Interfacial Coherence And Lateral Indium Segregation In Thick Ingaas Single Heterostructures Grown On Gaas Substrates

Interfacial coherence in low-strained InxGa1-xAs grown on GaAs substrates has been studied and the critical strains corresponding to layer thicknesses of 0.5, 1.0, and 2.0 mum have been determined. The measured critical strains exceeded those expected from current theoretical models and the discrepancy could not be accounted for by including additional dislocation pinning due to either a Peierls force or a dislocation atmosphere. A new model of Lateral Indium Segregation (LIS) in the vicinity of a grown-in threading dislocation is proposed as an alternative explanation of our observations.