Formation of a ternary oxide barrier layer and its role in switching characteristic of ZnO-based conductive bridge random access memory devices

The insertion of a metal layer between an active electrode and a switching layer leads to the formation of a ternary oxide at the interface. The properties of this self-formed oxide are found to be dependent on the Gibbs free energy of oxide formation of the metal (ΔGf°). We investigated the role of various ternary oxides in the switching behavior of conductive bridge random access memory (CBRAM) devices. The ternary oxide acts as a barrier layer that can limit the mobility of metal cations in the cell, promoting stable switching. However, too low (higher negative value) ΔGf° leads to severe trade-offs; the devices require high operation current and voltages to exhibit switching behavior and low memory window (on/off) ratio. We propose that choosing a metal layer having appropriate ΔGf° is crucial in achieving reliable CBRAM devices

Electrode engineering in memristors development for non-/erasable storage, random number generator, and synaptic applications

We report the process development of ZnO-based memristors and observe various switching phenomena by means of electrode engineering, such as digital-to-analogue transformation, irregular and uniform endurance, and non-erasable switching; we also discuss the potential applications for each of these switching phenomena. The use of inert electrodes induces a high injection of electrons into the switching layer triggering abrupt current changes and, in some cases, resulting in a device breakdown. Meanwhile, a low work function and oxidizable electrode encourage Ohmic contact at the oxide/electrode junction and exhibit gradual switching characteristics. This work addresses the importance of electrode configuration to achieve the desired switching behaviour for specific low-powered electronic applications

Formation of a ternary oxide barrier layer and its role in switching characteristic of ZnO-based conductive bridge random access memory devices

The insertion of a metal layer between an active electrode and a switching layer leads to the formation of a ternary oxide at the interface. The properties of this self-formed oxide are found to be dependent on the Gibbs free energy of oxide formation of the metal (Δ퐺∘푓). We investigated the role of various ternary oxides in the switching behavior of conductive bridge random access memory (CBRAM) devices. The ternary oxide acts as a barrier layer that can limit the mobility of metal cations in the cell, promoting stable switching. However, too low (higher negative value) Δ퐺∘푓 leads to severe trade-offs; the devices require high operation current and voltages to exhibit switching behavior and low memory window (on/off) ratio. We propose that choosing a metal layer having appropriate Δ퐺∘푓 is crucial in achieving reliable CBRAM devices