Integrated Selective Growth of Diamond and GaN for Maximum Heat Extraction from Electronic Devices

金刚石作为一种电子材料，具有最好的导热性能，易于通过商业设备和工艺生产。氮化镓是一种半导体材料，近年来在高效率发光二极管灯泡、无线电波通信和雷达以及功率转换开关方面取得了商业成功。然而，氮化镓的全部潜力受到材料不能有效导热的限制。因此，该项目的目标是将联合收割机金刚石和氮化镓结合在一种新的方法中，该方法将专注于（1）生产这两种材料的工艺，（2）电子和热性能的深入表征（强调热流），（3）测试结构的制造，以及（4）热传导模拟。在构成当今电子产品的单个电路中结合金刚石的热效益有着广泛的需求。众所周知，晶体管和开关（整个高科技产业的支柱）会产生大量的热量，随着设备变得越来越小，电路板上电子元件的密度越来越大，这个问题也越来越严重。(In个人电子产品，考虑智能手机和笔记本电脑在常规使用期间会变得多么热。将从研究中受益的具体应用包括电动汽车，将可再生能源灵活集成到国家电网的功率转换，雷达系统和用于第一响应者，国防和民用的通信系统。该研究将导致有关金刚石-氮化镓界面的基础和应用知识。研究结果将发表在同行评审的期刊上，并在国家和国际会议上发表。学生参与和教育工作将通过研究和课堂经验以及附属机构的本科研究的浓厚文化进行。研究的主要目标是开发一种新型的金刚石-GaN界面并充分表征其热传输特性。创新材料研究将涉及金刚石上GaN的三维集成，以显着改善大功率电子设备的热管理。金刚石的高导热性使其在减轻困扰开关和功率晶体管效率的自热效应方面极具吸引力。将开发一种创新的路径来选择性地生长金刚石和GaN，以实现与载流GaN二维电子气的紧密接近，从而实现有效的散热。系统的研究将侧重于材料的生长和表征。表征将强调这些材料的界面及其对热流的影响。将进行电气和抗扰度测试结构的制造。这些将与电学和光学测量相结合，以研究沉积和异质界面质量对基本特性的影响，包括边界热阻（TBR）。这些材料的性能对晶体管的操作限制的影响将与模拟的帮助下进行检查。选择性金刚石沉积将提供理解，以改善金刚石质量，界面性能，并管理由热膨胀失配引起的应力。生长步骤，特别是金刚石-GaN界面，对材料和器件性能的影响将通过物理和光学方法进行研究。将测量测试结构以确定热导率和TBR。广泛的表征将晶体质量和缺陷特性与热传输和电性能中的这些关键宏观量相关联。该研究将导致有关材料沉积和金刚石性能的基础和应用知识？GaN界面区。该奖项反映了NSF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。

Diamond, as an electronic material, has the best heat conduction properties and is readily produced by commercial equipment and processes. Gallium nitride is a semiconductor material that has seen recent commercial success in high efficiency light emitting diode bulbs, radio wave communications and radars, and power conversion switches.However, the full potential of gallium nitride is limited by the material's inability to efficiently conduct heat. Therefore, the project's aim is to combine diamond and gallium nitride in a novel approach that will focus on (1) the processes that produce both materials, (2) an in-depth characterization of the electronic and thermal properties (emphasizing heat flow), (3) fabrication of test structures, and (4) thermal conduction simulations. There are broad needs for combining diamond's thermal benefits within individual circuitry that comprises today's electronics.Transistors and switches (the backbone of the entire high-tech industry) are well known to produce substantial heat, and the problem is continually getting worse as devices become smaller and the density of electronic components packed together on circuit boards increases. (In personal electronics, consider how hot smart phones and laptops become during regular usage.) Specific applications that will benefit from the research include electric vehicles, power conversion for flexible integration of renewable energy sources to the nation's power grid, radar systems and communications systems for first-responder, defense and civilian uses. The research will result in basic and applied knowledge regarding the diamond-gallium nitride interface. Results will be published in peer-reviewed journals and presented at national and international conferences. Student engagement and education efforts will take place through research and classroom experiences and a strong culture of undergraduate research at the affiliate's institution.The primary goal of the research is to develop a novel diamond-GaN interface and fully characterize its thermal transport characteristics. Innovative materials research will involve three-dimensional integration of GaN on diamond to significantly improve thermal management in high-power electronics. The high thermal conductivity of diamond makes it highly attractive for mitigating self-heating effects that plague the efficiency of switches and power transistors. An innovative path will be developed to selectively grow diamond and GaN to achieve close proximity to the current-carrying GaN two-dimensional electron gas for efficient heat removal. Systematic studies will focus on material growth and characterization. Characterization will emphasize interfaces of these materials and its impact on heat flow. Fabrication of electrical and electrothermal test structures will be conducted. These will be used in combination with electrical and optical measurements to investigate the effects of deposition and heterointerface quality on fundamental properties, including and thermal boundary resistance (TBR). The impact of these material properties on transistor operational limits will be examined with the aid of simulations. Selective diamond deposition will provide understanding to improve diamond quality, interface properties, and manage stresses resulting from thermal expansion mismatches. The impact of the growth steps, particularly of the diamond-GaN interfaces, on material and device properties will be studied by physical and optical methods. Test structures will be measured to determine thermal conductivity and TBR. Extensive characterization will correlate crystal quality and defect properties with these key macroscopic quantities in thermal transport and electrical performance. The research will result in basic and applied knowledge regarding material deposition and properties of the diamond?GaN interface region. Results will be published in peer-reviewed journals and presented at national and international conferences.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.