E-mode p-GaN Gate HEMT with p-FET Bridge for Higher V<sub>TH</sub> and Enhanced V<sub>TH</sub> Stability
Mengyuan Hua, Junting Chen, Chengcai Wang, Ling Liu, Lingling Li, Junlei Zhao, Zuoheng Jiang, Jin Wei, Li Zhang, Zheyang Zheng, Kevin J. Chen
Abstract
a novel p-GaN gate topology is proposed to inherently increase threshold voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> ) and enhance V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> stability. The gate consists of a conventional Schottky-type p-GaN gate and a normally-on p-channel FET bridge connecting source and gate. By modulating the V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> of the p-channel FET, a wide-range positive V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> from 3.6 V to 8.2 V can be achieved without subthreshold voltage degradation. Owing to the well-grounded p-GaN through the normally-on p-FET channel, a stable V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> is also achieved without sacrificing the low gate leakage and large gate swing enabled by the Schottky gate metal/p-GaN contact.