Hostname: page-component-8448b6f56d-wq2xx Total loading time: 0 Render date: 2024-04-25T06:47:59.968Z Has data issue: false hasContentIssue false
  • English
  • Français

Resolution Limits of Secondary Electron Dopant Contrast in Helium Ion and Scanning Electron Microscopy

Published online by Cambridge University Press:  12 July 2011

Mark Jepson ,
Xiong Liu ,
David Bell ,
David Ferranti ,
Beverley Inkson  and
Cornelia Rodenburg
Mark Jepson*
Affiliation:
Department of Materials, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK
Xiong Liu
Affiliation:
Carl Zeiss NTS, Carl-Zeiss-Straße 56, 73447, Oberkochen, Germany
David Bell
Affiliation:
School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
David Ferranti
Affiliation:
Carl Zeiss SMT Inc., ALIS Business Unit, One Corporation Way, Peabody, MA 01960, USA
Beverley Inkson
Affiliation:
Materials Science and Engineering, The University of Sheffield, Sheffield, S. Yorkshire S1 3JD, UK
Cornelia Rodenburg
Affiliation:
Materials Science and Engineering, The University of Sheffield, Sheffield, S. Yorkshire S1 3JD, UK
*
Corresponding author. E-mail: m.a.e.jepson@lboro.ac.uk
Get access

Abstract

As the miniaturization of semiconductor devices continues, characterization of dopant distribution within the structures becomes increasingly challenging. One potential solution is the use of the secondary electron signal produced in scanning electron (SEMs) or helium ion microscopes (HeIMs) to image the changes in electrical potential caused by the dopant atoms. In this article, the contrast mechanisms and resolution limits of secondary electron dopant contrast are explored. It is shown that the resolution of the technique is dependent on the extent of electrical potential present at a junction and that the resolution of dopant contrast can be improved in the HeIM after an in-situ plasma cleaning routine, which causes an oxide to form on the surface altering the contrast mechanism from electrical potential to material contrast.

Keywords

scanning electron microscopy (SEM)helium ion microscopy (HeIM)dopant contrastcontrast mechanisms
Type
Helium Ion Microscopy
Information
Microscopy and Microanalysis , Volume 17 , Issue 4 , August 2011 , pp. 637 - 642
Copyright
Copyright © Microscopy Society of America 2011

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

REFERENCES

Ananth, M., Scipioni, L. & Notte, J. (2008). The helium ion microscope: The next stage in nanoscale imaging. Am Lab 40, 42–46.Google Scholar
Castell, M.R., Muller, D.A. & Voyles, P.M. (2003). Dopant mapping for the nanotechnology age. Nat Mater 2, 129–131.CrossRefGoogle ScholarPubMed
Chee, K.W.A., Rodenburg, C. & Humphreys, C.J. (2008). High resolution dopant profiling in the SEM, image widths and surface band-bending. J Phys Conf Ser 23, 012033.Google Scholar
Dapor, M., Jepson, M.A.E., Inkson, B.J. & Rodenburg, C. (2009). The effect of oxide overlayers on secondary electron dopant mapping. Microsc Microanal 15, 237–243.CrossRefGoogle ScholarPubMed
El-Gomati, M.M. & Wells, T.C.R. (2001). Very low energy electron microscope of coped semiconductors. Appl Phys Lett 79, 2931.CrossRefGoogle Scholar
Elliott, S.L., Broom, R.F. & Humphreys, C.J. (2002). Dopant profiling with the scanning electron microscope—A study of Si. J Appl Phys 91, 9116.CrossRefGoogle Scholar
Hill, R., Notte, J. & Ward, B. (2008). The ALIS He ion source and its application to high resolution microscopy. Phys Procedia 1, 135–141.CrossRefGoogle Scholar
Howie, A. (1995). Threshold energy effects in secondary electron emission. J Microsc 180, 192–203.CrossRefGoogle Scholar
Jepson, M.A.E., Inkson, B.J., Liu, X., Scipioni, L. & Rodenburg, C. (2009a). Quantitative dopant contrast in the helium ion microscope. Europhys Lett 86, 26005.CrossRefGoogle Scholar
Jepson, M.A.E., Inkson, B.J., Rodenburg, C. & Bell, D.C. (2009b). Dopant contrast in the helium ion microscope. Europhys Lett 85, 46001.CrossRefGoogle Scholar
Kazemian, P., Mentink, S.A.M., Rodenburg, C. & Humphreys, C.J. (2006). High resolution quantitative two-dimensional dopant mapping using energy-filtered secondary electron imaging. J Appl Phys 100, 054901.CrossRefGoogle Scholar
Kazemian, P., Rodenburg, C. & Humphreys, C.J. (2004). Effect of experimental parameters on doping contrast of Si p-n junctions in a FEGSEM. Microelec Eng 73–74, 948–953.CrossRefGoogle Scholar
Mika, F. & Frank, L. (2008). Two-dimensional dopant profiling with low-energy SEM. J Microsc 230, 76–83.CrossRefGoogle ScholarPubMed
Morita, M., Ohmi, T., Hasegawa, E., Kawakami, M. & Ohwada, M. (1990). Growth of native oxide on a silicon surface. J Appl Phys 68, 1272–1281.CrossRefGoogle Scholar
Mullerova, I., El-Gomati, M.M. & Frank, L. (2002). Imaging of the boron doping in silicon using low energy SEM. Ultramicroscopy 93, 223–243.CrossRefGoogle ScholarPubMed
Pasquariello, D., Hedlund, C. & Hjort, K. (2000). Oxidation and induced damage in oxygen plasma in situ wafer bonding. J Electrochem Soc 147, 2699–2703.CrossRefGoogle Scholar
Ramachandra, R., Griffin, B. & Joy, D. (2009). Model of secondary electron imaging in the helium ion scanning microscope. Ultramicroscopy 109, 748–757.CrossRefGoogle ScholarPubMed
Sealy, C.P., Castell, M.R. & Wilshaw, P.R. (2000). Mechanism for secondary electron dopant contrast in the SEM. J Electron Microsc 49, 311–321.CrossRefGoogle ScholarPubMed
Sze, S.M. (2001). Semiconductor Devices: Physics and Technology, 2nd ed.Hoboken, NJ: John Wiley and Sons.Google Scholar