Schottky barrier formation on InP(110) passivated with one monolayer of Sb

Abstract

To passivate InP(110) surfaces chemically and electrically, we have investigated a new method using one monolayer of Sb as an interlayer at metal-semiconductor interfaces. Prior work has established that one monolayer of Sb ideally terminates InP(110) by providing a surface which satisfies all chemical bonds and is lattice matched. The deposition of one monolayer of Sb followed by annealing near 300°C gives nearly the flat band condition for both n- and p-type InP, with a residual band bending of less than 0.2 eV. To make Schottky barriers on these surfaces, we have deposited five metals (Au, Pd, Ag, Cu, and Al). We have found that (1) Au and Ag are non-reactive and form big clusters, and (2) Pd, Cu, and Al are reactive on these surfaces. Although Schottky barrier heights on n-InP without an Sb interlayer range from 0.3 to 0.55 eV, those with an Sb interlayer range from 0.49 to 0.82 eV. By using this method, we have first succeeded in obtaining a technologically important large Schottky barrier height of about 0.82 eV at Au/n-InP(110) interfaces.