This was an unexpected but potentially extremely important spinoff of the project to study transport through buried quantum structures in the InGaAs/GaAs heterostructure system as a function of the In concentration. It is known from past work that, depending on the thickness of the InGaAs layer, misfit dislocations can be formed. Misfit dislocations 800Å below the surface were successfully imaged by BEEM as part of this project and these dislocations were carefully characterized through spectroscopy (see paper). The results can be explained by majority carrier scattering by charged dislocation cores. Unlike other techniques (such as cathodoluminescence, Transmission Electron Microscopy (TEM), and Electron Beam Induced Current (EBIC)), BEEM involves extremely low energy electrons, typically in the 1 - 2 Volt range versus the kilo-Volt range in other methods, and hence constitutes a unique tool to examine dislocation scattering (free of electron hole pair creation) and to study material buried well below the surface. This new form of microscopy could turn out to be a powerful tool for understanding the materials properties and the effects of defects/dislocations on important transport properties in the regime of interest for devices, i.e., few volts.