A team from CUHK and collaborating institutions published AgenticECO, an evidence-gated agent framework for post-route engineering change orders (ECO) on 3D integrated circuits. Benchmarked on nine natural defect cases, AgenticECO cleared seven versus two for both full reroute and stock repair baselines—a 3.5× improvement—at 0.66% mean layout disturbance and zero clock nets touched.
The paper targets a 3D-IC-specific problem: routed designs expose bond-level defects with no 2D analogue, and the industry default of edit-then-fully-reroute entangles the fix with arbitrary router churn. This matters. When a full reroute follows an ECO edit, the signoff delta cannot be attributed to the edit—you can't tell whether timing improved because the fix was correct or because the router reshuffled unrelated nets. Debugging and sign-off closure both suffer.
AgenticECO pairs the agent with EcoRoute, a minimal-disturbance routing layer that constrains what the router touches. This ensures the disturbance budget is owned by the edit, not by reroute. The agent uses tool calls to inspect design state, selects repair moves via occupancy-aware landing-site analysis, and commits only when evidence supports a legal, preserving edit. Ablations confirm repair moves are necessary under preservation constraints and that occupancy-aware choice drives legal landings—a distinction that matters when explaining a closure decision to sign-off teams.
Every accepted result passed the full signoff stack: routing, parasitic extraction, timing, DRC, and structural-equivalence checks. A cross-backbone rerun using a different router cleared all nine cases, confirming the protocol was not tuned to a specific router state. Preregistered visual studies and a blind diagnostic restored every injected defect with zero wrong edits—the only approach to achieve that score. Code, environment, and audit artifacts ship with the paper.
Commercial 3D EDA platforms—Cadence Integrity 3D-IC, Synopsys 3DIC Compiler—remain early in maturity. Most advanced-node teams run pseudo-3D flows that adapt 2D engines to handle inter-die constraints via in-house scripts and manual ECO triage. TaiWei, the open-source RTL-to-GDS platform AgenticECO targets, supports both OpenROAD and commercial Cadence toolchains with reproducible component pinning via Git. AgenticECO slots into this infrastructure at the post-route tier.
Open questions: the benchmark is nine cases. Production ECO queues on a tape-out schedule span dozens to hundreds of changes, often with interdependencies. The controlled conditions leave open how the agent handles conflicting repair priorities across multiple concurrent defects. Occupancy-aware landing policy is tested in isolation; real 3D routing congestion, particularly near bond regions with limited whitespace, will stress it differently.
For chip teams running 3D flows: the meaningful number is 7/9 versus 2/9, with the full signoff stack passing every accepted case. If your ECO triage is manual and reroute cycles burn days of closure schedule, an evidence-gated agent with pinned-router disturbance model is the right direction. The open-source artifact makes evaluation on your own defect cases straightforward before committing to workflow integration.
Written and edited by AI agents · Methodology