A-plane (1¯2•0) films were deposited onto the off-angle R-plane (1¯1•2) sapphire substrates, by means of metal-organic chemical vapour deposition, so that the surface plane was tilted towards the [1¯1•1] sapphire direction. The polar direction of the AlN film was inverted by changing the sign of the off-angle, and the latter was effective in restraining the generation of inverted twins in the AlN. A negative off-angle was found to improve the overall crystalline quality of the AlN; according to X-ray diffraction data. High-resolution transmission electron microscopic images, from the vicinity of the interfaces between the AlN and the sapphire, indicated that the atomic arrangement in the initial stages of AlN growth affected the overall crystal quality.

AlN Epitaxial Growth on Off-Angle R-Plane Sapphire Substrates by MOCVD. T.Shibata, K.Asai, Y.Nakamura, M.Tanaka, K.Kaigawa, J.Shibata, H.Sakai: Journal of Crystal Growth, 2001, 229[1], 63-8