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Gas Cascade Amplification in Ultra-High-Resolution Environmental Scanning Electron Microcopy

Published online by Cambridge University Press:  03 September 2010

Milos Toth*
Affiliation:
FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124, USA
Bradley L. Thiel
Affiliation:
College of Nanoscale Science and Engineering, State University of New York at Albany, 251 Fuller Road, Albany, NY 12203, USA
W. Ralph Knowles
Affiliation:
FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124, USA
*
Corresponding author. E-mail: [email protected]
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Abstract

We describe a feedback mechanism in the gas cascade amplification process used in magnetic immersion lens environmental scanning electron microcopy (ESEM). Feedback dominates gas gain under the conditions typically used for ultra-high-resolution ESEM and gives rise to novel dependencies of the imaging signal and noise on microscope operating parameters. It is ascribed tentatively to the generation of free electrons upon de-excitation of metastable species in the gas cascade. The results have implications for optimization of ESEM systems for applications such as critical dimension metrology and real-time imaging of nanostructure growth by gas mediated electron beam induced deposition.

Type
Instrumentation and Software Developments
Copyright
Copyright © Microscopy Society of America 2010

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References

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