Effect of Pressure on Composition and Property of SiC Hollow Shell

Silicon carbide (SiC) hollow shell was successfully fabricated at different working pressures by chemical vapor deposition (CVD)pyrolysis, using Si(CH₃)₄+C₄H₈+H₂ as the precursor gases. The chemical composition, surface morphology, surface roughness, sphericity and wall thickness uniformity of shells were studied by Xray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), white light interferometer (WLI) and X-ray camera, respectively. The results show that the surface root mean square roughness (R_q) of SiC firstly decreases then increases with pressure increase. R_q decreases to the minimum value of 98 nm when pressure is 15 Pa. Sphericity of SiC does not change significantly with the increase of pressure and the sphericities of all samples are higher than 97%. Wall thickness uniformity of SiC firstly increases then decreases as pressure increases. It increases to 95% when pressure is 15 Pa.