Influence of conducting filament dimension on the performance of ReRAM device in the SET state

Abstract

To achieve the current-day demand for data storage, resistive random access memory (ReRAM) is an emerging candidate in non-volatile memory (NVM) segment. The switching of ReRAM device deals with SET and RESET states where formation and dissolution of conducting filament (CF) decide the resistive state of the device. In SET state, the current flows through CF which induces Joule heat inside ReRAM. An electro-thermal numerical model has been designed to demonstrate the Joule heat induction and the temperature distribution caused by this. Following this model, the temperature distribution in two directions, such as along radial and longitudinal directions are executed numerically. The results obtained from numerical models are validated with an analytical model with the help of Weidemann-Franz-Lorenz law. In SET state, there are many factors to influence the width of CF such as concentration of defect in oxide layer, oxygen vacancies, presence of interface layer, applied voltage. Going further, to investigate the CF dimension influence on Joule heat, devices with different CF sizes have been modeled and then we have tracked the maximum temperature (Tmax) for each case. It has been found that with an increase in radius of cylindrical CF, Tmax increases linearly. To demonstrate the influence of CF dimension on device performances like device resistance, current, power dissipation; we further implemented an analytical framework considering an isothermal switching of the ReRAM device. With CF radius increment, current follows an exponential growth where resistance and power dissipation show an exponential decrement in the designed ReRAM devices.