Configurable ultra-low operating voltage resistive switching between bipolar and threshold behaviors for Ag/TaOx/Pt structures

Abstract

An ultra-low operating voltage bipolar resistive switching is observed in Ag/TaOx/Pt devices. They show a typical bipolar resistive switching with both low operating voltages and high cycling endurance when the compliance current (ICC) is 0.3 mA. Moreover, the operating voltage is considerably influenced by the grain size of the film. The VForming increases dramatically when the grain size exceeds a critical value. Meanwhile, the bipolar resistive switching and threshold switching in Ag/TaOx/Pt devices can be converted to each other by changing the magnitude of the ICC. Finally, a model based on the migration of Ag+ is proposed to explain the ultra-low operating voltage and the critical effect of grain size. The model is proved by simulation. These findings may lead to ultra-low power memories and contribute to a further understanding of the resistive switching effect.

Bipolar Resistive Switching in the Ag/Sb2Te3/Pt Heterojunction

“…Thus, the migration of Ag + along the pores in Sb 2 Te 3 would be enhanced, which is beneficial to reduce the forming voltage of the RRAM. 28 The SEM image that appeared in Figure 1d shows that the diameter of the Ag TE is 200 μm, which is in line with expectations. The cross section of the heterojunction described in Figure 1e demonstrates that the thickness of the Ag, Sb 2 Te 3 , and Pt films are 50, 110, and 130 nm, respectively.…”

“…Irregular pores may also be formed when the grain size of the film is small. Thus, the migration of Ag + along the pores in Sb 2 Te 3 would be enhanced, which is beneficial to reduce the forming voltage of the RRAM . The SEM image that appeared in Figure d shows that the diameter of the Ag TE is 200 μm, which is in line with expectations.…”

“…2,3,25,29 Hence, the Ag/Sb 2 Te 3 /Pt heterojunction is more inclined to form the Ag CFs by comparing with a similar device that forms the metallic CF. 28,32 Furthermore, based on the processing and analysis of the I−V curve, combined with the results obtained by numerical simulation, we eventually conclude that the CFs are more inclined to Ag CFs.…”

Atomic scale memristive photon source

“…Whereas high voltages are required in the reverse-bias case, the creation and aggregation of oxygen vacancies into oxygen vacancy clusters also occur in the case of forward-bias experiments at lower voltage in the presence of the Ag filament. It has been reported that the introduction of metal species (Ag in our device) lowers the energy barrier to create oxygen vacancies 31 , making the resistive switching more controllable with a reduced switching voltage 32 .…”

Polymer Analog Memristive Synapse with Atomic-Scale Conductive Filament for Flexible Neuromorphic Computing System

“…It is challenging to achieve the analog conductance update in the conventional binary memristors with abrupt switching which are operated by either atomic-scale modulation of cations (such as Cu − or Ag − ) or anions (oxygen ions). , Therefore, it is essential for memristors to exhibit gradual resistive changes during its switching process to obtain the analog type conductance response from memristor. Hwang et al reported that in electrochemical metallization (ECM) type memristors, the transition of reset behavior from abrupt to gradual mode occurred in Pt/TiO 2 /Cu memristor with decreasing size of the conducting filament .…”