High-Resolution Microscopy of Dissociated Screw Dislocations in GaAs

Abstract

The structure of dissociated screw dislocations in GaAs is analyzed by high‐resolution electron microscopy and image simulation. The stacking fault is invariably found to be intrinsic with a stacking‐fault energy of (45 ± 6) mJ/m2. The comparison between experimental and simulated images suggests that partial dislocation motion occurs during observation and the interaction of the dislocation core with point defects severely limits the determination of the dislocation core structure in terms of “glide” or “shuffle” models.

Atomic-resolution imaging of lattice imperfections in semiconductors by combined aberration-corrected HRTEM and exit-plane wavefunction retrieval

“…While most analyses of quantitative high-resolution microscopy were primarily concerned with distinguishing glide and shuffle set dislocations, i.e. discriminating whether dislocation cores lie on the narrowly or widely spaced {111} planes by interpreting characteristic contrast features in their vicinity [46][47][48], it is only recently that efforts have been made to investigate the core structure of 30 and 90 partials, both by theoretically applying ab initio calculations [49][50][51] and experimentally employing advanced electron microscopy techniques [53,53].…”