In-Depth Study on the Effect of Active-Area Scale-Down of Solution-Processed $\hbox {TiO}_{x}$

The effect of active-area scale-down and improved memory performance of solution-processed TiO_x were investigated using devices with active areas ranging from 50 × 50 m² to 200 × 200 nm². As the active area decreases, higher operation voltages were required owing to the reduction of unintended extrinsic defects resulting from solution processing. Moreover, faster switching speeds were observed with decreasing active area, which is induced by incremental Joule heating. These scale-down effects provided enhanced reliability characteristics such as highly uniform operation voltages and resistance states and improved pulse endurance by minimizing extrinsic defect-related nonuniformity and introducing additional heating-assisted filamentary switching.