Considerable efforts have been made to obtain high quality semiconductor heterostructures for electronic and optical applications. In the 3–5m mid wavelength infrared range (MWIR), an alternative to theHgCdTe dominating material technologies can be the InAs/GaSb superlattices(SL) and InSb quantum dots. In many cases, defects at the interfacesaffect the performance of the films in electronic and optoelectronicapplications. Thus, controlling the defect microstructure is of criticalimportance in these materials systems to realize their potential. In alarge lattice-mismatched system, it is almost impossible to suppress thegeneration of misfit dislocations until the epilayer grows to a usablethickness for device applications. In this talk we present GaSb/InAssupperlattice (SL) structures grown on GaSb (practically no latticemismatch) and GaAs (a large lattice mismatch) substrates and InSb QDstructure grown grown on GaSb substrate. Because of its extremely highspatial resolution transmission electron microscopy (TEM) is a naturaltechnique to apply to the nanometer-scale characterization of thesesemiconductor heterostructures. In particular, cross-sectionaltransmission electron microscopy is a powerful tool for investigatingnanometer-scale interface properties of semiconductor materials anddevices.
