中国物理B ›› 2012, Vol. 21 ›› Issue (8): 86105-086105.doi: 10.1088/1674-1056/21/8/086105

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

An AlGaN/GaN HEMT with reduced surface electric field and an improved breakdown voltage

谢刚a b, Edward Xua, Niloufar Hashemia, 张波b, Fred Y. Fuc, Wai Tung Nga   

  1. a The Edward S. Rogers Sr. Electrical and Computer Engineering Department, University of Toronto, Toronto, Ontario M5S 1A1, Canada;
    b State key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China;
    c Crosslight Software Inc. Burnaby, BC, Canada
  • 收稿日期:2011-12-15 修回日期:2012-02-14 出版日期:2012-07-01 发布日期:2012-07-01

An AlGaN/GaN HEMT with reduced surface electric field and an improved breakdown voltage

Xie Gang (谢刚)a b, Edward Xua, Niloufar Hashemia, Zhang Bo (张波)b, Fred Y. Fuc, Wai Tung Nga   

  1. a The Edward S. Rogers Sr. Electrical and Computer Engineering Department, University of Toronto, Toronto, Ontario M5S 1A1, Canada;
    b State key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China;
    c Crosslight Software Inc. Burnaby, BC, Canada
  • Received:2011-12-15 Revised:2012-02-14 Online:2012-07-01 Published:2012-07-01
  • Contact: Xie Gang E-mail:ngwt@vrg.utoronto.ca; xielyz@vrg.utoronto.ca

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摘要： A reduced surface electric field in AlGaN/GaN high electron mobility transistor (HEMT) is investigated by employing a localized Mg-doped layer under the two-dimensional electron gas (2-DEG) channel as an electric field shaping layer. The electric field strength around the gate edge is effectively relieved and the surface electric field is distributed evenly as compared with those of HEMTs with conventional source-connected field plate and double field plate structures with the same device physical dimensions. Compared with the HEMTs with conventional source-connected field plate and double field plate, the HEMT with Mg-doped layer also shows that the breakdown location shifts from the surface of the gate edge to the bulk Mg-doped layer edge. By optimizing both the length of Mg-doped layer, Lm, and the doping concentration, a 5.5 times and 3 times the reduction in the peak electric field near the drain side gate edge is observed as compared with those of the HEMTs with source-connected field plate structure and double field plate structure, respectively. In a device with VGS=-5 V, Lm=1.5 μm, a peak Mg doping concentration of 8× 1017 cm-3 and a drift region length of 10 μm, the breakdown voltage is observed to increase from 560 V in a conventional device without field plate structure to over 900 V without any area overhead penalty.

关键词: AlGaN/GaN HEMT, reduced surface electric field, Mg-doped layer, breakdown voltage

Abstract: A reduced surface electric field in AlGaN/GaN high electron mobility transistor (HEMT) is investigated by employing a localized Mg-doped layer under the two-dimensional electron gas (2-DEG) channel as an electric field shaping layer. The electric field strength around the gate edge is effectively relieved and the surface electric field is distributed evenly as compared with those of HEMTs with conventional source-connected field plate and double field plate structures with the same device physical dimensions. Compared with the HEMTs with conventional source-connected field plate and double field plate, the HEMT with Mg-doped layer also shows that the breakdown location shifts from the surface of the gate edge to the bulk Mg-doped layer edge. By optimizing both the length of Mg-doped layer, Lm, and the doping concentration, a 5.5 times and 3 times the reduction in the peak electric field near the drain side gate edge is observed as compared with those of the HEMTs with source-connected field plate structure and double field plate structure, respectively. In a device with VGS=-5 V, Lm=1.5 μm, a peak Mg doping concentration of 8× 1017 cm-3 and a drift region length of 10 μm, the breakdown voltage is observed to increase from 560 V in a conventional device without field plate structure to over 900 V without any area overhead penalty.

Key words: AlGaN/GaN HEMT, reduced surface electric field, Mg-doped layer, breakdown voltage

中图分类号:  (III-V and II-VI semiconductors)

  • 61.72.uj
51.50.+v (Electrical properties)