Non-polar a-plane (11•0) GaN films were grown onto r-plane (1¯1•2) sapphire substrates via metal organic chemical vapour deposition. The influence of the V/III ratio upon the species diffusion anisotropy of a-plane GaN films was investigated by using scanning electron microscopy, cathodoluminescence and high-resolution X-ray diffraction measurements. The anisotropy of a-plane GaN films was suggested to result from the differing migration lengths of adatoms along two in-plane directions. The V/III ratio had an effect upon the growth rates of various facets and upon the crystal quality.

Effects of V/III Ratio on Species Diffusion Anisotropy in the MOCVD Growth of Non-Polar a-Plane GaN Films. L.B.Zhao, T.J.Yu, J.J.Wu, Z.J.Yang, G.Y.Zhang: Chinese Physics B, 2010, 19[1], 018101