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

作　　者：Si-Qi Jing Xiao-Hua Ma Jie-Jie Zhu Xin-Chuang Zhang Si-Yu Liu Qing Zhu Yue Hao 荆思淇;马晓华;祝杰杰;张新创;刘思雨;朱青;郝跃(School of Advanced Materials and Nanotechnology,Xidian University,Xi'an 710071,China;Key Laboratory of Wide Bandgap Semiconductor Technology,Xidian University,Xi'an 710071,China)

机构地区：[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

出　　处：《Chinese Physics B》2020年第10期459-463,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 61704124, 11690042, and 61634005).

摘　　要：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 × 10^12 cm^−2 and 6.35 × 10^12 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.

关 键 词：AlGaN/GaN MOS-HEMTs interface traps border traps photo-assisted C-V measurement 

分 类 号：TN386[电子电信—物理电子学]