Excellent Roff/Ron ratio and short programming time in Cu/Al2O3-based conductive-bridging RAM under low-current (10 μA) operation

In this work, we prove that, for a current regime of 10 μA and using industry-relevant programming pulse-width, Cu/Al2O3-based conductive-bridging RAM (CBRAM) cells ensure reliably larger memory window (MW) than state-of-the-art oxygen-vacancy-based RRAM (OxRRAM) cells. Due to the intrinsically stochastic nature of the switching mechanism, the Ron and Roff values can be widely distributed, especially in a low-current regime, drastically reducing the overall memory window. For this reason, in this study we adopt a statistical approach, focusing on the tails of the distributions. Using a program-verify method we show that the larger median MW in CBRAM allows to program a MW ≥×10 using ×10 shorter programming time with respect to OxRRAM. Moreover, we show that, in order to ensure a MW >×10 after a fixed retention time, the programming time needs to be several decades larger for OxRRAM than for CBRAM.