Misfit dislocations and critical thickness in InGaAs/GaAs heterostructure systems

Abstract
The onset of misfit dislocation generation is investigated and the critical thickness is determined by transmission electron microscopy using the epitaxial lift-off technique for InGaAs/GaAs single heterostructures and single quantum wells. The observed geometries of the dislocations in both cases are in good agreement with the predicted models [J. Appl. Phys. 41, 3800 (1970) and J. Cryst. Growth 27, 118 (1974)]. However, each dislocation undergoes the predicted elongation mechanism [J. Appl. Phys. 41, 3800 (1970)] at different strained-layer thicknesses. A comparison of the predicted and the experimental critical thicknesses is given.