Measurement of the displacement field around an edge dislocation in silicon to 3 pm by high-resolution electron microscopy

The aim of the present work is to establish HREM as a tool for measuring strain in semiconductors and devices at the nanometre scale. To this end, we have measured the displacement field around a known object, a pure-edge dislocation in silicon, and compared results with elastic theory. Measurements were carried out using the geometric phase technique, including careful calibration of projector lens distortions. The continuous displacement field was calculated using full anisotropic elastic theory. Agreement with theory, in directions both perpendicular and parallel to the Burgers vector, will be shown to be better than 0.03 Angstrom or 3 pm. Accuracy - in this case, almost a hundred times the resolution of the instrument used - results from improved methodology and specimen preparation.