Nitride surface chemistry influence on band offsets at epitaxial oxide/GaN interfaces

Elizabeth A. Paisley, Michael T. Brumbach, Christopher T. Shelton, Andrew A. Allerman, Stanley Atcitty, Christina M. Rost, James A. Ohlhausen, Barney L. Doyle, Zlatko Sitar, Jon Paul Maria, Jon F. Ihlefeld

Research output: Contribution to journalArticlepeer-review

Abstract

GaN surface and near-surface chemistry influence on band offsets of oxide overlayers is demonstrated through X-ray photoelectron spectroscopy measurements using epitaxial (111)-oriented MgO films on (0001)-oriented Ga-polar GaN as a case study. For identical cleaning and MgO growth conditions, GaN subsurface oxygen impurities influence the GaN bare surface band bending and the ultimate band offset to MgO heterolayers. As the GaN surface oxygen concentration increases from an atomic concentration of 0.9% to 3.4%, the valence band offset to MgO decreases from 1.68 eV to 1.29 eV, respectively. This study highlights the sensitivity of the oxide/nitride interface electronic structure to GaN epilayer preparation and growth conditions.

Original languageEnglish (US)
Article number092903
JournalApplied Physics Letters
Volume112
Issue number9
DOIs
StatePublished - Feb 26 2018

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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