The wake-up effect which is observed in ferroelectric hafnium oxide is investigated in yttrium doped hafnium oxide prepared by chemical solution deposition. It can be shown that not the amount of cycles but the duration of the applied electrical field is essential for the wake-up. Temperature dependent wake-up cycling in a range of −160 °C to 100 °C reveals a strong temperature activation of the wake-up, which can be attributed to ion rearrangement during cycling. By using asymmetrical electrodes, resistive valence change mechanism switching can be observed coincident with ferroelectric switching. From the given results, it can be concluded that redistribution of oxygen vacancies is the origin of the wake-up effect.

Resistive switching (RS) devices are emerging electronic components that could have applications in multiple types of integrated circuits, including electronic memories, true random number generators, radiofrequency switches, neuromorphic vision sensors, and artificial neural networks. The main factor hindering the massive employment of RS devices in commercial circuits is related to variability and reliability issues, which are usually evaluated through switching endurance tests. However, we note that most studies that claimed high endurances >10⁶ cycles were based on resistance versus cycle plots that contain very few data points (in many cases even <20), and which are collected in only one device. We recommend not to use such a characterization method because it is highly inaccurate and unreliable (i.e., it cannot reliably demonstrate that the device effectively switches in every cycle and it ignores cycle-to-cycle and device-to-device variability). This has created a blurry vision of the real performance of RS devices and in many cases has exaggerated their potential. This article proposes and describes a method for the correct characterization of switching endurance in RS devices; this method aims to construct endurance plots showing one data point per cycle and resistive state and combine data from multiple devices. Adopting this recommended method should result in more reliable literature in the field of RS technologies, which should accelerate their integration in commercial products.

Different coplanar $\mathrm{Pt}∕\mathrm{Ag}$ structures were prepared by photolithography on $\mathrm{Si}{\mathrm{O}}_2$ substrates, and $\mathrm{Pt}∕{\mathrm{H}}_2\mathrm{O}∕\mathrm{Ag}$ cells were formed by adding de-ionized ${\mathrm{H}}_2\mathrm{O}$ to the coplanar $\mathrm{Pt}∕\mathrm{Ag}$ structures. The $\mathrm{Pt}∕{\mathrm{H}}_2\mathrm{O}∕\mathrm{Ag}$ cell is utilized here as a model system, due to the feasibility of visual inspection of the switching process. Bipolar switching was achieved for the cell. Scanning electron microscopy (SEM) investigations demonstrated that the growth and dissolution of Ag dendrites are responsible for the resistive switching. The Ag dendrite morphology is proposed to be the origin of the asymmetrical dissolution during the switching-off process, hence the bipolar nature of the switching characteristics.

The strongly nonlinear switching kinetics of electrochemical metallization memory (ECM) cells are investigated using an advanced 1D simulation model. It is based on the electrochemical growth and dissolution of a Ag or Cu filament within a solid thin film and accounts for nucleation effects, charge transfer, and cation drift. The model predictions are consistent with experimental switching results of a time range of 12 orders of magnitude obtained from silver iodide (AgI) based ECM cells. By analyzing the simulation results the electrochemical processes limiting the switching kinetics are revealed. This study provides new insights into the understanding of the limiting electrochemical processes determining the switching kinetics of ECM cells.