Electron microscopic analyses of microstructures in epitaxial laterally overgrown GaN were described. It was noted that dislocations lying on (00•1), or horizontal dislocations, were generated in layers which overlay a mask of amorphous SiO2. The horizontal dislocations had the form of a loop or semi-loop, and the morphology suggested that the horizontal dislocations were generated via a multiplication mechanism, with the assistance of internal stresses. On GaInN/GaN, a pit formed at the end of a threading dislocation having any Burgers vector: a, c or a+c. The density and distribution of threading dislocations could be estimated by observing growth pits following the subsequent deposition of a thin GaInN layer onto the GaN. The critical thickness for the formation of pits depended upon the concentration of In in the GaInN, and upon the Burgers vector. It was demonstrated that electron back-scattering diffraction pattern analyses could estimate the 3-dimensional distribution, of the c-axis orientation of epitaxial lateral overgrown GaN for a wide area, with an accuracy of 0.2 or better.

Electron Microscopy Analyses of Microstructures in ELO-GaN. N.Kuwano, K.Horibuchi, K.Kagawa, S.Nishimoto, M.Sueyoshi: Journal of Crystal Growth, 2002, 237-239, 1047-54