Specific Process Knowledge/Characterization/XPS/XPS technique: Difference between revisions
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; The X-ray source | ; The X-ray source | ||
: In the X-ray gun, electrons are extracted from a filament and accelerated by a high voltage onto an aluminium anode. Here, much like the primary beam in an SEM, X-rays with the characteristic energy of aluminium 1486.7 eV are generated. Emitted isotropically, some X-rays hit a quartz crystal that act as monochromator as the X-rays diffract on the crystal planes according to the Bragg equation. If curved, the crystal will also focus the beam of X-rays and in this way enable us to use X-ray spots (in the shape of ellipses) of different sizes - ranging from 400 µm to 40 µm. The smaller spots, however, only come at the price of a drastically lowered intensity - therefore it is generally advised only to use the default value of 400 µm unless strictly necessary for some reason. | : In the X-ray gun, electrons are extracted from a filament and accelerated by a high voltage onto an aluminium anode. Here, much like the primary beam in an SEM, X-rays with the characteristic energy of aluminium (1486.7 eV) are generated. Emitted isotropically, some X-rays hit a quartz crystal that act as monochromator as the X-rays diffract on the crystal planes according to the Bragg equation. If curved, the crystal will also focus the beam of X-rays and in this way enable us to use X-ray spots (in the shape of ellipses) of different sizes - ranging from 400 µm to 40 µm. The smaller spots, however, only come at the price of a drastically lowered intensity - therefore it is generally advised only to use the default value of 400 µm unless strictly necessary for some reason. | ||