10×10nm<sup>2</sup> Hf/HfO<inf>x</inf> crossbar resistive RAM with excellent performance, reliability and low-energy operation

We report on world's smallest HfO 2 -based Resistive RAM (RRAM) cell to date, featuring a novel Hf/HfO x resistive element stack, with an area of less than 10×10 nm 2 , fast ns-range on/off switching times at low-voltages and with a switching energy per bit of 7 cycles, large on/off verified-window (>;50), no closure of the on/off window after 30hrs/200C and failure-free device operation after 30hrs/250C thermal stress, the major device-level nonvolatile memory requirements are met. Furthermore, we clarify the impact of film crystallinity on cell operation from a scalability viewpoint, the role of the cap layer and bring insight into the switching mechanisms.