Specific Process Knowledge/Characterization/Element analysis: Difference between revisions
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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. | 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. | ||
<gallery caption="The techniques EDX and | |||
<gallery caption="The techniques EDX, SIMS and XPS" widths="240px" heights="240px" perrow="3"> | |||
image:EDX-scheme.jpg|The high energy electrons in the beam (denoted above as incident particle) collide with the core electrons of the sample atoms that are left in an excited state with higher energy. One decay mechanism is to let an outer electron fall into the unoccupied state under emission of a photon that carries the excess energy. This energy is determined by the electronic shells and hence characteristic of the atom. | image:EDX-scheme.jpg|The high energy electrons in the beam (denoted above as incident particle) collide with the core electrons of the sample atoms that are left in an excited state with higher energy. One decay mechanism is to let an outer electron fall into the unoccupied state under emission of a photon that carries the excess energy. This energy is determined by the electronic shells and hence characteristic of the atom. | ||
image:SIMScascade.gif|A beam of high energy ions is rastered on the surface of the sample. Some of the atoms that used to make up the surface are sputtered off and emitted as secondary ions. The mass of the these ions is measured with a mass spectrometer. image:Schematic XPS. | image:SIMScascade.gif|A beam of high energy ions is rastered on the surface of the sample. Some of the atoms that used to make up the surface are sputtered off and emitted as secondary ions. The mass of the these ions is measured with a mass spectrometer. | ||
</gallery> | image:Schematic XPS.JPG|The atoms in the sample is irradiated with X-rays and the energy of the incoming photons are adsorbed. Photoelectrons are ejected, and the energy of these electrons can be measured. Since the energy of the incoming photon is known, the binding energy of the electrons in the atom can be determined. The binding energy is characteristic for the element, and therefore the composition of the sample can be determined. | ||
</gallery> | |||
== Secondary Ion Mass Spectrometry == | == Secondary Ion Mass Spectrometry == | ||