Upwind electromigration of sub-10-nm metallic nano-interconnects.

Nanoscale electronic devices face critical reliability challenges under extreme operating conditions, where electromigration-atomic motion driven by high density current-progressively degrades metallic components. Conventional wisdom maintains that electron wind force drives atomic migration along electron flow direction in metallic interconnects. However, using an integrated in situ nanofabrication-electropulsing approach, we reveal an anomalous electromigration phenomenon in next-generation transition metal nano-interconnects at atomic scale, where surface atoms migrate against the direction of electron flow. This upwind migration demonstrates universality across different refractory nano-interconnects including tungsten and molybdenum. First-principles calculations attribute this reversal to the predominance of direct forces over electron wind forces in materials with complex electronic structures. Our findings challenge the existing paradigm of electromigration and hold great implications for optimizing the reliability of next-generation electronic interconnections toward extreme process.