Nonalloyed ohmic contact of AlGaN/GaN HEMTs by selective area growth of single-crystal n+-GaN using plasma assisted molecular beam epitaxy

Authors

  • Zhi Zheng,

    1. Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL 61801, USA
    2. On leave from University of Electronic Science and Technology of China, Sichuan 610054, P. R. China
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  • Huichan Seo,

    1. Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL 61801, USA
    2. Intel Corporation, Hillsboro, OR 97006, USA
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  • Liang Pang,

    1. Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL 61801, USA
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  • Kyekyoon (Kevin) Kim

    Corresponding author
    1. Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, IL 61801, USA
    • Phone: (217) 333-7162, Fax: (217) 244-2240
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Abstract

Selective area growth (SAG) based on plasma assisted molecular beam epitaxy (PAMBE) was demonstrated to be effective to achieve low contact resistance for nonalloyed ohmic metals. An AlGaN/GaN high-electron mobility transistor (HEMT) using SAG by PAMBE with nonalloyed ohmic metals and recessed drain/source structure exhibited a low specific contact resistance of 3.7 × 10−5 Ω cm2, high-peak drain current of 604 mA/mm, and small gate leakage current of 3.4 µA. These results demonstrate that SAG by PAMBE produces nonalloyed HEMT with comparable or more favorable electric performance versus conventional alloyed counterpart while avoiding problems of the latter resulting from high-temperature annealing.

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