Reaction kinetics of silicon carbide deposition by gas-source molecular-beam epitaxy

Thin films of silicon carbide (SiC) have been grown at 1000-1500°C on vicinal and on-axis α(6H)-SiC(0 0 0 1) substrates by gas-source molecular-beam epitaxy (GSMBE). Growth on on-axis and off-axis 6H-SiC(0 0 0 1) substrates using the SiH₄-C₂H₄ system resulted in 3C-SiC(1 1 1) epilayers under all conditions of reactant gas flow and temperature. By adding H₂ to the SiH₄-C₂H₄ system, films of 6H-SiC(0 0 0 1) were deposited on vicinal 6H-SiC substrates at deposition temperature ≥1350°C. Kinetic analysis of the deposition of 3C-SiC films with respect to reactant inputs and growth temperature is presented. From the data, the deposition of 3C-SiC appears to be surface-reaction-controlled. Reflection high-energy electron diffraction (RHEED) and high-resolution transmission electron microscopy (HRTEM) was used to determine the crystalline quality, surface character and epilayer polytype.