Patterned Copper Nanowires with Novel Electrical Effects
A micrograph of the sample layout and the copper nanowire (l = 2.04 um, w
= 90 nm, t = 50 nm) between the contact pads.
Metallic nanowires have various applications such as sensors and high-density interconnects in field-effect transistors. Monitoring
the influence of size and surface effects on material properties, such as electrical resistivity and failure properties, is important
in designing new, reliable nanowires.
Copper nanowires were patterned with e-beam lithography and fabricated with a copper film deposited by e-beam evaporation.
Electrical measurements show that surface and size have effects on the electrical properties. Smaller values for the temperature
coefficient of resistance and higher failure current density were found for copper nanowires with decreasing wire width. The experimental
finding of width-dependent failure current density also agrees with theoretical predictions of heat transfer of the nanowire and
substrate system as calculated with the finite-element method. These results suggest that mass transport during electromigration
may be dominated by surface diffusion.
CNM staff and collaborative users partnered for this project and used the CNM Omicron UHV Nanoprobe (four-probe scanning electron
microscope) and noncontact atomic-force microscope.
Q. Huang, C.M. Lilley, M. Bode, R. Divan, “Surface and size effects on the electrical properties of Cu nanowires,” J.
Appl. Phys., 104 (2), 023709/1-6 (2008). (online)