Bipolar resistive switching in amorphous titanium oxide thin films

Using isothermal and temperature-dependent electrical measurements, we investigated the resistive switching mechanism of amorphous titanium oxide thin films deposited by a plasma-enhanced atomic layer deposition method between two aluminum electrodes. We found a bipolar resistive switching behavior in the high temperature region (> 140 K), and two activation energies of shallow traps, 0.055 eV and 0.126 eV in the ohmic current regime. We also proposed that the bipolar resistive switching of amorphous TiO2 thin films is governed by the transition of conduction mode from a bulk-limited SCLC model (Off state) to an interface-limited Schottky emission (On state), generated by the ionic movement of oxygen vacancies.