Formation of an Au membrane incorporated with carbon atoms under electron beam irradiations

Abstract

Abstract The Au nanopore can be utilized as optical nano-bio sensor due to its plasmonic effect. Initially, we fabricated the pore membrane inside the focused ion beam drilled Au apertures by using various electron beam irradiations. Depending upon the electron beam current density, the pore closing and opening phenomena of the diffused membrane were examined and characterized by electron probe micro analysis (EPMA), transmission electron microscopy (TEM), and energy –dispersive X-ray analysis (EDAX). No Au atoms were observed right after electron beam irradiations due to the low Au atomic concentrations below the detection limit of TEM. However, after the samples were kept under a laboratory environment for one year, several Au clusters with a size of 5 nm–7 nm were formed on the diffused membrane. This phenomenon can be attributed to Ostwald ripening.