Mosaic structure of ternary Al1-xInxN films on GaN grown by metalorganic vapor phase epitaxy

Alt-xInxN 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 Al0.50In0.50N, the crystallinity progressively degraded with increasing thickness. On the contrary, the crystallinity of Al0.83In0.17N, which is in-plane lattice-matched with GaN. remained almost unchanged irrespective of the thickness. The crystallinity of Al0.83In0.17N was strongly dependent on the quality of the underlying GaN layer, while that of Al0.50In0.50N was not as sensitive.