Thick AlN layers were grown directly on sapphire substrates by hydride vapor phase epitaxy at growth rates of 40-60 mu m/h. The resulting films were colorless, smooth and specular. Subsurface cracking, attributed to the plastic relief of tensile strain from island coalescence, was observed by Nomarski optical contrast microscopy and cross-sectional scanning electron microscopy. Typical full-widths at half-maximum of X-ray rocking curves for the on-axis (0002) and off-axis (2021) reflections of the AlN films were 310-640" and 630-800", respectively. The threading dislocation density was 2 x 10(9) cm(-2) as determined by plan-view transmission electron microcopy. Convergent beam electron diffraction was used to deter-mine that the surfaces of our AlN films are Al-face. These results represent substantial progress towards rapid production of AlN templates and free-standing AlN substrates of high optical quality. (c) 2006 Elsevier B.V. All rights reserved.