Electromigration in metal interconnects remains a significant challenge in the continued scaling of integrated circuits towards ever‐smaller single‐nanometer nodes. Conventional damascene architectures of barrier/liner layers and conducting metal cause inevitable compromises between device performance and feature dimensions. In contrast to contemporary barrier/liner materials (e.g., Co, Ta, and Ru), an ultrathin passivation layer that can effectively mitigate electromigration is needed. At the ultimate atomically‐thin limit, 2D materials are promising candidates given their exceptional mechanical properties and impermeability. Here, a facile and effective approach is presented to mitigating electromigration in copper (Cu) interconnects via passivation with insulating monolayer 2D hexagonal boron nitride (hBN). The hBN‐passivated Cu interconnects, compared to otherwise identical but bare Cu interconnects, exhibit on average a >20% higher breakdown current density and a >2600% longer lifetime (at a high current density of 5.4 × 107 A cm−2). Post‐mortem metrology elucidates uniform conformal contact between the hBN‐passivated Cu interface and common failure features due to electromigration.

Ångström-thin hexagonal boron nitride (hBN) is a highly promising barrier/ liner dielectric material for passivating electrical interconnects in ultra-scaled integrated circuits (ICs). In article number 2100002, Michael Cai Wang and co-workers present a novel approach to mitigating electromigration in nanoscale copper interconnects. Significant improvements in the breakdown current density and operating lifetime are observed in hBN-passivated copper interconnects, paving the way for further single-nanometer node scaling of semiconductor and ICs manufacturing HEXAGONAL BORON NITRIDE