Resizing Metal‐Coated Nanopores Using a Scanning Electron Microscope

Abstract Electron beam‐induced shrinkage provides a convenient way of resizing solid‐state nanopores in Si₃N₄ membranes. Here, a scanning electron microscope (SEM) has been used to resize a range of different focussed ion beam‐milled nanopores in Al‐coated Si₃N₄ membranes. Energy‐dispersive X‐ray spectra and SEM images acquired during resizing highlight that a time‐variant carbon deposition process is the dominant mechanism of pore shrinkage, although granular structures on the membrane surface in the vicinity of the pores suggest that competing processes may occur. Shrinkage is observed on the Al side of the pore as well as on the Si₃N₄ side, while the shrinkage rate is observed to be dependent on a variety of factors.