Nanopore Fabrication by Heating Au Particles on Ceramic Substrates

We found that gold nanoparticles, when heated to close to their melting point on substrates of amorphous SiO₂ or amorphous Si₃N₄, move perpendicularly into the substrate. Dependent on applied temperatures, particles can become buried or leave nanopores of extreme aspect ratio (diameter ≅ 25 nm, length up to 800 nm). The process can be understood as driven by gold evaporation and controlled by capillary forces and can be controlled by temperature programming and substrate choice