Misfit dislocations and surface morphology of InGaAs/GaAs heterostructures grown by MOVPE

A two-dimensional network of misfit dislocations at the interface of the partially relaxed InxGa1-xAs epitaxial layers grown on (001)-oriented GaAs substrates by metalorganic vapor-phase epitaxy (MOVPE) has been revealed by transmission electron microscopy (TEM). A close correspondence between the distribution of interfacial misfit dislocations and undulating surface morphology in the form of a characteristic cross-hatch pattern has been observed by means of atomic force microscopy (AFM). Anisotropic strain relaxation attributed to the asymmetry in the formation of misfit dislocations has been also reproduced on the surface in the form of a fine pattern, cutting the cross-hatch one. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)