Electromigration-induced resistance switching in indented Al microstrips

Abstract

Non-volatile resistive memory cells are promising candidates to tremendously impact the further development of Boolean and neuromorphic computing. In particular, nanoscale memory-bit cells based on electromigration (EM)-induced resistive switching in monolithic metallic structures have been identified as an appealing and competitive alternative to achieve ultrahigh density while keeping straightforward manufacturing processes. In this work, we investigate the EM-induced resistance switching in indented Al microstrips. In order to guarantee a large switching endurance, we limited the on-to-off ratio to a minimum readable value. Two switching protocols were tested, (i) a variable current pulse amplitude adjusted to ensure a precise change of resistance, and (ii) a fixed current pulse amplitude. Both approaches exhibit an initial training period where the mean value of the device's resistance drifts in time, followed by a more stable behavior. Electron microscopy imaging of the devices show irreversible changes of the material properties from the early stages of the switching process. High and low resistance states show retention times of days and endurances of ∼10 3 switching cycles.

Stability of quantized conductance levels in memristors with copper filaments: toward understanding the mechanisms of resistive switching

“…Though such a model is able to provide only a semiquantitative insight into the effects taking place, it predicts quite a counterintuitive stabilization effect of the current on the filament for both current directions, which is also observed in our experiment. In fact, our model also predicts considerable changes in the geometries of thin filaments due to electron recoil effects-a kind of quantum counterpart of electromigration [35,36]-for quite realistic voltages around 1-2 V, typical of RS in memristors [15]. Thus, we suggest that a weaker effect of current-enhanced filament stability observed in our experiments could also be rooted in the same physics.…”

Direct Visualization of Current-Stimulated Oxygen Migration in YBa2Cu3O7−δ Thin Films

“…One particularly appealing aspect that could situate voltage-controlled electromigration as a privileged tool of choice for tuning the oxygen content is the possibility to heal a previously electromigrated sample, by simply inverting the direction of the electrical drive (antielectromigration). Although this technique seems to work fairly well for elemental materials, − its success in YBCO has been shown to be rather limited . In order to illustrate this effect, starting from the EM sample (inset of Figure b) we invert the polarity of the voltage in such a way that now the right bridge corresponds to the cathode side and the left bridge to the anode side.…”

Gold nanogap-based artificial synapses

“…However, there is still some room of discussion on the model of the phenomena and possible other mechanisms should be considered. [33][34][35][36][37] After characterizing the basic memristive properties of the Au nanogaps using the activation technique, we proceed to demonstrate the activity-dependent plasticity of our electronic synapse. Synaptic plasticity, which is believed to account for learning and memory in the biological brain, refers to the change in connection weight (ΔW) over time in response to action potentials.…”