Characteristic electroforming behavior in Pt/TiO2/Pt resistive switching cells depending on atmosphere

Electroforming effects on the composition, structure, and electrical resistance of Pt/TiO2/Pt switching cells are investigated. The correlation between the electroforming procedure and the resulting bipolar switching behavior is discussed. The dependence of electroforming behavior on atmosphere is also identified, from which we define symmetric or asymmetric electroforming. The symmetry of electroforming is a key factor determining the resulting bipolar switching characteristics. From the experimental results we suggest a possible mechanism for electroforming in Pt/TiO2/Pt in terms of the formation of oxygen gas and vacancies in the vicinity of the anode.