Depth Profiling of Anodic Tantalum Oxide Films with Gold Cluster Ions

In order to investigate the merits of cluster bombardment for inorganic sputter depth profiling, thin (50-nm) anodic Ta2O5 films were analyzed by ToF-SNMS using 25 keV Au-n(+) projectile ions. The same focused primary ion beam was employed both for sputter erosion and (static) data acquisition. Sputtered neutral particles were postionized by means of single photon ionization using a 157 nm F-2 excimer laser. The results show that, for the amorphous films investigated here, the transition from mono-to-polyatomic projectiles does not lead to a significant improvement of the apparent depth resolution. Copyright (C) 2010 John Wiley & Sons, Ltd.