中国物理B ›› 2022, Vol. 31 ›› Issue (5): 57301-057301.doi: 10.1088/1674-1056/ac48fb

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Improved device performance of recessed-gate AlGaN/GaN HEMTs by using in-situ N2O radical treatment

Xinchuang Zhang(张新创)1, Mei Wu(武玫)2, Bin Hou(侯斌)2, Xuerui Niu(牛雪锐)2, Hao Lu(芦浩)2, Fuchun Jia(贾富春)2, Meng Zhang(张濛)2, Jiale Du(杜佳乐)2, Ling Yang(杨凌)2, Xiaohua Ma(马晓华)2,†, and Yue Hao(郝跃)2   

  1. 1 School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, China;
    2 School of Microelectronics, Xidian University, Xi'an 710071, China
  • 收稿日期:2021-08-31 修回日期:2021-11-07 发布日期:2022-04-29
  • 通讯作者: Xiaohua Ma,E-mail:xhma@xidian.edu.cn E-mail:xhma@xidian.edu.cn
  • 基金资助:
    Project supported by the National Key Research and Development Program of China (Grant No.2018YFB1802100),the National Natural Science Foundation of China (Grant Nos.62104184,62090014,62104178,and 62104179),the Fundamental Research Funds for the Central Universities of China (Grant Nos.XJS201102,XJS211101,XJS211106,and ZDRC2002),and the Natural Science Foundation of Shaanxi Province,China (Grant Nos.2020JM-191 and 2018HJCG-20).

Improved device performance of recessed-gate AlGaN/GaN HEMTs by using in-situ N2O radical treatment

Xinchuang Zhang(张新创)1, Mei Wu(武玫)2, Bin Hou(侯斌)2, Xuerui Niu(牛雪锐)2, Hao Lu(芦浩)2, Fuchun Jia(贾富春)2, Meng Zhang(张濛)2, Jiale Du(杜佳乐)2, Ling Yang(杨凌)2, Xiaohua Ma(马晓华)2,†, and Yue Hao(郝跃)2   

  1. 1 School of Advanced Materials and Nanotechnology, Xidian University, Xi'an 710071, China;
    2 School of Microelectronics, Xidian University, Xi'an 710071, China
  • Received:2021-08-31 Revised:2021-11-07 Published:2022-04-29
  • Contact: Xiaohua Ma,E-mail:xhma@xidian.edu.cn E-mail:xhma@xidian.edu.cn
  • About author:2022-1-7
  • Supported by:
    Project supported by the National Key Research and Development Program of China (Grant No.2018YFB1802100),the National Natural Science Foundation of China (Grant Nos.62104184,62090014,62104178,and 62104179),the Fundamental Research Funds for the Central Universities of China (Grant Nos.XJS201102,XJS211101,XJS211106,and ZDRC2002),and the Natural Science Foundation of Shaanxi Province,China (Grant Nos.2020JM-191 and 2018HJCG-20).

摘要: The N2O radicals in-situ treatment on gate region has been employed to improve device performance of recessed-gate AlGaN/GaN high-electron-mobility transistors (HEMTs). The samples after gate recess etching were treated by N2O radicals without physical bombardment. After in-situ treatment (IST) processing, the gate leakage currents decreased by more than one order of magnitude compared to the sample without IST. The fabricated HEMTs with the IST process show a low reverse gate current of 10-9 A/mm, high on/off current ratio of 108, and high fT×Lg of 13.44 GHz· μm. A transmission electron microscope (TEM) imaging illustrates an oxide layer with a thickness of 1.8 nm exists at the AlGaN surface. X-ray photoelectron spectroscopy (XPS) measurement shows that the content of the Al-O and Ga-O bonds elevated after IST, indicating that the Al-N and Ga-N bonds on the AlGaN surface were broken and meanwhile the Al-O and Ga-O bonds formed. The oxide formed by a chemical reaction between radicals and the surface of the AlGaN barrier layer is responsible for improved device characteristics.

关键词: AlGaN/GaN, high-electron-mobility transistors, low gate leakage, radio frequency, radical treatment

Abstract: The N2O radicals in-situ treatment on gate region has been employed to improve device performance of recessed-gate AlGaN/GaN high-electron-mobility transistors (HEMTs). The samples after gate recess etching were treated by N2O radicals without physical bombardment. After in-situ treatment (IST) processing, the gate leakage currents decreased by more than one order of magnitude compared to the sample without IST. The fabricated HEMTs with the IST process show a low reverse gate current of 10-9 A/mm, high on/off current ratio of 108, and high fT×Lg of 13.44 GHz· μm. A transmission electron microscope (TEM) imaging illustrates an oxide layer with a thickness of 1.8 nm exists at the AlGaN surface. X-ray photoelectron spectroscopy (XPS) measurement shows that the content of the Al-O and Ga-O bonds elevated after IST, indicating that the Al-N and Ga-N bonds on the AlGaN surface were broken and meanwhile the Al-O and Ga-O bonds formed. The oxide formed by a chemical reaction between radicals and the surface of the AlGaN barrier layer is responsible for improved device characteristics.

Key words: AlGaN/GaN, high-electron-mobility transistors, low gate leakage, radio frequency, radical treatment

中图分类号:  (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)

  • 73.40.Kp
81.05.Ea (III-V semiconductors) 85.30.De (Semiconductor-device characterization, design, and modeling) 85.30.Tv (Field effect devices)