Control of Resistive Switching Endurance in TiO2/TiO2–x Memristors via Thermally Assisted Oxygen Plasma With Power Modulation

In this study, thermally assisted oxygen plasma (TAOP) treatment was used to reduce oxygen vacancies in TiO ${}_{{2} -{x}}$ thin films to improve the stability and control the resistive switching (RS) behavior of memristors. TAOP was applied at 160 °C for 5 min with varying power levels: 0 (pristine), 40, 80, and 120 W. The I–V curves showed the largest hysteresis at positive voltages for devices treated at 40 W, followed by 80, 0, and 120 W. However, retention tests revealed that the 40-W device exhibited the lowest stability, while the 80-W device showed the highest. To further compare performance, both 40- and 80-W devices were tested for 100 cycles from −3.5 to 3.5 V. The 80-W device maintained stable I–V behavior, whereas the 40-W device was unstable. UV-Vis transmittance measurements showed a gradual decrease in the bandgap energy in the order of pristine, 40, 80, and 120 W, indicating that TAOP facilitated oxygen ion injection into vacancies. These results confirm that TAOP at 80-W optimally reduces oxygen vacancies without causing excessive filament formation, thereby enhancing switching stability and device reliability.