Growing 3C-SiC heteroepitaxial layers on α-SiC substrate by vapour–liquid–solid mechanism from the Al–Ge–Si ternary system

Abstract

In this work, we present and compare the results obtained from different Si-based melts (Ge–Si, Al–Si and Al–Ge–Si) for growing SiC layers on α-SiC substrate by vapour–liquid–solid (VLS) mechanism. It was found that, depending on melt composition, the deposit could be either a complete 3C or α-SiC layer or even a mixture of these polytypes. The binary Al–Si melt leads systematically to a highly p-type homoepitaxial α-SiC deposit while Ge–Si melt gives a non-intentional n-type doped layers of either 3C or 6H polytypes depending on growth conditions. However, highly p-type doped 3C heteroepitaxial deposit can be obtained if a small amount of Al is added to the Ge–Si binary liquid phase. This means that the VLS mechanism is very flexible and allows growing either n- or p-type SiC layers of 3C or 6H polytypes.