Chinese Physics B, Volume. 29, Issue 10, (2020)
Interface and border trapping effects in normally-off Al2O3/AlGaN/GaN MOS-HEMTs with different post-etch surface treatments
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 (C–V) 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 C–V measurement. It is found that irradiation of monochromatic light results in negative shift of C–V 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.
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Si-Qi Jing, Xiao-Hua Ma, Jie-Jie Zhu, Xin-Chuang Zhang, Si-Yu Liu, Qing Zhu, Yue Hao. Interface and border trapping effects in normally-off Al2O3/AlGaN/GaN MOS-HEMTs with different post-etch surface treatments[J]. Chinese Physics B, 2020, 29(10):
Received: Apr. 24, 2020
Accepted: --
Published Online: Apr. 21, 2021
The Author Email: Zhu Jie-Jie (jjzhu@mail.xidian.edu.cn)