Novel Partitioning-Based Approach for Electromigration Assessment With Neural Networks

Due to continuing technology scaling, electromigration (EM) remains a prominent reliability concern in integrated circuit design. Traditional empirical methods often result in over-design in very large scale integration (VLSI) due to model inaccuracy. Recently, researchers have focused on analyzing EM susceptibility by tracking hydrostatic stress evolution in metal lines, governed by computationally expensive partial differential equations (PDEs). In this paper, we propose a partitioning-based approach using neural networks to efficiently forecast the stress evolution along interconnect trees during the void nucleation and growth phases. This approach begins by decomposing the interconnect tree into subcomponents, providing computationally efficient analytical solutions for predicting stress evolution within each subtree. Subsequently, we employ a lightweight neural network to reassemble these components with their corresponding solutions to the original structure, ensuring accurate stress prediction. This divide-and-conquer strategy can accommodate various tree structures, with offshoots at arbitrary junctions, and holds substantial promise for using NN-based methods to solve mesh-free stress evolution on much larger interconnect trees than previously possible, with reduced computational overhead and heightened accuracy. The proposed approach eliminates the need for time discretization and grid meshing typically required in numerical methods. Numerical results confirm its advantages in accuracy and computational efficiency.