Improvement in Threshold Switching Performance Using Al₂O₃ Interfacial Layer in Ag/Al₂O₃/SiOₓ/W Cross-Point Platform

An Al
₂
O
₃
/SiOx bi-layer cross-point selector was proposed and experimentally demonstrated in this work to mitigate the sneak path leakage issue in the high density passive crossbar array. A 2 nm Al
₂
O
₃
interfacial layer confines filament dissolution gap caused by Ag diffusion into the SiOx layer, enabling significant improvement in uniformity and other electrical performances as compared to the monolayer SiOx selector (without Al2O3 layer). Devices with Al
₂
O
₃
interfacial layer exhibit I-V characteristics with large selectivity of > 5 × 107, high rectifying ratio (RR) of >5 × 107, high ON state current density of >103 A·cm-2, steep slope subthreshold swing (SS) of <; 5 mV/decade, and fast relaxation speed of 200 ns. Furthermore, stable endurance and capability to withstand DC bias stress of > 10 4 seconds were also demonstrated.