12-4 Multi-layer Tunnel Barrier (Ta2O5/TaOx/TiO2) Engineering for Bipolar RRAM Selector Applications Jiyong Woo1, Wootae Lee2, Sangsu Park3, Seonghyun Kim2, Daeseok Lee1, Godeuni Choi1, Euijun Cha1, Ji hyun Lee1, Woo young Jung1, Chan gyung Park1, and Hyunsang Hwang1 1 Dept. of Mat. Sci. and Eng., Pohang University of Science and Technology (POSTECH), Pohang, Korea 2 School of Mat. Sci. and Eng., 3Dept. of Nanobio Mat. and Elec., Gwangju Institute of Science and Technology (GIST), Gwangju, Korea Phone: +82-54-279-5123, Fax: +82-54-279-5122, e-mail:
[email protected] Abstract Ultrathin stoichiometric Ta2O5 layer, which was formed by thermal oxidation of Ta layer on ALD TiO2, exhibits excellent selector characteristics. To maximize the selector performance, we adopted various interface engineering techniques such as Ta2O5 thickness, control of oxygen profile in TaOx layer, top electrode materials, and band gap of bottom insulating oxide layer. By optimizing process conditions, we obtained outstanding selector performances such as high current density (>107A/cm2), high selectivity (~104), better off-current (
