Studying of threshold switching behavior based on programmable metallization cells selector by KMC method

Programmable metallization cells (PMCs) selectors are considered with great potential in various properties including suppressing the current and mimicking the neurons while its mechanism is still difficult to study by direct observation. In this work, a Kinetic Monte Carlo (KMC) model was established to understand the mechanism of selector with the W/Ag/HfO2/Pt structure, which performed typical threshold switching characteristics. By comparing experiment and simulation of threshold switching behavior, the model was verified and the morphological change of conductive filaments (CF) was displayed. The interfacial energy and migration of ions had a great influence on the formation and rupture of the filament and the threshold switching (TS) behavior. Moreover, the mechanism of TS property was studied by analyzing the dynamic changes of CF in switching and cycling processes. This work provided a KMC model of PMC selectors which was possibly helpful for predicting the performance of the device and guided further optimization of selectors.