Copper electrodeposition localized in picoliter droplets using microcantilever arrays

Abstract

A patterning tool that allows electrochemical reactions to take place inside microdroplets is introduced. This tool relies on the use of a microfabricated array of silicon cantilevers that incorporate a channel into which a gold electrode is patterned. The deposition process consists in forming picoliter droplets onto a conducting surface by a contact method and applying a voltage between the surface and the cantilevers. To demonstrate the capability of the system, arrays of 20μm diameter copper islands are electrodeposited onto gold surfaces. As expected, the copper bumps exhibit increasing heights as a result of longer deposition times.