一种新的磷化铟复合沟道高电子迁移率晶体管小信号物理模型

A new small signal physical model of InP-based composite channel high electron mobility transistor

针对磷化铟(InP)复合沟道高电子迁移率晶体管(HEMT)的特点,对常规单沟道HEMT的小信号物理模型进行了修正,提出了一种新的用于复合沟道HEMT的小信号物理模型,用商用器件模拟软件ISE(integratedsystemsengineering)对其进行了仿真验证,对比了实测和仿真的I-V特性及转移特性曲线,重点研究了在InGaAs/InP双层沟道中考虑量子效应后的电场和电流密度随着不同栅电压的变化趋势,研究结果表明,由于在沟道中存在量子效应,在栅下靠源端低电场区域,电流主要分布在InGaAs沟道,而在靠漏端高电场区域,电流主要分布在InP沟道,电流在InGaAs与InP沟道中的分配比例随着栅压的变化而变化,从而验证了新模型的正确性.

In view of the specific properties of InP-based composite channel High Electron Mobility Transistor（ HEMT）, we made a correction to the traditional single channel HEMT and promote a new small signal physical model which can be applied to composite channel HEMT. The commercial device simulation program-ISE（ Integrated Systems Engineering） has been used to simulate and verify this new model. We have compared the measured and simulated Hemt＇ s I-V and transference characteristics, The change of electric field and electric current density in InGaAs/InP composite channel when quantum effect is taken into consideration are studied, The results show that due to quantum effect in InGaAs channel, in the area under the gate and near the source where electric field is low, current flow is distributed mostly in the InGaAs channel, while in the area under the gate and near the drain where electric field is high , current flow is distributed mostly in the InP channel. Under different gate voltages , the current flow shows different proportions in both InGaAs and InP channel. The new model is proved to be valid.