Engineering ZnO/GaN Interfaces for Tunneling Ohmic Contacts to GaN

摘要

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/p- GaN 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 behavior in terms of a tunnel n+-ZnO - p-GaN junction.