Formation of the Schottky barrier at the Pd/Si interface

Abstract

The formation of the Schottky barrier (SB) at the PdSi interface and its correlation to electronic and structural properties has been investigated. Experiments have been carried out using interfaces with thick and thin metal coverages. The thick contact experiment shows that the SBH Φb is independent of the bulk silicide structure and that it can be established upon Pd deposition at room temperature. In the thin contact experiment, the use of a synchrotron radiation source and high-resolution photoemission spectroscopy makes possible simultaneous observations of variations in SBH and valence band spectra from a clean Si surface up to several monolayers of metal coverage. The SBH values from thin and thick-contacts establish the true interface character of Φb. Valence spectra show that SBH can be established without a full development of the metallic character of the reacted overlayer. Combining these results, we conclude that the SBH for the PdSi interface is determined by the basic interaction between Pd and Si atoms at the interface prior to the development of a metallic band structure and a well-defined silicide phase in the overlayer. © 1983.