Novel nanomaterials, such as nanotubes and nanowires are used to build optical and electronic nanodevices as well as chemical and biological sensors. In order to fabricate and interconnect these nanodevices, controlled microdeposition and surface patterning methods with lateral resolution in the nanometer range are required. Local polymerization to produce conducting polymers (such as polypyrrole or polyaniline) or local deposition of metals can be achieved by scanning electrochemical microscopy (SECM) with high lateral resolution.

Modification and etching of semiconductors have a high technical importance for microelectronic device fabrication. Commonly this is achieved by photolithography using photoresist masks. Scanning electrochemical microscopy offers high-resolution etching of semiconductors in a single step. A strong oxidant, such as bromine is produced locally at the microelectrode tip in the feedback mode and the material within the vicinity of the microelectrode is etched. This method allows a very controlled and easy modification of the surface.

Mandler, Daniel, and Allen J. Bard. “High resolution etching of semiconductors by the feedback mode of the scanning electrochemical microscope.” Journal of The Electrochemical Society 137.8 (1990): 2468-2472. View article.

SECM surface modification patterning
SECM surface patterning deposition
SECM application conducting polymers

Polypyrrole was locally polymerized to form a conducting line over a gap between two conducting Au structures on an insulating substrate. The electropolymerisation from the monomer was performed in a pulse program using a 3-electrode setup and connecting one Au structure as the working electrode and the Pt microelectrode as the counter electrode. The described method provides an easy and well-controllable tool for the connection of conducting microstructures via conducting polymers.

Kranz, Christine, et al. “Lateral deposition of polypyrrole lines over insulating gaps. Towards the development of polymer‐based electronic devices.” Advanced Materials 7.6 (1995): 568-571.