ORIGIN OF OPTICAL ANISOTROPY IN STRAINED INXGA1-XAS INP AND INYAL1-YAS/INP HETEROSTRUCTURES/

Optical anisotropy in mismatched InxGa1-xAs/InP and InyAl1-yAs/InP het erostructures has been investigated by variable azimuthal angle ellips ometry and reflectance difference spectroscopy. The two approaches are shown to yield strongly correlated results. A comparison to high reso lution x-ray diffraction, transmission electron microscopy, and atomic force microscopy studies indicates that large optical anisotropies ar e associated with surface roughening that results from three-dimension al growth. Our findings demonstrate that fast and nondestructive measu rements of optical anisotropy can provide important information about the growth mode and crystalline quality of strained epitaxial layers.