The critical thickness of a heterostructure in electronic or optoelectronic devices is studied on the basis of equilibrium dislocation analysis. Two geometric models, a single dislocation and an array of dislocations in heteroepitaxial system, are considered respectively to calculate the misfit dislocation formation energy. The isotropic elastic fields for two geometries are obtained by means of complex potentials and alternating technique, and are used for calculating the formation energies.
As a result, the effect of elastic mismatch between film and substrate critical thickness is presented and lastly the work hardening effect in a heterostructure is also explained on the basis of the present study.
