Misfit dislocation development in this lattice-mismatched system was studied by means of transmission electron microscopy. The InAs was 11% lattice-mismatched with respect to the GaP, and most of the strain relaxation during initial growth occurred via the introduction of misfit dislocations directly next to island edges. Introduction of dislocations into the islands had an appreciable effect upon the island morphology and the prevailing strain state. The island aspect-ratio decreased with increasing dislocation content, and led rapidly to island coalescence. However, the misfit was not entirely accommodated before the layer became continuous. Subsequent strain relaxation occurred via the introduction of glissile pairs of 60° dislocations, which then combined to form sessile 90° segments at the interface. The latter mechanism was seen during early growth, but became more pronounced after island coalescence had occurred. Complete strain relaxation resulted in a 2-dimensional network of predominantly edge-type misfit dislocations; spaced about 4nm apart. Subsequent in situ annealing caused non-
conservative motion of the misfit dislocations on the (001) plane to homogenize the spacing and thus reduce the energy of the configuration.

Strain Relaxation and Dislocation Introduction in Lattice-Mismatched InAs/GaP Heteroepitaxy. V.Gopal, A.L.Vasiliev, E.P.Kvam: Philosophical Magazine A, 2001, 81[10], 2481-501