Author:
Hu Yansheng,Wang Yuangang,Wang Wei,Lv Yuanjie,Guo Hongyu,Zhang Zhirong,Yu Hao,Song Xubo,zhou Xingye,Han Tingting,Dun Shaobo,Liu Hongyu,Bu Aimin,Feng Zhihong
Abstract
Abstract
In this letter, high power density AlGaN/GaN high electron-mobility transistors (HEMTs) on a freestanding GaN substrate are reported. An asymmetric Γ-shaped 500-nm gate with a field plate of 650 nm is introduced to improve microwave power performance. The breakdown voltage (BV) is increased to more than 200 V for the fabricated device with gate-to-source and gate-to-drain distances of 1.08 and 2.92 μm. A record continuous-wave power density of 11.2 W/mm@10 GHz is realized with a drain bias of 70 V. The maximum oscillation frequency (f
max) and unity current gain cut-off frequency (f
t) of the AlGaN/GaN HEMTs exceed 30 and 20 GHz, respectively. The results demonstrate the potential of AlGaN/GaN HEMTs on free-standing GaN substrates for microwave power applications.
Subject
Materials Chemistry,Electrical and Electronic Engineering,Condensed Matter Physics,Electronic, Optical and Magnetic Materials