Abstract
The depth resolutions by the Auger electron spectroscopy and the X-ray photoelectron spectroscopy are reviewed. The analytical depth is determined by the following 3 factors. (1) The first is the penetration depth of the incident primary electron or the incident soft X-ray. (2) The second is the ionization cross-section by which the yields of the Auger electrons or the photo-electrons are determined. (3) The last is the electron escape depth itself.
The penetration depth and the ionization cross-section varies about 10% at the most inside the range of the electron escape depth. The electron escape depth has the value of 5-20A in the energy range of 10-1, 500eV. When the composition is not uniform in the range of 5-20A from the top most surface, the composition determination becomes difficult due to the differences of the electron mean free paths of the Auger electrons and/or the photoelectrons from the component materials.
