Abstract
Probing the structure of material layers just a few nanometres thick requires analytical techniques with high depth sensitivity. X-ray photoelectron spectroscopy1 (XPS) provides one such method, but obtaining vertically resolved structural information from the raw data is not straightforward. There are several XPS depth-profiling methods, including ion etching2, angle-resolved XPS (ref. 2) and Tougaard's approach3, but all suffer various limitations2,3,4,5. Here we report a simple, non-destructive XPS depth-profiling method that yields accurate depth information with nanometre resolution. We demonstrate the technique using self-assembled multilayers on gold surfaces; the former contain ‘marker’ monolayers that have been inserted at predetermined depths. A controllable potential gradient is established vertically through the sample by charging the surface of the dielectric overlayer with an electron flood gun. The local potential is probed by measuring XPS line shifts, which correlate directly with the vertical position of atoms. We term the method ‘controlled surface charging’, and expect it to be generally applicable to a large variety of mesoscopic heterostructures.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Briggs, D. & Seah, M. P. (eds) Practical Surface Analysis Vol. 1, 2nd edn (Wiley, New York, 1990).
Hofmann, S. in Practical Surface Analysis Vol. 1, 2nd edn (eds Briggs,D. & Seah, M. P.) 143–199 (Wiley, New York, 1990).
Tougaard, S. Quantitative analysis of the inelastic background in surface electron spectroscopy. Surf. Interface Anal. 11, 453– 472 (1988).
Tyler, B. J., Castner, D. G. & Ratner, B. D. Regularization—A stable and accurate method for generating depth profiles from angle-dependent XPS data. Surf. Interface Anal. 14, 443–450 (1989).
Frydman, E., Cohen, H., Maoz, R. & Sagiv, J. Monolayer damage in XPS measurements as evaluated by independent methods. Langmuir 13, 5089–5106 ( 1997).
Seah, M. P. in Practical Surface Analysis Vol. 1, 2nd edn (eds Briggs, D. & Seah, M. P.) 541–554 (Wiley, New York, 1990).
Tielsch, B. J., Fulghum, J. E. & Surman, D. J. Differential charging in XPS. 2. Sample mounting and x-ray flux effects on heterogeneous samples. Surf. Interface Anal. 24, 459–468 ( 1996).
Barr, T. L. Studies in differential charging. J. Vac. Sci. Technol. A 7, 1677–1683 (1989).
Lewis, R. T. & Kelley, M. A. Binding energy reference in XPS of insulators. J. Electron Spectrosc. Relat. Phenom. 20, 105–115 (1980).
Miller, J. D., Harris, W. C. & Zajac, G. W. Composite interface analysis using voltage contrast XPS. Surf. Interface Anal. 20, 977– 983 (1993).
Beamson, G. et al. Characterization of PTFE on silicon wafer tribological transfer films by XPS, imaging XPS and AFM. Surf. Interface Anal. 24, 204–210 (1996).
Barr, T. L. in Practical Surface Analysis Vol. 1, 2nd edn (eds Briggs, D. & Seah, M. P.) 370 (Wiley, New York, 1990).
Shabtai, K., Rubinstein, I., Cohen, S. & Cohen, H. High-resolution lateral differentiation using a macroscopic probe: XPS of organic monolayers on composite Au-SiO2 surfaces. J. Am. Chem. Soc. 122, 4959–4962 (2000).
Hatzor, A. et al. Coordination-controlled self-assembled multilayers on gold. J. Am. Chem. Soc. 120, 13469– 13477 (1998).
Moav, T. et al. Coordination-based symmetric and asymmetric bilayers on gold surfaces. Chem. Eur. J. 4, 502– 507 (1998).
Yang, H. C. et al. Growth and characterization of metal(II) alkanebisphosphonate multilayer thin-films on gold surface. J. Am. Chem. Soc. 115, 11855–11862 (1993).
Hatzor, A. et al. A metal-ion coordinated hybrid multilayer. Langmuir 16, 4420–4423 ( 2000).
Umemura, Y., Yamagishi, A. & Tanaka, K.-I. X-ray photoelectron spectroscopic study of alternately layered zirconium and hafnium phosphate thin films on silicon substrates. Bull. Chem. Soc. Jpn 70, 2399– 2403 (1997).
Acknowledgements
This work was supported by the Israel Science Foundation, and the Tashtiot Infrastructure Program of the Israel Ministry of Science.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Doron-Mor, I., Hatzor, A., Vaskevich, A. et al. Controlled surface charging as a depth-profiling probe for mesoscopic layers. Nature 406, 382–385 (2000). https://doi.org/10.1038/35019025
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/35019025
This article is cited by
-
Unidirectional rotation of micromotors on water powered by pH-controlled disassembly of chiral molecular crystals
Nature Communications (2023)
-
Operando X-ray photoelectron spectroscopy of solid electrolyte interphase formation and evolution in Li2S-P2S5 solid-state electrolytes
Nature Communications (2018)
-
Protective molecular passivation of black phosphorus
npj 2D Materials and Applications (2017)
-
Measuring fundamental properties in operating solid oxide electrochemical cells by using in situ X-ray photoelectron spectroscopy
Nature Materials (2010)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.