Memristive and artificial synapse performance by using TiOx/Al2O3 interface engineering in MoS2-based metallic filament memory

Abstract

The MoS2 as a switching material has recently shown promising resistive switching characteristics. In this work, we demonstrate the impact of TiOx/Al2O3 interfacial layer on memristive/artificial synapse characteristics using MoS2-based Al/Cu/TiOx (or)Al2O3/MoS2/TiN structure. Owing to its barrier properties over Cu migration, the memristor with 2 nm-thick TiOx layer shows significant improvement in resistive switching as compared to both Al2O3 interfacial layer and 4 nm-thick MoS2. The memristor shows uniform long P/E endurance of 2 × 109 cycles under a low operation current of 200 μA and the high switching speed of 100 ns is applied. The ex-situ transmission electron microscope image reveals the formation of Cu metallic filament in MoS2 layer after long P/E endurance. At high operation current (1 mA), both the TiOx and Al2O3 interfacial layers show long P/E endurance of >109 cycles. In addition, the TiOx based memory device shows excellent RESET voltage controlled gradual RESET behavior without memory loss, enhanced uniform artificial synapse behavior with a maximum long-term potentiation/depression states of 55/500 at a small energy consumption of 5.7 pJ for future memory in computing application.