中国物理B ›› 2020, Vol. 29 ›› Issue (10): 107302-.doi: 10.1088/1674-1056/ab99bb

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Si-Qi Jing(荆思淇)1,2, Xiao-Hua Ma(马晓华)2, Jie-Jie Zhu(祝杰杰)1,2,†(), Xin-Chuang Zhang(张新创)1,2, Si-Yu Liu(刘思雨)1,2, Qing Zhu(朱青)1,2, Yue Hao(郝跃)2   

  • 收稿日期:2020-04-24 修回日期:2020-06-01 接受日期:2020-06-05 出版日期:2020-10-05 发布日期:2020-10-05
  • 通讯作者: Jie-Jie Zhu(祝杰杰)

Interface and border trapping effects in normally-off Al2O3/AlGaN/GaN MOS-HEMTs with different post-etch surface treatments

Si-Qi Jing(荆思淇)1,2, Xiao-Hua Ma(马晓华)2, Jie-Jie Zhu(祝杰杰)1,2,†, Xin-Chuang Zhang(张新创)1,2, Si-Yu Liu(刘思雨)1,2, Qing Zhu(朱青)1,2, and Yue Hao(郝跃)2   

  1. 1 School of Advanced Materials and Nanotechnology, Xidian University, Xi’an 710071, China
    2 Key Laboratory of Wide Bandgap Semiconductor Technology, Xidian University, Xi’an 710071, China
  • Received:2020-04-24 Revised:2020-06-01 Accepted:2020-06-05 Online:2020-10-05 Published:2020-10-05
  • Contact: Corresponding author. E-mail: jjzhu@mail.xidian.edu.cn
  • About author:
    †Corresponding author. E-mail: jjzhu@mail.xidian.edu.cn
    * Project supported by the National Natural Science Foundation of China (Grant Nos. 61704124, 11690042, and 61634005).

Abstract:

Trapping effect in normally-off Al2O3/AlGaN/GaN metal–oxide–semiconductor (MOS) high-electron-mobility transistors (MOS-HEMTs) with post-etch surface treatment was studied in this paper. Diffusion-controlled interface oxidation treatment and wet etch process were adopted to improve the interface quality of MOS-HEMTs. With capacitance–voltage (CV) measurement, the density of interface and border traps were calculated to be 1.13 × 1012 cm−2 and 6.35 × 1012 cm−2, effectively reduced by 27% and 14% compared to controlled devices, respectively. Furthermore, the state density distribution of border traps with large activation energy was analyzed using photo-assisted CV measurement. It is found that irradiation of monochromatic light results in negative shift of CV curves, which indicates the electron emission process from border traps. The experimental results reveals that the major border traps have an activation energy about 3.29 eV and the change of post-etch surface treatment process has little effect on this major activation energy.

Key words: AlGaN/GaN MOS-HEMTs, interface traps, border traps, photo-assisted C-V measurement

中图分类号:  (III-V semiconductors)

  • 73.61.Ey
73.40.Qv (Metal-insulator-semiconductor structures (including semiconductor-to-insulator)) 73.50.Gr (Charge carriers: generation, recombination, lifetime, trapping, mean free paths)