p型栅GaN基增强型高电子迁移率晶体管（p-gate GaN HEMT）是高速高效电力电子器件领域的前沿课题之一。为克服传统方案制备p型栅器件难以兼具高开态导通和栅关断特性等问题，本项目提出基于二次外延AlGaN势垒层的p-gate GaN HEMT新工艺新结构，该方案对刻蚀工艺要求降低，基于无掩膜整面二次外延，可合理设计接入区和栅区外延结构提高器件性能。本项目从外延结构设计和能带调制出发，拟重点开展以下研究：（1）以实现高导通特性为目标的接入区二次外延控制技术和物理机理研究，包括二次外延界面缺陷修复及二次外延势垒层生长行为；（2）以实现良好栅关断能力为目标的栅区多界面系统缺陷/界面态抑制及电学特性研究，包括p型层Mg杂质的高温扩散行为、栅极金半界面优化及栅极漏电行为机制。最终实现低导通电阻、高阈值电压、稳定阈值电压和动态电阻、高栅压摆幅特性的具有自主知识产权的GaN基增强型器件。

p-gate GaN-based high electron mobility transistor (p-gate GaN HEMT) is one of the forefront topics in the field of high-speed and high-efficiency power electronics. It is difficult to balance high-conduction characteristic in accessed region and good turn-off capacity in gate region for p-gate devices fabricated by traditional methods. To tackle this issue, this project proposes a scheme for a novel p-gate GaN HEMT structure based on regrown AlGaN barrier layer without the usage of mask, therefore, the requirement of etching process is reduced, and the epitaxy structure of access and gate region can be designed more reasonably to obtain high-performance device characteristics. Starting from the design of epitaxial structure and the modulation of energy band, the project intends to focus on the following researches: (1) the regrown control technology and its physical mechanism aiming at achieving high-conduction characteristics in access region, including the repair of regrown interface defects and the growth behavior of the regrown barrier layer; (2) the suppression methods of defects/interface traps in gate region with multi-interface and its influence on electrical properties aiming at achieving a better turn-off capability, including the behavior of Mg diffusion in p-type layer under high temperature, the optimization of metal-semiconductor contact interface and the mechanism of gate leakage. Ultimately, this project looks forward to realizing e-mode GaN-based power devices with independent intellectual property rights, and superior properties of low on-resistance, high threshold voltage, stable dynamic resistance and threshold voltage as well as large gate voltage swing.