Evidence for Fermi-energy pinning relative to either valence or conduction band in Schottky barriers.

Abstract

Using the temperature dependence of Schottky-barrier heights in epitaxial silicide-silicon diodes, we show that the metal Fermi level at the interface is pinned either relative to the Si conduction band or to the Si valence band. The contribution of the semiconductor to the interface states is restricted to the semiconductor band nearest in energy. We then discuss the effect of the metal on the interface states and propose different models of Schottky-barrier formation that may account for these results.