algangan hemt器件的特性仿真研究word格式论文.docxVIP

摘要宽禁带半导体材料氮化镓（GaN）是近年来迅速发展起来的第三代新型半导体 材料。与第一、二代半导体材料相比，GaN 基器件耐高温、高压、高频、大功率 等独特特性彰显了它在电子领域所具有的应用潜力。然而，GaN 基 HEMT 器件的 击穿电压和电流崩塌仍然是影响其输出功率升高的重要因素。本文基于 Silvaco TCAD-ATLAS 平台，着重对 AlGaN/GaN HEMT 器件的基本特性进行研究。论文首先对 GaN 材料的特性和 AlGaN/GaN 异质结器件进行了分析介绍，并 对 AlGaN/GaN HEMT 器件的当前研究状况进行了概述。其次，分析了 AlGaN/GaN HEMT 器件的基本工作原理，指出极化效应是产生 2DEG 的主要动力源，并分别 从 Al 组分和势垒层厚度两方面分析了对 2DEG 浓度的影响，模拟了自热效应对器 件输出电流的影响。再次，着重从虚栅模型、背栅效应模型和应力模型分别解析 了 AlGaN/GaN HEMT 器件电流崩塌的机理，以及提出了采用表面钝化技术、引入 场板结构和改善 GaN 缓冲层等措施可以减小电流崩塌的方法。最后，设计了栅浮 空复合场板结构 AlGaN/GaN HEMT，并对其特性进行了模拟研究。通过对结果分析总结出了浮空复合场板结构的优化规律，而且在相同有效长 度的场板前提下，证明了栅浮空复合场板 HEMT 器件能够有效地提高击穿电压， 并改善器件的频率特性。关键字：AlGaN/GaN HEMTs电流崩塌Silvaco 仿真场板AbstractThe semiconductor material GaN with wide bandgap is considered the third generation semiconductor material. It has been rapid development in recent years. Compared with the most current semiconductor material, GaN has enormous potential applications in the field of electronic temperature because of the characteristics of high pressure, high-frequency and high-power. But, the current collapse and breakdown voltage of the HEMTs become the main factors that obstacles the enhancement of the output power. The characteristics of the AlGaN/GaN HEMT device have been researched on the Silvaco TCAD-ATLAS platform in this paper.Firstly, the characteristics of GaN materials and AlGaN/GaN heterostructure devices was analysed in this paper. Secondly, there analyses the working principle of AlGaN/GaN HEMTs was analysed. Sencodly, a conclusion that polarization effects are the major motive power of 2DEG was proposed. The change of the 2DEG concentration from composition of Al and thickness of AlGaN was researched, and the effect of self-heating was also simulated. Thirdly, the thesis analyses the mechanism of current collapse from the float-gate model, back gate effect models and stress models. And the physical mechanism models of reducing the current collapse was analysed, such as surface passivation techniques, field plate structure a