Mosaic Structure of Ternary Al_1-xIn_xN Films on GaN Grown by Metalorganic Vapor Phase Epitaxy

Abstract

Al 1- x In x N heteroepitaxial films were grown on GaN by atmospheric pressure metalorganic vapor phase epitaxy. The films were characterized by X-ray diffraction and atomic force microscopy. In the case of Al 0.50 In 0.50 N, the crystallinity progressively degraded with increasing thickness. On the contrary, the crystallinity of Al 0.83 In 0.17 N, which is in-plane lattice-matched with GaN, remained almost unchanged irrespective of the thickness. The crystallinity of Al 0.83 In 0.17 N was strongly dependent on the quality of the underlying GaN layer, while that of Al 0.50 In 0.50 N was not as sensitive.