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Charging Processes in Low Vacuum Scanning Electron Microscopy

Published online by Cambridge University Press:  01 December 2004

Bradley L. Thiel ,
Milos Toth  and
John P. Craven
Bradley L. Thiel
Affiliation:
Polymers and Colloids Group, Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
Milos Toth
Affiliation:
Polymers and Colloids Group, Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
John P. Craven
Affiliation:
Polymers and Colloids Group, Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE, UK
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Abstract

A framework is presented for understanding charging processes in low vacuum scanning electron microscopy. We consider the effects of electric fields generated above and below the specimen surface and their effects on various processes taking place in the system. These processes include the formation of an ionic space charge, field-enhanced electron emission, charge trapping and dissipation, and electron–ion recombination. The physical mechanisms behind each of these processes are discussed, as are the microscope operating conditions under which each process is most effective. Readily observable effects on gas gain curves, secondary electron images, and X-ray spectra are discussed.

Keywords

environmental SEMlow vacuum SEMimagingmicroanalysischargingdielectricsinsulators
Type
Research Article
Information
Microscopy and Microanalysis , Volume 10 , Issue 6 , December 2004 , pp. 711 - 720
Copyright
© 2004 Microscopy Society of America

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References

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