A normally-off hybrid-gate p-GaN high-electron-mobility transistor (HEMT) is presented in this paper. The gate region is designed as a parallel connection between the Schottky-gate and the metal–insulator–semiconductor gate by inserting a dielectric layer under part of the gate metal. Compared to the conventional Schottky-gate p-GaN HEMT, the fabricated hybrid-gate p-GaN HEMT showed a higher threshold voltage of 3.2V (increases by 167%), and the maximum transconductance is only a slight decrease (reduces by 23%). At the same time, the forward gate leakage current of the hybrid-gate structure is smaller. Furthermore, through simulation, we revealed that the increase in the threshold voltage originated from the delayed full opening of the two-dimensional electron gas. And we also find that the parameters of the gate dielectric layer have a great influence on the performance of the device. The results show that the hybrid-gate structure is a more promising device structure.

本文介绍了一种常关型混合栅极 p-GaN 高电子迁移率晶体管 (HEMT)。通过在部分栅极金属下方插入介电层，栅极区域被设计为肖特基栅极和金属-绝缘体-半导体栅极之间的并联连接。与传统的肖特基栅 p-GaN HEMT 相比，制造的混合栅 p-GaN HEMT 显示出更高的阈值电压 3.2V（增加了 167%），最大跨导仅略有下降（减少了 23%） ）。同时，混合栅极结构的正向栅极漏电流更小。此外，通过模拟，我们发现阈值电压的增加源于二维电子气的延迟全开。并且我们还发现栅介质层的参数对器件的性能有很大的影响。结果表明，混合栅结构是一种更有前途的器件结构。