Investigation on Electromigration Failure Mechanism and Lifetime Prediction of Interconnects Under Multifield Coupling for Chiplet Applications

The electromigration (EM) can introduce voids and hillocks in through-silicon vias (TSVs) and redistributed layer (RDL) interconnects, increasing the risks of short-circuit and open-circuit failures and thereby severely affecting the reliability of chiplet systems. In this article, the EM failure mechanism of the interconnects under electrical–thermal–stress multiphysics coupling is investigated, and a novel method for EM lifetime prediction based on coupled multiphysics modeling and finite element simulation is proposed. The implementation of dynamic failure simulation through element activation/deactivation technology employs a 20% void area ratio as the interconnect failure criterion, allowing for quantitative lifetime prediction. The consistency between the experimental and simulation results demonstrated the accuracy and effectiveness of the proposed lifetime prediction method. The overall prediction error is reduced by 11% with the state-of-the-art EM prediction method. Furthermore, based on this method, the effect of different interposer materials and TSV radii on interconnect EM is investigated. The evidence exhibits that using diamond as an interposer material can significantly mitigate interconnect EM phenomenon and enhance the reliability of the whole structure compared with silicon and glass. Furthermore, increasing the radius of TSV enhances EM resistance in interconnects, with each$1~\mu $m increase in radius extending the average interconnect lifetime by 12.75 h. Finally, the sensitivity analysis of diffusion-related constants further validates the robustness of the proposed model to critical parameters.