Symposium on discontinuous films,Nal'chik,U.S.S.R., 8–13 April, 1976

The dislocation structure in an InGaAs/GaAs heterojunction with an epilayer thickness of 8 μm and a misfit of 0.003 was studied by X-ray topographic techniques. Misorientations in the approximately square cross-grid of dislocations permit the three-dimensional nature of the dislocation structure in the epilayer to be studied. The evidence presented here suggests that a source other than one of those previously favored is the dominant contributor to the interfacial dislocation structure; the most likely possibility is that the majority of dislocations are introduced at sources created by interactions of gliding threading dislocations.