Determining On-Axis Crystal Thickness with Quantitative Position-Averaged Incoherent Bright-Field Signal in an Aberration-corrected STEM

TL;DR

This paper presents a method using position-averaged incoherent bright-field signals in aberration-corrected STEM to accurately measure on-axis crystal thickness with high precision, accounting for both crystalline and amorphous regions.

Contribution

It introduces a novel quantitative approach for thickness determination that reduces systematic errors from surface plasmons in electron microscopy.

Findings

Achieves thickness measurement precision of ±1.6 nm.

Effectively measures both crystalline and amorphous parts of samples.

Avoids systematic errors from surface plasmon contributions.

Abstract

An accurate determination of specimen thickness is essential for quantitative analytical electron microscopy. Here we demonstrate that a position-averaged incoherent bright-field signal recorded on an absolute scale can be used to determine the thickness of on-axis crystals with a precision of \pm1.6 nm. This method measures both the crystalline and the non-crystalline parts (surface amorphous layers) of the sample. However, it avoids the systematic error resulting from surface plasmons contributions to the inelastic mean free path thickness estimated by electron energy loss spectroscopy.