Résumé
We have investigated the heteroepitaxial growth of indium nitride on sapphire substrates having different orientations. Growths were performed on C-, A-, M-, and R-plane-oriented sapphire in order to analyze the substrate orientation effect on the structural, optical, and electronic properties of InN. The orientation relationship between InN and sapphire was deduced by theta/2 theta High-resolution X-ray diffraction (HRXRD) measurements. These experiments show the ability to grow InN along nonpolar (11 (2) under bar0) orientation and the semipolar (11 (2) under bar2) orientation, depending of the orientations of the sapphire substrate. The crystalline quality was assessed by XRD symmetric and asymmetric rocking curve. measurements. We observed no drastic disparity between our samples, all exhibiting a reasonable crystalline quality. Atomic force microscopy imaging on these, layers, revealed different surface morphologies with a roughness varying between 30 and 60 nm. Electrical properties of the InN samples were investigated by room temperature Hall effbt.Cmeasourements and a line shape fitting of the photoluminescence was performed in order to get optically the values of the residual carrier density in the nitride layers. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim