A Self-Consistent Substrate Thermal Profile Estimation Technique for Nanoscale ICs—Part II: Implementation and Implications for Power Estimation and Thermal Management

As transistors continue to evolve along Moore's Law and silicon devices take advantage of this evolution to offer increasing performance, there is a critical need to accurately estimate the silicon-substrate (junction or die) thermal gradients and temperature profile for the development and thermal management of future generations of all high-performance integrated circuits (ICs) including microprocessors. This paper presents an accurate chip-level leakage-aware method that self-consistently incorporates various electrothermal couplings between chip power, junction temperature, operating frequency, and supply voltage for substrate thermal profile estimation and also employs a realistic package thermal model that comprehends different packaging layers and noncubic structure of the package, which are not accounted for in traditional analyses. The evaluation using the proposed methodology is efficient and shows excellent agreements with an industrial-quality computational-fluid-dynamics (CFD) based commercial software. Furthermore, the methodology is shown to become increasingly effective with increase in leakage as technology scales. It is shown that considering electrothermal couplings and realistic package thermal model not only improves the accuracy of estimating the heat distribution across the chip but also has significant implications for precise power estimation and thermal management in nanometer-scale CMOS technologies.