Towards quantitative scanning electron microscopy: Applications to nano-scale analysis

Mohamed M El Gomati, C. G. H. Walker, X. Zha

Research output: Contribution to journalArticlepeer-review

Abstract

Although the Scanning Electron Microscope (SEM) has been in existence for many decades, it cannot be
yet regarded as a true quantitative instrument—certainly when applied at the nanoscale. This is due to
the presence of carbonaceous deposits at the surface and a poor understanding of the emission of
secondary electrons from materials. In this paper, a short review is given of some of the progress made
in the efforts to improve quantification in the SEM at York. We present results which strongly suggest
that the currently accepted theory, which explains why there is a correlation between the secondary
electron yield and the work function of a metal, is incorrect. In addition, we show that the
backscattering coefficient from materials can be strongly influenced by surface layers at low primary
electron energy. Finally, we present Auger electron spectra, which have been acquired at high speed at
high vacuum (107 mbar) and thus represent a new way to determine the composition of nanostructures
in the SEM.
Original languageEnglish
Pages (from-to)68-73
Number of pages6
JournalNuclear instruments & methods in physics research section a-Accelerators spectrometers detectors and associated equipment
Volume645
Issue number1
DOIs
Publication statusPublished - 21 Jul 2011

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