Simultaneously Achieving Large Gate Swing and Enhanced Threshold Voltage Stability in Metal/Insulator/n-GaN Gate HEMT
Junjie Yang, Jin Wei, Maojun Wang, Teng Li, Jingjing Yu, Xuelin Yang, Jinyan Wang, Yilong Hao, Bo Shen
Abstract
For the development of enhancement-mode GaN power transistors, the gate swing and V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> stability are often mutually exclusive. In this work, a metal/insulator/p-GaN gate HEMT (MIP-HEMT) with built-in p-GaN potential stabilizer (PPS) is demonstrated to simultaneously achieve a large gate swing and an enhanced V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> stability. The MIP-gate structure enlarges the gate swing to 19.5 V, and serves as an AC-coupled capacitor (which is often adopted in gate driver to accelerate the switching speed of Ohmic-type p-GaN gate HEMT). The PPS consists of two D-mode HEMTs paralleled between metal gate and p-GaN gate. One D-HEMT provides a small constant gate current to maintain the p-GaN potential in ON-state. The other D-HEMT grounds the p-GaN to source in OFF-state. Therefore, the floating p-GaN effect is eliminated, resulting in superior V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TH</inf> stability.