GROWTH-PROCESSES AND RELAXATION MECHANISMS IN THE MOLECULAR-BEAM EPITAXY OF INAS/GAAS HETEROSTRUCTURES

The very first stages of growth during the molecular beam epitaxy of InAs on GaAs are studied. The growth mode is found to be closely related to the mechanisms of strain relaxation. The onset of 3D nucleation initiates strain relief by the formation of relaxed islands with subsequent segregation and intermixing of the group III elements. In multilayer structures, a competition between different relaxation paths is observed, regulated by the individual layer thickness rather than by the net strain in the structure.