Memristors for non-volatile resistive memory based on an Al$_2$O$_3$/ZrO$_2$(Y) dielectric bilayer

In the present papper, memristors based on an Al$_2$O$_3$/ZrO$_2$(Y) dielectric bilayer with an Al$_2$O$_3$ layer of 0, 3, 6 and 9 nm in thickness manufactured by magnetron sputtering, were investigated. The presence of the additional Al$_2$O$_3$ layer between the chemically active Ta electrode and the ZrO$_2$(Y) functional dielectric allows localizing the sites of rupture and subsequent restore of the filaments during cyclic resistive switching and leads to an improvement in the stability of the resistive states of the memristor. The as-manufactured memristor stacks with different thicknesses of the Al$_2$O$_3$ can be either in the conductive state or in the non-conductive one. The stacks beijg in different resistive states initially and subjected to electroforming or “antiforming” did not demonstrate significant differences in the values of switching currents and voltages during subsequent measurements. The results obtained can be applied in the development of the “forming-free” memristors, which are relevant for their CMOS integration.