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Highlights • Single phase (10 1 ¯ 1), (10 1 ¯ 2) and (20 2 ¯ 3) GaN grown on 4°-miscut 3C-SiC/Si. • Different Al x Ga 1−x N interlayers used to control GaN surface orientations. • Substrate miscut caused twins in (10 1 ¯ 1) GaN. • (10 1 ¯ 2) and (20 2 ¯ 3) GaN only grown along the miscut direction. Abstract Heteroepitaxial growth of GaN buffer layers on 3C-SiC/(001) Si substrates (4°-miscut towards [110]) by metalorganic vapour phase epitaxy has been investigated. High-temperature grown Al x Ga 1 - x N/AlN interlayers were employed to control GaN surface orientations. Semipolar GaN layers with (10 1 ¯ 1), (20 2 ¯ 3) and (10 1 ¯ 2) surface orientations were achieved, as confirmed by X-ray diffraction. Due to the substrate miscut, the growth of (10 1 ¯ 1) layers was twinned along [ 1 1 ¯ 0 ] 3 C - SiC / Si and [ 1 ¯ 10 ] 3 C - SiC / Si while the growth of (20 2 ¯ 3) and (10 1 ¯ 2) layers was only along [ 110 ] 3 C - SiC / Si . The (10 1 ¯ 1) layers have rough surface morphology while the (20 2 ¯ 3) and (10 1 ¯ 2) layers have mirror-like smooth surface. For all samples with various surface orientations, different photoluminescence peak emission energies were observed at ∼ 3.45 eV, 3.78 eV and 3.27 eV at 10 K. These emissions are attributed to the near-band edge of hexagonal GaN, basal-plane stacking faults and partial dislocations, respectively. The dominant luminescence intensity of stacking faults indicates their high density in the GaN layers. [ABSTRACT FROM AUTHOR]

Abstract: Highly oriented AlN film was prepared on a c-plane sapphire substrate by laser chemical vapor deposition using a newly proposed aluminum acetylacetonate precursor and ammonia gas as source reactants. The c-axis oriented AlN films were obtained on the c-plane sapphire substrate at deposition temperatures from 900 to 1230K. AlN film prepared at 1047K showed an epitaxial relation as The full width at half maximum (FWHM) of the X-ray rocking curve for AlN (0002) plane increased with increasing deposition temperature. The c-axis lattice parameter decreased with increasing deposition temperature. [Copyright &y& Elsevier]