AlGaN/GaN高电子迁移率晶体管解析模型

Analytical Model for AlGaN/GaN High Electron Mobility Transistor

基于电荷控制理论 ,考虑到极化效应和寄生漏源电阻的影响 ,建立了能精确模拟AlGaN/GaN高电子迁移率晶体管直流I V特性和小信号参数的解析模型 .计算表明 ,自发极化和压电极化的综合作用对器件特性影响尤为显著 ,2V栅压下 ,栅长为 1μm的Al0 .2 Ga0 .8N/GaNHEMT获得的最大漏电流为 1370mA/mm ;降低寄生源漏电阻可以获得更高的饱和电流、跨导和截至频率 .模拟结果同已有的测试结果较为吻合 ,该模型具有物理概念明确且算法简单的优点 ,适于微波器件结构和电路设计 .

Based on the charge control theory, an accurate analytical model for the DC I-V characteristics and small signal parameters of an AlGaN/GaN high electron mobility transistor (HEMT) is developed considering the effects of polarization and parasitic source-drain resistances. Results show that the joint effects of spontaneous and piezoelectric polarization on the performance of the device are highly dominant. The proposed model predicts a maximum saturation current of 1370 mA/mm at a gate bias of 2 V for a 1.0 μm Al0.2Ga0.8N/GaN HEMT. The calculated results also indicate that higher saturation current, transconductance, and cutoff frequency can be achieved by lowering the parasitic resistances. The comparison between simulations and physical measurements shows a good agreement. The model is simple in calculations and distinct in physical mechanism, therefore suitable for design and research of microwave device and circuit.