Specific Process Knowledge/Characterization/XPS/XPS technique: Difference between revisions
| Line 8: | Line 8: | ||
There are two reasons why the technique is extremely useful: | There are two reasons why the technique is extremely useful: | ||
* '''Chemical sensitivity:''' The kinetic energy of the photoelectrons may be determined with such high accuracy (for instance, the resolution of the spectrometer is roughly 1 eV compared to the ~130 eV resolution of the spectrometer in an EDX X-ray detector ) that the small changes in binding energy of the sample electrons caused by the binding to other atoms may be detected. It is therefore possible to | * '''Chemical sensitivity:''' The kinetic energy of the photoelectrons may be determined with such high accuracy (for instance, the resolution of the spectrometer is roughly 1 eV compared to the ~130 eV resolution of the spectrometer in an EDX X-ray detector ) that the small changes in binding energy of the sample electrons caused by the binding to other atoms may be detected. It is therefore possible to obtain information about the chemical environment of the elements - for instance in terms: | ||
** Oxidation state | |||
** Double bonds | |||
** Surface states | |||
* '''Surface sensitivity:''' The inelastic mean free path of the photoelectrons is very short - as a result, photoelectrons from depths larger than some 10 monolayers will not contribute to the peaks as they have lost part of their kinetic energy. | * '''Surface sensitivity:''' The inelastic mean free path of the photoelectrons is very short - as a result, photoelectrons from depths larger than some 10 monolayers will not contribute to the peaks as they have lost part of their kinetic energy. | ||