SiO_(2)提升ITO/HfO_(2)/SiO_(2)/Ag忆阻器的开关比和稳定性  

The switching ratio and stability of ITO/HfO_(2)/SiO_(2)/Ag memristors improved by SiO_(2) functional layer

作　　者：徐辛 张宏 杨峰 张勇[1] XU Xin;ZHANG Hong;YANG Feng;ZHANG Yong(School of Electrical Engineering,Key Laboratory of Magnetic Levitation Technologies and Maglev Trains,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;School of Physical Science and Technology,Southwest Jiaotong University,Chengdu,610031,China)

机构地区：[1]西南交通大学电气工程学院,磁浮技术与磁浮列车教育部重点实验室,成都610031 [2]西南交通大学物理科学与技术学院,成都610031

出　　处：《功能材料与器件学报》2025年第1期34-41,共8页Journal of Functional Materials and Devices

基　　金：国家重点研发计划国家磁约束核聚变专项基金(2022YFE03020002)。

摘　　要：导电细丝生长及其熔断的随机性一直是影响忆阻器开关比和稳定性的关键因素。本研究通过磁控溅射在ITO基底上制备了以HfO_(2)/SiO_(2)异质结为功能层的ITO/HfO_(2)/SiO_(2)/Ag忆阻器。与单层HfO_(2)忆阻器相比,开关比约提升10倍,最大开关比达到了50;并且稳定性也有了较大提升,在6 000 s+的时间内开关比保持在20以上。使用XPS对器件断面进行了分析,得到了器件断面的全谱图和O1s能级精细谱图。全谱图显示,SiO_(2)功能层中的Ag含量多于HfO_(2)功能层,O1s能谱图则表明氧空位含量较少。通过对器件的I-V曲线进行导电机理拟合分析,发现器件在正电压区主要为欧姆导电机制,在负电压区则符合空间电荷限制电流机制。在此基础上,建立了一种倒锥型导电细丝模型来解释器件的复位/设置记忆行为。通过改变溅射时间来改变SiO_(2)层的厚度,将不同溅射时间的I-V特性曲线图作对比,确定了SiO_(2)的最佳溅射时间为10分钟。The randomness of conductive filament growth and rupture has always been a key factor affecting the switching ratio and stability of memristors.In this paper,an ITO/HfO_(2)/SiO_(2)/Ag memristor with an HfOz/SiO_(2) heterojunction as the functional layer was fabricated on an ITO substrate via magnetron sputtering.Compared to single-layer HfO_(2)memristors,the switching ratio was improved by approximately 10 times, reaching a maximum of 50, and the switching ratio remained above 20 for over6000 seconds, showing significant enhancement in stability. XPS analysis was performed on the devicecross-section, obtaining both the full spectrum and the fine spectrum of the Ols energy level. The fullspectrum showed that the Ag content in the SiO_(2) functional layer was higher than that in the HfO_(2) layer,and the Ols spectrum indicated a lower concentration of oxygen vacancies. Through fitting the device's IVcurve to analyze its conduction mechanism, it was found that the conduction mechanism in the positivevoltage region follows Ohmic conduction, while in the negative voltage region, it aligns with the spacecharge-limited current mechanism. Based on this, a physical model was proposed to explain the reset/setmemory behavior of the device. By varying the sputtering time to change the thickness of the SiO_(2) layerand comparing the I-V characteristic curves for different sputtering times, the optimal sputtering time forSiO_(2) was determined to be 10 minutes.

关 键 词：忆阻器 倒锥型导电细丝 空间电荷限制电流 欧姆导电机制 异质结 

分 类 号：TB32[一般工业技术—材料科学与工程] TB34