pressure and substrate temperature, the nanocrystalline SiC film with the higher hardness and elasticity modulus of approximately 23 GPa and 320 GPa, respectively, was obtained at a working pressure of 0.75 kPa and substrate temperature of 620 °C.