Secondary electron topographical contrast formation in scanning transmission electron microscopy

TL;DR

This paper develops an analytical model for secondary electron contrast in STEM, improving surface topography interpretation by accounting for SE emission physics and magnetic interactions, aiding in 3D surface reconstruction.

Contribution

It introduces a novel analytical model that incorporates SE physics and magnetic field interactions for better contrast interpretation in STEM images.

Findings

Enhanced understanding of SE contrast formation.

Potential for improved 3D surface reconstruction algorithms.

More reliable interpretation of surface topography in STEM images.

Abstract

Secondary electron (SE) imaging offers a powerful complementary capabilities to conventional scanning transmission electron microscopy (STEM) by providing surface-sensitive, pseudo-3D topographic information. However, contrast interpretation of such images remains empirical due to complex interactions of emitted SE with the magnetic field in the objective field of TEM. Here, we propose an analytical physical model that takes into account the physics of SE emission and interaction of the emitted SEs with magnetic field. This enables more reliable image interpretation and potentially lay the foundation for novel 3D surface reconstruction algorithms.