On scanning electron microscope conduction-mode signals in bulk semiconductor devices: Annular geometry

Beam-induced signals in the scanning electron microscope provide a means of studying the bulk of semiconductors. This paper develops a two-dimensional theory to predict the spatial distribution of the signal in annular devices and it is shown that geometry and field-dependent contrast can occur. These signals provide a means of studying crystal defects and resistivity variations. Experiments on planar geometry GaAs transferred electron devices support the theoretical predictions.