Simulation Study of an Ultralow Switching Loss p-GaN Gate HEMT With Dynamic Charge Storage Mechanism
Fangzhou Wang, Wanjun Chen, Xiaorui Xu, Ruize Sun, Zeheng Wang, Yun Xia, Yajie Xin, Chao Liu, Qi Zhou, Bo Zhang
Abstract
In this article, a dynamic charge storage mechanism is proposed for designing the p-GaN gate dynamic charge storage high-electron-mobility transistor (DCS-HEMT) with ultralow switching loss. The device features a p-doped DCS layer in AlGaN buffer. When the DCS-HEMT is turning off, the net negative charges in the DCS layer significantly contribute to the depletion of 2-D-electron-gas (2DEG) channel, leading to low turn-off loss (${E} _{OFF}$ ). During turn-on process, reduction of the negative charges amount could accelerate the formation of electrons at the 2DEG channel, which results in low turn-on loss (${E} _{ON}$ ). Verified by the calibrated simulation, total switching loss (${E} _{\text {SW}} \boldsymbol = {E}_{OFF} +{E}_{ON}$ ) of the designed DCS-HEMT is 61% lower than that of the conventional p-GaN gate HEMT (C-HEMT). The improved performance makes the DCS-HEMT a competitive candidate for low switching loss power applications.