Nanogaps by direct lithography for high-resolution imaging and electronic characterization of nanostructures

TL;DR

This paper introduces a direct electron beam lithography method to create nanogaps with sub-nanometer precision on thin films, enabling high-resolution imaging and electronic characterization of nanostructures.

Contribution

A novel fabrication technique using EBL on thin films to produce ultra-narrow nanogaps suitable for detailed imaging and electronic measurements.

Findings

Nanogaps under one nanometer were successfully fabricated.

High-resolution TEM imaging of nanogaps was achieved.

Charge transport measurements correlated with structural data.

Abstract

We report a method for fabricating nanogaps directly with electron beam lithography (EBL). The primary resolution-limit of EBL, electron back-scattering, is reduced dramatically by using a thin-film as a substrate. We show that this resolution enhancement allows one to fabricate metal electrodes with separation from arbitrarily large to under one nanometer. Furthermore, because these nanogaps are on a thin film, they can be imaged with high-resolution transmission electron microscopy (HRTEM). Using these nanogaps we measured the charge transport through several coupled PbSe nanocrystals and correlated the data with detailed structural information obtained by performing HRTEM on the same device.