Description
The effects of surface pretreatment, dielectric growth, and post deposition annealing on interface electronic structure and polarization charge compensation of Ga- and N-face bulk GaN were investigated. The cleaning process consisted of an ex-situ wet chemical NH[subscript 4]OH treatment and an in-situ elevated temperature NH[subscript 3] plasma process to remove carbon contamination, reduce oxygen coverage, and potentially passivate N-vacancy related defects. After the cleaning process, carbon contamination decreased below the x-ray photoemission spectroscopy detection limit, and the oxygen coverage stabilized at ∼1 monolayer on both Ga- and N-face GaN. In addition, Ga- and N-face GaN had an upward band bending of 0.8 ± 0.1 eV and 0.6 ± 0.1 eV, respectively, which suggested the net charge of the surface states and polarization bound charge was similar on Ga- and N-face GaN. Furthermore, three dielectrics (HfO[subscript 2], Al[subscript 2]O[subscript 3], and SiO[subscript 2]) were prepared by plasma-enhanced atomic layer deposition on Ga- or N-face GaN and annealed in N[subscript 2] ambient to investigate the effect of the polarization charge on the interface electronic structure and band offsets. The respective valence band offsets of HfO[subscript 2], Al[subscript 2]O[subscript 3], and SiO[subscript 2] with respect to Ga- and N-face GaN were 1.4 ± 0.1, 2.0 ± 0.1, and 3.2 ± 0.1 eV, regardless of dielectric thickness. The corresponding conduction band offsets were 1.0 ± 0.1, 1.3 ± 0.1, and 2.3 ± 0.1 eV, respectively. Experimental band offset results were consistent with theoretical calculations based on the charge neutrality level model. The trend of band offsets for dielectric/GaN interfaces was related to the band gap and/or the electronic part of the dielectric constant. The effect of polarization charge on band offset was apparently screened by the dielectric-GaN interface states.
Details
Title
- Surface band bending and band alignment of plasma enhanced atomic layer deposited dielectrics on Ga- and N-face gallium nitride
Contributors
- Yang, Jialing (Author)
- Eller, Brianna S. (Author)
- Nemanich, Robert (Author)
- College of Liberal Arts and Sciences (Contributor)
- Department of Physics (Contributor)
Date Created
The date the item was original created (prior to any relationship with the ASU Digital Repositories.)
2014-09-28
Resource Type
Collections this item is in
Identifier
-
Digital object identifier: 10.1063/1.4895985
-
Identifier TypeInternational standard serial numberIdentifier Value0272-4944
Note
-
Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. along with the following message: The following article appeared in 116, 123702 (2014) and may be found at http://dx.doi.org/10.1063/1.4895985
Citation and reuse
Cite this item
This is a suggested citation. Consult the appropriate style guide for specific citation guidelines.
Yang, Jialing, Eller, Brianna S., & Nemanich, Robert J. (2014). Surface band bending and band alignment of plasma enhanced atomic layer deposited dielectrics on Ga- and N-face gallium nitride. JOURNAL OF APPLIED PHYSICS, 116:123702. http://dx.doi.org/10.1063/1.4895985