Magnetron Sputtered Ni‐rich Nickel Oxide Nano‐Films for Resistive Switching Memory Applications

Abstract

Radio-frequency magnetron sputtering has been used to deposit Ni-rich nickel oxide nano-films to form a metal-insulator-metal structure, which exhibits resistive switching behavior. Memory characteristics of the structure have been investigated. The ratio of the current of the structure at the reading voltage of 0.05 V between a low-resistance state (LRS) and a highresistance state (HRS) was observed to be >10 3 , showing a large memory window at a very low reading voltage. The memory window was well maintained within the time limit of the experiment (5 9 10 4 s), exhibiting good memory retention. The current transport at both the LRS and HRS has been studied, and the result suggests that the formation and annihilation of a conductive filament are responsible for the resistive switching. *echentp@ntu.edu.sg

Modification of reactively sputtered NiOxthin films by pulsed UV laser irradiation

“…The amorphous nature is attributed to a Ni‐rich NiO x sample according to Ref. , and such films are considered more suitable for resistive random access memory (ReRAM) applications. The laser irradiation likely causes an increase in the Ni interstitials concentration, leading to n‐type conduction.…”

“…The laser irradiation likely causes an increase in the Ni interstitials concentration, leading to n‐type conduction. Ni‐rich NiO x can also be obtained by sputtering Ni target in 3–20% oxygen content in the gas mixture . Therefore, from Ref.…”

Lateral Conduction Switching in Sputtered Ni‐rich NiO Thin Films for Write‐Once‐Read‐Many‐Times Memory Applications

“…The situation is different from that of a vertical RRAM device where a reset process is present to switch the device from the ON state back to the OFF state . The details of the reversible switching behaviors in the vertical devices based on the same Ni‐rich NiO thin films synthesized in this work were reported elsewhere . Besides the voltage sweep, a voltage pulse can be used to carry out the write operation as well.…”

“…The ohmic conduction at low fields could be due to the hopping of the thermally excited electrons from one isolated state to another in the Ni‐rich NiO film . When the voltage increases beyond ~0.3 V, the I–V characteristic departs from the ohmic conduction, indicating that other conduction processes including the space‐charge‐limited current transport and/or tunneling via the Ni nanoparticles/nanoclusters or the traps distributed in the thin film become significant at higher fields . For the ON state, ohmic conduction with a much higher conductance is observed.…”

Effect of HfO<italic><sub>x</sub></italic> buffer layer on the resistive switching characteristics of γ-Fe<sub>2</sub>O<sub>3</sub> nanoparticle films

“…除了复杂的层状钙钛矿氧化物(如SrTiO 3 [3] )之外, 化 学组分相对简单的二元金属氧化物薄膜(如NiO [4,5] , TiO 2 [6] , Al x O y [7] , ZnO [8] , V x O y [9] 等)因其显著的RS特性 而备受研究者关注. 2004年, 韩国三星公司研究人员 首次将一个NiO薄膜阻变存储器和一个金属-氧化物-半导体(MOS)场效应晶体管集成在一起 [10] , 突破了 阻变存储器与当今硅基半导体器件集成不兼容的难 题 , 从 而 使 得 阻 变 随 机 存 储 器 (Resistive Random Access Memory, 简称RRAM) 凭借存储速度快、 功耗 低、结构简单、可高密度集成等优点迅速成为除铁电 随机存储器、 磁电阻随机存储器和相变随机存储器外 的另一种新型快闪存储器件.…”