XPS depth profiling studies of L-CVD SnO2 thin films

In this paper we present the results of the XPS atomic depth profile analysis, using ion beam sputtering, of L-CVD SnO₂ thin films grown on an atomically clean SiO₂ substrate after annealing at 400 °C in dry atmospheric air. From the evolution of the Sn 3d_5/2, O 1s, Si 2p and C 1s core level peaks our experiments allowed the determination of the in depth atomic concentration of the main components of the SnO₂/SiO₂ interface. Thin (few nm) nearly stoichiometric SnO₂ films are present at the topmost layer of the thin films, and progressive intermixing with SnO and silicon oxide is observed at deeper layer. The interface between the Sn and the Si oxide layers (i.e. the effective Sn oxide thickness) is measured at 13 nm.