BALLISTIC-ELECTRON-EMISSION MICROSCOPY (BEEM) - STUDIES OF METAL-SEMICONDUCTOR INTERFACES WITH NANOMETER RESOLUTION

Ballistic-electron emission microscopy (BEEM) is a relatively new technique, based on the scanning-tunneling microscope, to study potential steps at interfaces with a lateral resolution in the nanometer scale. Up to now, BEEM has mainly been applied to metal/semiconductor interfaces. In this article, the technique and its opportunities will be presented, and a detailed overview will be given over the experimental results on Schottky-barrier heights, scattering effects, and the homogeneity of metal/semiconductor interfaces. Furthermore, the theoretical background for the description of electron transport in BEEM will be given. Studies of related systems, like semiconductor heterojunctions or interfaces with intralayers, will also be presented.