Metal-semiconductor junction for (110) surfaces of zinc-blende compounds

Abstract

The behavior of the metal-semiconductor junction is studied for some III-V and II-VI zinc-blende compounds, within the framework of a one-electron theory. Using a pseudopotential description of the semiconductor crystals, the density of interface states is analyzed performing the matching of the wave functions at the interface. The characteristics of the different types of interface states are discussed in detail, and particular examples are given for contacts with metals of high and low electronic densities. As a byproduct, the surface states at the semiconductor vacuum interface are also calculated. Finally, the barrier potential of the junction is obtained as a function of the metal work function (for metals of high density). Although very good agreement has been found with the experimental data for the compounds of the covalent group, large discrepancies arise for those of the ionic group. Some comments on the reasons for these discrepancies are made.