Impact of Active Electrode on the Synaptic Properties of SiO2-Based Forming-Free Conductive Bridge Memory

The influence of active top electrode (TE) material is thoroughly investigated in order to shed light into the manifestation of various switching modes and the concomitant repercussion on a variety of synaptic properties in conductive-bridge random access memory (CBRAM) SiO
₂
-based devices. While both threshold and bipolar switching effects were captured when Ag was selected for TE, only the latter switching mode was confirmed for the case of Cu. The SiO
₂
-based memristors exhibit not only conductance tuning properties at low bias conditions, but can emulate the synaptic potentiation and depression procedures under the same pulse polarity (Ag TE). Moreover, by modulating the time interval difference of the pulses train, we can obtain short-term (STP) to long-term potentiation (LTP) transition properties along Spike-Timing Dependent Plasticity (STDP) performance. Our results indicate thus, that by leveraging the rich internal dynamic nature of the resistive switching effect, several on-demand neuromorphic properties can be attained.