Influence of structure changes of oxide films on their physical properties

A correlation between structural and electrical properties of tin and zinc oxide films deposited on a glass substrate by ion-beam deposition and magnetron sputtering, respectively, has been studied. Various annealing regimes were applied to alter the films structure, and then sample's electrical properties were investigated. The films structures were studied by X-ray diffraction. It is shown that immediately after deposition, the structure of tin oxides is a mixture of amorphous regions and β-Sn crystallites. Significant decrease of film resistance (about 25 times) was observed after the stepwise annealing in vacuum up to 200 °C and explained by β-Sn crystallites reconstruction. At temperatures exceeding Sn melting point, tin excess forms aggregates of β-Sn on the film-substrate boundary, resulting in significant increase of film resistance up to 200 kΩ. Two-order ZnO film resistance decrease is observed after annealing it in vacuum at 400 °C. The decreasing is reversible by applying following annealing in air.