Adaptive Regression-Based Thermal Modeling and Optimization for Monolithic 3-D ICs

In this paper, we first present a comprehensive study of the unique thermal behavior in monolithic 3-D integrated circuits (ICs) in contrast to through silicon via-based 3-D ICs. In particular, we study the impact of the thin interlayer dielectric between the device tiers on vertical thermal coupling. We then study and compare the impact of different application-based package structures on the thermal behavior of monolithic 3-D ICs. With these unique properties and behavior, we develop a fast and accurate compact full-chip thermal analysis model based on nonlinear regression technique which adapts to the package structure during development and hence considers it during temperature evaluation. Our model is extremely fast and highly accurate with an error of less than 5%. This model is incorporated into a thermal-aware 3-D-floorplanner that runs without significant runtime overhead. We use the floorplanner with our package-aware thermal model and observe up to 22% reduction in the maximum temperature with insignificant area and performance overhead.