Time dependence of electrical properties of SrBi2Ta2O9 thin films after top electrode annealing

The time dependence of electrical properties of SrBi2Ta2O9 (SBT) thin films after top electrode annealing was studied. The high leakage current densit y was measured immediately after the top electrode annealing but leakage cu rrent characteristics were improved with increasing time. In C-F characteri stics, the low frequency dielectric dispersion was also observed and the di spersion frequency moved to low frequency due to the increase of the interf ace resistance. The time dependence of electrical properties can be explain ed to be due to the gradual decrease of the conductivity of (semi)conductin g paths. The conducting path may be formed by the diffusion of metallic Bi and the reduction of Bi oxide during the top electrode annealing and its co nductivity may be decreased due to the interaction of metallic Bi with oxyg en atoms after the stabilization. (C) 2000 Elsevier Science B.V. All rights reserved.