Spherical aberration correction in a scanning transmission electron microscope using a sculpted foil

TL;DR

This paper introduces a simple, low-cost method to correct spherical aberration in scanning transmission electron microscopes by sculpting a foil, significantly improving resolution without hardware modifications.

Contribution

The authors demonstrate a novel nanofabrication technique to create a foil-based refractive corrector that enhances microscope resolution without extensive re-engineering.

Findings

Achieved higher resolution imaging of Si and Cu samples.

Demonstrated the corrector can be installed on existing microscopes.

Surpassed the resolution of uncorrected microscopes.

Abstract

Nearly twenty years ago, following a sixty year struggle, scientists succeeded in correcting the bane of electron lenses, spherical aberration, using electromagnetic aberration correction. However, such correctors necessitate re-engineering of the electron column, additional space, a power supply, water cooling, and other requirements. Here, we show how modern nanofabrication techniques can be used to surpass the resolution of an uncorrected scanning transmission electron microscope more simply by sculpting a foil of material into a refractive corrector that negates spherical aberration. This corrector can be fabricated at low cost using a simple process and installed on existing electron microscopes without changing their hardware, thereby providing an immediate upgrade to spatial resolution. Using our corrector, we reveal features of Si and Cu samples that cannot be resolved in the uncorrected microscope.