Theoretical analysis of proton irradiation effects on AlGaN/GaN high-electron-mobility transistors

• Published in: Journal of vacuum science and technology. B, Nanotechnology & microelectronics Nanotechnology & microelectronics, 2015-09, Vol.33 (5)
• Main Authors: Lv, Ling, Ma, Xiaohua, Xi, He, Liu, Linyue, Cao, Yanrong, Zhang, Jincheng, Shan, Hengsheng, Hao, Yue
• Format: Article
• Language: English
• ISSN: 2166-2746; 2166-2754
• DOI: 10.1116/1.4929544

To study radiation damage, the authors irradiated AlGaN/GaN high-electron-mobility transistors with 3 MeV protons at various fluences. This irradiation caused displacement damage, which decreased the saturated drain current, maximum transconductance, cutoff frequency, and maximum frequency of oscillation. The authors extracted the damage factors of the threshold voltage, two-dimensional electron gas (2DEG) surface density, and mobility, which are usually used to simulate and estimate device performance in radiation environments. Calculations based on the charge control model show that the acceptor defects induced in the GaN layer play a leading role, while defects induced in the AlGaN barrier layer rarely matter. The removal rate of carriers from the 2DEG is unrelated to the thickness of undoped AlGaN layer, the conduction band discontinuity, and the doping concentration of AlGaN barrier layer; it only depends on the concentration of acceptor defects induced.