Electromigration (EM) is a severe reliability issue in power grid networks. The via array possesses special EM characteristics and suffers from Joule heating and current crowding, closely related to EM violations. In this study, a power grid EM analysis method was developed to solve temperature variation effects for the via array EM.
The new method is based on the temperature-aware EM model, which considers the effects of self-heating and thermal coupling of interconnected lines in a power grid. According to the model, the proposed methodology introduces a locality-driven strategy and current tracking to perform full-chip EM assessment for multilayered power grids. The results show that temperature due to Joule heating indeed has significant impacts on the via EM failure.
The results further demonstrate that the proposed method might reasonably improve efficiency while ensuring the accuracy of the analysis.