基于极化电荷补偿界面态钝化理论的GaN基功率开关可靠性及增强技术研究

项目名称： 基于极化电荷补偿界面态钝化理论的GaN基功率开关可靠性及增强技术研究

项目编号： No.61474138

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 黄森

作者单位： 中国科学院微电子研究所

项目金额： 75万元

中文摘要： 凭借优良的抗击穿和二维电子气（2DEG）电学特性，AlGaN/GaN高电子迁移率晶体管（HEMT）已经成为构建下一代高效率高压开关器件的热门候选者之一。尽管传统SiNx钝化能够有效抑制工作电压低于100V的GaN基微波功率器件的电流坍塌，然而对于100V伏以上的功率开关器件，SiNx钝化后电流坍塌依然严重。本项目申请人利用等离子增强原子层沉积（PEALD）技术制备出近似单晶的薄AlN层以钝化GaN基功率开关，在无场板辅助200V电压下成功抑制了SiNx钝化所存在的电流坍塌问题，获得了较低的动态电阻，并在此基础上提出了极化电荷补偿界面态的新型钝化概念。本申请项目基于极化电荷补偿界面态新型钝化理论，以GaN基功率开关器件的应用要求为契机，开展PEALD-AlN钝化GaN基HEMT的漏电和击穿机理，高压大电流，高频及高温可靠性等关键问题研究，探索基于AlN钝化的可靠性加固技术。

中文关键词： 氮化镓；高压；功率开关；氮化铝；钝化

英文摘要： Owing to the high breakdown voltage of GaN material and the superior 2-D electron gas (2DEG) electrical performance, AlGaN/GaN high electron mobility transistors (HEMTs) have emerged as one of the most promising candidate for next generation of high-efficient power-switching devices. Plasma-enhanced chemical vapor deposition (PECVD)-grown SiNx has been widely adopted as an effective passivation material to suppress the current collapse in RF/microwave power amplifiers that typically feature moderate drain bias voltage (<100V). However for power switching devices that work at high drain bias larger than 100V, SiNx passivation alone is not adequate, and sophisticated multiple field plates are required to help realize low dynamic ON-resistance.The applicant of this project has developed a novel passivation theory of compensation of interface states by polarization charges, which was implemented by suppression of current collapse in GaN-based power switching devices with high-breakdown-voltage,high-crystal-quality thin AlN film grown by plasma-enhanced atomic layer deposition (PEALD). Compared to the traditional SiNx passivation, PEALD-AlN passivation is capable of realized much better current collapse suppression and lower dynamic ON-resistance, especially under high-drain-bias switching conditions (～200 V). Based on the innovation of the PEALD-AlN passivation, this project will carry out a systematic investigation on the leakage/breakdown mechanism, the reliability of PEALD-AlN-passivated GaN-based power HEMTs under high voltage, high current, high switching frequency, and high temperature conditions. Moreover, techniques based on AlN passivation to enhance the reliability will also be investigated. The project is intended to accelerate the application of GaN-based power switching devices based on the PEALD-AlN passivation technique. The applicant of this project has been engaged in the research of GaN-based materials and devices. With a solid background on surface and interface physics of semiconductor devices and good experiences in GaN-based HEMT fabrication and passivation technology, he has make several progress in the R&D of GaN-based power switching devices. The application is an extension of his previous work, which focus on searval key issues in PEALD-AlN-passivated AlGaN/GaN HEMTs. The target and content of the application are the hot area in research on GaN-based HEMT and power switching devices.

英文关键词： GaN;high voltage;power switch;AlN;passivation