Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure

Thomas Kowoll; Erich Müller; Susanne Fritsch-Decker; Simon Hettler; Heike Störmer; Carsten Weiss; Dagmar Gerthsen

doi:10.1155/2017/4907457

Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure

Scanning. 2017 Apr 6:2017:4907457. doi: 10.1155/2017/4907457. eCollection 2017.

Authors

Thomas Kowoll¹, Erich Müller¹, Susanne Fritsch-Decker², Simon Hettler¹, Heike Störmer¹, Carsten Weiss², Dagmar Gerthsen¹

Affiliations

¹ Laboratory for Electron Microscopy, Karlsruhe Institute of Technology (KIT), Campus South, Engesserstr. 7, 76131 Karlsruhe, Germany.
² Institute of Toxicology and Genetics, Karlsruhe Institute of Technology (KIT), Campus North, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.

Abstract

This study is concerned with backscattered electron scanning electron microscopy (BSE SEM) contrast of complex nanoscaled samples which consist of SiO₂ nanoparticles (NPs) deposited on indium-tin-oxide covered bulk SiO₂ and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC-) simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.