2, ETH Zürich, Zürich, , Switzerland
Bottom-up fabrication holds great commercial potential due to the cost-effectiveness of saving material. Solution-based fabrication methods are particularly attractive due to their scalability, low cost, and mild operating conditions. In this respect, electrodeposition using scanning probe microscopy provides a unique platform. Scanning probes allow for additive nanoscale manufacturing under ambient conditions, and additionally provide 3-dimensional spatial freedom which enables the fabrication of structures that are hard to realize in conventional cleanroom environments.
We report on the direct writing of Copper and Cobalt nanostructures using pulsed mechanical and electrical techniques in both an Atomic Force Microscope (AFM) and a Scanning Tunneling Microscope (STM). We demonstrate the writing of arbitrary structures beyond the sizes characteristic of single clusters and with lateral dimensions down to tens of nanometers, which can be read in-situ using the scanning probe. The extent of the deposition is interpreted based on the charging dynamics of ions in the liquid, determined by fundamental constants of the electrolyte such as the concentration, dielectric constant, and diffusion coefficient.
Due to the wide variety of electrochemical deposition and conversion processes, the technique of controlled electrochemical deposition with a scanning probe can be extended to different materials and morphologies. As such, we envision this technique to enable the manufacturing and rapid prototyping of novel devices at the nanoscale such as optical resonators, magnetic elements, and semiconductor devices.