Hostname: page-component-78c5997874-t5tsf Total loading time: 0 Render date: 2024-11-10T11:29:11.823Z Has data issue: false hasContentIssue false

Improvement of Depth Resolution of ADF-SCEM by Deconvolution: Effects of Electron Energy Loss and Chromatic Aberration on Depth Resolution

Published online by Cambridge University Press:  12 April 2012

Xiaobin Zhang*
Affiliation:
Materials Science and Engineering, Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293, Japan Transmission Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan
Masaki Takeguchi
Affiliation:
Materials Science and Engineering, Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293, Japan Transmission Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan
Ayako Hashimoto
Affiliation:
Transmission Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Global Research Center for Environment and Energy Based on Nanomaterials Science, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan
Kazutaka Mitsuishi
Affiliation:
Materials Science and Engineering, Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293, Japan Transmission Electron Microscopy Station, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Global Research Center for Environment and Energy Based on Nanomaterials Science, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan
Meguru Tezuka
Affiliation:
Materials Science and Engineering, Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293, Japan
Masayuki Shimojo
Affiliation:
Global Research Center for Environment and Energy Based on Nanomaterials Science, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003, Japan Department of Materials Science and Engineering, Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548, Japan
*
Corresponding author. E-mail: ZHANG.Xiabin@nims.go.jp
Get access

Abstract

Scanning confocal electron microscopy (SCEM) is a new imaging technique that is capable of depth sectioning with nanometer-scale depth resolution. However, the depth resolution in the optical axis direction (Z) is worse than might be expected on the basis of the vertical electron probe size calculated with the existence of spherical aberration. To investigate the origin of the degradation, the effects of electron energy loss and chromatic aberration on the depth resolution of annular dark-field SCEM were studied through both experiments and computational simulations. The simulation results obtained by taking these two factors into consideration coincided well with those obtained by experiments, which proved that electron energy loss and chromatic aberration cause blurs at the overfocus sides of the Z-direction intensity profiles rather than degrade the depth resolution much. In addition, a deconvolution method using a simulated point spread function, which combined two Gaussian functions, was adopted to process the XZ-slice images obtained both from experiments and simulations. As a result, the blurs induced by energy loss and chromatic aberration were successfully removed, and there was also about 30% improvement in the depth resolution in deconvoluting the experimental XZ-slice image.

Type
Techniques Development
Copyright
Copyright © Microscopy Society of America 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Cosgriff, E.C., D'Alfonso, A.J., Allen, L.J., Findlay, S.D., Kirkland, A.I. & Nellist, P.D. (2008). Three-dimensional imaging in double aberration-corrected scanning confocal electron microscopy, part I: Elastic scattering. Ultramicroscopy 108, 15581566.CrossRefGoogle ScholarPubMed
D'Alfonso, A.J., Cosgriff, E.C., Findlay, S.D., Behan, G., Kirkland, A.I., Nellist, P.D. & Allen, L.J. (2008). Three-dimensional imaging in double aberration-corrected scanning confocal electron microscopy, part II: Inelastic scattering. Ultramicroscopy 108, 15671578.CrossRefGoogle ScholarPubMed
Einspahr, J.J. & Voyles, P.M. (2006). Prospects for 3D, nanometer-resolution imaging by confocal STEM. Ultramicroscopy 106, 10411052.CrossRefGoogle ScholarPubMed
Frigo, S.P., Levine, Z.H. & Zaluzec, N.J. (2002). Submicron imaging of buried integrated circuit structures using scanning confocal electron microscopy. Appl Phys Lett 81, 21122114.CrossRefGoogle Scholar
Gonzalez, R.C., Woods, R.E. & Eddins, S.L. (2003). Digital Image Processing Using Matlab. Upper Saddle River, NJ: Prentice Hall.Google Scholar
Hashimoto, A., Shimojo, M., Mitsuishi, K. & Takeguchi, M. (2009). Three-dimensional imaging of carbon nanostructures by scanning confocal electron microscopy. J Appl Phys 106, 086101.CrossRefGoogle Scholar
Hashimoto, A., Shimojo, M., Mitsuishi, K. & Takeguchi, M. (2010). Three-dimensional optical sectioning by scanning confocal electron microscopy with a stage-scanning system. Microsc Microanal 16, 233238.CrossRefGoogle ScholarPubMed
Intaraprasonk, V., Xin, H.L. & Muller, D.A. (2008). Analytic derivation of optimal imaging conditions for incoherent imaging in aberration-corrected electron microscopes. Ultramicroscopy 108, 14541466.CrossRefGoogle ScholarPubMed
Kirkland, E.J. (1998). Advanced Computing in Electron Microscopy. New York: Springer.CrossRefGoogle Scholar
Mitsuishi, K., Hashimoto, A., Takeguchi, M., Shimojo, M. & Ishizuka, K. (2010). Imaging properties of bright-field and annular-dark-field scanning confocal electron microscopy. Ultramicroscopy 111, 2026.CrossRefGoogle ScholarPubMed
Mitsuishi, K., Iakoubovskii, K., Takeguchi, M., Shimojo, M., Hashimoto, A. & Furuya, K. (2008). Bloch wave-based calculation of imaging properties of high-resolution scanning confocal electron microscopy. Ultramicroscopy 108, 981988.CrossRefGoogle ScholarPubMed
Nellist, P.D., Behan, G., Kirkland, A.I. & Hetherington, C.J.D. (2006). Confocal operation of a transmission electron microscope with two aberration correctors. Appl Phys Lett 89, 124105.CrossRefGoogle Scholar
Nellist, P.D., Cosgriff, E.C., Behan, G. & Kirkland, A.I. (2008). Imaging modes for scanning confocal electron microscopy in a double aberration-corrected transmission electron microscope. Microsc Microanal 14, 8288.CrossRefGoogle Scholar
Takeguchi, M., Hashimoto, A., Mitsuishi, K., Zhang, X., Shimojo, M., Ishikawa, T., Deguchi, S., Naruse, T. & Kondo, Y. (2010). Development of a double-tilt stage-scanning sample holder for scanning confocal electron microscopy of single crystal samples. 2nd International Symposium on Advanced Microscopy and Theoretical Calculations (AMTC-2), Nagoya, Japan, vol. 2, pp. 110–111.Google Scholar
Takeguchi, M., Hashimoto, A., Shimojo, M., Mitsuishi, K. & Furuya, K. (2008). Development of a stage-scanning system for high-resolution confocal STEM. J Electron Microsc 57, 123127.CrossRefGoogle ScholarPubMed
Wang, P., Behan, G., Takeguchi, M., Hashimoto, A., Mitsuishi, K., Shinojo, M., Kirkland, A. & Nellist, P. (2010). Nanoscale energy-filtered scanning confocal electron microscopy using a double-aberration-corrected transmission electron microscope. Phy Rev Lett 104, 200801.CrossRefGoogle ScholarPubMed
Xin, H.L. & Muller, D.A. (2009). Aberration-corrected ADF-STEM depth sectioning and prospects for reliable 3D imaging in S/TEM. J Electron Microsc 58, 157165.CrossRefGoogle ScholarPubMed
Xin, H.L. & Muller, D.A. (2010). Three-dimensional imaging in aberration-corrected electron microscopes. Microsc Microanal 16, 445455.CrossRefGoogle ScholarPubMed
Zaluzec, N. J. (2003). The scanning confocal electron microscope. Microscopy Today 6, 812.CrossRefGoogle Scholar