Silver Growth on AFM Tip Apexes from Silver Nitrate Solutions Triggered by Focused-Ion-Beam Irradiation

Silver nanostructures are directly grown on the apex of commercially available silicon AFM probes using our area-selective electroless deposition: the apex of a silicon AFM probe is irradiated using a focused ion beam (FIB), and then the FIB-irradiated AFM probe is exposed to a pure AgNO 3 aqueous solution. With this method, a silver nanostructure selectively grows on the tip apex where the native oxide layer has been removed in response to FIB irradiation. Silver ions are reduced by the electrons flowing from the silicon probes into the solution through the FIB-irradiated area owing to the difference in Fermi energy between silicon and the solution. The morphology of the growing silver depends on the concentration of both AgNO 3 and the electrons. The growth of a gold nanoflower is also demonstrated on the apex of a silicon AFM probe.