Beem imaging and spectroscopy of buried structures in semiconductors

Ballistic Electron Emission Microscopy (BEEM) has been shown to be a powerf ul tool for nanometerscale characterization of the spatial and electronic p roperties of semiconductor structures. In this article, we will discuss gen eral aspects of BEEM experiment and theory in true ballistic and quasi-ball istic hot carrier transport. We will review the current state and recent pr ogress in the use of the BEEM imaging and spectroscopy to study metal-semic onductor and metal-insulator-semiconductor interfaces, buried semiconductor heterojunctions and novel quantum objects. Various theoretical BEEM models are discussed, and their ability to describe BEEM experiments is examined. Special attention is drawn to the role of the electron scattering in the m etal base layer, at the metal-semiconductor interface and in the semiconduc tor heterostructure on BEEM spectra. (C) 2001 Elsevier Science B.V. All rig hts reserved.