Electrode-induced digital-to-analog resistive switching in TaO_x-based RRAM devices

Abstract

In RRAM devices, electrodes play a significant role during the switching process. In this paper, different top electrodes are used for TaO y /Ta2O5-x /AlO σ triple-oxide-layer devices. Top electrode-induced digital resistive switching to analog resistive switching was observed. For Pt top electrode (TE) devices, abrupt digital resistive switching behavior was observed, while Al TE devices showed gradual analog resistive switching behavior. Devices with various AlO σ thicknesses and sizes were fabricated and characterized to evaluate the reliability of the analog resistive switching. The physical mechanisms responsible for this electrode-induced resistive switching behavior were discussed.

Analog‐Type Resistive Switching Devices for Neuromorphic Computing

“…During SET, O 2− moves back to the semiconductor layer under an opposite bias, leading to a metal–semiconductor (M–S) contact with a Schottky diode‐like behavior. Interfacial RRAM intrinsically enables analog weight storage and analog switching because the shift of the O 2− distribution is gradual . Generally, interfacial RRAM exhibits better device‐to‐device and cycle‐to‐cycle uniformities than filamentary RRAM, as the formation and rupture of the CF in filamentary RRAM is a local effect, with only a few O 2− / V O contributing to the switching, while in interfacial RRAM, O 2− / V O throughout the entire area uniformly contributes to the switching.…”

Tuning analog resistive switching and plasticity in bilayer transition metal oxide based memristive synapses

“…We have further examined the above hypothesis in other transition metal oxide systems, and Fig. 6a summarizes the reported NOS values in memristive synapses based on four different transition metal oxides that have been reported previously, 14,15,17,18,[20][21][22][27][28][29] where HfO x and TaO x are typical material systems with few thermodynamically stable oxide phases while WO x and TiO x represent material systems with rich intermediate phases. 40,43,[49][50][51][52] The extraction of NOS should takes into account the noise level and conductance change that could be recognized (ESI Table S1 and related discussions †).…”

“…in terms of the number of states (NOS) that can be reliably accessed during resistive switching. To date, synaptic devices based on various binary transition metal oxides such as TaO x , 14,15 HfO x , [16][17][18] TiO x [19][20][21][22] and WO x [23][24][25][26][27][28] have been widely studied. The RS behaviors have been further engineered by introducing different interfacial layers and forming a bilayer structure.…”

Dynamic Memristor-based Reservoir Computing for High-Efficiency Spatiotemporal Signal Processing

“…Then, the functional 30 nm-thick TaO y and 16 nm-thick TiO x oxide layers were deposited by the reactive sputtering method with Ar and O 2 mixed atmosphere. 43 Finally, the top electrode Ti was deposited and patterned with the same thickness and width as the bottom electrode.…”