高功率GaN HEMT器件建模研究

发布时间：2018-05-14 03:02

本文选题：GaN + HEMT　；参考：《中国科学技术大学》2015年硕士论文

【摘要】：随着CMOS工艺进入10nm制程,摩尔定律能否维持下去一直备受争议。人们一直在探索新的材料,GaN作为第三代半导体材料,其宽禁带、高击穿电压、高电子迁移率的特性,一直备受青睐,可以应用在各个领域,如雷达、卫星和基站等。GaN器件虽然性能优越,但是其电气特性复杂,会降低电路的设计效率,无法充分发挥器件的性能。所以一个可以准确预测其输出电特性的大信号模型,对提高GaN器件设计效率至关重要。本文将对GaN器件建模中的I-V关系和陷阱效应等关键问题进行研究,通过理论分析并给出相应的测试验证结果。输出漏电流随栅电压、漏电压的变化(I-V)关系是器件建模中的关键问题。本文分析了I-V模型选择和建立的过程,同时通过分析各模型参数随外部偏置电压的变化关系,发现原有的Angelov模型不能很好的拟合测试数据。本文在原有的Angelov模型的基础上,修改其中φ、α、Vpkm等参数,提出了新的I-V函数关系,并通过测试结果验证其准确性。为了正确描述GaN器件的输出电流,对陷阱效应进行建模至关重要。现有的陷阱效应模型,常描述陷阱效应导致的部分电特性,对工作在RF信号下的器件,不能很好的拟合。本文详细的分析了陷阱效应的物理机制,其俘获、发射过程和外部偏置电压的关系,以及有陷阱效应导致的各种电特性。本文将陷阱效应分为栅延时和漏延时来处理。提出了用静态偏置依赖的方法来处理栅端延时,用漏延时子电路的方法处理漏端延时。其中,漏延时子电路可以完整的描述陷阱的俘获发射效应,更加接近器件的真实工作状态。测试和仿真结果验证了所提陷阱效应模型。
[Abstract]:As the CMOS process enters the 10nm process, whether Moore's law can be maintained has been controversial. As the third generation semiconductor material, the characteristics of wide band gap, high breakdown voltage and high electron mobility have been widely used in many fields, such as radar, etc. Although the performance of gan devices such as satellite and base station is superior, its electrical characteristics are complex, which will reduce the design efficiency of the circuit and can not give full play to the performance of the devices. Therefore, a large signal model which can accurately predict the output electrical characteristics is very important to improve the design efficiency of GaN devices. In this paper, the key problems of I-V relation and trap effect in GaN device modeling are studied, and the corresponding test results are given through theoretical analysis. The relation of output leakage current with gate voltage and leakage voltage is a key problem in device modeling. In this paper, the selection and establishment of I-V model are analyzed. By analyzing the relationship between the parameters of each model and the external bias voltage, it is found that the original Angelov model can not fit the test data well. Based on the original Angelov model, the parameters 蠁, 伪 -Vpkm are modified, and a new I-V function relation is proposed, and the accuracy is verified by the test results. In order to correctly describe the output current of GaN devices, it is very important to model the trap effect. The existing trap effect models often describe some of the electrical characteristics caused by the trap effect and can not be fitted well for devices working in RF signals. In this paper, the physical mechanism of trap effect, its trapping, the relationship between emission process and external bias voltage, and various electrical characteristics due to trap effect are analyzed in detail. In this paper, the trap effect is divided into gate delay and leakage delay. A static bias dependent method is proposed to deal with the gate delay and a drain delay subcircuit is used to deal with the leakage delay. Among them, the leakage delay subcircuit can describe the trap capture and emission effect completely, which is closer to the real working state of the device. The test and simulation results verify the proposed trap effect model.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN386

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