Thermal Transport in Diamond Thin Films: Roles of the Nanostructure and Interfaces

点击翻译按钮获取中文摘要

PI: Raj N. Singh, Univ. of CincinnatiCBET-1133516 Heat dissipation in high performance microprocessors and power semiconductor devices is a critical challenge facing the microelectronics industry. One of the most effective ways to remove heat from integrated circuits (ICs) is to use materials with high thermal conductivity in contact with ICs. In this context, a high thermal conductivity material, especially diamond with the highest thermal conductivity of any known materials, is promising for thermal management of ICs. In particular, the objective of this research is to synthesize layered thin films of diamond in which one layer (nanocrystalline diamond-NCD) will provide smooth surfaces for lower interface resistance and the second layer (microcrystalline diamond-MCD) will result in high thermal conductivity. The approach will involve the synthesis of NCD and MCD films individually and as layered NCD/MCD films using an in-house microwave plasma enhanced chemical vapor deposition system and measuring the thermal properties using a custom-built modulated photothermal reflectance system. A novel approach of nanoseeding will be employed to reduce roughness and interface thermal resistance. Advanced materials characterization techniques will be used to identify defects in the films and relate to mean free path for phonon scattering for identifying the dominant defect controlling thermal transport in layered diamond thin films. The proposed research is significant and transformative because the results will be, to the best of our knowledge, the first comprehensive study on the effect of processing on the nanostructure, defects, and thermal transport mechanisms in NCD and layered NCD/MCD films with improved thermal properties.The proposed research has potentials for enormous payoffs because thermal management plays a critical role in several high-technology areas including optoelectronics, microelectronics, power electronics and microelectromechanical systems. In addition, with the current emphasis on conserving our limited natural resources for energy production, efficient thermal management strategies will result in direct savings in cooling costs leading to lower energy consumption and a significant positive environmental impact. An essential component of this research will be training and education of students and post docs, and dissemination of the results through publications in journals and presentations at conferences. The minority/women and high school students will be mentored and exposed to research through several programs at our university. A significant outreach to high schools is proposed through camps for teachers and students.