Analysis of strain relaxation process in GaInN/GaN heterostructure by in situ X-ray diffraction monitoring during metalorganic vapor-phase epitaxial growth

Abstract

Strain relaxation in a GaInN/GaN heterostructure is analyzed by combining in situ X-ray diffraction (XRD) monitoring and ex situ observations. Two different characteristic thicknesses of GaInN films are defined by the evolution of in situ XRD from the full width at half-maximum of symmetric (0002) diffraction as a function of GaInN thickness. This in situ XRD measurement enables to clearly observe the critical thicknesses corresponding to strain relaxation in the GaInN/GaN heterostructure caused by the formation of surface pits with bent threading dislocations and the generation of misfit dislocations on GaInN during growth. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.