algangan hemt耐压结构设计与特性仿真研究word格式论文.docxVIP

摘 要以GaN为代表的第三代宽禁带半导体材料，近年来因其优良的特性（临界 击穿电场高、 电子饱和速率高、 耐高温、 抗辐照）成为研究热点，在大功率、 高频等领域得到快速发展。 III-V 族氮化合物AlGaN/GaN高迁移率晶体管（High Mobility Electron Transistors, AlGaN/GaN HEMTs）异质结构（Heterojunction）因 极化效应在不掺杂的情况下产生高浓度的高迁移率二维电子气（2-DEG），形成导 电沟道。 尽管AlGaN/GaN HEMT 器件发展迅速，但到目前为止，其击穿电压仍然 远低于其理论值。 针对这一问题，本文利用 Sentaurus TCAD仿真软件建立相应模 型，通过数值计算仿真，优化器件电场分布，降低栅极边缘的峰值电场，提高器 件击穿电压。 本论文对以下两个方面进行了研究：（1）单层栅金属场板（Gate connected Field Plate）。 器件采用栅场板结构后 可以改变沟道中的电场分布情况，降低第一峰值电压，产生第二电场峰值，使栅 漏之间的电场分布更加均匀，提高器件的击穿电压，从105 V增大到了300 V。（2）阶梯AlGaN势垒层。 根据沟道2DEG浓度随AlGaN势垒层厚度的变化规 律，设计一种带有阶梯AlGaN势垒层的新型 AlGaN/GaN HEMTs 器件结构，研究 阶梯长度和高度对器件性能影响，取最优值时，击穿电压为127.5 V，对器件击 穿电压提升有一定的帮助。 最后加入栅场板，得到的新结构，其导通电阻为2.28 m?.??2 ，击穿电压为379 V，结果比较理想。关键词：AlGaN/GaN HEMT，击穿电压，栅场板，阶梯势垒层ABSTRACTIn recent years,GaN as representative of the third generation of wide band gap semi- conductor material, because of its excellent properties (high critical breakdown electric field, electron saturation velocity, high temperature, anti-radiation) become a hot topic,is rapidly developed in the field of high-frequency, high-power occasions. Due to po- larization effects,III-V nitride compound AlGaN/GaN High Mobility Electron Transis- tors(AlGaN/GaN HEMTs) heterostructure without high doping can generate high mo- bility two-dimensional electron gas (2-DEG) to form a conductive channel.Although the AlGaN/GaN HEMT developed rapidly, but so far, its breakdown voltage is still far below its theoretical value.To solve this problem, this paper which is based on Sentaurus TCAD simulation software to establish an appropriate model through numerical simulation aim to optimize the distribution of the electric field components, reduce peak electric gate edge and improve the device breakdown voltage by numerical simulation.In this paper, the following aspects were studied:Single gate metal field plate.the device with the gate field plate structure can change the distribution of the electric field in the channel, lower the first peak voltage, generate a second p