Published online by Cambridge University Press: 31 January 2011
SiC (3C-SiC) was grown on the top Si layer of SIMOX (Si/SiO2/Si) by carbonization followed by chemical vapor deposition (CVD). Subsequently, GaN was deposited on the SiC by metalorganic (MO) CVD to produce a GaN/SiC/Si/SiO2/Si multilayer structure. This multilayer film was investigated by conventional transmission electron microscopy (TEM) and high-resolution (HR) TEM from cross-sectional view. The GaN layer was found to consist of predominately hexagonal gallium nitride (h-GaN), and a small fraction of cubic GaN (c-GaN) crystallites. The orientation relationship between most of the h-GaN grains and SiC (3C-SiC) was found to be (0001)Ga N||s(111)SiC; [1120]GaN||[110]SiC, while most of the c-GaN grains had an orientation relationship (001)GaN||(001)SiC; [110]GaN||[110]SiC with respect to 3C-SiC substrate. The hexagonal grains of GaN were found to grow as two variants. The defects in both h-GaN and c-GaN are also discussed.