Nanopore fabrication and characterization by helium ion microscopy

TL;DR

This paper demonstrates the use of Helium Ion Microscopy to precisely fabricate and analyze nanopores in various materials, achieving diameters as small as 1.3 nm and providing insights into the beam's profile.

Contribution

It introduces a method for creating and characterizing nanopores with high precision using helium ion beams, advancing nanofabrication techniques.

Findings

Nanopores down to 1.3 nm diameter were successfully fabricated.

Helium ion microscopy enables detailed imaging and characterization of nanopores.

Analysis of nanopore growth provides insights into the helium ion beam profile.

Abstract

The Helium Ion Microscope (HIM) has the capability to image small features with a resolution down to 0.35 nm due to its highly focused gas field ionization source and its small beam-sample interaction volume. In this work, the focused helium ion beam of a HIM is utilized to create nanopores with diameters down to 1.3 nm. It will be demonstrated that nanopores can be milled into silicon nitride, carbon nanomembranes (CNMs) and graphene with well-defined aspect ratio. To image and characterize the produced nanopores, helium ion microscopy and high resolution scanning transmission electron microscopy were used. The analysis of the nanopore's growth behavior, allows inferring on the profile of the helium ion beam.