Effects of O2/Ar mixing and annealing on the properties of MgTiO3 films prepared by RF magnetron sputtering

MgTiO3 thin films were prepared on n-type silicon substrate by RF magnetron sputtering with various O2/Ar ration and subsequent annealing. The crystallinity and electrical properties of the films were investigated. It was demonstrated that the electrical properties, such as leakage current and capacitance, of the films depend strongly on the oxygen content of the sputtering gas. With increasing oxygen content of the sputtering gas, the leakage current increases and the capacitance decreases. The microstructure and surface morphology of the MgTiO3 films deposited on n-Si(100) were observed by X-ray diffraction (XRD), and scanning electron microscopy (SEM). The grain size of the film increased with the increase of both the Ar partial pressure and the annealing temperature. Both the dielectric constant and the leakage current density increase with increasing annealing temperatures. It is believed that the electrical properties of MgTiO3 films depend strongly on the grain size of the films.