Simultaneously Achieving Large Gate Swing and Enhanced Threshold Voltage Stability in Metal/Insulator/n-GaN Gate HEMT

For the development of enhancement-mode GaN power transistors, the gate swing and V
TH
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
TH
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
TH
stability.