The growth characteristics of chemical vapour-deposited β-SiC on a graphite substrate by the SiCl4/C3H8/H2 system

Silicon carbide has been grown at 1300–1800°C by chemical vapour deposition using the SiCl₄/C₃H₈/H₂ system on a graphite substrate. The effect of C₃H₈ flow rate and deposition temperature on the growth characteristics and structure of the deposit has been studied. The experimental results show that the degree of film density is changeable from a dense plate to a porous one with increasing C₃H₈ flow rate. The activation energy increases with increasing C₃H₈ flow rate. The grain size of the polycrystalline β-SiC becomes coarser when the C₃H₈ flow rate and the deposition temperature are increased. The preferred orientation of the deposited SiC layers changes from (111) to (220) on increasing deposition temperature from 1300°C to 1400°C. The deposition mechanism is also discussed.