A double barrier memristive device

We present a quantum mechanical memristive Nb/Al/Al(2)O(3)/Nb(x)O(y)/Au device which consists of an ultra-thin memristive layer (Nb(x)O(y)) sandwiched between an Al(2)O(3) tunnel barrier and a Schottky-like contact. A highly uniform current distribution for the LRS (low resistance state) and HRS (high resistance state) for areas ranging between 70 μm(2) and 2300 μm(2) were obtained, which indicates a non-filamentary based resistive switching mechanism. In a detailed experimental and theoretical analysis we show evidence that resistive switching originates from oxygen diffusion and modifications of the local electronic interface states within the Nb(x)O(y) layer, which influences the interface properties of the Au (Schottky) contact and of the Al(2)O(3) tunneling barrier, respectively. The presented device might offer several benefits like an intrinsic current compliance, improved retention and no need for an electric forming procedure, which is especially attractive for possible applications in highly dense random access memories or neuromorphic mixed signal circuits.