中国物理B ›› 2016, Vol. 25 ›› Issue (10): 108504-108504.doi: 10.1088/1674-1056/25/10/108504

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

Photoresponse and trap characteristics of transparent AZO-gated AlGaN/GaN HEMT

Chong Wang(王冲), Meng-Di Zhao(赵梦荻), Yun-Long He(何云龙), Xue-Feng Zheng(郑雪峰), Kun Zhang(张坤), Xiao-Xiao Wei(魏晓晓), Wei Mao(毛维), Xiao-Hua Ma(马晓华), Jin-Cheng Zhang(张进成), Yue Hao(郝跃)   

  1. 1 Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, Xi'an 710071, China;
    2 The School of Microelectronics, Xidian University, Xi'an 710071, China
  • 收稿日期:2016-03-25 修回日期:2016-05-24 出版日期:2016-10-05 发布日期:2016-10-05
  • 通讯作者: Chong Wang E-mail:wangchong@hotmail.com
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61574110, 61574112, and 61106106).

Photoresponse and trap characteristics of transparent AZO-gated AlGaN/GaN HEMT

Chong Wang(王冲)1,2, Meng-Di Zhao(赵梦荻)1,2, Yun-Long He(何云龙)1,2, Xue-Feng Zheng(郑雪峰)1,2, Kun Zhang(张坤)1,2, Xiao-Xiao Wei(魏晓晓)1,2, Wei Mao(毛维)1,2, Xiao-Hua Ma(马晓华)1,2, Jin-Cheng Zhang(张进成)1,2, Yue Hao(郝跃)1,2   

  1. 1 Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, Xi'an 710071, China;
    2 The School of Microelectronics, Xidian University, Xi'an 710071, China
  • Received:2016-03-25 Revised:2016-05-24 Online:2016-10-05 Published:2016-10-05
  • Contact: Chong Wang E-mail:wangchong@hotmail.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61574110, 61574112, and 61106106).

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摘要： AZO-gated and Ni/Au-gated AlGaN/GaN HEMTs are fabricated successfully, and an excellent transparency of AZO-gated electrode is achieved. After a negative gate bias stress acts on two kinds of the devices, their photoresponse characteristics are investigated by using laser sources with different wavelengths. The effect of photoresponse on AZO-gated electrode device is more obvious than on Ni/Au-gated electrodes device. The electrons are trapped in the AlGaN barrier of AZO-gated HEMT after it has experienced negative gate bias stress, and then the electrons can be excited effectively after it has been illuminated by the light with certain wavelengths. Furthermore, the trap state density DT and the time constant τT of the AZO-gated Schottky contact are extracted by fitting the measured parallel conductance in a frequency range from 10 kHz to 10 MHz. The constants of the trap range from about 0.35 μs to 20.35 μs, and the trap state density increased from 1.93×1013 eV-1·cm-2 at an energy of 0.33 eV to 3.07×1011 eV-1·cm-2 at an energy of 0.40 eV. Moreover, the capacitance and conductance measurements are used to characterize the trapping effects under different illumination conditions in AZO-gated HEMTs. Reduced deep trap states' density is confirmed under the illumination of short wavelength light.

关键词: AlGaN/GaN, HEMT, AZO, trap

Abstract: AZO-gated and Ni/Au-gated AlGaN/GaN HEMTs are fabricated successfully, and an excellent transparency of AZO-gated electrode is achieved. After a negative gate bias stress acts on two kinds of the devices, their photoresponse characteristics are investigated by using laser sources with different wavelengths. The effect of photoresponse on AZO-gated electrode device is more obvious than on Ni/Au-gated electrodes device. The electrons are trapped in the AlGaN barrier of AZO-gated HEMT after it has experienced negative gate bias stress, and then the electrons can be excited effectively after it has been illuminated by the light with certain wavelengths. Furthermore, the trap state density DT and the time constant τT of the AZO-gated Schottky contact are extracted by fitting the measured parallel conductance in a frequency range from 10 kHz to 10 MHz. The constants of the trap range from about 0.35 μs to 20.35 μs, and the trap state density increased from 1.93×1013 eV-1·cm-2 at an energy of 0.33 eV to 3.07×1011 eV-1·cm-2 at an energy of 0.40 eV. Moreover, the capacitance and conductance measurements are used to characterize the trapping effects under different illumination conditions in AZO-gated HEMTs. Reduced deep trap states' density is confirmed under the illumination of short wavelength light.

Key words: AlGaN/GaN, HEMT, AZO, trap

中图分类号:  (Field effect devices)

  • 85.30.Tv
85.30.De (Semiconductor-device characterization, design, and modeling) 85.35.Be (Quantum well devices (quantum dots, quantum wires, etc.))