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. | ||
You can read futher about the technique here: [http://en.wikipedia.org/wiki/X-ray_photoelectron_spectroscopy] | |||
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[[image:Si2p.JPG|420x420px|left|thumb|XPS Si2p spectrum of Si sample]] | [[image:Si2p.JPG|420x420px|left|thumb|XPS Si2p spectrum of a Si reference sample (red curve), and a Si sample that was treated in HF shortly before the measurment was done (green curve). ]] | ||
Due to the so called Chemical shift, it is possible to get information about the chemical state of the probed atoms. | Due to the so called Chemical shift, it is possible to get information about the chemical state of the probed atoms. | ||
The core electrons of the atoms are affected, meaning that the binding energy of the electrons are slightly shifted, when an atom is bonded to atoms of other elements. | The core electrons of the atoms are affected, meaning that the binding energy of the electrons are slightly shifted, when an atom is bonded to atoms of other elements. | ||
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In the graph, you see the atomic % as a function of etch depth, and it is possible to detect that the relationship between Ni and Cr is fairly constant through the metallic film. | In the graph, you see the atomic % as a function of etch depth, and it is possible to detect that the relationship between Ni and Cr is fairly constant through the metallic film. | ||
==A rough overview of XPS-ThermoScientific characteristics== | ==A rough overview of XPS-ThermoScientific characteristics== | ||