Surface morphology of micro-sized defects on the surface of various high-index GaAs substrates was investigated using an atomic force microscope. The surfaces investigated were the top layer of 1- and 17-period In0.45GaAs0.55/GaAs structures with quantum dots or buffer layer. These structures were characterized by the formation of oval defects on (100) surfaces, and micro-sized defects possessing the shape of multifaceted pits and hillocks on (N11)A/B (N = 7, 5, 4, 3) surfaces. The micro-sized defects were found to chaotically distribute on the surface and, as a rule, gathering in groups with some number of defects. Their density did not depend on the substrate orientation while the shape and orientation of the micro-sized defects were found to depend on the crystallographic orientation of the substrate. This dependence was determined to be the result of anisotropy of surface diffusion and surface elastic properties. The anisotropy of elastic properties of high-index surfaces was found to be the dominating factor in determining the micro-sized defect shape. Direct evidence was also found for the fact that the effect of quantum-dot lateral ordering observed on high-index (N11)B surfaces was determined by the anisotropy of surface elastic properties as well as by elastic interactions between adjacent quantum dots.

Microsize Defects in InGaAs/GaAs (N11)A/B Multilayers Quantum Dot Stacks. P.M.Lytvyn, I.V.Prokopenko, V.V.Strelchuk, Y.I.Mazur, Z.M.Wang, G.J.Salamo: Journal of Crystal Growth, 2005, 284[1-2], 47-56