Collaborative Research: ECCS-EPSRC: Nitride Super-Junction HEMTs for Robust, Efficient, Fast Power Switching

奖项建议编号：2036740&amp；2036915主要研究员：张玉浩和王涵(共同-PI)标题：合作研究：ECCS-EPSRC：用于坚固、高效、快速电源切换的氮化物超级结型HEMT机构：弗吉尼亚理工学院、州立大学(LEAD)和南加州大学非技术摘要：电力半导体器件经常被用作电力电子系统中的固态开关，广泛应用于消费电子、数据中心、电动汽车、电网和可再生能源系统。2019年，全球电力设备市场规模超过150亿美元，而且还在快速增长。氮化镓(GaN)高电子迁移率晶体管(HEMT)通常被认为是下一代功率器件。尽管它们最近开始商业化，但由于可靠性和健壮性的限制，它们在工业应用中的广泛采用受到阻碍，导致大量过度设计，使设备性能远远低于材料限制。该项目将通过半导体材料和器件结构的创新来开发新一代坚固的、电荷平衡的GaN HEMT。通过弗吉尼亚理工学院与美国南加州大学以及英国剑桥大学的合作，将在材料、器件、制造工艺和电路水平测试方面进行跨学科研究，该研究将在“NSF工程-UKRI工程和物理科学研究理事会牵头机构机会(ENG-EPSRC)”下进行。这个美英合作项目为学生教育和国际交流提供了机会，开发了跨大学教学模块，并为潜在的技术转让提供了产业合作。这个跨学科、跨大陆的项目还包括面向K-12学生和教师的外联活动，并促进与微电子和电力电子技术相关的教育活动。技术摘要：这一总体假设是，通过在二维电子气(2DEG)沟道中选择性地、几乎无缺陷地嵌入p型区域，可以实现健壮的GaN高电子迁移率晶体管(HEMTs)，形成一种新型的电荷平衡超结结构。这种新颖的2D-3D超结结构不仅可以通过管理电场和雪崩能力来增强器件的稳健性，而且可以在保持正常关断操作的同时允许更高的2D EG密度，从而降低器件的特定导通电阻并提高其开关频率。尽管有这些前景，但在新型超结的器件物理、界面材料特性以及电力电子电路中超结HEMT的动态性能方面仍存在重大差距。该项目由NSF Engineering-UKRI工程和物理科学研究理事会牵头机构Opportunity(ENG-EPSRC)资助，旨在通过美英研究合作解决四个相关领域的科学知识空白：(A)探索新型超结HEMT器件的设计空间和性能极限；(B)探索选择性地在2DEG沟道中引入p型掺杂以实现超结功能的新方法；(C)深入了解氮化物超结结构中的掺杂分布、载流子输运和陷阱动力学；以及(D)将纳米/中尺度材料和界面属性与GaN HEMT的动态特性和坚固性相关联。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Award AbstractProposal Number: 2036740 & 2036915Principal Investigator: Yuhao Zhang and Han Wang (co-PI)Title: Collaborative Research: ECCS-EPSRC: Nitride Super-Junction HEMTs for Robust, Efficient, Fast Power SwitchingInstitution: Virginia Polytechnic Institute and State University (Lead) and University of Southern CaliforniaNon-Technical Abstract:Power semiconductor devices are regularly utilized as solid-state switches in power electronic systems that are widely used in consumer electronics, data centers, electric vehicles, electricity grid, and renewable energy systems. The global power device market exceeds $15 billion in 2019 and is fast growing. Gallium nitride (GaN) high-electron-mobility transistors (HEMTs) are commonly perceived as the next generation of power devices. Despite their initial commercialization recently, their wide adoption in industrial applications is hindered by the limitation in reliability and robustness, resulting in considerable over design, rendering device performance far below the material limit. This project will develop a new generation of robust, charge-balanced GaN HEMTs through innovation in the semiconductor materials and device structure. Interdisciplinary research will be carried out in materials, devices, fabrication processes, and circuit-level tests through collaboration between Virginia Tech and the University of Southern California in the United States, as well as University of Cambridge in United Kingdom under the “NSF Engineering - UKRI Engineering and Physical Sciences Research Council Lead Agency Opportunity (ENG-EPSRC)”. This US-UK collaborative project provides opportunities for student education and international exchange, development of cross-university teaching modules, and industrial collaboration for potential technology transfer. This interdisciplinary, cross-continent project also involves outreach activities for K-12 students and teachers, and promotes educational activities related to microelectronics and power electronics technologies.Technical Abstract:This overarching hypothesis is that robust gallium nitride (GaN) high-electron-mobility transistors (HEMTs) can be implemented by selective-area, nearly defect-free embedding of p-type regions into the two-dimensional electron gas (2DEG) channel, forming a novel charge-balanced super-junction structure. This novel 2D-3D super-junction structure can not only enhance the device robustness by managing the electric field and avalanche capability, but also allow significantly higher 2DEG density while maintaining the normally-off operation, thereby decreasing the device specific on-resistance and boosting its switching frequency. Despite these promises, major gaps exist in the device physics of the novel super-junction, interfacial material properties, and the dynamic performance of super-junction HEMTs in power electronic circuits. Funded by the “NSF Engineering - UKRI Engineering and Physical Sciences Research Council Lead Agency Opportunity (ENG-EPSRC)”, this project aims to address the scientific knowledge gaps in four relevant areas through the US-UK research collaboration: (a) to explore the design space and performance limits of the novel super-junction HEMT device; (b) to probe new methods of selectively introducing p-type dopants into the 2DEG channel to realize the super-junction functionality; (c) to develop an in-depth understanding of the dopant profiles, carrier transport, and trap dynamics in the nitride super-junction structure; and (d) to correlate the nano/mesoscale materials and interface properties with the dynamic characteristics and robustness of GaN HEMTs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.