AUGER ELECTRON SPECTROSCOPY

PRINCIPLES AND APPLICATIONS
Yash CNS
CUG
WHAT IS AUGER ELECTRON
SPECTROSCOPY ?
Auger Electron Spectroscopy (AES), is a widely
used technique to investigate the com...
THE PARTICLE-SURFACE
INTERACTIONS
Auger Electron Spectroscopy
Ions
Electrons
Photons

Ions
Electrons
Photons

Vacuum
3
BASIC OF AUGER ELECTRON
SPECTROSCOPY
Auger spectroscopy can be considered as involving three basic steps
:

(1) Atomic ion...
PHOTOELECTRON VS. AUGER
ELECTRON EMISSION

5
AUGER ELECTRON
SPECTROSCOPY

6
PHYSICS BASIS
An Auger transition is therefore characterized primarily by :1. the location of the initial hole
2. the loca...
SITE DIFFERENTIATION

CATSYMP19 PRESCHOOL
17TH JAN 2009

8
9
SURFACE ANALYSIS DEPTHS

CATSYMP19 PRESCHOOL
17TH JAN 2009

10
SCANNING AUGER ELECTRON
SPECTROMETER

11
CATSYMP19 PRESCHOOL
17TH JAN 2009

12
13
ELEMENTAL SHIFTS

14
QUANTITATIVE SURFACE ANALYSIS:
AES

By assuming the concentration to be a relative ratio of
atoms,
we can neglect the term...
Auger Analysis Examples
A - Chemical composition, thickness and spatial distribution of the
elements on cerium conversion ...
17
AES DEPTH PROFILING: AN
EXAMPLE

18
CHEMICAL SHIFT

19
SEMICONDUCTOR DOPING
SHIFT IN AES

CATSYMP19 PRESCHOOL

20
DOPING MAP BY AES

21
THANK YOU
FOR ATTENTION

FROM
YASH
22
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Auger electron Spectroscopy

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electron spectroscopy of core electrons

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Auger electron Spectroscopy

  1. 1. AUGER ELECTRON SPECTROSCOPY PRINCIPLES AND APPLICATIONS Yash CNS CUG
  2. 2. WHAT IS AUGER ELECTRON SPECTROSCOPY ? Auger Electron Spectroscopy (AES), is a widely used technique to investigate the composition of surfaces.  First discovered in 1923 by Lise Meitner and later independently discovered once again in 1925 by Pierre Auger [1]  Lise Meitner Pierre Victor Auger 1. P. Auger, J. Phys. Radium, 6, 205 (1925). 2
  3. 3. THE PARTICLE-SURFACE INTERACTIONS Auger Electron Spectroscopy Ions Electrons Photons Ions Electrons Photons Vacuum 3
  4. 4. BASIC OF AUGER ELECTRON SPECTROSCOPY Auger spectroscopy can be considered as involving three basic steps : (1) Atomic ionization (by removal of a core electron) (2) Electron emission (the Auger process) (3) Analysis of the emitted Auger electrons This last stage is simply a technical problem of detecting charged particles with high sensitivity, with the additional requirement that the kinetic energies of the emitted electrons must be determined. 4
  5. 5. PHOTOELECTRON VS. AUGER ELECTRON EMISSION 5
  6. 6. AUGER ELECTRON SPECTROSCOPY 6
  7. 7. PHYSICS BASIS An Auger transition is therefore characterized primarily by :1. the location of the initial hole 2. the location of the final two holes In general, since the initial ionisation is non-selective and the initial hole may therefore be in various shells, there will be many possible Auger transitions for a given element - some weak, some strong in intensity. AUGER SPECTROSCOPY is based upon the measurement of the kinetic energies of the emitted electrons. Each element in a sample being studied will give rise to a characteristic spectrum of peaks at various kinetic energies. This is an Auger spectrum of Pd metal - generated using a 2.5 keV electron beam to produce the initial core vacancies and hence to stimulate the Auger emission process. The main peaks for palladium occur between 220 & 340 eV. The peaks are situated on a high background which arises from the vast number of so-called secondary electrons generated by a multitude of inelastic scattering processes. Auger spectra are also often shown in a differentiated form : the reasons for this are partly historical, partly because it is possible to actually measure spectra directly in this form and by doing so get a better sensitivity for detection. The plot below shows the same spectrum in such a 7 differentiated form.
  8. 8. SITE DIFFERENTIATION CATSYMP19 PRESCHOOL 17TH JAN 2009 8
  9. 9. 9
  10. 10. SURFACE ANALYSIS DEPTHS CATSYMP19 PRESCHOOL 17TH JAN 2009 10
  11. 11. SCANNING AUGER ELECTRON SPECTROMETER 11
  12. 12. CATSYMP19 PRESCHOOL 17TH JAN 2009 12
  13. 13. 13
  14. 14. ELEMENTAL SHIFTS 14
  15. 15. QUANTITATIVE SURFACE ANALYSIS: AES By assuming the concentration to be a relative ratio of atoms, we can neglect the terms that depend only on the instrument: The values of S are determined theoretically or empirically with standards. AES is considered to be a semi-quantitative technique 15
  16. 16. Auger Analysis Examples A - Chemical composition, thickness and spatial distribution of the elements on cerium conversion layers deposited on galvanised steel. Effect of the treatment time. 16
  17. 17. 17
  18. 18. AES DEPTH PROFILING: AN EXAMPLE 18
  19. 19. CHEMICAL SHIFT 19
  20. 20. SEMICONDUCTOR DOPING SHIFT IN AES CATSYMP19 PRESCHOOL 20
  21. 21. DOPING MAP BY AES 21
  22. 22. THANK YOU FOR ATTENTION FROM YASH 22

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