Thermomechanical Fatigue Damage of Semiconductor/Metal Dissimilar Interfaces

This award funds research that will investigate the fundamental mechanics of thermomechanical fatigue in next-generation semiconductors, which is a critical failure mode affecting the reliability, safety, and durability of these devices. As semiconductors drive advancements in energy sustainability, environmental protection, quantum computing, communication, and artificial intelligence, understanding how temperature and mechanical stress at material interfaces impact device performance is essential.

This award will support fundamental research looking to understand the mechanics of interfacial thermomechanical fatigue of semiconductor/metal joints through an integrated experimental and modeling approach. Research outcomes intend to provide insights that can guide the design, fabrication, and packaging of more durable and reliable semiconductor devices for use in supercomputers, automobiles, and deep space exploration.

By addressing the challenges of interfacial fatigue, this work will enhance U.S. competitiveness in semiconductor manufacturing, strengthen national defense capabilities, and support the development of the next generation of semiconductor professionals. By involving students at various educational levels in research-integrated activities, this project will foster a skilled workforce and contribute to the continued advancement of semiconductor technology in critical sectors.

The objective of this project is to understand the thermomechanical fatigue behavior of semiconductor/metal interfaces under cyclic thermal and mechanical loading. The research will focus on developing an energy dissipation criterion to evaluate thermomechanical fatigue damage in these interfaces, which are prone to failure due to thermal expansion coefficient mismatches.

To achieve this, the study will measure changes in the impedance of the semiconductor/metal interface to assess interfacial debonding and fatigue crack propagation rates. Numerical simulations will guide the selection of appropriate fatigue testing amplitudes, while the simulation results will provide insights into key state variables, such as crystal lattice discontinuities, that influence crack initiation.

These simulations will be validated through thermomechanical fatigue testing and microstructure analysis. The research will extend beyond traditional silicon-based semiconductors to include next-generation materials such as silicon carbide, gallium oxide, zirconium-doped hafnium oxide, and gallium nitride. The project looks to establish a unified material parameter—the specific energy of interfacial debonding—used to evaluate the fatigue damage in semiconductor/metal interfaces, providing a comprehensive framework for improving the durability and reliability of future semiconductor devices.

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.