1. Spectroscopy
FNI 1C

2. Spectroscopy
Inputs
Outputs e- γ A+
Sample
FNI 1C

3. Probe: Electrons γ Sample e- e- Electrons Out Photons out Electrons In
Auger electrons
Secondary electron imaging
Backscattered electron imaging
Transmitted electrons
Electron diffraction
Probe: Electrons
Photons out
Energy Dispersive Spectroscopy
Wavelength Dispersive Spectroscopy
Electrons In e- e- γ
Sample
FNI 1C

4. Probe: Photons γ γ Sample e- Photons Out Photons In Electrons Out
Fourier Transform Infrared Spectroscopy
Raman
Visible
Ultraviolet
X-Ray Fluorescence
X-Ray Diffraction
Photons In
Infrared
Visible
Ultraviolet
X-Rays
Electrons Out
XPS, X-ray Photoelectron Spectroscopy γ γ e-
Sample
FNI 1C

5. Probe: Ions Sample A+ A+ Ions Out Ions In
SIMS, Secondary Ion Mass Spectrometry
ToF SIMS, Time of Flight SIMS,
ICP MS, Inductively Coupled Plasma Mass Spectrometry
Ions In A+ A+
Sample
FNI 1C

6. X-Ray Tools X-Ray Spectroscopy X-ray fluorescence (XRF)
Energy Dispersive X-ray Spectroscopy (EDS)
Wavelength Dispersive X-ray Spectroscopy (WDS)
X-ray fluorescence (XRF)
X-ray photoelectron spectroscopy (XPS)
X-Ray Diffraction
FNI 1C

7. Energy Dispersive X-Ray Spectroscopy, EDS
Element maps
Spectra
Applications
System overview
System image
X-Ray detector
FNI 1C

8. EDS Applications
Used to determine the elemental composition of a sample.
Can perform both qualitative (What is it?) and quantitative (How much?) analysis.
Depending on the window low atomic number elements may not be visible.
Super ultra thin windows detect down to berilium.
Older detectors may only detect fluorine and higher.
Window less detectors are available.
FNI 1C

9. FNI 1C

10. FNI 1C

11. EDS Element Map
FNI 1C

12. EDS Image
FNI 1C

13. Energy Dispersive X-Ray Detector System
FNI 1C

14. Solid state Si Li X-Ray Detector
FNI 1C

15. Example of Electron Transitions
FNI 1C

16. Vendors EDAX Princeton Gamma Tech Noran/Kevex/Thermo
Princeton Gamma Tech
Noran/Kevex/Thermo
Oxford Instruments
FNI 1C

17. Wavelength Dispersive X-Ray Spectroscopy, WDS
System Overview
Detector
Image
FNI 1C

18. WDS System
FNI 1C

19. WDS Detector
P10 gas is 90% argon and 10% methane
FNI 1C

20. Image of WDS Detector
FNI 1C

21. Wavelength Dispersive X-Ray Spectroscopy
System Overview
Detector
Image
FNI 1C

22. Other X-Ray Analysis X-Ray Photoelectron Spectroscopy (XPS)
X-Ray Tomography Nano CT
XRD X-Ray Diffraction
FNI 1C

23. X-Ray Photoelectron Spectroscopy
An incoming X-Ray removes a core electron which will have a characteristic energy based on the difference between the initial X-Ray energy, which is of known energy, and the energy to remove the inner electron from the atom, which is characteristic.
This has very high sensitivity.
FNI 1C

24. Links
FNI 1C

25. Quantum Numbers Number Name Permitted Values Defines n Principal
(1, 2, 3, …)
Electron shell
(1=K, 2=L, 3=M …) l
Azimuthal
0 to n-1
Electron cloud shape m
Magnetic
-l to +l
Electron shell orientation in a magnetic field s
Spin ±½
Electron spin direction j
Inner precession
l±½
But j≠-½
Total angular momentum
FNI 1C

26. Electron Shells K LI LII LIII MI MII MIII MIV MV n 1 2 3 l s +½ -½ j ½s +½ -½ j 1½ 2½
FNI 1C

27. Electron Transitions The change in n must be ≥ 1 (Δn ≠ 0)
The change in l can only be ±1
The change in j can only be ±1 or 0
FNI 1C

28. Other Surface Analysis Methods
Focused ion beam (FIB)
Mass spectrometry/Residual gas analyzer (Mass spec/RGA)
Secondary ion mass spectrometry (SIMS)
Time of Flight SIMS (ToF SIMS)
Atom probe microscopy
Auger electron spectroscopy (Auger or AES)
Rutherford Backscattering Spectroscopy (RBS)
Fourier transform infrared spectroscopy (FTIR)
Raman spectroscopy
FNI 1C

29. Mass Spectrometry, Mass Spec
Residual Gas Analyzer, RGA
Sorts atoms, molecules and molecule fragments based on mass.
FNI 1C

30. Secondary Ion Mass Spectrometry
FNI 1C

31. SIMS
FNI 1C

32. ToF SIMS
ToF SIMS
FNI 1C

33. Atom Probe Microscopes
Imago Scientific Instruments
FNI 1C

34. Imago 3D Atom Probe Microscope
FNI 1C

35. Imago LEAP
FNI 1C

36. Auger Electron Spectroscopy AES
AES has a number of advantages over X-Ray analysis.
It can be confined confined to a very small spot.
Signals are generated only from a very shallow depth into the sample (3 nm).
It can be combined with an ion mill to create a very detailed analysis of bulk materials.
Intermediate in price between SEM/EDS and more expensive systems.
FNI 1C

37. Rutherford Backscattering Spectroscopy, RBS
Uses alpha particles (He++) to analyze a material.
FNI 1C

38. Fourier Transform Infrared Spectroscopy FTIR
Uses Infra-Red EM radiation to analyze molecules, especially organic compounds.
Bending, stretching, rotation
Infrared light of different energies is passed through the sample. How the sample absorbs light is analyzed.
FNI 1C

39. Raman Spectroscopy
A change in polarizability of the molecule results in a shift in frequency of a laser.
FNI 1C

40. Focused Ion Beam FIB
This method uses a beam of ions and magnetic lenses to focus the ions onto the sample.
FIB is used to drill tiny holes in a sample.
This is usually used to see the cross sectional structure of the device.
FNI 1C

41. Example of FIB
FNI 1C

42. FIB Preparation for TEM
FNI 1C

43. FIB Links http://www.ipr.umd.edu/ionbeam/ast-fib.html
FNI 1C

44. Links
FNI 1C

45. Other Surface Analysis Methods
Focused ion beam (FIB)
Mass spectrometry/Residual gas analyzer (Mass spec/RGA)
Secondary ion mass spectrometry (SIMS)
Time of Flight SIMS (ToF SIMS)
Atom probe microscopy
Auger electron spectroscopy (Auger or AES)
Rutherford Backscattering Spectroscopy (RBS)
Fourier transform infrared spectroscopy (FTIR)
Raman spectroscopy
FNI 1C