Defects and metal states: Towards a predictive model for the Schottky barrier

In the presence of metallic states, deposition-generated midgap levels at the semiconductor surface evolve into resonances that accommodate the fractional charge density that ultimately determines the Fermi level and hence the Schottky-barrier height. This concept is applied to calculate both the barrier heights of GaAs for nonalloyed metal-semiconductor interfaces, and the index-of-interface behavior for 15 tetrahedrally coordinated semiconductors.