STRAIN AND SURFACE-MORPHOLOGY IN LATTICE-MATCHED ZNSE INXGA1-XAS HETEROSTRUCTURES/

Lattice-matched ZnSe/InxGa1-xAs heterostructures were fabricated by mo lecular beam epitaxy on GaAs(001)2x4 surfaces. We find that the partia l character of the strain relaxation within the ternary layer can be c ompensated by a suitable excess in the In concentration to match the f ree-surface lattice parameter to ZnSe. The surface of the II-VI epilay er, however, exhibits a cross-hatched pattern of surface corrugations oriented along orthogonal [110] directions. This complex surface morph ology reflects the formation of surface slip steps during the nucleati on of dislocation half-loops at the surface and the establishment of t he misfit dislocation network at the InxGa1-xAs/GaAs interface. (C) 19 98 American Institute of Physics.