Measurement of the mean free path of dislocation glide in the InGaAs/GaAs materials system

Abstract

A method for measuring the mean free path of laterally gliding threading dislocations, based on the growth of lattice mismatched epitaxial layers on patterned substrates has been presented. The method requires no post growth annealing and permits an accurate measurement of the glide process as it occurs during epitaxial growth. This method has been applied to an InGaAs/GaAs heterostructure with a lattice mismatch of 0.5%. Mean free paths of 960 μm for α type dislocations and 1000 μm for β type dislocations were measured. It was concluded that the interaction of threading dislocations with clusters of misfit dislocations and/or edge type dislocations was the primary mechanism of glide length attenuation.

Study of Ga/sub x/In/sub 1×x/P layers grown on InP for HFET application

“…The investigated layer thickness was in the range of 1700A to 7000A. Our results thus indicate that anisotropic relaxation develops mainly in bulk material in a manner consistent with the results reported in [6], whereas the interface dictates isotropic strain relaxation in thin layers.…”

“…Anisotropic strain relaxation was first observed in tensile and in compressivley strained GaxInl.,P (x=0.59 and x=0.45) grown on GaAs [ 6 ] . The major relaxation axis was in the [ 1701 direction regardless of the sign of the strain.…”

Investigation of threading dislocation blocking in strained-layer InGaAs/GaAs heterostructures using scanning cathodoluminescence microscopy

“…4 On the other hand, threading dislocations degrade the active device layers as well as the region surrounding the interface, because they continue through the entire film terminating at the film surface. 5 The blocking mechanism proposed by Freund 3 produces a high density of threading dislocations since the blocked dislocation must thread to the film surface in order to terminate.…”