Forming low resistance nano-scale contacts using solder reflow

We describe the use of solder reflow on the 100 nanometer scale to form electrically conductive contacts. We fabricated nanowires using electrodeposition in nanoporous templates. We investigated the use of directed assembly and nanoscale soldering to integrate the nanowires with microfabricated bond pads, and measured the electrical characteristics of the soldered wires. The electrical resistance of a single nanowire on top of two adjacent contact pads dropped by an order of magnitude after solder reflow. The results in this paper demonstrate that it is possible to use solder films as thin as 100 nm to electrically bond nanocomponents to substrates with contact resistances as low as 5 Ω.