Thermal assisted reset modelling in nickel oxide based unipolar resistive switching memory

Abstract

This paper utilizes an analytical and a filament dissolution model to calculate the local temperature increase in conducting filaments (CFs) of pulsed laser ablated unipolar NiO resistive switching memory devices. Electrical current voltage characteristics indicate unipolar switching. The formation of NiO phases is confirmed from the X-ray diffraction study. Transmission electron microscopy confirms the polycrystalline nature of NiO films having a thickness of ∼20 nm. Electrothermal simulations based on the filament dissolution model are performed using COMSOL Multiphysics® to model the CF rupture during the reset transition in the samples owing to the Joule heating effect. Obtained temperature profiles from the simulations are compared with the analytical model. Both the models corroborate with each other, allowing us to closely approximate the maximum temperature across the CF (Tcrit). This is the point corresponding to which the voltage applied across the cell (Vreset) drives the device into the reset state. The effect of annealing temperature on the maximum temperature, reset voltage, and CF diameter of the device is also discussed. The CF diameter and area of the filament are precisely estimated from the simulation.