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

The high leakage current density was measured immediately after the top electrode annealing but leakage current characteristics were improved with increasing time. In C-F characteristics, the low frequency dielectric dispersion was observed and the dispersion frequency moved to low frequency due to an increase of the interface resistance. The time dependence of electrical properties are attributed to the gradual decrease of conductivity of (semi)conducting 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 conductivity may be decreased due to the interaction of metallic Bi with oxygen atoms after the stabilisation. 12 refs.