【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HfO₂/SiO₂异质结为功能层的ITO/HfO₂/SiO₂/Ag忆阻器。与单层HfO₂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，SiO₂功能层中的Ag含量多于HfO₂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SiO₂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SiO₂的最佳溅射时间为10分钟。更多还原

【Abstract】 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/HfO₂/SiO₂/Ag memristor with an HfO₂/SiO₂ heterojunction as the functional layer was fabricated on an ITO substrate via magnetron sputtering. Compared to single-layer HfO₂ memristors, the switching ratio was improved by approximately 10 times, reaching a maximum of 50, and the switching ratio remained above 20 for over 6 000 seconds, showing significant enhancement in stability. XPS analysis was performed on the device cross-section, obtaining both the full spectrum and the fine spectrum of the O1s energy level. The full spectrum showed that the Ag content in the SiO₂ functional layer was higher than that in the HfO₂ layer,and the O1s spectrum indicated a lower concentration of oxygen vacancies. Through fitting the device’s IV curve to analyze its conduction mechanism, it was found that the conduction mechanism in the positive voltage 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/set memory behavior of the device. By varying the sputtering time to change the thickness of the SiO₂ layer and comparing the I-V characteristic curves for different sputtering times, the optimal sputtering time for SiO₂ was determined to be 10 minutes.更多还原