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Highly Reproducible Secondary Electron Imaging under Electron Irradiation Using High-Pass Energy Filtering in Low-Voltage Scanning Electron Microscopy

Published online by Cambridge University Press:  27 February 2012

Daisuke Tsurumi ,
Kotaro Hamada  and
Yuji Kawasaki
Daisuke Tsurumi*
Affiliation:
Analysis Technology Research Center, Sumitomo Electric Industries, Ltd., 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa 244-8588, Japan
Kotaro Hamada
Affiliation:
Analysis Technology Research Center, Sumitomo Electric Industries, Ltd., 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa 244-8588, Japan
Yuji Kawasaki
Affiliation:
Analysis Technology Research Center, Sumitomo Electric Industries, Ltd., 1 Taya-cho, Sakae-ku, Yokohama, Kanagawa 244-8588, Japan
*
Corresponding author. E-mail: tsurumi-daisuke@sei.co.jp
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Abstract

The reproducibility of contrast in secondary electron (SE) imaging during continuous electron irradiation, which caused surface contamination, was investigated using SE high-pass energy filtering in low-voltage scanning electron microscopy (SEM). According to high-pass energy-filtered imaging, dopant contrast in an indium phosphide remained remarkably stable during continuous electron irradiation although the contrast in unfiltered SE images decreased rapidly as a contamination layer was formed. Charge neutralization and the SE energy distributions indicate that the contamination layer induces a positive charge. This results in a decrease of low-energy SE emissions and reduced dopant contrast in unfiltered SE images. The retention of contrast was also observed in high-pass energy-filtered images of a gold surface. These results suggest that this imaging method can be widely used when SE intensities decrease under continuous electron irradiation in unfiltered SE images. Thus, high-pass energy-filtered SE imaging will be of a great assistance for SEM users in the reproducibility of contrast such as a quantitative dopant mapping in semiconductors.

Keywords

reproducibilityhigh-pass energy-filtered imagingLV-SEMcontaminationdopant mapping
Type
Techniques and Software Development
Information
Microscopy and Microanalysis , Volume 18 , Issue 2 , April 2012 , pp. 385 - 389
Copyright
Copyright © Microscopy Society of America 2012

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