Ion Scattering Spectroscopy (ISS)

Ion scattering spectroscopy (ISS, also known as LEIS – low energy ion scattering) is used to obtain elemental information from the first atomic layer of the surface. It uses He+ gas ions, which are directed at the surface, scattered and then detected by the hemispherical analyser. The kinetic energy of the scattered ions is measured which is then used to calculate the mass of the surface atom. The extreme surface sensitivity means that samples must be clean to detect the actual surface and not any surface overlayers which may be present.

ISS can be used to determine elemental surface composition, surface segregation and monolayer coverage or growth when using techniques such as atomic layer deposition (ALD).