Nanopatterning of Suspended Graphene Films by Local Catalytic Etching Using Atomic Force Microscopy Equipped with an Ag-Coated Probe

We have developed a novel technique for fabrication of nanopores in suspended graphene (SG) films using atomic force microscopy (AFM) equipped with a catalytic Ag-coated probe. By applying voltages between an Ag-coated tip and SG films in tapping mode AFM under ambient conditions at room temperature, Ag nanoparticles on the tip contact to the graphene surface, and simultaneously local Joule heating is generated at the tip–Ag nanoparticle–graphene contact. As a result, the SG films can be etched via oxidation assisted by the heated Ag catalytic nanoparticles, forming a nanopore. Because the hole shape and size on the SG films depend on the shape of the AFM tip, we can regulate the patterns on the graphene films by optional AFM tips