Role of Ti Electrode on the Electrical Characterization of Filament within Al2O3 Based Antifuse

In this paper, we investigated the properties of conductive filament within Al2O3 dielectric for metal-insulator-metal (MIM) antifuse structure used for one-time programmable memory. The initial formed filament after breakdown is found to exhibit metallic behavior. The antifuse on-state resistance increases and transforms to a semiconducting-like filament when a negative voltage ranges from 0 V to -1 V is applied to the top Ti electrode. Consequently, the initial formed filament would grow larger resulting in resistance decrease if the positive sweep voltage is applied on top Ti. This opposite transition is found to be related with reactive material metal Ti, which can extract a large number of oxygen ions and produce oxygen vacancies at the Ti/Al2O3 interface. Furthermore, the oxygen vacancy density near the Ti electrode dominates the properties of the filament. (C) 2018 The Electrochemical Society.