High‐quality AlN epitaxial films on (0001)‐faced sapphire and 6H‐SiC substrate

Abstract

This paper presents crystal qualities of high-quality AlN epitaxial films on (0001)-faced sapphire and6H-SiC substrates. The AlN epitaxial films are grown using a low-pressure metal organic vapor phase epitaxy (LP-MOVPE) method. 0.5–1 μm-thick AlN films without any cracks are realized on both substrates. Both of AlN films are found to have similar crystal qualities in spite of large difference in in-plane lattice mismatch between AlN and each substrate. The AlN films have an atomically flat surface with clear atomic steps. Results of X-ray rocking curve (XRC) measurement indicate that both of the AlN films have small tilted mosaicity, however relatively large twisted mosaicity. Dislocation density of the AlN films in its surface region is approximately as low as 1 × 1010 cm−2 and most of dislocations consist of edge-type dislocations. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)