ON PLASTIC-FLOW AND WORK-HARDENING IN STRAINED-LAYER HETEROSTRUCTURES

We present an alternate model for metastable strain relaxation in heteroepitaxial semiconductor structures which includes the elastic interaction between misfit dislocations. The concept of the self-stress of straight misfit dislocations lying in the interface in two orthogonal arrays is introduced and applied to standard expressions for the residual in-plane epitaxial film stress of noninteracting dislocations. Our model of plastic flow and work hardening in strained layer heterostructurcs agrees well with the experimental work. The theoretical analysis can be applied to most of the pseudomorphic and heteroepitaxial material systems of current interest.