Effect of CH4/SiCl4 ratio on the composition and microstructure of 〈110〉-oriented β-SiC bulks by halide CVD

Halide chemical vapor deposition process was carried out for fast fabricating oriented stoichiometric β-SiC through controlling flow rate of precursors (SiCl 4 and CH 4 ). The effects of molar ratio of C and Si precursors ( R C/Si ) on composition, preferred orientation, microstructure and deposition rate ( R dep ) were investigated. The deposits transformed from silicon-rich to stoichiometric β-SiC to carbon-rich with increasing R C/Si . 〈110〉-oriented stoichiometric β-SiC with lower density of defects were obtained at R C/Si in the range of 0.86–1.00, where the maximum R dep was 883   μm/h at R C/Si   =   1.00, leading to a thickness of 1.7   mm in 2   h deposition. Formation of ridge-like morphology has been discussed based on a twin plane propagation model .