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

Most measurement techniques of the Schottky barrier height (SBH) conta in an inherent assumption of homogeneity. The vast majority of electri cal 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 assumptio ns of the pinning models are not born out by recent theoretical calcul ations. A large body of experimental data from well-characterized epit axial metal-semiconductor interfaces has firmly established the critic al dependence of the SBH on local structure. Thus, understanding the f ormation of interface structure is likely a prerequisite of any predic tive SB theory.