Effect of c‐plane sapphire misorientation on the growth of AlN by high‐temperature MOVPE

Abstract

Abstract AlN layers were directly grown on sapphire substrates with slightly different miscut angles from the c‐plane by metalorganic vapor phase epitaxy at 1300 °C. By X‐ray diffraction analysis, the structural quality was found to improve with the increase in substrate off‐angle. When the substrate off‐angle was 0.5°, the X‐ray rocking curve (XRC) full widths at half maximum (FWHMs) of symmetric and asymmetric planes were 170 and 550 arcsec, respectively. At smaller off‐angle, XRC‐FWHMs were wider. When the substrate off‐angle was zero, the XRC‐FWHM was considerably inferior to that on 0.5o‐off‐angle sapphire. The surface morphology was investigated. Atomic steps were observed on the substrates with a small misorientation. In contrast, macro steps appeared on larger‐off‐angle sapphire substrates. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)