Delocalization of defects: A new model for the Schottky barrier

A Schottky barrier model is developed based on the existence of a large density of midgap impurity/defect levels at the interface, which evolve into resonance as the result of their interaction with the metallic states. The degree of charging of the resonances determines the position of the Fermi level, and consequently the Schottky barrier heights. Model predictions compare favorably with experimental results for metals on GaAs. The consequences of inhomogeneously broadened impurity levels on model predictions are briefly considered as well. © 1989.