Growth of boron nitride on 6H-SiC substrate by flow-rate modulation epitaxy

Boron nitride (BN) layers on 6H-SiC substrate were grown by metalorganic vapor phase epitaxy (MOVPE) using triethylboron (TEB) and ammonia (NH ₃). The growth rate of the BN decreased as the NH₃ flow rate increased, indicating that a strong parasitic reaction occurred between TEB and NH₃. Flow-rate modulation epitaxy (FME), which is based on alternating the gas supply, was applied to the BN growth for the first time and it was found that the parasitic reactions could be effectively reduced. The structural properties of BN grown by FME were also investigated by X-ray diffraction (XRD) and transmission electron microscopy. In contrast with amorphous BN layers grown by MOVPE. the BN structure grown by FME was turbostratic with a weakly preferred orientation to the c-axis.