Oxide Dissolution Mediated Formation of Conducting Filament in ReRAM Devices: A Phase Field Study

Abstract

Formation of oxygen vacancy-rich conducting filament in the metal-oxide insulating layer due to applied electric field is studied using phase field modelling. We consider that the formation of the Frenkel defects plays a dominant role in the process of filament formation. The choice of any other type of defects have been neglected due to the consideration of charge neutrality. We find that during the initial stages of filament formation, intrinsic defect concentration plays a crucial role. However, during the late stages, when the filament formation approaches completion, because of the increased electric field, the generation of new Frenkel defects dominates the growth mechanism. Our observation confirms that the intrinsic defects are not sufficient for the completion of conducting filament in the insulating memresistive layer. Our numerical analysis helps us to better understand the formation mechanism of conducting filament and to determine the key material parameters that influence the operation of oxide based non-volatile random access memory (RAM) i.e. resistive RAM (ReRAM).