Transmission electron microscopic investigations were made of highly mismatched sphalerite-type epilayers with misfit dislocations that were confined to a narrow region which was close to the interface. The layers were grown, by using metalorganic vapor phase epitaxy, onto 0 and 2 misoriented (111) GaAs substrates. High-resolution electron micrographs showed that most of the misfit dislocations had Burgers vectors which were parallel to the interface plane. Thus, the misfit dislocations were confined to (111) planes which were near to the interface. Misfit dislocations with Burgers vectors that were inclined with respect to the interface plane disappeared completely in the case of the 2 misoriented substrate. This system was almost defect-free, apart from stacking faults which were due to dissociated perfect 60 misfit dislocations in a region that extended to about 10nm from the interface.

A.Rosenauer, H.Stanzl, K.Wolf, S.Bauer, M.Kastner, M.Grün, W.Gebhardt: Materials Science Forum, 1994, 143-147, 567-72