It was recalled that threading dislocation glide relieved strain in strained-layer heterostructures, by increasing the total length of the interface misfit dislocations, and that the Freund blocking theory predicted the thickness above which gliding threading dislocations were able to overcome the resistive force that was produced by pre-existing orthogonal misfit dislocations. Wedge-shaped samples of Ga0.96In0.04As/GaAs strained-layer heterostructure were grown, by using molecular-beam epitaxy, in order to test the theory of dislocation-blocking for a range of thicknesses within one sample. Scanning cathodoluminescence microscopy results supported the Freund model.

Investigation of Threading Dislocation Blocking in Strained-Layer InGaAs/GaAs Heterostructures Using Scanning Cathodoluminescence Microscopy. J.J.Russell, J.Zou, A.R.Moon, D.J.H.Cockayne: Journal of Applied Physics, 2000, 88[3], 1307-11