Study Of Memristor-based Electronic Synapse In Neuromorphic Computing

With the rapid development of information technology,human society has entered the era of big data.While the traditional computing system architecture and semiconductor technology are insufficient to deal with the explosive growth of computing data.The use of memristors as electronic synapses to implement large-scale,low-power hardware neuromorphic computing systems is an important way to break through the limitations of traditional computing architecture and improve the computing performance.The memristor has the advantages of simple structure,low power consumption,good micronizability,etc.The resistance of memristors can be continuously modulated,which is very similar to the synaptic characteristics in human brain,so a memristor is an ideal device to mimick electronic synapse.In this paper,research on memristor-based electronic synapse is carried out to develop excellent synaptic performances in memristors and to further promote the hardware implementation of neuromorphic computing systems.The main work of this thesis is as follows:Chapter 2 is a literature review,which summarizes the research status of memristor electronic synapses.In Section 2.1,the basic characteristics of the memristor is introduced,including resistive switching,electrical operation,material system and conductive mechanism.Section 2.2 introduces the research of memristors as electronic synapses.Firstly,the synaptic plasticity in the biological nervous system is presented.Then,the research status of using the memristor to simulate the biological synaptic characteristics is reviewed.Finally the exiting problems are analysied and summaried,which leads to the research content of this subject.In Chapter 3,a highly sensitive cation-based memristor synapse is developed.Section 3.1 mainly introduces the design scheme of electronic synapse.The design goal of a high sensitive synaptic device is proposed according to the application of the bionic neuromorphic system.And the material selection and structural design of the device are carried out given the characteristics of the material.Section 4.2 is introduces the device fabrication.We analyze the properties of different fabricaton methods,and make selections.Then we introduce the device fabrication process.Finally,the structure of the fabricated device is examized using SEM.In Section 4.3,The synaptic characteristics of the fabricated memristor is evaluated by a semi-conductor analyzer.In Chapter,an oxygen vacancy memristor synapse with continuously modulating property is studied.Section 4.1 mainly introduces the research scheme of the device.The design goal of the device is proposed to bo used the application of MLP nervous system.Then the device material and structure is selected according to the material properties and the contact surface characteristics between different materials.In Section 4.2,the fabrication process of the device is introducted and the structural characterization after device fabrication is performed.In section 4.3,The synaptic characteristics of the fabricated memristor is evaluated.