Stability-Enhanced Resistive Random-Access Memory via Stacked In_xGa_1–xO by the RF Sputtering Method

Abstract

The stability of a resistive random-access memory (RRAM) device over long-term use has been widely acknowledged as a pertinent concern. For investigating the stability of RRAM devices, a stacked In x Ga 1– x O structure is designed as its switching layer in this study. Each stacked structure in the switching layer, formed via sputtering, consists of varying contents of gallium, which is a suppressor of oxygen vacancies; thus, the oxygen vacancies are well controlled in each layer. When a stacked structure with layers of different contents is formed, the original gradients of concentration of oxygen vacancies and mobility influence the set and reset processes. With the stacked structure, an average set voltage of 0.76 V, an average reset voltage of −0.66 V, a coefficient of variation of set voltage of 0.34, and a coefficient of variation of reset voltage of 0.18 are obtained. Additionally, under DC sweeps, the stacked RRAM demonstrates a high operating life of more than 4000 cycles. In conclusion, the performance and stability of the RRAM are enhanced herein by adjusting the concentration of oxygen vacancies via different compositions of elements.

Improved Resistive Switching Behaviors of Al/Ag-Doped Fe2O3 Film/ITO Devices Fabricated with a Radio-Frequency Co-Sputtering System

“…The working mechanism of metal oxide RRAM devices is based on the formation of conductive filaments through oxygen vacancies. 55,56 In our study, the formation of the conductive filament was mainly induced by oxygen vacancies and Ag atoms. At low bias voltage, oxygen vacancies in the film slowly migrated to the TE interface.…”

Memory Performance Enhancement by Inducing Conductive Channel via Doping

“…Its simple structure, fast computing speed, and low power consumption boost RRAM potential applications such as neural networks and artificial synapses [5] . However, the stability of RRAM devices still needs to improve essentially so that we can deal with the big challenge of storing big data in the era [6] [7] . Among the new memory prototype, HfO 2based resistive memories are considered the most promising productization because HfO 2 is characteristic of high dielectric constant and wide forbidden bandwidth [8] , and the device is compatible with the IC process and simple fabrication in 3D structure [9] .…”