Considered the most surface sensitive elemental analysis technique in existence, LEIS uses a low energy beam of He or Ne ions to probe the top atomic layer of a sample.

Schematic showing how the ions are focused on the sample

3-10 keV He or Ne ions are focused onto the surface of a sample. A toroidal analyzer determines the energy of the backscattered ion, which can be used to determine the element from which it scattered. Due to the low energy of the technique, only the top monolayer of atoms contributes to the signal. Analysis of rough and non-conductive surfaces is possible.

Applications

  • Surface composition of metal oxide catalysts
  • Pinhole detection in ALD thin films
  • Impurity detection on semiconductor surfaces
  • Oxygen exchange via 18O detection

Sample Preparation

  • O/H plasma cleaning
  • Heating up to 600°C
  • Gas dosing up to 10 mbar
  • Glass fracturing in vacuum
  • Ar sputter depth profiling