Description
GaN-based devices are currently limited by reliability issues such as gate leakage and current collapse, where the mechanisms responsible for degradation are closely related to the electronic surface state configuration. Therefore, understanding the electronic surface state configuration of GaN-based materials

GaN-based devices are currently limited by reliability issues such as gate leakage and current collapse, where the mechanisms responsible for degradation are closely related to the electronic surface state configuration. Therefore, understanding the electronic surface state configuration of GaN-based materials will help improve device performance. Since GaN has an inherent polarization, these materials are also subject to a bound polarization charge, which influences the electronic state configuration. In this study, the surface band bending of N-face GaN, Ga-face GaN, and Ga-face AlGaN was measured with x-ray photoemission spectroscopy after various cleaning steps to investigate the effects of the polarization. Despite the different surface bound charge on these materials, similar band bending was observed regardless of the magnitude or direction of the charge. Specifically, the band bending varied from −0.1 eV to 0.9 eV on these samples, which supported the models of a Fermi level pinning state at ∼0.4 eV to 0.8 eV below the conduction band. Based on available literature, we suggest this pinning state is indirectly evident of a nitrogen vacancy or gallium-dangling bond.
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Details

Title
  • Polarization Effects of GaN and AlGaN: Polarization Bound Charge, Band Bending, and Electronic Surface States
Contributors
Date Created
2014-12-01
Resource Type
  • Text
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    Identifier
    • Digital object identifier: 10.1007/s11664-014-3383-z
    • Identifier Type
      International standard serial number
      Identifier Value
      0361-5235
    • Identifier Type
      International standard serial number
      Identifier Value
      1543-186X
    Note
    • This is the authors' final accepted manuscript. The final publication is available at http://link.springer.com.ezproxy1.lib.asu.edu/article/10.1007/s11664-014-3383-z

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    Eller, Brianna S., Yang, Jialing, & Nemanich, Robert J. (2014). Polarization Effects of GaN and AlGaN: Polarization Bound Charge, Band Bending, and Electronic Surface States. JOURNAL OF ELECTRONIC MATERIALS, 43(12), 4560-4568. http://link.springer.com.ezproxy1.lib.asu.edu/article/10.1007/s11664-01…

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