INVESTIGATION OF ALUMINUM GALLIUM-ARSENIDE GALLIUM-ARSENIDE SUPERLATTICES BY ATOMIC FORCE MICROSCOPY

We have analyzed AlGaAs/GaAs superlattices by imaging freshly cleaved, untreated sample cross sections with the atomic force microscope in air. We were also able to image the same superlattice on a sample cross section after etching It for 5 min in 0.1 M HCl. The reverse contrast of the AlGaAs/GaAs multilayer system between both samples suggests an explanation for the observed corrugation of 0.5 nm on the untreated sample and 0.2-0.6 nm on the etched sample. The described method might also be useful for analytical characterization of a variety of other materials and for the study of surface reactions.