The epitaxial growth of aluminum nitride films on Al2O3 (0 0 0 1) by sputtering is achieved using a 30 nm thick buffer layer of aluminum and titanium nitride. Both buffer layers facilitate epitaxial growth. In particular, an epitaxial film can be deposited at room temperature if the buffer layer is Al. Pole figures of X-ray diffraction elucidate the crystallinity of films. (C) 2003 Published by Elsevier Science B.V.