Research On Preparation Of Molybdenum Disulfide Multi-gate Controlled Memristor And Its Memristive Characteristics

In the face of the huge data processing requirements in the era of full data and artificial intelligence,the bottleneck of the"storage wall"in the traditional von Neumann architecture has become increasingly prominent,and there is an urgent need for new computing architecture and storage devices to meet the requirements of data processing.Neural morphological devices have become the focus of current research because of their integration of storage and computing.Because of its excellent electrical properties and good mechanical flexibility,two-dimensional molybdenum disulfide shows great potential in simulating synapses and constructing neural morphological computing system.In this paper,the controllable preparation of large area and high-quality molybdenum disulfide is realized,and the memristor based on molybdenum disulfide is constructed.The specific research contents are as follows:1.Controllable equipment for large size and high quality MoS₂.Firstly,the preparation of large size and high-quality single crystal single layer MoS₂ was explored by chemical vapor deposition(CVD).The uniformity of Mo O₃ precursor supply was improved by oxidizing nickel foams,and the effects of temperature and gas flow rate on the grain size and nucleation density of MoS₂ were optimized.The single crystal monolayer MoS₂ above 150?m was prepared at 780?and 70sccm.After that,the controllable layer number of large areas MoS₂ was explored by two-step method.Firstly,the wafer-level uniform Mo O₃ precursor film of 1.8?4.6nm was deposited by atomic layer deposition(ALD),and then the layer number of wafer-scale 2 to 5 layers MoS₂was realized by optimizing CVD annealing and vulcanization process.The physical properties of MoS₂ were characterized by atomic force microscope(AFM),spherical aberration correction high resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy(Raman).The results show that the prepared MoS₂ thin films have high crystallization quality and good uniformity.2.The construction and performance of MoS₂-based memristor.The corresponding memristor devices are designed and fabricated based on single crystal single layer and 3 layers polycrystal MoS₂,respectively.The yield of array devices is?96%.After that,the electrical properties of two kinds of devices with different structures are tested and analyzed.By optimizing the pulse test parameters,98%conductance update linearity and good symmetry are achieved under the low voltage pulse signal of-1.2V,100ms.At the same time,the endurance of the device is more than 10⁵.The typical biological synaptic behaviors are simulated by electricity,ion regulation and light,including excitatory/inhibitory post-synaptic current(EPSC/IPSC),long-term plasticity(LTP),spike rate-dependent plasticity(SRDP)and spike timing-dependent plasticity(STDP),etc.Finally,the memristor mechanism of the device is explored.The change of channel conductance is caused by the change of the band gap of MoS₂ and the reversible phase transition between 2H and 1T phase caused by the insertion and detachment of lithium ion under the control of electric field.The results show that the MoS₂-based memristor can achieve more flexible conductance modulation to meet the needs of complex applications.