Hybrid Selector With Excellent Selectivity and Fast Switching Speed for X-Point Memory Array

In this letter, we demonstrate a new concept of threshold selector by combining Ag-based selector with NbO_x insulator metal transition (IMT) selector. To overcome intrinsic limits of slow turn-off speed (>1μs) of the Ag-based selector, we adopted NbO_x IMT selector with fast turn-off speed. The hybrid device exhibits excellent selector characteristics, such as extremely low off-current (<;1 pA) and fast turn-off speed (<;1 μs). It shows excellent readout margin (>75% at >2¹⁰ word lines) in a fast sequential operation of cross point memory array.