INTERFACIAL ROUGHNESS IN INAS GASB SUPERLATTICES

Using high-resolution transmission electron microscopy (HRTEM), we hav e studied InAs/GaSb superlattices grown by molecular beam epitaxy. Our HRTEM observations indicate that the apparent interface width is on t he order of 1 monolayer for InSb-like interfaces, and on the order of 2 monolayers for GaAs-like interfaces. The combination of these result s with x-ray diffraction and Raman scattering measurements leads us to conclude that these interface widths are principally due to roughness rather than to interfacial diffusion.