Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-23T09:10:40.703Z Has data issue: false hasContentIssue false
  • English
  • Français

X-Ray Microanalysis Combined with Monte Carlo Simulation for the Analysis of Layered Thin Films: The Case of Carbon Contamination

Published online by Cambridge University Press:  16 March 2009

Aldo Armigliato  and
Rodolfo Rosa
Aldo Armigliato*
Affiliation:
CNR-IMM, Sezione di Bologna, Via P. Gobetti 101, 40129 Bologna, Italy
Rodolfo Rosa
Affiliation:
CNR-IMM, Sezione di Bologna, Via P. Gobetti 101, 40129 Bologna, Italy Università di Bologna, Dipartimento di Scienze Statistiche, Via delle Belle Arti, 41, 40126 Bologna, Italy
*
Corresponding author. E-mail: armigliato@bo.imm.cnr.it
Get access

Abstract

A previously developed Monte Carlo code has been extended to the X-ray microanalysis in a (scanning) transmission electron microscope of plan sections, consisting of bilayers and triple layers. To test the validity of this method for quantification purposes, a commercially available NiOx (x ∼ 1) thin film, deposited on a carbon layer, has been chosen. The composition and thickness of the NiO film and the thickness of the C support layer are obtained by fitting to the three X-ray intensity ratios I(NiK)/I(OK), I(NiK)/I(CK), and I(OK)/I(CK). Moreover, it has been investigated to what extent the resulting film composition is affected by the presence of a contaminating carbon film at the sample surface. To this end, the sample has been analyzed both in the (recommended) “grid downward” geometry and in the upside/down (“grid upward”) situation. It is found that a carbon contaminating film of few tens of nanometers must be assumed in both cases, in addition to the C support film. Consequently, assuming the proper C/NiOx/C stack in the simulations, the Monte Carlo method yields the correct oxygen concentration and thickness of the NiOx film.

Keywords

analytical electron microscopyMonte Carlo simulationnickel-oxide filmsbilayers
Type
Microanalysis
Information
Microscopy and Microanalysis , Volume 15 , Issue 2 , April 2009 , pp. 99 - 105
Copyright
Copyright © Microscopy Society of America 2009

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

Armigliato, A. (1999). Thin film X-ray microanalysis with the analytical electron microscope. J Anal At Spectrom 14, 413–418.CrossRefGoogle Scholar
Armigliato, A. & Rosa, R. (1990). Simultaneous determination of composition and thickness of thin films by X-ray microanalysis at 300 kV and Monte Carlo simulation. Ultramicroscopy 32, 127–136.CrossRefGoogle Scholar
Bethe, H.A. (1930). Zur Theorie des Durchgangs Schneller Korpuskolarstrahlen Durch Materie. Ann Phys 5, 325–400.CrossRefGoogle Scholar
Cliff, G. & Lorimer, G. (1975). The quantitative analysis of thin films. J Microsc 103, 203–207.CrossRefGoogle Scholar
Egerton, R.F. (1996). Electron Energy-Loss Spectroscopy in the Electron Microscope, 2nd ed. New York: Plenum Press.CrossRefGoogle Scholar
Egerton, R.F. & Cheng, S.C. (1994). Characterization of an analytical electron microscope with a NiO test specimen. Ultramicroscopy 55, 43–54.Google Scholar
Horita, Z., Ichitani, K., Sano, T. & Nemoto, M. (1989). Applicability of the differential X-ray absorption method to the determinations of foil thickness and local composition in the analytical electron microscope. Phil Mag A 59, 939–952.CrossRefGoogle Scholar
Horita, Z., Sano, T. & Nemoto, M. (1986). An extrapolation method for the determination of Cliff-Lorimer k AB factors at zero foil thickness. J Microsc 143, 215–231.CrossRefGoogle Scholar
Krause, M.O. (1979). Atomic radiative and radiationless yields for K and L shells. J Phys Chem Ref Data 8, 307–327.CrossRefGoogle Scholar
Pouchou, J.L. & Pichoir, F. (1991). Quantitative analysis of homogeneous or stratified microvolumes applying the model “PAP.” In Electron Probe Quantitation, Heinrich, K.F.J. & Newbury, D.E. (Eds.), pp. 31–75. New York: Plenum Press.CrossRefGoogle Scholar
Powell, C.J. (1976). Cross sections for ionization of inner shell electrons by electrons. Rev Mod Phys A 48, 33–47.CrossRefGoogle Scholar
Rosa, R. & Armigliato, A. (1989). Monte-Carlo simulation of thin film X-ray microanalysis at high energies. X-ray Spectrom 18, 19–23.CrossRefGoogle Scholar
Schreiber, T.P. & Wims, A.M. (1982). Relative intensity factors for K, L and M shell X-ray lines. X-ray Spectrom 11, 42–45.Google Scholar
Veigele, W.M.J. (1973). Photon cross sections from 0.1 keV to 1 MeV for elements Z = 1 to Z = 94. Atom Data Tables 5, 51–111.CrossRefGoogle Scholar
Watanabe, M. & Williams, D.B. (2006). The quantitative analysis of thin specimens: A review of progress from the Cliff-Lorimer to the new ζ-factor methods. J Microsc 221, 89–109.CrossRefGoogle Scholar
Westwood, A.D., Michael, J.R. & Notis, M.R. (1992). Experimental determination of light-element k-factors using the extrapolation technique: Oxygen segregation in aluminium nitride. J Microsc 167, 287–302.Google Scholar
Williams, E.J. (1933). Applications of the method of impact parameter in collisions. Proc Roy Soc A 139, 163–186.Google Scholar