A ballistic electron emission microscopy (BEEM) study of the barrier height change of Au/n-GaAs Schottky barriers due to reactive ion etching

Abstract

Ballistic electron emission microscopy (BEEM) has been applied to determine the barrier height change of contacts in which the GaAs substrate was dry etched by using . The distribution of barrier heights over the contact area could be determined. It was found that dry etching introduced a second Gaussian distribution, with lower mean barrier height, next to the Gaussian distribution already found to be present in wet etched reference samples. This additional distribution occurred over the main part of the contact area. A model is proposed based on a change of the stoichiometry of the surface region produced by the reactive ion etching.