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

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.

Automated summary

In this article, the bio-inspired synaptic features of the TiN/ZrOx/Pt capacitor structure for neuromorphic engineering are demonstrated. The verification of the chemical and material compositions and layer thicknesses of each layer is done using TEM images and EDS maps. Stable resistive switching with a low set voltage is achieved, along with characteristics of multi-level cells based on compliance current and reset stop voltage. Artificial synapse behaviors such as paired-pulse facilitation, paired-pulse depression, electric excitatory postsynaptic current, and spike-timing-dependent plasticity are emulated using the RRAM device.