Heat Transfer Across Nanostructured Metal-Semiconductor Interfaces

从晶体管等半导体器件中去除热量是许多具有高商业和环境影响的技术面临的主要挑战之一，这些技术包括下一代手机网络、电动汽车电源转换器、激光二极管和固态照明。大部分热量积聚发生在半导体器件与其所附接的衬底材料之间的界面处。该项目的重点是通过用纳米结构（即亚微米线和锥体阵列）对其进行修改，以使热量更容易从半导体进入衬底，从而降低该界面处的热流阻力。如果成功，该项目将产生一种可靠的方法，大大提高基于半导体的许多技术的性能和效率。此外，这项研究将通过培训研究生和本科生，并通过参与K-12推广计划产生教育影响。这项建议的具体研究目标是：1）创建一种可扩展和可转移的方法，使用界面纳米结构的新技术来增强界面上的热传输;以及2）通过提出并验证纳米结构界面上声子输运的多尺度模型来推进热输运领域。该研究计划描述了一种在两种材料的配合表面上合理设计和制造高纵横比纳米结构阵列的方法，然后用软润湿金属（如铟）将它们以容错方法结合在一起。该项目的重点是改善宽带隙半导体和高热导率衬底之间的热传输，重点是金刚石。界面将使用热反射技术进行测量，并与多尺度模型进行比较，该模型将纳米结构中声子输运的第一原理计算结果纳入更大尺度的连续模型中。该项目的结果将为理解和优化界面铺平道路，以改善具有广泛不同原子结构和声子性质的材料之间的传热。

Removing heat from semiconductor devices such as transistors is one of the primary challenges facing many technologies with high commercial and environmental impact, such as next-generation cell phone networks, electric vehicle power converters, laser diodes, and solid-state lighting. Much of the heat buildup occurs at the interface between the semiconductor device and the substrate material to which it is attached. This project focuses on reducing the resistance to heat flow at this interface by modifying it with nanostructures (i.e. arrays of sub-micron wires and cones) in a way that will allow heat to more easily travel from the semiconductor into the substrate. If successful, this project will result in a reliable method to greatly improve the performance and efficiency of many technologies based on semiconductors. In addition, this research will have an educational impact through the training of graduate and undergraduate students, and through participation in K-12 outreach programs.The specific research objectives of this proposal are 1) create a scalable and transferrable method to enhance thermal transport across an interface using a novel technique of nanostructuring at the interface; and 2) advance the field of thermal transport by proposing then validating multiscale models of phonon transport across nanostructured interfaces. The research plan describes an approach to rationally design and fabricate arrays of high-aspect-ratio nanostructures on the mating surfaces of two materials and then bond them together in a fault-tolerant approach with a soft wetting metal such as indium. The project focuses on improving thermal transport between wide bandgap semiconductors and high thermal conductivity substrates, with an emphasis on diamond. The interfaces will be measured using thermoreflectance techniques and compared with a multiscale model that incorporates results from first principles calculations for phonon transport in nanostructures into a larger scale continuum model. The results of this project will pave the way for understanding and optimizing interfaces for improved heat transfer between materials with widely different atomic structures and phonon properties.