MICRO-SCRIBES IN SEMIINSULATING GAAS STUDIED BY CROSS-SECTIONAL TRANSMISSION ELECTRON-MICROSCOPY

A micromanipulator was used to create well-defined and exactly oriente d micro-scribes in a GaAs (001) wafer surface. The resulting dislocati on slip systems were identified by cross-sectional transmission electr on microscopy (XTEM). A heating sequence simulating that of a standard epitaxial process was applied, and the response of the lattice defect s was investigated by XTEM. It was found that differently oriented mic ro-scribes generate different types of plasticity behaviour, and that subsequent annealing causes considerable recovery of the strain-harden ed zones near the scribes. These observations are of importance to the understanding of the transfer of dislocations from a damaged substrat e to an epilayer.