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On the discrimination between bulk and surface traps in AlGaN/GaN HEMTs from trapping characteristics

Authors

  • Milan Ťapajna,

    1. Centre for Device Thermography and Reliability (CDTR), H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
    2. Present address: Institute of Electrical Engineering, Slovak Academy of Sciences, Dubravska cesta 9, 841 04 Bratislava, Slovakia
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  • Jose L. Jimenez,

    1. TriQuint Semiconductor, 500 West Renner Road, Richardson, TX 13440, USA
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  • Martin Kuball

    Corresponding author
    1. Centre for Device Thermography and Reliability (CDTR), H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
    • Phone: +44 117 928 8734, Fax: +44 117 925 5624, Web: http://spectra.phy.bris.ac.uk/.
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Abstract

Drain current trapping characteristics is shown to be able to distinguish between bulk and surface traps. This is illustrated on stressed and unstressed AlGaN/GaN HEMTs with different surface oxygen content. A trapping characteristic with positive amplitude is shown to be related to surface traps located in the transistor access region close to the gate edge. In contrast, current trapping characteristic with negative amplitude is related to emission from AlGaN bulk traps located underneath the gate. This method enables easy distinguishing between bulk and surface traps generated during reliability testing.

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