A technique to grow low-dislocation-density AlGaN films is presented in this paper. The Al0.17Ga0.83N films using middle temperature (MT)-intermediate layer technique grown by metalorganic chemical vapor deposition on c-plane patterned sapphire were confirmed. The AlGaN films have been investigated by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques. MT-intermediate layer technique can effectively reduce the dislocation density in the AlGaN films. (c) 2006 Elsevier B.V. All rights reserved.