Schottky barrier characteristics and carrier transport mechanism for ohmic contacts to strained p-Type InGaN/GaN superlattice

Abstract

We report on the metal work function dependence on Schottky barrier characteristics and the carrier transport mechanism for ohmic contacts to strained p-InGaN/GaN superlattices. Measurements showed that specific contact resistances are dependent on metal work functions, whereas Schottky barrier heights exhibit relatively little dependency on metal work functions. These indicate that the overall contact properties are directly affected by polarization-induced carriers near the surface of the strained InGaN. The carrier conduction mechanism for the contacts to the InGaN/GaN is described in terms of tunneling or compensation effect, depending on temperatures. © 2010 The Electrochemical Society.