ENGINEERING ZnO/GaN INTERFACES FOR TUNNELING OHMIC CONTACTS TO GaN

Abstract

ABSTRACT We have investigated two approaches for the fabrication of thin ZnO films: sputter deposition from the ZnO target and thermal oxidation of vacuum deposited Zn. The microstructure and electronic properties after consecutive steps of the formation of n-ZnO/pGaN contacts have been studied using electron transmission microscopy and x-ray photoelectron spectrometry. We have achieved ohmic contacts by Zn oxidation and explain their ohmic behaviour in terms of a tunnel n + -ZnO -p-GaN junction