Reduced Preferential Sputtering of TiO2 using Massive Argon Clusters

In this study, we demonstrate low damage etching of titania for depth profile analysis using large Ar cluster ions. Sample damage caused by impinging ion beams is discussed and a comparison is made between monatomic Ar ions and Arn cluster ions with respect to surface damage. Monatomic ions of beam energy 5 kV cause considerable changes to the structure of amorphous titania resulting in the preferential removal of oxygen and damage to the lattice structure. Titanium is reduced from the +4 oxidation state to +3 and +2 oxidation state during this preferential removal. In contrast, the use of clusters greatly diminishes this damage and also reduces the incorporation of the impinging ion into the sample surface. Here we discuss the use of Arn clusters as a new methodology for reducing the damaging effects caused by ion bombardment.