Heterogeneous integration of ultra-wide bandgap (UWB) diamond and beta-Ga2O3 nanomembranes towards next-generation power switching devices

宽禁带半导体具有更好的功率转换效率和更高的电流处理能力。在各种宽禁带半导体中，b-Ga2O3具有稳定的热力学性质、大的禁带和高的电子迁移率，使其成为下一代电力电子和光电子领域有吸引力的半导体候选者。尽管b-Ga2O3具有良好的材料性能，但b-Ga2O3的两个众所周知的缺陷，即导热性差和缺乏有效的p型掺杂剂，在很大程度上阻碍了b-Ga2O3在广谱功率电子器件中的应用。本课题旨在通过与p型单晶金刚石的异质集成，解决n型b-Ga2O3单极掺杂和热性能差的难题，使我们能够在不受b-Ga2O3和金刚石晶格常数限制的情况下结合两种不同的半导体。为了制造新型的n型b-Ga2O3和p型金刚石异质结，将使用超薄形式的半导体，也称为半导体纳米膜。在此基础上，本课题的具体目标是利用p型金刚石纳米膜和n型b-Ga2O3纳米膜实现基于多p-n结的新型超宽带隙高功率异质结双极晶体管。该研究的结果将导致在更高功率密度水平下运行的大功率电子设备的发展，这可能会彻底改变功率分配和调节，允许一个更通用和稳定的电力系统，提高功率转换或处理效率，面向未来的大功率电子设备。本课题旨在开发基于新型异质集成方法的新型超宽带隙高功率器件。它将提供一个全面的解决方案，以开发一种全新的高效大功率开关，这将大大提高开关性能指标，而不是今天的电力电子产品。我们期望在这个项目的成功之后，相关的商业化将经历一个重大的变化，在许多可能的方式上采用我们的新异质结技术。这项研究也将有助于培养下一代科学家/工程师，他们将在物理，材料科学和工程的界面工作。在项目期间，将在研究生、本科生、K-12和社区等不同层次开展各种教育和推广活动。该计划的愿景是为这些学生提供动手，跨学科的计算模拟和实验研究课题的经验，以应对当前的技术和社会挑战。该项目将为本科生和研究生提供良好的教育和培训机会，他们将接触到材料科学和半导体纳米科学的各个跨学科领域。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。

The wide bandgap semiconductors have the potential for having better power conversion efficiency and higher current handling capability. Among various wide bandgap semiconductors, b-Ga2O3 has a stable thermodynamic property with a large bandgap and high electron mobility which makes it an attractive semiconductor candidate for next-generation power electronics and optoelectronics. Despite promising material property of b-Ga2O3, two well-known deficiencies of b-Ga2O3, namely, the poor thermal conductivity and the lack of efficient p-type dopant largely prohibit the use of b-Ga2O3 toward wider spectrum power electronics. This proposal aims to address the unipolar doping challenge and poor thermal property of n-type b-Ga2O3 by heterogeneously integrating with p-type single crystalline diamond, which allows us to bond two dissimilar semiconductors without restricted by lattice constants of b-Ga2O3 and diamond. To create a novel n-type b-Ga2O3 and p-type diamond heterojunction, an ultra-thin form of semiconductor, also called semiconductor nanomembranes, will be used. Building upon this, the specific objective of the proposed project is to realize the new class of ultra-wide bandgap high power heterojunction bipolar transistors based on the multiple p-n junctions using p-type diamond nanomembrane and n-type b-Ga2O3 nanomembrane. The outcome of the proposed research will result in the development of high power electronic devices operating at higher power density level, which could revolutionize power distribution and conditioning, allow for a more versatile and stable power system with the improved power conversion or handling efficiencies toward future high-power electronics.The proposed research aims to develop the new class of ultra-wide bandgap high power device based on the novel heterogeneous integration method. It will provide a comprehensive solution to develop a completely new class of highly efficient high-power switches which will lead to greatly enhanced switching performance metrics over that of today's power electronics. We expect that upon the success of this project, the related commercialization will experience a significant change toward employing our new heterojunction technology in many possible ways. This research will also help train the next generation of scientists/engineers who will work at the interface of physics, materials science, and engineering. During the project period, various educational and outreach activities will be given at several different levels, including graduate, undergraduate, K-12, and community. The vision of this program is to provide these students with hands-on, interdisciplinary experiences in computational simulation and experimental research topics for tackling current technological and societal challenges. The project will provide excellent opportunities to educate and train undergraduate and graduate students, who will be exposed to various interdisciplinary fields of materials science and semiconductor nanoscience.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.