LAUSR

By introducing a thin non-stoichiometric CeO2-x switching layer between the high oxygen affinity metal TaN top electrode and the TiO2 layer in a TaN/CeO2-x/TiO2/Pt bilayer (BL) device, it is possible to enhance the endurance characteristics and overcome the reliability issue. Compared with a single layer device, a BL device significantly enhances the number of direct current overswitching cycles to >1.2 × 104, non-destructive retention (>104 s), and switching uniformity. A TaON interface layer is formed which served as a reservoir of oxygen ions (O2−) in the SET-process and acts as an O2− supplier to refill the oxygen vacancies in the RESET-process and so plays a key role in the formation and rupture of conductive filaments. This study demonstrates that simply introducing a thin non-stoichiometric CeO2-x switching layer into TiO2-based devices can facilitate the enhancement of the endurance property for future nonvolatile memory applications.