Volume control of metal-plating deposition using a nanopipette probe by controlling electric charge

We describe a novel volume control technique for local metal-plating deposition using a scanning probe microscope with a nanopipette probe. The nanopipette probe, a thermally pulled capillary glass tube, was filled with CuSO₄ electrolyte solution. A Cu dot was electrochemically deposited on an Au surface when the nanopipette probe was nearly in contact with the surface by applying a dc bias voltage between the electrolyte solution and the surface. The volume of the deposited Cu dot was dependent on the electric charge during the electrochemical reaction. By controlling the electric charge during the deposition, it was possible to control the volume of the Cu dot. This technique of local metal plating with deposition volume control is applicable for the fabrication of various nanometer-scale structures in fields such as nanomechanics and nanoelectronics.