Leakage current asymmetry and resistive switching behavior of SrTiO3

The resistive switching characteristics of SrTiO₃ metal-insulator-metal capacitors are investigated. The current-density versus voltage (J-V) characteristics show asymmetry at all temperatures examined, with resistive switching behavior observed at elevated temperatures. The asymmetry is explained by the relative lack of electron traps at one electrode, which is determined from the symmetric J-V curve obtained at room temperature due to the redistribution of the dominant electrical defects in the film. We present evidence for the model of resistive switching originating from defect diffusion (possibly oxygen vacancies) at high temperatures.