Research Based On All-ITO Memristor

At present,the architecture of traditional computers is Von Neumann structure,which is characterized by separate calculation and storage.However,the inefficiency of von Neumann structure has become one of the main obstacles hindering the development of artificial intelligence and machine learning.The emerging memristor device not only has the characteristics of small size and low energy consumption,but also has the function of simulating biological nerve synapses.Therefore,it is widely used in storage,computing,and various devices that simulate neuromorphology,breaking the bottleneck of Von Neumann architecture.Traditional memristors based on metal / insulator / metal(MIM)stack structures usually require a voltage of about several volts to switch between different resistance states.If the working voltage of the memristor can be reduced as much as possible,it will have a significant impact on the development of such devices.In order to achieve low power consumption or enhance device sensitivity,some solutions have been proposed to reduce the operating voltage,including doping the insulator with impurity ions to increase the defect concentration,exploring insulator materials with strong defect migration capabilities,and concentrating electric fields.Based on the above background,this paper selects only one material of ITO film as the memristor material,and studies the resistance change behavior of the two memristors in the horizontal structure and the double-layer longitudinal structure and the application of the device in information recognition and memory.The research content and results of this article mainly include:(1)In the memristor based on the lateral structure of the ITO film,the electrical signal is directly applied to the single-layer ITO film to form the simplest memristor structure.The device needs to experience a voltage of about 5 volts,and the bipolar resistance change behavior is completed after the initialization process;however,in this structure,the electrical performance of the device is not stable,and the fluctuation range of the set and reset voltages is very large.Then we separately verified the influence of factors such as electrode size and spacing between electrodes on the performance of the device,assisted in the analysis of the conduction mechanism;finally,combined with the characterization technology of the thin film,it was demonstrated that the resistive behavior of this special structure device was caused by the electric field Induces migration of oxygen vacancies / oxygen ions at the interface.Compared with the MIM structure,the preparation process of the device is simpler,but the stability and controllability of the device performance still have great problems.(2)In terms of memristors based on a double-layer ITO longitudinal structure,the device shows an ultra-low set voltage of about 14 mV and a reset voltage of about 0.3 V after the initialization process,and its durability and retention of electrical properties are very stable.Through the characterization test of the device,we believe that the ultra-low working voltage may be contributed by two aspects: one is the loose and porous structure in the ITO deposited by the upper electron beam evaporation;the other is the formation of the oxygen concentration gradient during the initialization process.Then,based on the excellent resistance transition characteristics of ITO / ITO devices,the ultra-low electrical pulse stimulation was applied to realize the synaptic function and image memory function of human brain nerves.Such a small operating voltage is the minimum value currently reported in oxide-based memristors.The memristor designed in this paper uses only a commercial transparent electrode material ITO.Because it is both a resistive material and an electrode material,it simplifies the device structure compared with the traditional memristor MIM structure;at the same time we also The operating voltage is greatly reduced,and the minimum voltage is used to simulate the function of the device's nerve synapse and image memory.Therefore,our work not only provides ideas for simplifying the device structure and film deposition process,but also effectively leads and guides the development of transparent memristors with low power consumption.