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

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Nanoscale electronic devices face reliability issues due to electromigration under extreme conditions.
• Electromigration, atomic motion driven by current, degrades metallic components, with conventional theories stating atoms move with electron flow.

Purpose of the Study:

• To investigate anomalous electromigration phenomena in next-generation transition metal nano-interconnects.
• To challenge the existing paradigm of electromigration and its driving forces at the atomic scale.

Main Methods:

• Utilized an integrated in situ nanofabrication-electropulsing approach for atomic-scale analysis.
• Performed first-principles calculations to understand the underlying physics of atomic migration.

Main Results:

• Observed anomalous electromigration where surface atoms migrate against the electron flow direction (upwind migration).
• Demonstrated universality of this upwind migration across refractory nano-interconnects like tungsten and molybdenum.
• First-principles calculations revealed direct forces dominate over electron wind forces in complex electronic structures.

Conclusions:

• The study challenges the conventional understanding of electromigration, revealing an upwind atomic migration mechanism.
• Findings have significant implications for enhancing the reliability of next-generation electronic interconnections operating under extreme conditions.