Low Power and Improved Switching Properties of Selector-Less Ta₂O₅ Based Resistive Random Access Memory Using Ti-Rich TiN Electrode

Abstract

The effects of TiN top electrode composition (TiN vs Ti-rich TiN) on the resistive switching characteristics of selector-less TiN/TiO x /Ta2O5/TiN resistive random access memory (ReRAM) are investigated. Ti-rich TiN enables TiO x to have a higher concentration of oxygen vacancy and reduce barrier height between top electrode and TiO x . This leads to higher on/off current ratio and lower operation voltage without degradation of non-linearity which is the important factor for selector-less type ReRAM, compared to the stoichiometric TiN resistor stack. Consequently, it is verified that the switching mechanism is hybrid combination of filament formation and redox reaction in switching operation. This work is applicable to both high density and cost-effective ReRAM.

Linking Conductive Filament Properties and Evolution to Synaptic Behavior of RRAM Devices for Neuromorphic Applications

“…Simulations allow also to understand and explain the analog behavior exhibited by the Ta2O5 RRAM. Forming results show that the CF is created only in the thin Ta2O5, whereas the overlying TiOx acts as a reservoir for the generated oxygen ions (O -) [12], [16], Figs. 5(e)-(f).…”

Structurally Engineered Nanoporous Ta2O5–x Selector-Less Memristor for High Uniformity and Low Power Consumption

“…The design and fabrication of electronic memory devices for ultralow power consumption have become a key issue in modern electronic device applications because of the enormous demand for big data storage, Internet of Things applications, and the perpetual power-consuming nature of organized information in communication networks. ,,− Figure c,d shows the statistical analysis of the ON power ( P ON ) with a logarithmic scale for the NP Ta 2 O 5– x memristor devices fabricated under different anodization conditions (∼25 individual devices for each condition). When the anodization time and the applied dc voltage were increased, the P ON ( V set × I ) changed from ∼5.43 × 10 –4 to ∼0.96 × 10 –5 W due to the porosity dependence of the switching current; this change is much lower than that of other nonporous metal-oxide memories by a factor of up to ∼10 4 , which indicates its potential use in ultralow power memory applications (Figure e, Tables S1 and S2, Supporting information) .…”

Nonlinear and complementary resistive switching behaviors of Au/Ti/TaOx/TiN devices dependent on Ti thicknesses

“…In other reports, the nonlinearity was reported to have a value above 10. 7,8,10 To improve the suppression characteristics, the thickness of the reactive Ti insertion layer is increased from 1 to 7 nm whereupon, after fabrication of the Au/Ti (7 nm)/TaO x /TiN device, post-RTA treatment is carried out in the same manner as the previous sample. applied voltage is swept in a sequence of 0 V !…”