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

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.