中国物理B ›› 2021, Vol. 30 ›› Issue (9): 97302-097302.doi: 10.1088/1674-1056/abf34c

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Protection of isolated and active regions in AlGaN/GaN HEMTs using selective laser annealing

Mingchen Hou(侯明辰)1,2, Gang Xie(谢刚)1,2,†, Qing Guo(郭清)1,3, and Kuang Sheng(盛况)1,2   

  1. 1 College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
    2 Hangzhou Innovation Center, Zhejiang University, Hangzhou 310027, China;
    3 Ningbo Chipex Semiconductor Co., LTD., Ningbo 315000, China
  • 收稿日期:2021-02-08 修回日期:2021-03-12 接受日期:2021-03-30 出版日期:2021-08-19 发布日期:2021-08-30
  • 通讯作者: Gang Xie E-mail:xielyz@zju.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51577169 and 51777187), the National Key Research and Development Program of China (Grant No. 2017YFB0402804), and the “Science and Technology Innovation 2025” Major Program of Ningbo (Grant No. 2018B10098).

Protection of isolated and active regions in AlGaN/GaN HEMTs using selective laser annealing

Mingchen Hou(侯明辰)1,2, Gang Xie(谢刚)1,2,†, Qing Guo(郭清)1,3, and Kuang Sheng(盛况)1,2   

  1. 1 College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
    2 Hangzhou Innovation Center, Zhejiang University, Hangzhou 310027, China;
    3 Ningbo Chipex Semiconductor Co., LTD., Ningbo 315000, China
  • Received:2021-02-08 Revised:2021-03-12 Accepted:2021-03-30 Online:2021-08-19 Published:2021-08-30
  • Contact: Gang Xie E-mail:xielyz@zju.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 51577169 and 51777187), the National Key Research and Development Program of China (Grant No. 2017YFB0402804), and the “Science and Technology Innovation 2025” Major Program of Ningbo (Grant No. 2018B10098).

摘要: AlGaN/GaN high-electron-mobility transistors with Au-free ohmic contacts are fabricated by selective laser annealing and conventional rapid thermal annealing. The current transport mechanism of ohmic contacts is investigated. High-temperature annealing can be avoided in the isolated region and the active region by selective laser annealing. The implanted isolation leakage current is maintained 10-6 mA/mm even at 1000 V after selective laser annealing. On the contrary, high-temperature annealing will cause obvious degradation of the isolation. The morphology of AlGaN surface is measured by atomic force microscope. No noticeable change of the AlGaN surface morphology after selective laser annealing, while the root-mean-square roughness value markedly increases after rapid thermal annealing. The smaller frequency dispersion of capacitance-voltage characteristics confirms the lower density of surface states after selective laser annealing. Thus, dynamic on-resistance is effectively suppressed.

关键词: gallium nitride, ohmic contacts, laser annealing

Abstract: AlGaN/GaN high-electron-mobility transistors with Au-free ohmic contacts are fabricated by selective laser annealing and conventional rapid thermal annealing. The current transport mechanism of ohmic contacts is investigated. High-temperature annealing can be avoided in the isolated region and the active region by selective laser annealing. The implanted isolation leakage current is maintained 10-6 mA/mm even at 1000 V after selective laser annealing. On the contrary, high-temperature annealing will cause obvious degradation of the isolation. The morphology of AlGaN surface is measured by atomic force microscope. No noticeable change of the AlGaN surface morphology after selective laser annealing, while the root-mean-square roughness value markedly increases after rapid thermal annealing. The smaller frequency dispersion of capacitance-voltage characteristics confirms the lower density of surface states after selective laser annealing. Thus, dynamic on-resistance is effectively suppressed.

Key words: gallium nitride, ohmic contacts, laser annealing

中图分类号:  (III-V semiconductors)

  • 73.61.Ey
81.40.Rs (Electrical and magnetic properties related to treatment conditions) 42.55.-f (Lasers)