Skip to main content Accessibility help
×
Home

Dark-Field Scanning Transmission Ion Microscopy via Detection of Forward-Scattered Helium Ions with a Microchannel Plate

  • Taylor J. Woehl (a1), Ryan M. White (a1) and Robert R. Keller (a1)

Abstract

A microchannel plate was used as an ion sensitive detector in a commercial helium ion microscope (HIM) for dark-field transmission imaging of nanomaterials, i.e. scanning transmission ion microscopy (STIM). In contrast to previous transmission HIM approaches that used secondary electron conversion holders, our new approach detects forward-scattered helium ions on a dedicated annular shaped ion sensitive detector. Minimum collection angles between 125 mrad and 325 mrad were obtained by varying the distance of the sample from the microchannel plate detector during imaging. Monte Carlo simulations were used to predict detector angular ranges at which dark-field images with atomic number contrast could be obtained. We demonstrate atomic number contrast imaging via scanning transmission ion imaging of silica-coated gold nanoparticles and magnetite nanoparticles. Although the resolution of STIM is known to be degraded by beam broadening in the substrate, we imaged magnetite nanoparticles with high contrast on a relatively thick silicon nitride substrate. We expect this new approach to annular dark-field STIM will open avenues for more quantitative ion imaging techniques and advance fundamental understanding of underlying ion scattering mechanisms leading to image formation.

Copyright

Corresponding author

* Corresponding author. taylor.woehl@nist.gov

Footnotes

Hide All

Contribution of the National Institute of Standards and Technology. Not subject to copyright in the United States.

Footnotes

References

Hide All
Bell, D.C. (2009). Contrast mechanisms and image formation in helium ion microscopy. Microsc Microanal 15(2), 147153.
Brodusch, N., Demers, H. & Gauvin, R. (2013). Dark-field imaging of thin specimens with a forescatter electron detector at low accelerating voltage. Microsc Microanal 19(6), 16881697.
D’Alfonso, A.J., Forbes, B.D. & Allen, L.J. (2013). The interaction of a nanoscale coherent helium-ion probe with a crystal. Ultramicroscopy 134, 1822.
Hall, A.R. (2013). In situ thickness assessment during ion milling of a free-standing membrane using transmission helium ion microscopy. Microsc Microanal 19(3), 740744.
Holm, J. & Keller, R.R. (2015). Analytical transmission scanning electron microscopy: Extending the capabilities of a conventional SEM using an off-the-shelf transmission detector. Microsc Microanal 21(Suppl. S3), 18671868.
Joy, D., Ko, Y. & Hwu, J. (2000). Metrics of resolution and performance for CD-SEMs. Proceedings of SPIE, Santa Clara, CA, February 27, 3998.
Klein, T., Buhr, E. & Frase, C.G. (2012). TSEM: A review of scanning electron microscopy in transmission mode and its applications. In Advances in Imaging and Electron Physics, Vol 171, Hawkes, P.W. (Ed.), pp. 297356. San Diego, CA: Elsevier.
LeBeau, J.M., Findlay, S.D., Allen, L.J. & Stemmer, S. (2010). Standardless atom counting in scanning transmission electron microscopy. Nano Lett 10(11), 44054408.
Loferer-Krossbacher, M., Klima, J. & Psenner, R. (1998). Determination of bacterial cell dry mass by transmission electron microscopy and densitometric image analysis. Appl Environ Microbiol 64(2), 688694.
Notte, J., Hill, R., McVey, S.M., Ramachandra, R., Griffin, B. & Joy, D. (2010). Diffraction imaging in a He+ ion beam scanning transmission microscope. Microsc Microanal 16(5), 599603.
Scipioni, L., Sanford, C.A., Notte, J., Thompson, B. & McVey, S. (2009). Understanding imaging modes in the helium ion microscope. J Vac Sci Technol B 27(6), 32503255.
Ward, B.W., Notte, J.A. & Economou, N.P. (2006). Helium ion microscope: A new tool for nanoscale microscopy and metrology. J Vac Sci Technol B 24(6), 28712874.
Woehl, T.J. & Keller, R.R. (2016). Dark-field image contrast in transmission scanning electron microscopy: Effects of substrate thickness and detector collection angle. Ultramicroscopy, submitted.
Ziegler, J.F., Biersack, J.P. & Littmark, U. (1985). The Stopping and Range of Ions in Solids. New York: Pergamon.

Keywords

Type Description Title
WORD
Supplementary materials

Woehl supplementary material
Woehl supplementary material 1

 Word (4.1 MB)
4.1 MB

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed