Exploring resistive switching properties and mechanisms in sol-gel derived Gd₂Ti₂O₇ thin films for RRAM applications

This study focused on investigating the effects of film thicknesses and thermal treatments on the resistance-switching characteristics of Gd₂Ti₂O₇-based RRAM devices for the first time. Gd₂Ti₂O₇ thin films were successfully synthesized using a sol-gel deposition technique on ITO/glass substrates as the foundation for this research. The conduction mechanism of the filament was found to be primarily influenced by oxygen vacancies. The study found that annealing at 300 °C resulted in a slight increase in oxygen vacancies and switching cycles. However, annealing at 200 °C and 400 °C led to a significant decrease in oxygen vacancies, resulting in reduced switching cycles. To further enhance the device performance, a post-metal annealing process was applied at 300 °C to form an extra AlOx layer. This additional layer facilitated the coexistence of oxygen vacancies and aluminum ions, promoting the formation of conductive filaments and enhancing the resistive switching performance of the devices. As a result, the device subjected to 300 °C post-metal annealing demonstrated optimized resistive switching properties, including a maximum of 1248 switching cycles, a R_on/R_off ratio of 10², and V_Set/V_Reset = −5.38 V/2.08 V. These findings highlight the promising potential of Gd₂Ti₂O₇-based RRAM devices for practical applications in Resistive Random Access Memory (RRAM).