Growth of thin protective AlN layers on sapphire substrates at 1065 °C for hydride vapor phase epitaxy of AlN above 1300 °C

Abstract

AbstractA thin protective AlN layer was grown on a (0001) sapphire substrate at 1065 °C for main AlN layer growth at high temperature (> 1300 °C) by hydride vapor phase epitaxy (HVPE). The formation of surface pits on the surface of the epitaxial AlN layer, grown directly on the sapphire substrate at 1320 °C, could be prevented by growing the protective layer. The full‐width at half‐maximum (FWHM) of X‐ray diffraction (XRD) rocking curves of asymmetric (10 $\bar 1$ 0) and symmetric (0002) AlN decreased to 19.8 and 9.6 min, respectively. The concentration of oxygen impurities in the layer grown at 1320 °C was also reduced from 3 × 1019 to 4 × 1018 cm−3 by protecting sapphire substrate at 1065 °C. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)