Improving leakage currents of Pt/Ba0.8Sr0.2TiO3/Pt capacitors using multilayered structures

Pt/Ba0.8Sr0.2TiO3 (BST)/Pt capacitors fabricated by the sol–gel process generally show abnormally high leakage currents. In this paper, we report the reduction of this leakage current in multilayered sol–gel Pt/BST/Pt thin film capacitors. The multilayered structure also provided the flexibility of adjusting the dielectric constant of the film. The thin films were fabricated by a step-by-step annealing scheme at 750 °C except that the top and bottom layers were annealed at less than 750 °C. The observed results are explained by an amorphous/polycrystalline structure, which was confirmed by scanning electron microscopy and X-ray diffraction analysis.