Enhancement-Mode AlGaN/GaN Nanowire Channel High Electron Mobility Transistor With Fluorine Plasma Treatment by ICP

• Published in: IEEE electron device letters Vol. 38; no. 10; pp. 1421 - 1424
• Main Authors: He, Yunlong, Mi, Minhan, Wang, Chong, Zheng, Xuefeng, Zhang, Meng, Zhang, Hengshuang, Wu, Ji, Yang, Ling, Zhang, Peng, Ma, Xiaohua, Hao, Yue
• Format: Journal Article
• Language: English
• Published: IEEE 01.10.2017
• Subjects: AlGaN/GaN; Aluminum gallium nitride; Enhancement-mode; Fluorine; fluorine plasma; HEMTs; ICP; Iterative closest point algorithm; Logic gates; MODFETs; nano-wire channel; Plasmas
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2017.2736780

This letter reports on a novel enhancement-mode (E-mode) AlGaN/GaN high electron mobility transistor (HEMT) that combines nanowire channel and fluorine plasma treatment using inductively coupled plasma (ICP). Compared with the conventional HEMTs, the threshold voltage of E-mode HEMT shifts from -2.8 to +0.7 V, and the Schottky reverse leakage current is reduced by one order of magnitude. The device exhibits a superior performance with a drain current of 460 mA/mm at V GS -V TH = 2 V. High I ON /I OFF ratio of approximately 10 9 and high breakdown voltage of 138 V with L DS = 4 μm are obtained, i.e., the breakdown voltage of E-mode HEMT is improved by 25% than that in conventional HEMTs. The drain induced barrier lowering (DIBL) is as low as 4 mV/V, and the subthreshold swing (SS) of 70 mV/decade is achieved. The device exhibits an intrinsic current gain cutoff frequency f T of 22 GHz and a maximum oscillation frequency f max of 60 GHz.