CAREER: Nitride FinFET on Silicon for Medium-Voltage Monolithically Integrated Power Electronics

职务名称：职业：2045001主要研究者：Yuhao Zhang机构：弗吉尼亚理工学院和州立大学非技术摘要中压（600-1700 V）功率器件是电动汽车、太阳能发电场、电网等应用中高效功率转换的关键。它们是400亿美元功率半导体市场中增长最快的行业之一。当今的中压器件主要由硅（Si）和碳化硅（SiC）制成。对于功率应用，氮化镓（GaN）具有优于Si和SiC的上级物理性质。最近，垂直GaN功率场效应晶体管（FinFET），一种利用亚微米鳍沟道的新型功率晶体管，已经展示了所有中压晶体管中最好的性能之一。然而，所有现有的垂直GaN FinFET都采用小直径和高成本的GaN衬底，这阻碍了它们的商业化。该CAREER提案旨在开发新一代低成本、大直径Si衬底上的高性能中压垂直GaN功率FinFET，并将其与低压横向GaN FinFET或三栅晶体管制造在同一晶圆上，从而首次实现驱动电路和中压功率器件的单片集成。该项目如果成功，将使中压电力电子系统的性能、频率、效率和形状因数实现前所未有的进步。该项目为学生提供了教育和推广的机会：（a）建立一个综合的本科研究计划，解决材料，器件和电力电子领域的跨学科问题;（B）指导参与学生与工业合作者，并促进学生与电力半导体行业的互动;（c）为大学预科夏令营作出贡献，并为K-12学生和教师提供微电子学的暑期研究机会。该计划将积极吸引来自代表性不足的少数群体的学生参与微电子研究和教育。技术摘要本项目的总体目标是在硅衬底上建立一个单片“全GaN FinFET”平台，该平台共享通用的处理技术和器件构建模块，其中高压垂直GaN FinFET用于功率处理，低压横向GaN FinFET/三栅极FET用于信息处理。该项目的跨学科性质在材料、器件、加工技术和功率模块方面提供了显著的智力优势：（a）将建立新的表征方法，以空间分辨率低至纳米的方式映射GaN-on-Si中的漏电流，并以时间分辨率低至纳秒的方式表征陷阱介导的击穿电压。(b)创新的功能结构将被探索以克服GaN-on-Si结构中的绝缘和高度缺陷的缓冲层，并使全垂直GaN-on-Si功率FinFET具有优异的上级电学、热学和机械性能。(c)将建立创新的外延结构和制造工艺，以实现中压垂直FinFET和横向数字FinFET/三栅FET的单片集成。(d)先进的模型和模拟将被探索，以将微观材料非理想性和电路动力学与器件设计和优化联系起来，这一直是氮化物器件和材料的长期知识差距。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Title: CAREER: Nitride FinFET on Silicon for Medium-Voltage Monolithically Integrated Power ElectronicsProposal Number: 2045001Principal Investigator: Yuhao ZhangInstitution: Virginia Polytechnic Institute and State UniversityNontechnical AbstractMedium-voltage (600-1700 V) power devices are key for efficient power conversion in electric vehicles, solar farms, power grids, among other applications. They are among the fastest-growing sectors in the $40 billion power semiconductor market. Today’s medium-voltage devices are mainly made of silicon (Si) and silicon carbide (SiC). Gallium nitride (GaN) has superior physical properties over Si and SiC for power applications. Recently, the vertical GaN power field-effect transistor (FinFET), a new power transistor utilizing sub-micron-meter fin channels, has demonstrated one of the best performances in all medium-voltage transistors. However, all existing vertical GaN FinFETs employ small-diameter and high-cost GaN substrates, which hinders their commercialization. This CAREER proposal aims at developing a new generation of medium-voltage vertical GaN power FinFETs on low-cost, large-diameter Si substrates with high performance, and fabricating them on the same wafer with the low-voltage lateral GaN FinFETs or tri-gate transistors, hence allowing monolithic integration of the driving circuitry and medium-voltage power devices for the first time. This project, if successful, will enable an unprecedented advancement in the performance, frequency, efficiency, and form factor of the medium-voltage power electronic systems. This project provides opportunities for student education and outreach: (a) establishing an integrated undergraduate research program tackling interdisciplinary problems in the fields of materials, devices, and power electronics; (b) mentoring the participating students with the industrial collaborators and promoting the student interactions with the power semiconductor industries; (c) contributing to the pre-college summer camps and providing summer research opportunities to K-12 students and teachers in microelectronics. The program will actively engage students from underrepresented minority groups in microelectronics research and education. Technical AbstractThe overarching objective of this project is to build a monolithic “full GaN FinFET” platform on Si substrates, which shares common processing technologies and device building blocks, where the high-voltage, vertical GaN FinFET is employed for power processing and the low-voltage, lateral GaN FinFETs/trigate FETs are used for information processing. The interdisciplinary nature of this project offers significant intellectual merits in materials, devices, processing technologies, and power modules: (a) New characterization methods will be established to map the leakage current in GaN-on-Si with spatial resolutions down to the nanometers and characterize the trap-mediated breakdown voltage with temporal resolutions down to the nanoseconds. (b) Innovative function structures will be explored to overcome the insulating and highly-defective buffer layers in GaN-on-Si structure and enable superior electrical, thermal, and mechanical performances in fully-vertical GaN-on-Si power FinFETs. (c) Innovative epitaxial structure and fabrication processes will be established to enable the monolithic integration of medium-voltage vertical FinFETs and lateral digital FinFETs/tri-gate-FETs. (d) Advanced models and simulations will be explored to link the microscopic material non-idealities and circuit dynamics to device designs and optimizations, which has been a long knowledge gap in nitride devices and materials.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.