Understand the Resistive Switching and Reliability Mechanisms of 2D TMD Material: Defect Engineering, Finite Element Analysis and Monte Carlo Modeling

Two-dimensional (2D) materials become a promising candidate for the resistive random-access memory (memristor) devices. However, reliability is one of the major challenges to the realistic application. We employ an electron irradiation treatment on monolayer MoS₂ film to modify the defect properties and improve the reliability. A sulfurization method has been proposed to tune the defect from the beginning of material synthesis. MoS₂ memristors are fabricated afterwards. Tuning the sulfurization parameters (temperature/metal precursor thickness) is found to be a simple but effective strategy to improve reliability of memristors. To explain the switching and reliability mechanisms, we proposed the dissociation-diffusion-adsorption (DDA) and cluster model for monolayer 2D MoS₂ memristors. Thermoelectric simulations are designed and conducted by COMSOL Multiphysics to demonstrate the Joule heating effect caused by the low resistance regions within the MoS₂ layers, which illustrates the mechanism of the RESET. A Monte Carlo (MC) simulator is designed for multilayer 2D memristor to expand the application of DDA and cluster models. The COMSOL simulation results are implemented in the design of resistive switching process in the MC simulator. It is found that the endurance characteristic is mainly determined by the formation and collapsing of an intermediate layer. Also, the thickness of intermediate layer is independent from the total thickness of MoS₂ and the initial status of the devices.