Specific Process Knowledge/Characterization/XPS: Difference between revisions
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In the XPS spectrometer system the probed samples are irradiated by photons with a specific energy, and the photoelectrons that leaves the sample are detected. The energy levels of the electrons are elemental specific, and by measuring the energy of the outgoing electrons, it is possible to detect which elements that are present in a sample. | In the XPS spectrometer system the probed samples are irradiated by photons with a specific energy, and the photoelectrons that leaves the sample are detected. The energy levels of the electrons are elemental specific, and by measuring the energy of the outgoing electrons, it is possible to detect which elements that are present in a sample. | ||
The technique can be used for different purposes: | |||
'''Elemental composition''' | |||
[[image:Overview spectra Labadvisor.JPG|350x350px|left|thumb|XPS spectrum of a sample consisting of the elements silicon, oxygen and carbon.]] | |||
Each element give a specific "finger-print" in the XPS spectrum. The electrons in the atoms have different binding energies for all elements, and when measuring a photoelectron spectrum over a wide range of energies, the main line from each element will be placed at a specific energy in the spectra. | |||
Here is shown a spectra measured over the energy range 0-1350 eV, and characteristic lines from three elements (C,O and Si) are seen and indicated in the spectrum. | |||
The instrument program can use this information to give an estimate of the sample composition, giving the atomic procentage of the different elements. | |||
'''Chemical state''' | |||
[[image:Si spectra Labadvisor.JPG|350x350px|left|thumb|XPS Si2p spectrum of Si sample]] | |||
'''Depth profiling''' | |||
[[Image:Stochiometry 20110510.JPG|350x350px|left|thumb|Stochiometry as a function of film depth (etch time). The relationship between Cr and Ni is quite stabel through the film. Measurements done with XPS-ThermoScientific ]] | |||
==A rough overview of XPS-ThermoScientific characteristics== | ==A rough overview of XPS-ThermoScientific characteristics== | ||