This paper investigates the impact of redundancy on electromigration (EM) risk in unit cells derived from power delivery networks (PDN) in advanced technology nodes. Test structures were fabricated in a commercial 28-nm technology node with minimum feature sizes of 45 nm. For the first time, activation energy was extracted for PDN tiles composed of different metal dimensions, showing that it can vary depending on the adopted failure criterion and is related to the metallization layers present in the stack. Linewidth scaling worsens shunting effect, as void incubation in advanced nodes tends to produce near-open failures with a sharp resistance increase (\textasciitilde{}0.4 kΩ for 45 nm lines). Nevertheless, the presence of redundant current paths can partially mitigate this effect by allowing current redistribution, delaying functional degradation. Further, in this study, a new chip level reliability assessment methodology is proposed that considers available IR-drop margins rather than relying on the conventional resistance-change failure criterion, which is overly conservative and significantly impacts the reliability margin of PDN tiles. Finally, a three-dimensional TCAD simulator was calibrated with single line experiments and employed to validate experimental trends.
Esposto, S, Farr, H, Grate, L, Chavez, T, Thesberg, M, Schneider, H, Ciofi, I, Sisto, G, Croes, K, Milojevic, D & Zahedmanesh, H 2026, IR-drop-based Electromigration-Compliance Checks of Grid Unit-Cells in Power Delivery Networks. in International Interconnect Technology Conference 2026. IEEE, pp. 1-3.
Esposto, S., Farr, H., Grate, L., Chavez, T., Thesberg, M., Schneider, H., Ciofi, I., Sisto, G., Croes, K., Milojevic, D., & Zahedmanesh, H. (Accepted/In press). IR-drop-based Electromigration-Compliance Checks of Grid Unit-Cells in Power Delivery Networks. In International Interconnect Technology Conference 2026 (pp. 1-3). IEEE.
@inproceedings{215a9e4b6b2b4dee904797532ae1759d,
title = "IR-drop-based Electromigration-Compliance Checks of Grid Unit-Cells in Power Delivery Networks",
abstract = "This paper investigates the impact of redundancy on electromigration (EM) risk in unit cells derived from power delivery networks (PDN) in advanced technology nodes. Test structures were fabricated in a commercial 28-nm technology node with minimum feature sizes of 45 nm. For the first time, activation energy was extracted for PDN tiles composed of different metal dimensions, showing that it can vary depending on the adopted failure criterion and is related to the metallization layers present in the stack. Linewidth scaling worsens shunting effect, as void incubation in advanced nodes tends to produce near-open failures with a sharp resistance increase (\textasciitilde{}0.4 kΩ for 45 nm lines). Nevertheless, the presence of redundant current paths can partially mitigate this effect by allowing current redistribution, delaying functional degradation. Further, in this study, a new chip level reliability assessment methodology is proposed that considers available IR-drop margins rather than relying on the conventional resistance-change failure criterion, which is overly conservative and significantly impacts the reliability margin of PDN tiles. Finally, a three-dimensional TCAD simulator was calibrated with single line experiments and employed to validate experimental trends. ",
author = "Simone Esposto and Hosain Farr and Leslie Grate and Tony Chavez and Mischa Thesberg and Helena Schneider and Ivan Ciofi and Giuliano Sisto and Kristof Croes and Dragomir Milojevic and Houman Zahedmanesh",
year = "2026",
language = "English",
pages = "1--3",
booktitle = "International Interconnect Technology Conference 2026",
publisher = "IEEE",
}