新型InAlN/GaN异质结功率器件新结构与模型

The novel GaN-based heterostructure material and device is one of the cutting-edge research topics of GaN semiconductor technology.In this application the key issues of high voltage InAlN/GaN device which bases on the novel GaN heterostructure platform will be studied by means of theory and experiments including: 1)To propose the Composite-Modulated-Tunneling (CMT) high voltage InAlN/GaN HEMT, by using band theory of semiconductor to study the impact of device structure and applied electric-field on the energy band of the heterostructure to reveal a new operating principle of GaN device; 2)To propose a physical model for device breakdown based on the Source-Electron-Injection (SEI) in GaN heterostructure device, which provides a new theory foundation for GaN power device research. Under the guidance of the proposed SEI model to explore the physical nature responsible for the breakdown of InAlN/GaN device. The advantage of the proposed CMT InAlN/GaN HEMT can be theoretically explained by the SEI model. To obtain the novel CMT high voltage InAlN/GaN HEMT with breakdown voltage higher than 600 V and maximum drain current density larger than 300 mA/mm through device simulation and experimental validation. This application is a fundamental research including device theory and experiment, which is of great scientific and practical value for GaN device development.

新型氮化镓（GaN）异质结材料及其器件技术是GaN半导体研究领域的热点和前沿课题之一。本申请针对新型GaN异质结-InAlN/GaN高压器件技术的关键问题进行理论与实验的创新研究：1)提出一种复合调制遂穿（CMT）高压InAlN/GaN HEMT新结构，运用半导体能带理论研究器件结构、外加电场对异质结能带的影响，揭示GaN器件一种新的工作机理；2)建立GaN异质结器件基于源极电子注入(SEI)的器件击穿物理模型，为研究GaN功率器件提供新的理论基础。在SEI模型指导下探索InAlN/GaN器件耐压与击穿的物理本质，阐明新结构的优越性。通过器件仿真与实验验证获得耐压>600 V、漏极电流>300 mA/mm的新型高压InAlN/GaN HEMT器件。本申请是一项器件理论与实验相结合的应用基础研究，对GaN电子器件的发展具有重要意义。

在本项目的支持下，已申请中国发明专利2项；发表SCI期刊论文和国际会议论文15篇。其中包括 IEEE EDL/TED/TIE/APL等器件领域顶级期刊论文10篇，在功率半导体国际顶级会议ISPSD发表论文2篇，2015年在该会议作大会口头报告并成为GaN领域中国大陆在 ISPSD 迄今唯一大会口头报告。其中两项研究成果被国外知名在线科技新闻媒体《Semiconductor Today》作为GaN功率器件重要研究进展进行专题报道。.针对InAlN/GaN HFET漏电大、击穿电压低这一业界普遍面临的问题，揭示了源极电子注入诱发沟道碰撞电离物理模型，准确阐释了InAlN/GaN HFET击穿机理，提出低势垒肖特基接触技术，通过优化器件体内电场分布显著提高击穿电压。发明了肖特基源/漏和肖特基/欧姆混合源/漏两种InAlN/GaN晶体管新结构，器件耐压分别提高170 %和253 %，达InAlN/GaN HEMT国际同期最好。本项目全面完成了预期研究目标，研究成果包括：1.提出了CMT高压InAlN/GaN HEMT新结构。根据半导体能带理论，从器件物理出发揭示了GaN异质结器件利用源极肖特基接触技术来提高InAlN/GaN器件耐压的工作机理。2.建立了CMT高压InAlN/GaN HEMT器件耐压机理与SEI模型。从InAlN/GaN异质结材料上探索了器件漏电及击穿的本质关系，为高压功率器件的突破提供了理论基础与指导思想。3.研制了肖特基源极/漏极（SSD）InAlN/GaN HEMT和肖特基源（SS）InAlN/GaN HEMT等器件。获得耐压650 V、漏极电流334 mA/mm 的新型高压CMT器件。.