Underlying layers can be examined by the use of XPS in conjunction with a gas cluster ion source (GCIS) providing elemental depth information due to the destructive nature of the ion bombardment. oxidation state) and quantitative (> ~0.1 atom %) information for all elements except hydrogen. The position and intensity of the peaks provide both chemical (e.g. The sample is illuminated with monochromatic X-rays which have sufficient photon energy to cause the photoemission of the core level electrons whose binding energies are characteristic of the elements present. X-ray Photoelectron Spectroscopy (XPS), also known as ESCA - Electron Spectroscopy for Chemical Analysis, is a non-destructive technique which provides chemical analysis of the outermost 5 – 10 nm of any vacuum compatible solid.
