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

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