We studied the growth of ZnO layers on 6H-SiC substrates, focusing on the effects of annealing the ZnO layer, and the thickness of an annealed ZnO layer on a 6H-SiC substrate, on the properties of the layer. X-ray diffraction (XRD) measurements revealed c-axis-oriented growth of the ZnO layer on a 6H-SiC substrate. On annealing, the full width at half maximum (EWHM) of the XRD peaks decreased by a factor of about two and the island size became two times larger, regardless of the ZnO film thickness. (C) 2010 Elsevier B.V. All rights reserved.