Process Oxygen Flow Influence on the Structural Properties of Thin Films Obtained by Co-Sputtering of (TeO(2))(x)-ZnO and Au onto Si Substrates

In this study, we investigated the structural properties of TeO(2)-ZnO (TZ) and TeO(2)-ZnO-Au (TZA) thin films sputtered under different oxygen concentrations and either annealed or not annealed at 325 °C in air for 10 or 20 h. The lattice changes of the tellurium oxide were shown to be inherent in the polymorph properties of the α and β phases. The β phase was formed for null oxygen flow and the α phase was formed for different oxygen flows (0.5–7.0 sccm) during TZ and TZA sputtering. Au was encountered in its single phase or as AuTe(2). The annealing had very little influence on the α and β phases for both TZ and TZA. It is worth noting that SiO(2) and orthotellurate anions are both formed for not-null oxygen flow. An electrochemical mechanism was proposed to explain the SiO(2) growth at the TZ/Si or TZA/Si interface, taking the orthotellurate anion as oxidizing agent into account.