SEMICONDUCTOR INTERFACE STUDIES USING CORE AND VALENCE LEVEL PHOTOEMISSION

The application of core and valence level photoelectron spectroscopy to the study of semiconductor heterojunctions and metal-semiconductor interfaces (Schottky barriers) is outlined, with an emphasis on recent results and their explanation in terms of current theories. While the determination of transport barriers (valence band offsets and Schottky barriers) is stressed, the identification of chemical reactions at the interface is also discussed using several examples. Photoemission can precisely determine many important quantities in these junctions; also demonstrated, however, is the disturbing influence of the photoemission process itself through the creation of a surface photovoltage in metal-semiconductor interfaces, and its possible consequences for recent investigations of Schottky barrier heights in metal overlayers on low temperature substrates. © 1990 Springer-Verlag.