XPS - X-ray Photoelectron Spectroscopy
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 -10nm of any vacuum compatible solid. 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. The position and intensity of the peaks provide both chemical (e.g. oxidation state) and quantitative (> ~0.1 atom %) information for all elements except hydrogen. Underlying layers can be examined by the use of XPS in conjunction with argon-ion bombardment providing elemental depth information due to the destructive nature of the ion bombardment.
The X-ray analysis facility is equipped with a state of the art Kratos Axis Ultra photoelectron spectrometer which uses Al Kα (1253.6eV) x-rays with the following capabilities:
· Sample sizes up to 2cm in diameter and up to 10mm thick
· Load lock for fast sample interchange
· Precision auto stage for multiple unattended sample analysis
· Depth Profiling for multilayered thin film analysis
· Variable angle sample orientation- angular dependent XPS
· Sample heating (600C) and sample cooling (-150C)
· Elemental imaging (min 200 µm x 200 µm) on selected samples
· Small spot analysis (min 27µm) on selected samples
Casa XPS data processing software is available for use within the facility by all CMM members.