Relation between the Generation of Misfit Dislocations at InAs/GaAs(110) Heterointerface and the Growth Mode.

Abstract

We clarified the atomic and electronic structures of misfit dislocations generated at InAs/GaAs(110) heterointerface by first-principles calculations, and also investigated the behavior of the misfit dislocations during heteroepitaxies, using elastic continuum theory. Our first-principles calculations indicate that the dislocation core has asymmetric five-fold coordinated In atoms, which originate from the charge transfer at the heterointerface. In order to investigate the heteroepitaxial growth mode, we formulated the free energy of the heterointerface system. It was found that the formulation could describe the heteroepitaxial growth mode when some physical parameters were determined appropriately. These parameters are successfully determined by combining the first-principles calculations and elastic continuum theory via total energies of the system. As a result, we found that the formation energy of 90o misfit dislocation was 0.96 eV/A, and also that the growth mode determined by our theory using these parameters reproduced the growth mode observed by STM studies.