Fully room-temperature-fabricated TiN/TaO_x/Pt nonvolatile memory devices

The reliable resistive switching properties of TiN/TaO_x/Pt structures fabricated with a fully room-temperature process are demonstrated in this letter. The devices exhibited a low operation voltage of 0.6 V as well as good endurance up to 10⁵ cycles. No data loss was reported upon continuous readout for more than 10⁴ s at 125 °C. Multilevel storage is feasible due to the dependence of the low resistance state (LRS) on the initial "SET" (switch from high to low RS) compliance current. The values of LRS showed no dependence on the size of the device, which correlated with the localized conductive filament mechanism. This nonvolatile multilevel memory effect and the fully room-temperature fabrication process make the TiN/TaO_x/Pt memory devices promising for future nonvolatile memory application. Devices under study in this Letter show promising properties regarding reproducible switching, long retention times, nondestructive readout, and multilevel storage potential. Particular emphasis is put on the TiN electrode dependence of the electrical properties, with the observed excellent bipolar resistive switching attributed to oxygen reservoir effects.