CONVERGENT-BEAM ELECTRON-DIFFRACTION STUDY OF MODULATIONS IN SEMICONDUCTOR SUPERLATTICES

The dependence of zone axis superlattice higher-order Laue zone (HOLZ) lines of reflections of AlAs/GaAs superlattices on the accelerating voltage of the electron microscope and the specimen thickness has been studied by conventional zone axis convergent-beam electron diffraction (CBED) and large-angle CBED Tanaka dark-field patterns. This is compared with satellite sidebands in a GeSi/Si strained-layer superlattice with a larger period of modulation. It is shown that zone axis superlattice HOLZ lines and satellite sidebands in Tanaka dark-field patterns are equivalent.