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

项目编号：2036740和2036915项目负责人：张宇豪、王涵（联合主持）项目名称：ECCS-EPSRC：用于稳健、高效、快速电源开关的氮化超结hemt摘要：功率半导体器件在电力电子系统中经常被用作固态开关，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中。2019年，全球功率器件市场超过150亿美元，并且正在快速增长。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，但它们在工业应用中的广泛采用受到可靠性和鲁棒性限制的阻碍，导致相当大的过度设计，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，开发新一代坚固、电荷平衡的GaN hemt。在“美国国家科学基金会工程-英国科学院工程与物理科学研究委员会领导机构机会（ENG-EPSRC）”下，将通过弗吉尼亚理工大学和美国南加州大学以及英国剑桥大学之间的合作，在材料、设备、制造工艺和电路级测试方面开展跨学科研究。这个美英合作项目为学生教育和国际交流、跨大学教学模块的开发以及潜在技术转移的产业合作提供了机会。这个跨学科、跨大陆的项目还包括为K-12学生和教师提供外展活动，并促进与微电子和电力电子技术有关的教育活动。技术摘要：这个总体假设是，通过在二维电子气（2DEG）通道中嵌入p型区域，形成一种新的电荷平衡超结结构，可以实现鲁棒的氮化镓（GaN）高电子迁移率晶体管（hemt）。这种新颖的2D-3D超级结结构不仅可以通过管理电场和雪崩能力来增强器件的鲁棒性，而且可以在保持正常关断工作的同时显著提高2DEG密度，从而降低器件的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、界面材料特性和超结hemt在电力电子电路中的动态性能方面存在主要差距。该项目由“NSF工程- UKRI工程与物理科学研究委员会领导机构机会（engepsrc）”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差距：(a)探索新型超结HEMT器件的设计空间和性能限制；(b)探索在2DEG通道中选择性引入p型掺杂剂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物分布、载流子输运和陷阱动力学；(d)将纳米/中尺度材料和界面特性与GaN hemt的动态特性和鲁棒性联系起来。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.