Study on Scanning Probe-Induced Electrochemical Deposition of Atomic and Close-to-Atomic-Scale Structures

The probe tip of a scanning tunneling microscope can induce various processes, including conformational changes, dissociation, and chemical reactions, in individual atoms or molecules. This capability allows for the bottom-up assembly of precise atomic and close-to-atomic-scale (ACS) structures through the manipulation of atomic and molecular interactions. In this study, an electrochemical deposition process based on the probe of a scanning tunneling microscope was developed. This process enables the precise and controlled fabrication of metal ACS structures on a substrate through the application of an electric field to the scanning probe, which induces localized metal electrochemical deposition. The impact of the applied electric field on the local metal deposition behavior at the probe was investigated. The optimal parameters for probe voltage, substrate voltage, probe–substrate spacing, and deposition duration were determined. The relationship between the experimental parameters and the dimensions of the deposited copper ACS particles was investigated, and the resulting ACS structure was analyzed via in situ scanning tunneling microscopy characterization. Copper metal deposition at the ACS, with a height of 1 nm, was successfully achieved.