Tuning resistive switching on single-pulse doped multilayer memristors

Abstract

Short-period multilayers containing ultrathin atomic layers of Al embedded in titanium dioxide (TiO2) film—here called single-pulse doped multilayers—are fabricated by atomic layer deposition (ALD) growth methods. The approach explored here is to use Al atoms through single-pulsed deposition to locally modify the chemical environment of TiO2 films, establishing a chemical control over the resistive switching properties of metal/oxide/metal devices. We show that this simple methodology can be employed to produce well-defined and controlled electrical characteristics on oxide thin films without compound segregation. The increase in volume of the embedded Al2O3 plays a crucial role in tuning the conductance of devices, as well as the switching bias. The stacking of these oxide compounds and their use in electrical devices is investigated with respect to possible crystalline phases and local compound formation via chemical recombination. It is shown that our method can be used to produce compounds that cannot be synthesized a priori by direct ALD growth procedures but are of interest due to specific properties such as thermal or chemical stability, electrical resistivity or electric field polarization possibilities. The monolayer doping discussed here impacts considerably on the broadening of the spectrum of performance and technological applications of ALD-based memristors, allowing for additional degrees of freedom in the engineering of oxide devices.