Study of sub-5 nm RRAM, tunneling selector and selector less device

By using sidewall electrode technology, both record small functional TiO 2 selection device (1 × 5 nm 2 ) and HfO 2 based RRAM device (1 × 3 nm 2 ) were for the first time successfully demonstrated in this work, improving the understanding of the switching mechanism in an ultra-small, functional resistive random access memory (RRAM) device. The tunneling based low temperature back-end selection devices show high driving current density of u003e 10 MA/cm 2 and selectivity of u003e 10 3 . The pulse driven cycle endurance of sub-5nm selection device and RRAM device reaches 10 6 and 10 3 , respectively. Well controlled TiO 2 barrier produced with conformal plasma oxidation exhibits tight uniformity. The 1 × 3 nm 2 RRAM device exhibited an excellent performance, featuring a large on/off verified window (u003e100), and reasonable reliability (stress time u003e 10 3 s). Furthermore, the 1 × 3 nm 2 RRAM device exhibited distinctive unipolar behavior when a high voltage and rapid switching operation (7 V, 50 ns) were applied. We also study on double oxide layer device and propose a physical mechanism picture to compare with previous study. This technology demonstrates the potential of future atomic-scale memories.