On the origin of misfit dislocations in InGaAs/GaAs strained layers

Abstract

InxGa1−xAs/GaAs (x≤0.25) strained layers grown by molecular-beam epitaxy have been examined by plan-view transmission electron microscopy. Evidence is presented for the existence of two critical thicknesses, corresponding to the turnover of threading disloca- tions and the nucleation of new dislocations. From a quantitative analysis of dislocation intersections it is deduced that not all interfacial dislocations act to relieve the misfit strain.