Oxygen vacancy engineering of TaO _x -based resistive memories by Zr doping for improved variability and synaptic behavior

Abstract

Resistive switching (RS) devices are promising forms of non-volatile memory. However, one of the biggest challenges for RS memory applications is the device-to-device (D2D) variability, which is related to the intrinsic stochastic formation and configuration of oxygen vacancy (VO) conductive filaments (CFs). In order to reduce the D2D variability, control over the formation and configuration of oxygen vacancies is paramount. In this study, we report on the Zr doping of TaO x -based RS devices prepared by pulsed-laser deposition as an efficient means of reducing the VO formation energy and increasing the confinement of CFs, thus reducing D2D variability. Our findings were supported by XPS, spectroscopic ellipsometry and electronic transport analysis. Zr-doped films showed increased VO concentration and more localized VOs, due to the interaction with Zr. DC and pulse mode electrical characterization showed that the D2D variability was decreased by a factor of seven, the resistance window was doubled, and a more gradual and monotonic long-term potentiation/depression in pulse switching was achieved in forming-free Zr:TaO x devices, thus displaying promising performance for artificial synapse applications.

Mimicking Pain-Perceptual Sensitization and Pattern Recognition Based on Capacitance- and Conductance-Regulated Neuroplasticity in Neural Network

“…The presence of oxygen vacancies in TaO x is characterized by X-ray photoelectron spectroscopy as shown in Figure S3c. The result contains a percentage of 16.68% in the nonlattice oxygen peak, which can be associated with the presence of oxygen vacancies. , …”

“…The result contains a percentage of 16.68% in the nonlattice oxygen peak, which can be associated with the presence of oxygen vacancies. 31,32 2.3. Emulation of Synaptic Functions.…”

Nano t-Se Peninsulas Embedded in Natively Oxidized 2D TiSe2 Enable Uniform and Fast Memristive Switching

“…Noted that our device is still large in size, e.g., 5 × 3 μm 2 , and by further reducing the device area, the number of peninsula structures in the device can be limited and the energy consumption of the device can be further reduced. We summarize our device performance, including the uniformity and switching time in comparison with other prototypical memristors in Figure c,d ,,− (detailed data can be found in Table S1 of the Supporting Information).…”

Tuning resistive switching properties of WO3−x-memristors by oxygen vacancy engineering for neuromorphic and memory storage applications

“…Skaja et al reported manifestation of reduced forming voltage and high R off /R on upon increasing V O s content in sputterdeposited Ta 2 O 5−x thin films, in which V O s concentration had been controlled by the sputter power and O 2 /Ar ratio [15]. Palhares et al reported on Zr doping in TaO x thin films as an efficient method of reducing V O s formation energy, increasing confinement of the CFs which led to reduced deviceto-device variability [16]. Ghenzi et al demonstrated that a small variation of O 2 /Ar ratio during reactive sputter growth of TiO 2−x -based devices led to different RS characteristics, e.g.…”