Comparison between the energies of ejected ions in the cases of KrF laser ablation and Ar ion sputtering

The kinetic energy distributions of positive ions ejected from Si, Co, Ni and Pb-Zr-Ti-O targets subjected to KrF excimer laser or Ar ion irradiation were measured. It was found that the average energies of the ejected ions originating from laser ablation were in excess of 100 eV, while those from Ar ion sputtering were a few tens of eV. The energy distributions of the ejected ions by laser ablation were peculiar ones, characterized by having a lot of peaks, which are thought to show the plasma states on the target surface, for example generation of high electrical field. On the other hand, the energy distributions in the case of Ar ion sputtering showed the ones based on the collision cascade process.