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Sample Thickness Determination by Scanning Transmission Electron Microscopy at Low Electron Energies

Published online by Cambridge University Press:  13 December 2013

Tobias Volkenandt ,
Erich Müller  and
Dagmar Gerthsen
Tobias Volkenandt*
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstr. 7, 76131 Karlsruhe, Germany
Erich Müller
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstr. 7, 76131 Karlsruhe, Germany
Dagmar Gerthsen
Affiliation:
Laboratorium für Elektronenmikroskopie, Karlsruher Institut für Technologie (KIT), Engesserstr. 7, 76131 Karlsruhe, Germany
*
*Corresponding author. E-mail: tobias.volkenandt@kit.edu
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Abstract

Sample thickness is a decisive parameter for any quantification of image information and composition in transmission electron microscopy. In this context, we present a method to determine the local sample thickness by scanning transmission electron microscopy at primary energies below 30 keV. The image intensity is measured with respect to the intensity of the incident electron beam and can be directly compared with Monte Carlo simulations. Screened Rutherford and Mott scattering cross-sections are evaluated with respect to fitting experimental data with simulated image intensities as a function of the atomic number of the sample material and primary electron energy. The presented method is tested for sample materials covering a wide range of atomic numbers Z, that is, fluorenyl hexa-peri-hexabenzocoronene (Z = 3.5), carbon (Z = 6), silicon (Z = 14), gallium nitride (Z = 19), and tungsten (Z = 74). Investigations were conducted for two primary energies (15 and 30 keV) and a sample thickness range between 50 and 400 nm.

Keywords

scanning transmission electron microscopysample thickness determinationMonte Carlo simulationscattering cross-sectionquantificationlow energy
Type
Techniques, Software, and Instrumentation Development
Information
Microscopy and Microanalysis , Volume 20 , Issue 1 , February 2014 , pp. 111 - 123
Copyright
Copyright © Microscopy Society of America 2014 

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