Effect of filament regimes in the resistive switching behavior of oxide-based complementary memristor

Oxide-based complementary memristor, derived from standard bipolar device, offers a promising solution to the challenge of sneak path currents in large-scale crossbar arrays. In this work, we investigate the impact of filament regimes on resistive behavior in tantalum oxide-based complementary memristor through finite element simulations. Our results reveal that the memristor exhibits bipolar resistive switching (BRS) characteristics within a voltage range of (-1.6 V, + 1.6 V) and transitions to a complementary resistive switching (CRS) over a broader voltage range (-1.8 V, + 1.8 V). In the CRS regime, increasing the radius of conductive filament (CF) from 5 to 10 nm and decreasing the CF length from 15 to 7.5 nm can enhance the Ion/Ioff ratio by 23% and 15%, respectively, due to improved thermal effects. Conversely, reducing the CF radius to 1.2 nm or extending its length to 26 nm diminishes the internal thermal effects, affecting the CF and causing the device to exhibit BRS characteristics. Moreover, decreasing the kth of electrodes can also improve the Ion/Ioff of the complementary memristor. This research advances the understanding of the interconversion between BRS and CRS and offers strategies to improve the performance of complementary memristors.