Technical Concept The sample is irradiated with monochromatic x-rays causing photoelectrons to be emitted from inner-shell orbitals of the sample surface. The binding energy of these electrons are measured, characteristic of the elements and associated chemical bonds (chemical state) in the top few atomic layers of the material.
The same atom is bonded to the different chemical species, leading to the change in the binding energy of its core electron. The variation of binding energy results in the shift of the corresponding XPS peak. This effect is termed as "chemical shift", which can be applied to studying the chemical status of element in the surface. Application
Surface failure analysis: XPS is a surface analytical technique that measures the elemental and chemical state composition of the material top 1nm to 10nm. Contamination analysis of surface discolor, defect and metal corrosion are the typical applications
Thin film analysis: composition, stoichiometry and layer thickness of thin film can be obtained by XPS. Combining argon ion source sputtering, it can produce high quality depth profile with excellent depth resolution.
Surface oxidation of metals and oxide thickness determination: XPS can provide composition of metal alloy, surface oxidation and oxide thickness. Surface oxide thickness can be determined either by non-destructive (film thickness is less than 10nm) or destructive depth profiling.
