Improvement of TiO2 memristor properties by α-particles irradiation A. S. Ilin, P. A. Forsh, Yu. V. Balakshin, B. S. Shvetsov, D. V. Gusev, D. M. Rusakov, I. I. Zadiriev, E. V. Kukueva, M. N. Martyshov, A. V. Emelyanov, A. A. Shemukhin, P. K. Kashkarov Applied Physics Letters, 2025 This paper investigates the effect of alpha-particle irradiation on the memristive properties of titanium oxide-based structures. Multilayer TiOx/Ti structures were fabricated by magnetron sputtering and subjected to alpha-particle irradiation with a fluence of 2 × 1012 ions/cm2. Defect formation was modeled using the Monte Carlo method. The memristive characteristics of the structures were studied before and after bombardment. Ion bombardment was found to increase the number of stable resistive states by nearly three times, extend the number of switching cycles by 1.5 times, and significantly enhance the ROFF/RON ratio. This optimization of memristive parameters is attributed to the formation of locally created defects.
Impedance Spectroscopy of Memristive Structures Based on Hafnium Oxide M. N. Martyshov, I. D. Kuchumov, B. S. Shvetsov, D. M. Zhigunov, A. S. Ilyin, P. A. Forsh, P. K. Kashkarov Nanobiotechnology Reports, 2025 Memristive structures of Ti/HfO2/Au/c-Si, which are characterized by high ductility, are studied using the impedance spectroscopy method. Impedance hodographs are obtained for several stable resistive states. An equivalent circuit is proposed that takes into account the change in the resistance of filaments during their growth and allows for a good description of the observed changes in the type of the hodograph. Using simulation, the numerical values of the equivalent-circuit parameters are calculated. It is shown that during the switching process a significant change in the capacitance of the structure occurs. The data obtained allow us to better understand the processes that occur in such structures during switching, and open up the possibility of creating elements in which both resistance and capacitance can be controllably changed simultaneously.
Influence of Contact Area on Memristive Characteristics of Parylene-Based Structures in Single and Crossbar Geometry B. S. Shvetsov, G. A. Iukliaevskikh, K. Yu. Chernoglazov, A. V. Emelyanov Technical Physics, 2024 Abstract The key elements of neuromorphic computing systems (NCS) are memristors—resistors with a memory effect—that can be used for simultaneous processing and storage of information. It is promising to create them in crossbar geometry, where memristors are located at the intersections of the transverse electrode buses. In this work, the influence of the area and geometry of contacts on the main memristive characteristics of parylene-based structures is investigated. The results obtained indicate the independence of such memristive characteristics as the switching voltage into the low-resistance (Uset) and high-resistance states (Ureset), as well as the resistance of the samples in the low-resistance (Ron) state, from the contact area. At the same time, resistances in the high-resistance (Roff) state increase with decreasing area, which confirms the single-filament model of resistive switching, and also makes it possible to increase the window of resistance in such structures.
Electron-Beam Deposition for the Synthesis of Memristive Structures Based on Hafnium Oxide B. S. Shvetsov, A. N. Matsukatova, M. N. Martyshov, D. M. Zhigunov, A. S. Ilyin, T. P. Savchuk, P. A. Forsh, P. K. Kashkarov Nanobiotechnology Reports, 2023 Нafnium oxide is currently considered one of the most promising metal-oxide materials for creating memristive structures. Memristive structures find their application in many areas of science and technology; for example, with their help, the biosimilar emulation of synapses in neuromorphic computing systems is possible. One of the important obstacles to the industrial use of memristors is the variability of resistive switching. Nonstoichiometry in memristor structure can be an important tool for controlling resistive switching. Therefore, in this work, memristors based on hafnium oxide in a metal–insulator–metal sandwich structure are synthesized by electron-beam deposition, which makes it possible to create nonstoichiometric films. The effect of resistive switching is studied depending on the material of the upper electrode and the thickness of the hafnium-oxide layer. The synthesis parameters are determined to achieve a balance between the main memristive characteristics.
Parylene-based memristive crossbar structures with multilevel resistive switching for neuromorphic computing B. Shvetsov, A. Minnekhanov, A. Emelyanov, Aleksandr I Ilyasov, Y. Grishchenko, M. Zanaveskin, A. A. Nesmelov, D. Streltsov, T. Patsaev, A. Vasiliev, V. V. Rylkov, V. A. Demin Nanotechnology, 2022 Currently, there is growing interest in wearable and biocompatible smart computing and information processing systems that are safe for the human body. Memristive devices are promising for solving such problems due to a number of their attractive properties, such as low power consumption, scalability, and the multilevel nature of resistive switching (plasticity). The multilevel plasticity allows memristors to emulate synapses in hardware neuromorphic computing systems (NCSs). The aim of this work was to study Cu/poly-p-xylylene(PPX)/Au memristive elements fabricated in the crossbar geometry. In developing the technology for manufacturing such samples, we took into account their characteristics, in particular stable and multilevel resistive switching (at least 10 different states) and low operating voltage (<2 V), suitable for NCSs. Experiments on cycle to cycle (C2C) switching of a single memristor and device to device (D2D) switching of several memristors have shown high reproducibility of resistive switching (RS) voltages. Based on the obtained memristors, a formal hardware neuromorphic network was created that can be trained to classify simple patterns.
Stability of Quantized Conductance Levels in Memristors with Copper Filaments: Toward Understanding the Mechanisms of Resistive Switching O. Kharlanov, B. Shvetsov, V. V. Rylkov, A. Minnekhanov Physical Review Applied, 2022 Memristors are among the most promising elements for modern microelectronics, having unique properties such as quasi-continuous change of conductance and long-term storage of resistive states. However, identifying the physical mechanisms of resistive switching and evolution of conductive filaments in such structures still remains a major challenge. In this work, aiming at a better understanding of these phenomena, we experimentally investigate an unusual effect of enhanced conductive filament stability in memristors with copper filaments under the applied voltage and present a simplified theoretical model of the effect of a quantum current through a filament on its shape. Our semi-quantitative, continuous model predicts, indeed, that for a thin filament, the “quantum pressure” exerted on its walls by the recoil of charge carriers can well compete with the surface tension and crucially affect the evolution of the filament profile at the voltages around 1 V. At lower voltages, the quantum pressure is expected to provide extra stability to the filaments supporting quantized conductance, which we also reveal experimentally using a novel methodology focusing on retention statistics. Our results indicate that the recoil effects could potentially be important for resistive switching in memristive devices with metallic filaments and that taking them into account in rational design of memristors could help achieve their better retention and plasticity characteristics.
Poly-para-xylylene-Based Memristors on Flexible Substrates B. S. Shvetsov, A. N. Matsukatova, A. A. Minnekhanov, A. A. Nesmelov, B. V. Goncharov, D. A. Lapkin, M. N. Martyshov, P. A. Forsh, V. V. Rylkov, V. A. Demin, A. V. Emelyanov Technical Physics Letters, 2019
On the resistive switching mechanism of parylene-based memristive devices Anton A. Minnekhanov, Boris S. Shvetsov, Mikhail M. Martyshov, Kristina E. Nikiruy, Elena V. Kukueva, Mikhail Yu Presnyakov, Pavel A. Forsh, Vladimir V. Rylkov, Victor V. Erokhin, Vyacheslav A. Demin, Andrey V. Emelyanov Organic Electronics, 2019
