Electronic structure of oxidized Ni/Au contacts on p-GaN investigated by x-ray absorption spectroscopy
Journal
Applied Physics Letters
Journal Volume
78
Journal Issue
18
Pages
2718-2720
Date Issued
2001
Author(s)
Abstract
X-ray absorption spectroscopy has been used to investigate the electronic structure of as-deposited and oxidized Ni/Au contacts on p-GaN. The Ni K-, L2,3-, and O K-edges x-ray absorption spectra clearly show the formation of NiO in the annealed contacts. Annealing in air increases Ni-site hole concentration and slightly shortens the nearest-neighbor Ni-O bond length, which enhances p-d hybridization and charge transfer from Ni to O. The observed very low specific contact resistance in the oxidized contacts is found to be due to the enhanced hole concentration at the Ni site. © 2001 American Institute of Physics.
Type
journal article