Resistive switching properties of amorphous Sm2Ti2O7 thin film prepared by RF sputtering for RRAM applications

The resistive switching (RS) characteristics of amorphous Sm2Ti2O7 thin films prepared by using RF sputtering were investigated and the effect of post-metallization annealing (PMA) on the RS properties were analysed. Comparison of as-deposited Sm2Ti2O7 thin film device and the device after PMA treatment, the latter exhibits better RS properties, including more uniform set voltages, switching cycle times and higher Ron/Roff ratio. The prepared samples all revealed bipolar resistive switching (BRS) behaviour. The results indicated that the conductive mechanism in terms of the concentration of oxygen vacancies can be controlled by different deposition atmosphere (Ar/O2) ratio and film thickness. Additionally, the resistive switching properties can be enhanced by PMA treatment due to the formation of AlOx interface layer, which prevents the oxygen ions from out-diffusion through the boundaries. At the PMA temperature of 350 degrees C, the two resistance states can be distinguished in a range of > 10 over 8099 switching cycles along with a retention of 104 s at room temperature and 85oC, showing promise for non-volatile memory applications. (c) 2022 Elsevier B.V. All rights reserved.