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，例如下一代移动电话网络，电动汽车电源转换器，激光二极管和固态照明。大部分热量的积累发生在半导体器件和它所附着的衬底材料之间的界面上。这个项目的重点是通过纳米结构（即亚微米线和锥体阵列）来改变这个界面，从而使热量更容易从半导体传播到基板上，从而减少热流阻力。如果成功，该项目将为大大提高基于半导体的许多技术的性能和效率提供可靠的方法。此外，这项研究将通过研究生和本科生的培训，并通过参与K-12外展计划产生教育影响。本提案的具体研究目标是：1)利用界面纳米结构的新技术，创建一种可扩展和可转移的方法来增强界面上的热传递；2)提出并验证了声子跨纳米结构界面输运的多尺度模型，从而推动了热输运领域的发展。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，然后用柔软的润湿金属（如铟）以容错方式将它们粘合在一起。该项目的重点是改善宽禁带半导体和高导热基板之间的热传输，重点是金刚石。这些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性原理计算结果纳入更大尺度连续体模型。该项目的结果将为理解和优化具有广泛不同原子结构和声子性质的材料之间改善传热的界面铺平道路。

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.