The effect of thermal annealing on the Ni/p-GaN interface

摘要

The interface properties of Ni/p-GaN were investigated by ultra-violet photoemission spectroscopy. It was found that residual oxide on p-GaN surface was removed by Ni deposition, and the diffusion of Au and Ni was enhanced with annealing in O{sub}2 ambient. Such annealing effects result in a direct contact of Au with atomically clean GaN in Au/Ni/p-GaN structure. From these results, cleaning effect of Ni and the enhancement of Ni migration may play an important role in making ohmic contact to p-GaN in Au/Ni/p-GaN system.