SUBJECT: Ph.D. Dissertation Defense
BY: Diego Vaca
TIME: Friday, September 1, 2023, 3:00 p.m.
PLACE: Microsoft Teams, N/A
TITLE: Investigation of Thermal Performance of Thin Films for Emerging Electronic Applications
COMMITTEE: Dr. Satish Kumar, Co-Chair (ME)
Dr. Vanessa Smet, Co-Chair (ME)
Dr. Yogendra Joshi (ME)
Dr. Zhuomin Zhang (ME)
Dr. Mark Losego (MSE)


The evolution of electronics, driven by demands for faster communication, advanced computation, and portable devices, requires critical components like transistors to be faster, smaller, and more efficient. This necessitates new materials with specific thermal properties for effective thermal management. Fabrication methods also impact these properties. This dissertation delves into the thermal properties of materials crucial for emerging electronic devices, offering insights that contribute significantly to the field. The study begins by investigating the thermal conductivity of β-Ga2O3 thin films on various substrates using techniques like TDTR, AFM, and TEM. Defect densities were estimated, providing insights into their impact on thermal conductivity. The research then examines the thermal conductivity of Ti-containing materials used in memristor electrodes. Ti2AlN is found to enhance HfO2-based memristor performance compared to traditional TiN. Machine learning models are also explored for thermal conductivity analysis, with complex results that require further optimization. The feasibility of using hexagonal boron nitride (h-BN) and highly oriented pyrolytic graphite (HOPG) as heat spreaders for silicon chips is investigated. Simulations and h-BN transfer methods are studied, concluding that HOPG is superior in thermal performance, cost, and availability. The study also explores CYTOP and nanoporous copper (NP-Cu) for bonding HOPG heat spreaders on Si substrates. Although optimal bonding conditions need further determination, strategies to reduce thermal resistance through thinner bond lines (CYTOP) and improved thermal conductivity (NP-Cu) show potential. In summary, this dissertation advances the understanding of thermal properties in emerging electronic materials. It offers insights that guide future research and applications in the evolving field of thermal management.