Specific Process Knowledge/Characterization/XPS/XPS technique: Difference between revisions

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 ; Transport towards the vacuum
-: The inelastic mean free path of the photoelectrons is very short. The information carried by the photoelectrons will therefore quickly degrade as they collide inelastically and loose part of their energy. This means that only photoelectrons originating from the ~10 topmost atomic layers of the sample contribute to the signal - in this way making XPS extremely surface sensitive. The tail of former photoelectrons with non-specific energy is called the background.
+: The inelastic mean free path of the photoelectrons is very short. The information carried by the photoelectrons will therefore quickly degrade as they collide inelastically and loose part of their energy. This means that only photoelectrons originating from the ~10 topmost atomic layers of the sample contribute to the signal - in this way making XPS extremely surface sensitive. The tail of former photoelectrons with non-specific energy is called the background. From inside the sample the electrons must pass the socalled work function in order to escape into the vacuum.
 ; Detection in the analyzer
+: In the analyzer the electrons are separated according to the kinetic energy by two concentric spheres held at some potential. By playing on the acceptance angle of the entrance/exit slits of the analyzer one can tune the energy resolution with the parameter called pass energy. Subsequently detected by the spectrometer, the number of electrons may be plotted as a function of energy thus making up an XPS spectrum.
-== X-ray Photoelectron Spectroscopy analysis (XPS) ==
-=== Typical applications of XPS ===
-The XPS can be used for different applications, for example:
-* Do an elemental analysis of the outermost layer of your surface.
-* Check the composition of a film at different depths.
-* Check for a contaminations.
-** It not as sensitive as the SIMS, but faster, so it can be an alternative if you are checking for a bit higher contamination levels (like 1 %)
-* Do a analysis of the chemical state of atoms present on the surface.
-** See what effect a surface treatment of your sample has on the surface chemistry.
-** Check a polymer covered surface. Are for example (C=O), (C-OH) (C-C) groups present in the polymer after it been deposited on a surface.