Role of Local Chemical Potential of Cu on Data Retention Properties of Cu-Based Conductive-Bridge RAM

In this letter, we experimentally investigate data retention in a copper (Cu)-based conductive bridge random-access memory device at a low current regime (10 μA) in which retention is governed by factors other than just the conductive filament. Our findings show that the retention characteristics are determined by the local chemical potential of Cu between the conductive filament and its surrounding medium. Furthermore, the retention tendencies are described by the electrochemical reaction in accordance with the potential difference of Cu ions. Therefore, an appropriate quantity of Cu ions around the filament is important for achieving thermally reliable high and low resistance states over time.