GaN基HEMT器件结构设计及其性能仿真

利用Silvaco TCAD器件模拟软件研究了AlGaN/GaN高电子迁移率晶体管(HEMT)器件势垒层的厚度、沟道宽长比和掺杂浓度对器件的转移特性和跨导曲线的影响。结果表明,器件势垒层厚度的变化可以调节器件的电流开关比和开启电压,实现由耗尽型器件向增强型器件的转变;沟道宽长比的改变可以调节器件的开启电压,并且随着沟道宽长比的增加,栅极电压控制量子阱中二维电子气的能力增强;势垒层适量掺杂提高了输出电流,并且使跨导的峰值增大,但过度掺杂会造成器件不易关断情况出现。

Structure Design and Performance Simulation of GaN-based HEMTs

The effects of barrier layer thickness, gate width length ratio and doping concentration on the transfer characteristics and transconductance curve of AlGaN/GaN HEMTs devices were studied by using Silvaco TCAD device simulation software. The results show that the change of barrier layer thickness can adjust the current switching ratio and threshold voltage of the device, and realize the transformation from depletion device to enhancement device. The ability of the gate voltage to control the two-dimensional electron gas in the quantum well increases with the increase of the gate width length ratio. The doping of barrier layer increases the output current and the peak value of transconductance, but the doping of too high concentration makes it difficult to turn off the device. This is of practical guiding significance for the practical preparation of GaN based HEMTs devices.