Diverse synaptic weight adjustment of bio-inspired ZrOx-based memristors for neuromorphic system

Abstract

In this article, we demonstrate the bio-inspired synaptic features of the TiN/ZrOx/Pt capacitor structure for neuromorphic engineering. The chemical and material compositions and the thicknesses of each of the layers are verified by using transmission electron microscopy (TEM) images and energy-dispersive X-ray spectroscopy (EDS) maps. Stable resistive switching with a low set voltage (-1 V) was determined by scanning the DC I-V curves of many cells. The DC endurance of-104 cycles and retention (10,000 s) in five states was achieved. Multi-level cells (MLC) characteristics were achieved based on the compliance current and reset stop voltage in DC sweep and pulses. Finally, we emulated paired-pulse facilitation (PPF), paired-pulse depression (PPD), electric excitatory postsynaptic current (EPSC), and spike-timing-dependent plasticity (STDP) of the artificial synapse by using the RRAM device.