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为了简化后期栅极驱动电路设计、降低成本,工业界对增强型高电子迁移率晶体管的需求与日俱增。采用p型栅结构制备增强型器件的方法是目前极有前景的一种增强型方法。该方法致力于提高器件的正向阈值电压和输出饱和电流,通过Silvaco TCAD软件调节AlGaN势垒层厚度及其Al组分,仿真器件转移特性曲线和输出特性曲线。将AlGaN势垒层厚度优化为20 nm,Al组分优化为0.27,使器件具有更大的阈值电压和输出饱和电流。并通过仿真器件能带结构和AlGaN/GaN沟道中电子浓度,进一步分析器件结构影响其性能的物理机制。结果表明,Al GaN势垒层厚度及其Al组分增加,则器件阈值电压减小,输出饱和电流增加。器件阈值电压与关态时能带结构有关,输出饱和电流与开态时AlGaN/GaN沟道电子浓度有关。
Abstract：In order to simplify the complexity of circuit design and reduce the cost, normally-off high electron mobility transistors are more preferable in the industry. The device with p-GaN gate has drawn increasing attention in the industry. In order to improve the threshold voltage and output saturation current of the device, the transfer and output curves are provided by Silvaco TCAD with adjustable thickness of AlGaN barrier layer and Al mole fraction.The thickness of the AlGaN barrier layer is optimized as 20 nm, and the Al mole fraction is optimized as 0.27,resulting in a lager threshold voltage and output saturation current. The band structure of the device and the electron concentration in the AlGaN/GaN channel are simulated to further study the physical mechanism on the relationship between device structure and the performance of the device. The results of the simulation shows that with increase of the thickness of AlGaN barrier layer and Al mole fraction the threshold voltage of the device decreases, while the output saturation current increases. The threshold voltage of the device is related to the band structure when the device is at the off-state, and the output saturation current is related to the electron concentration in the AlGaN/GaN channel when the device is at on-state.
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基本信息:
DOI：10.12194/j.ntu.20191010001
中图分类号:TN386
引用信息:
[1]葛梅,李毅,王志亮,等.p型栅结构氮化镓基高电子迁移率晶体管结构优化[J],2021,20(02):57-61+68.DOI:10.12194/j.ntu.20191010001.
基金信息:
国家自然科学基金项目（61874168,62004109）;; 南通市科技计划项目（JC2019006）