MISFIT DISLOCATION MICROSTRUCTURE AND KINETICS FOR INXGA1-XAS/INP(100) AND (110) INTERFACES UNDER TENSILE AND COMPRESSIVE STRESS

Misfit dislocation microstructures and strain relaxation kinetics are studied for 1% lattice mismatched (100) and (110) interfaces under tensile and compressive stress in the InxGa1-xAs/InP system. Misfit dislocations are observed to be either 60-degrees a/2[101] total [for (100) compressive and (110) tensile configurations] or 90-degrees a/6[112] partial [dominant for (100) tensile and (110) compressive configurations] types. Relaxation kinetics are observed to be substantially faster for 90-degrees a/6[112] than 60-degrees a/2[101] dislocations. This produces significantly different relaxation rates for (100) versus (110) interfaces and compressive versus tensile stress. The relaxation is also found to be an extremely strong function of excess stress, with an increase of about two orders of magnitude of dislocation density per 100 MPa increase in excess stress for interfacial dislocation densities in the range 10(2)-10(6) cm-1.