Current-voltage characteristics and interface state density of GaAs Schottky barrier

Abstract

A density distribution of the interface states in GaAs Schottky barrier was derived for the first time from observed nonideal I-V characteristics of a GaAs Schottky barrier with an oxidized interface. With increasing forward bias voltage, the ideality factor increases and then decreases after passing a maximum. Fermi level of the interface states shifts with the applied bias in the interfacial layer model adopted for the analysis. The obtained energy level of the interface states is in agreement with a previously reported value. However, the absolute magnitude of the state density is quite small compared with that obtained from the weak dependence of the barrier height on metal work functions. Implications of this result are discussed.