R&D: Resistive Switching Properties of Amorphous Sm2Ti2O7 Thin Film Prepared by RF Sputtering for RRAM Applications

Journal of Alloys and Compounds has published an article written by Yu-Ta Chen, Tsung-Hsien Hsu, and Cheng-Liang Huang, Department of Electrical Engineering, National Cheng Kung University, 1 University Road, Tainan City 70101, Taiwan.

Abstract: “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 R_on/R_off 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 AlO_x interface layer, which prevents the oxygen ions from out-diffusion through the boundaries. At the PMA temperature of 350 °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.“