Vapour-liquid-solid mechanism for the growth of SiC homoepitaxial layers by VPE

In order to reach fast growth regime, we have investigated the SiC homoepitaxial growth on off-axis 4H-SiC substrates from a vapour-liquid-solid (VLS) mechanism in a vertical cold wall CVD reactor. The experiments involved silane and propane diluted in hydrogen as feeding vapour phase and melted silicon as "liquid catalyst". Growth rates up to 25 mum/h at 1500 degreesC and 35 mum/h at 1600 degreesC with a bunched step-terrace structure are demonstrated in such a system. The formation and stability of the VLS equilibrium is discussed with respect to the experimental parameters and a first approach of the mechanism is proposed. (C) 2002 Elsevier Science B.V. All rights reserved.