Transition metal binary oxides for ReRAM applications

Resistive switching characteristics of polycrystalline nickel oxide were studied for non volatile memory applications. NiO was deposited by atomic layer deposition and electron beam evaporation on silicon and various metal bottom electrodes. After an initial electroforming step, NiO based devices with Pt top electrode and Si, Pt, Ni, TiN or W bottom electrodes exihibit reproducible unipolar switching. The film physical properties as well as electrode combinations influence the programming voltages and resistance window. While Pt and Si electrodes give a reduced dispersion of programming voltages and currents, the largest resistance window (up to four order of magnitude) is obtained when W is used. Preliminary data on the switching properties of amorphous Nb2O5 and polycrystalline ZrO2 films are also discussed.