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

摘要

A two-dimensional network of misfit dislocations at the interface of the partially relaxed In_xGa_(1-x)As 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 undulat-rning surface morphology in the form of a characteristic cross-hatch pattern has been observed by means of atomic force microcopy (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.