Forming-Free $\hbox {TiO}_{2}$ -Based Resistive Switching Devices on CMOS-Compatible W-Plugs

In this letter, bipolar resistive switching in TiO₂-based memory elements deposited on CMOS-compatible W-plugs is examined. By comparison with a Pt/TiO₂/W resistive switch, it is demonstrated that the use of a 5-nm-thin Ti or W interlayer between the Pt top electrode and the 25-nm TiO₂ film is the key step for the release from the necessity of electroforming, which is usually required in redox-based resistive switching elements. This is explained by an intentional barrier lowering between the oxide and the electrode materials. The forming-free characteristics on W-plugs make the devices very attractive for future nonvolatile memory applications.