Quantitative comparison of energy-filtering transmission electron microscopy and atom probe tomography

Stender P, Heil T, Kohl H, Schmitz G

Abstract

Whereas transmission electron microscopy (TEM) is a well established method for the analysis of thin film structures down to the sub-nanometer scale, atom probe tomography (APT) is less known in the microscopy community. In the present work, local chemical analysis of sputtered Fe/Cr multilayer structures was performed with energy-filtering transmission electron microscopy (EIFTEM) and APT. The single-layer thickness was varied from 1 to 6 nm in order to quantify spatial resolution and chemical sensitivity. While both the methods are able to resolve the layer structure, even at 2 nm thickness, it is demonstrated that the spatial resolution of the APT is about a factor of two, higher in comparison with the unprocessed EFFEM data. By calculating the influence of the instrumental parameters on EIFTEM images of model structures, remaining interface roughness is indicated to be the most important factor that limits the practical resolution of analytical TEM. (C) 2009 Elsevier B.V. All rights reserved.