RF-MBE growth of semipolar InN(10-13) and InGaN(10-13) on GaAs(110)

Abstract

We have studied InN and InGaN films grown on GaAs(110) substrates by RF-assisted molecular beam epitaxy. Reflection high-energy diffraction observation and X-ray diffraction (XRD) measurements revealed that the InN films were epitaxially grown with InN(10-13)// GaAs(110). From XRD pole figure measurements, only one InN(0002) peak was found at an angle of 31.8° from the pole, indicating that the semipolar InN films were free from twin crystals. This can be explained by the similarity in the anisotropic structure between InN(10-13) and GaAs(110) surfaces. By using low-temperature InN buffer layers, we could obtain semipolar InN films with a smooth surface. Polarization anisotropy in the photoluminescence peak observed at 0.67 eV from semipolar InN(10-13) was weaker than that from a -plane InN, which is reasonable considering the smaller angle between the c-axis and the perpendicular direction to the semipolar InN surface. We have also successfully grown In-rich InGaN(10-13) on GaAs(110) substrates with an InN(10-13) intermediate layer, and observed strong photoluminescence from the semipolar InGaN films. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.