The inversion domain (ID) formed in the Al0.17Ga0.83N layer grown by metalorganic chemical vapor deposition on c-plane patterned sapphire was confirmed by transmission electron microscopy. The IDs were found to be generated at the sapphire/AlGaN interface. Most of IDs vanish in the grown layer but some IDs propagate to the surface. Contriving the growth process remarkably reduced the density of IDs. (c) 2006 Elsevier B.V. All rights reserved.