Specific Process Knowledge/Characterization/Element analysis: Difference between revisions

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 [[image:EDX-scheme.jpg|300x300px|right|thumb|X-rays, with an energy that is characteristic of the atom they are emitted from, are created when the high energy electrons impinge on the sample. ]]
-You can make detailed analysis on the elemental composition and distribution in a sample with 3 instruments at Danchip. The [[Specific Process Knowledge/Characterization/SEM: Scanning Electron Microscopy/Leo|Leo SEM]] and [[Specific Process Knowledge/Characterization/SEM: Scanning Electron Microscopy/FEI|FEI SEM]] are both equipped with an X-ray detector that allows you to make elemental analysis by using the technique Energy Dispersive Analysis or EDX. The [[Specific Process Knowledge/Characterization/SIMS: Secondary Ion Mass Spectrometry|Atomika SIMS]] uses a technique called Secondary Ion Mass Spectrometry or SIMS.
+You can make detailed analysis on the elemental composition and distribution in a sample with 3 instruments at Danchip. The [[Specific Process Knowledge/Characterization/SEM: Scanning Electron Microscopy/Leo|Leo SEM]] and [[Specific Process Knowledge/Characterization/SEM: Scanning Electron Microscopy/FEI|FEI SEM]] are both equipped with an X-ray detector that allows you to make elemental analysis by using the technique Energy Dispersive X-ray analysis or EDX. The [[Specific Process Knowledge/Characterization/SIMS: Secondary Ion Mass Spectrometry|Atomika SIMS]] uses a technique called Secondary Ion Mass Spectrometry or SIMS.
 == Energy Dispersive X-ray analysis ==
-The technique of extracting information from the X-rays generated in a sample that is irradiated with electrons is called energy dispersive X-ray analysis or EDX. (Other acronyms are Energy Dispersive x-ray Spectroscopy, EDS, or Electron Probe Microanalysis, EPMA). The energetic electrons in the incident beam create core level vacancies as they collide with sample atoms electrons in a multiple scattering process. To decay from this excited state photons may be emitted. The energy of these photons is determined by the difference in energy of the shells involved. Since atomic shells are unique for every element so will be the transitions between them. Thus, every element has its own characteristic X-ray spectrum that can be used to determine the elemental composition.
+The technique of extracting information from the X-rays generated in a sample that is irradiated with electrons is called energy dispersive X-ray analysis or EDX. (Other acronyms are Energy Dispersive x-ray Spectroscopy, EDS, or Electron Probe Microanalysis, EPMA). The energetic electrons in the incident beam create core level vacancies as they collide with sample atoms electrons in a multiple scattering process. This leaves the atoms in the sample in an excited state. In the process of decaying from this state photons may be emitted. The energy of these photons is determined by the difference in energy of the shells involved. Since atomic shells are unique for every element so will be the transitions between them. Thus, every element has its own characteristic X-ray spectrum that can be used to determine the elemental composition.
+Adding an EDX detector to a SEM provides a very powerful tool for elemental analysis. The capability of the SEM to precisely maneuver the electron beam in a number of ways enables us to make point-like analysis with nanometer precision.
 == Secondary Ion Mass Spectrometry ==
 [[image:SIMScascade.gif|200x200px|right|thumb|Atoms that used to make up the surface are sputtered off by the high energy ions; some are emitted as secondary ions. ]]
 When a solid sample is sputtered by primary ions of few keV energy, a fraction of the particles emitted from the target is ionized. Secondary Ion Mass Spectrometry consists of analyzing these secondary ions with a mass spectrometer. Secondary ion emission by a solid surface under ion bombardment supplies information about the elemental, isotopic and molecular composition of its uppermost atomic layers.