Nature Materials, Published online: 08 September 2026; doi:10.1038/s41563-026-02740-1The electrical resistivity of conventional copper interconnects increases as their dimensions decrease. In contrast, the resistivity of CoSi nanoflakes decreases as their thickness is reduced from 1 μm to ∼20 nm. These nanoflakes demonstrate high reliability and serve as promising interconnects at the nanoscale.