Recovery-Aware Proactive TSV Repair for Electromigration Lifetime Enhancement in 3-D ICs

Electromigration (EM) becomes a major reliability concern in 3-D integrated circuits (3-D ICs). To mitigate this problem, a typical solution is to use through-silicon via (TSV) redundancy in a reactive manner, maintaining the operability of a 3-D chip in the presence of EM failures by detecting and replacing faulty TSVs with spares. In this paper, we explore an alternative, more preferred approach to enhance the EM-related lifetime reliability of TSV grid, in which redundancy is used proactively to allow nonfaulty TSVs to be temporarily deactivated. In this way, EM wear-out can be extended by exploiting its recovery property. The proposed solution is based on two consecutive stages, in which TSV redundancy allocation and TSV repair are finalized at both design-time and runtime, respectively. Applied to 3-D benchmark designs, the recovery-aware proactive repair approach increases EM-related lifetime reliability (measured in mean-time-to-failure) of the entire TSV grid by up to 12\times relative to the conventional reactive method, with similar area overhead. In addition, a runtime dynamic recovery approach is proposed to further improve EM-related lifetime reliability to account for stress variation across different chips and over the operational lifetime.