Characterization of GaN grown on SiC on Si/SiO2/Si by metalorganic chemical vapor deposition

SiC (3C-SiC) was grown on the top Si layer of SIMOX (Si/SiO2/Si) by carboni zation followed by chemical vapor deposition (CVD). Subsequently, GaN was d eposited on the SiC by metalorganic (IVIO) CVD to produce a GaN/SiC/Si/SiO2 /Si multilayer structure. This multilayer film was investigated by conventi onal transmission electron microscopy (TEM) and high-resolution (HR) TEM fr om cross-sectional view. The GaN layer was found to consist of predominatel y hexagonal gallium nitride (h-GaN), and a small fraction of cubic GaN (c-G aN) crystallites. The orientation relationship between most of the h-GaN gr ains and SiC (3C-SiC) was found to be (0001)(GaN)parallel to(111)SiC; [11 ( 2) over bar 0](GaN)parallel to[1 (1) over bar 0](SiC) while most of the c-G aN grains had an orientation relationship (001)(GaN)parallel to(001)sic; [1 (1) over bar 0](GaN)parallel to[1 (1) over bar 0](SiC) With respect to 3C- SiC substrate. The hexagonal grains of GaN were found to grow as two varian ts. The defects in both h-GaN and c-GaN are also discussed.