Mass transport phenomena in copper nanowires at high current density
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Electromigration in Cu has been extensively investigated as the root cause of typical breakdown failure in Cu interconnects. In this study, Cu nanowires connected to Au electrodes are fabricated and observed using in situ transmission electron microscopy to investigate the electro- and thermo-migration processes that are induced by direct current sweeps. We observe the dynamic evolution of different mass transport mechanisms. A current density on the order of 106 A/cm2 and a temperature of approximately 400 °C are sufficient to induce electro- and thermo-migration, respectively. Observations of the migration processes activated by increasing temperatures indicate that the migration direction of Cu atoms is dependent on the net force from the electric field and electron wind. This work is expected to support future design efforts to improve the robustness of Cu interconnects.
KeywordsCu interconnect nanowires electromigration thermomigration mass transport high current density
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- Huang, Y. T.; Yu, S. Y.; Hsin, C. L.; Huang, C. W.; Kang, C. F.; Chu, F. H.; Chen, J. Y.; Hu, J. C.; Chen, L. T.; He, J. H. et al. In situ TEM and energy dispersion spectrometer analysis of chemical composition change in ZnO nanowire resistive memories. Anal. Chem. 2013, 85, 3955–3960.CrossRefGoogle Scholar
- Huntington, H. B. 6 - Electromigration in metals. In Diffusion in Solids; Burton, A. S. N. J., Ed.; Academic Press: New York, 1975; pp 303–352.Google Scholar
- Ostwald, W. Studien über die Bildung und Umwandlung fester Körper. 1. Abhandlung: Übersättigung und Überkaltung. Z. Phys. Chem. 1897, 22, 289–330.Google Scholar