Interactions of heavy, low-energy ions with a Ru surface

The interactions between Xe ions in the keV-energy regime and a Ru surface have been studied. The
light sources of the modern EUV lithography machines create Sn-ion debris, which may collide with
EUV optics and damage them. Previous attempts to understand the interaction between a Sn ion beam
and transition metal surfaces such as Mo and Ru, using the Binary Collision Approximation (BCA)
have ended up with a discrepancy: the absence of a single collision peak in the scattering energy
spectrum. The aim of this thesis is to test to what extent the BCA works for explaining ion surface
interactions by using Xe, another element heavier than Ru, as a projectile, and to see whether this
discrepancy is specific to Sn or if it is about being heavier than the target atoms. The experiments are
conducted by hitting a surface with an ion beam obtained from an ECR ion source at the Zernike Low-
Energy Ion Facility (ZERNIKELEIF) at the University of Groningen. As a result of the experiments, it
has been observed that the intensities of all peaks decrease as the initial energy of the beams increases.
The recoil peaks are dominant in the spectra for all beams with different energies. Another series of
experiments has been performed with the same initial energy, but different initial charge states, and
it shows that the initial charge state does not have a significant effect on the shape and overall counts
of the resulting spectra. In conclusion, between the predictions of BCA and the experimental results,
a fairly good match is found. However, the projectiles being heavier than the target atoms causes the
recoil peak to be so intense that the SC peak appears to be hidden underneath the recoil peak