SCHOTTKY-BARRIER HEIGHT - DO WE REALLY UNDERSTAND WHAT WE MEASURE

Most measurement techniques of the Schottky barrier height (SBH) contain an inherent assumption of homogeneity. The vast majority of electrical characteristics experimentally obtained from SB junctions actually display clear evidence for inhomogeneities, contradicting the concept of a unique Fermi-level position which is an essential part of Fermi-level pinning models. It is also shown that many other basic assumptions of the pinning models are not born out by recent theoretical calculations. A large body of experimental data from well-characterized epitaxial metal-semiconductor interfaces has firmly established the critical dependence of the SBH on local structure. Thus, understanding the formation of interface structure is likely a prerequisite of any predictive SB theory.