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

• 作者: Jie-Jie Zhu Qing Zhu Si-Qi Jing Si-Yu Liu Xiao-Hua Ma Xin-Chuang Zhang Yue Hao
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2020,（10）
• 所属期刊栏目: CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL,MAGNETIC,AND OPTICAL PROPERTIES
• 页码范围: 559-564
• 页数: 6页
• 语种: 英文
• DOI: 10.1088/1674-1056/ab99bb

摘要

Trapping effect in normally-off Al2O3/AlGaN/GaN metal–oxide–semiconductor (MOS) high-electron-mobility tran-sistors (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 distri-bution 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.