A Modeling Study on Electrical and Thermal Behavior of CNT TSV for Multilayer Structure

Carbon nanotube (CNT) is recently proposed as an alternative material for through-silicon via (TSV) to meet the requirements for high-density scaling and 3-D stacking. In this article, by establishing the physical model and applying COMSOL simulation, the electrical and thermal characteristics of CNT TSV in multilayer structures are analyzed. We find that CNT TSV has good electrical properties, comparable transmission loss with Cu TSV, and better heat dissipation capabilities, suitable for 3-D integration circuits (3DIC) applications. According to the model, we give quantitative indicators of the difficulties that the current process still needs to overcome. Furthermore, even in a multilayer stack structure, CNT TSV maintains good IR-Drop and transmission loss, while having a smaller temperature rise. More importantly, the median time-to-failure (MTTF) of CNT is better than Cu about 99.4% in the ideal case, showing outstanding reliability.