Shrinking solid-state nanopores and nanoslits using electron beam induced deposition with different precursors

Solid-state nanopores of only a few nanometres in size have been in the spot-light during the last decade because of their potential use in applications such as molecule detection and DNA sequencing. They show greater stability than their biological counterparts, and can therefore be used in a broader range of environments. In most cases, the fabrication of such a nanopore requires the high-energy beam of a transmission electron microscope (TEM) or focused ion beam (FIB) tool to drill or reshape a small hole in a freestanding membrane. Here, we present a novel method to reduce the size of existing nanopores using electron beam induced deposition (EBID) in a conventional scanning electron microscope (SEM). The existing nanopores are etched in a silicon membrane using anisotropic wet etching and can be shrunk down to a few nanometres using EBID. In an unmodified SEM, shrinking can occur using the hydrocarbon contamination as a precursor, but we will show that by using a specifically designed environmental cell, it is possible to introduce different precursors and shrink the pore using almost any material desired.