Bipolar and unipolar resistive switching behaviors of sol-gel-derived SrTiO3 thin films with different compliance currents

The SrTiO3 (STO) thin films on a Pt/Ti/SiO2/Si substrate were synthesized using a sol-gel method to form a metal-insulator-metal structure. This device shows the bipolar resistance switching (BRS) behavior for a compliance current I-cc of less than 0.1 mA but exhibits soft breakdown at a higher level of compliance current. A transition from the BRS behavior to the stable unipolar resistive switching behavior (URS) was also observed. We found that the BRS behavior may be controlled by the structure interface while the URS behavior is likely bulk controlled. Our study indicates that the external compliance current is a key factor in resistance switching phenomenon of STO thin films.