NiO纳米碗状阵列的低压电阻开关特性  

Low-voltage resistive switching characteristics of nano-bowllike Nio arrays

作　　者：殷元祥 谢雨莎 陈涛 张涛 陈鹏[1,2] 邱晓燕[1,2] YIN YuanXiang;XIE YuSha;CHEN Tao;ZHANG Tao;CHEN Peng;QIU XiaoYan(School of Physical Science and Technology,Southwest University,Chongqing 400715,China;Chongqing Key Laboratory of Micro&Nano Structure Opoelectronics,Southwest University,Chongqing 400715,China)

机构地区：[1]西南大学物理科学与技术学院,重庆400715 [2]西南大学微纳结构光电子学重庆市重点实验室,重庆400715

出　　处：《中国科学：物理学、力学、天文学》2023年第4期89-98,共10页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：重庆市自然科学基金面上项目(编号:cstc2019jcyj-msxmX0451)资助。

摘　　要：我们利用单层胶体球自组装模板结合电化学沉积和磁控溅射方法在覆盖Pt导电层的白云母衬底上制备了NiO纳米碗状阵列(Nano-bowl-like NiO Array,nb-NiO).每个NiO纳米碗高约450 nm,碗口直径约450 nm,碗深约300 nm,在Pt导电层上密排形成二维阵列.在nb-NiO阵列上覆盖厚约20 nm的HfO_(2)薄膜,然后制备Ag或Pt点电极形成Ag(Pt)/HfO_(2)/nb-NiO/Pt堆栈器件.器件在小于±0.4 V的翻转电压下即可在高低电阻态之间周期性可逆跳变,表现出良好的电阻开关特性:器件在高低电阻态之间翻转的时间<8.7μs;初始高/低电阻比值~10^(4),连续测试1500个周期后依然>10^(3).断电后,器件稳定在高(低)电阻态的时间>104s.纳米碗状阵列结构使得NiO薄膜厚度在150–450 nm内周期性连续变化;由于氧空位导电细丝更易在厚度较小的纳米碗底部导通,因此碗状阵列结构使得原本空间随机分布的氧空位导电细丝通道具有了局域有序性,进而提升了器件电阻开关性能的稳定性.HfO_(2)薄膜层降低了器件漏电流,提高了器件的高/低电阻值比.Ag电极与氧离子的氧化还原反应加速了氧空位导电细丝的导通和断裂,从而降低了翻转电压.The monolayer colloidal sphere template technology,electrochemical deposition,and magnetron sputtering were used to fabricate nano-bowl-like NiO(nb-NiO)arrays covered by a HfO_(2)buffer layer on Pt-coated mica(Pt-mica)substrates.Scanning electron microscope images and X-ray diffraction spectra reveal that each polycrystalline NiO nano-bowl has a height of~450 nm,a rim diameter of~450 nm,and a depth of~300 nm.On the Pt-mica substrate,these nano-bowls were self-assembled into a close-packed array,which was then coated by 0.2 mm diameter Ag or Pt dot electrodes.When applied with a bias voltage lower than 0.4 V,the Ag/HfO_(2)(20 nm)/nb-NiO/Pt cell can reversibly switch between a high and a low resistance state within a time shorter than 8.7μs.It exhibits a ratio of the high to the low resistance(Rg/RL)greater than 10^(3) at the reading voltage of O.1 V,a data retention time longer than 10^(4)s,and a cycling endurance of more than 1500 cycles.The nano-bowl-like structure makes the NiO film thickness change periodically in the range of 150-450 nm.The distribution of oxygen-vacancy conductive filaments in the plane parallel to the substrate becomes locally ordered,which consequently improves the resistive switching reliability,because they prefer to form in the thinnest bowl bottom area.The HfO,buffer layer depresses the leakage current of the cell in the high resistance state,thus greatly increasing the R/R,ratio.Compared with inert Pt electrodes,the redox reaction of Ag electrodes with oxygen ions is more active,which enhances the formation and rupture of the oxygen-vacancy conductive filaments in the nb-NiO array and thus decreases the switching voltages.

关 键 词：NiO纳米碗状阵列 电阻开关特性 低电压 

分 类 号：TP333[自动化与计算机技术—计算机系统结构] TB383.1[自动化与计算机技术—计算机科学与技术] TQ138.13[一般工业技术—材料科学与工程]