Role of amphoteric defects in the formation of metal/GaAs Schottky barriers

Abstract

The effect of near interface bulk defects on metal/GaAs Schottky barriers, calculated using a modified amphoteric native defect (MAND) model, is shown to explain the measured experimental data. The simulation results successfully predict the trend in barrier heights for interfaces which undergo thermal processing for both n- and p-type substrates. It also correctly gives the surface Fermi level positions for pulsed laser melted GaAs which contain a large quantity of As vacancies. The MAND model provides an alternative approach to the understanding of the Schottky barrier formation mechanism on GaAs.