温度改变对钛氧化物忆阻器导电特性的影响

相同测试条件下,纳米钛氧化物忆阻器的导电过程存在不稳定性,制约了对器件瞬态阻抗的精确读取与控制,并影响了器件应用于电路设计的可靠性与稳定性.杂质漂移与隧道势垒的共存是导致上述不稳定性的可能因素,且杂质漂移特性与环境温度密切相关.然而,目前尚无通过控制温度提高忆阻器导电稳定性的具体研究.基于杂质漂移与隧道势垒共存,本文分析了温度与忆阻器导电特性的关联,研究了器件活跃区域厚度及初始掺杂层厚度的改变对临界温度的影响,利用SPICE软件进行了仿真验证并给出结果,得出提高忆阻器导电稳定性的方法有:增大活跃区域厚度、降低初始杂质浓度及保持环境温度稳定且低于临界温度,从而为制备性能稳定的忆阻器及推动器件在实际电路中的应用提供依据.     

横截面积参数对钛氧化物忆阻器导电特性的影响

纳米钛氧化物忆阻器的导电过程因自身参数的改变及不同机理的共存而呈现复杂特性,但现有研究缺乏针对横截面积参数的改变对忆阻器导电特性影响的讨论.基于杂质漂移及隧道势垒机理,本文分析了忆阻器导电过程,研究了横截面积参数与导电过程中各关键物理要素间的关联,并基于此,分别研究了钛氧化物横截面积及隧道势垒横截面积的改变对忆阻器导电特性的影响,分析了两者的区别与联系.验证了两种机理共存情况下,相对于钛氧化物横截面积的改变,隧道势垒横截面积的改变是引发忆阻器导电特性变化的主要因素,且是导致忆阻器非理想导电特性的可能因素.研究成果有助于进一步解释忆阻器导电过程的复杂性,并为优化忆阻器模型的构建提供依据.     

The conductive mechanisms of a titanium oxide memristor with dopant drift and a tunnel barrier

Nano-scale titanium oxide memristors exhibit complex conductive characteristics, which have already been proved by existing research. One possible reason for this is that more than one mechanism exists, and together they codetermine the conductive behaviors of the memristor. In this paper, we first analyze the theoretical base and conductive process of a memristor, and then propose a compatible circuit model to discuss and simulate the coexistence of the dopant drift and tunnel barrier-based mechanisms. Simulation results are given and compared with the published experimental data to prove the possibility of the coexistence. This work provides a practical model and some suggestions for studying the conductive mechanisms of memristors.     

基于蒙特卡洛方法的钛氧化物忆阻器辐射损伤研究

纳米钛氧化物忆阻器有望成为新一代阻性存储器基本单元并应用于辐射环境中的航天器控制及数据存储系统. 辐射能量, 强度, 方向, 持续时间等要素发生改变均可能对钛氧化物忆阻器受到的辐射损伤构成影响, 然而, 目前尚无相关具体研究. 基于以蒙特卡洛方法为核心的SRIM仿真, 本文针对宇宙射线主体组成部分——质子及 α射线定量研究了各个辐射要素与钛氧化物忆阻器辐射损伤的关联, 依据器件实测数据研究了辐射要素与导通阻抗, 截止阻抗及氧空缺迁移率等忆阻器主要参数的关系, 进一步利用SPICE仿真讨论了辐射对杂质漂移与隧道势垒共存特性的影响, 从而为评估及降低钛氧化物忆阻器辐射损伤, 提高器件应用于辐射环境的可靠性提供依据.     

Characteristics of titanium oxide memristor with coexistence of dopant drift and a tunnel barrier

The recent published experimental data of titanium oxide memristor devices which are tested under the same experi- mental conditions exhibit the strange instability and complexity of these devices. Such undesired characteristics preclude the understanding of the device conductive processes and the memristor-based practical applications. The possibility of the coexistence of dopant drift and tunnel barrier conduction in a memristor provides preliminary explanations for the undesired characteristics. However, current research lacks detailed discussion about the coexistence case. In this paper, dopant drift and tunnel barrier-based theories are first analyzed for studying the relations between parameters and physical variables which affect characteristics of mernristors, and then the influences of each parameter change on the conductive behaviors in the single and coexistence cases of the two mechanisms are simulated and discussed respectively. The simulation results provide further explanations of the complex device conduction. Theoretical methods of eliminating or reducing the coex- istence of the two mechanisms are proposed, in order to increase the stability of the device conduction. This work also provides the support for optimizing the fabrications of memristor devices with excellent performance.     

The design and simulation of a titanium oxide memristor-based programmable analog filter in a simulation program with integrated circuit emphasis

In many communication and signal routing applications, it is desirable to have a programmable analog filter. According to this practical demand, we consider the titanium oxide memristor, which is a kind of nano-scale electron device with low power dissipation and nonvolatile memory. Such characteristics could be suitable for designing the desired filter. However, both the non-analytical relation between the memristance and the charges that pass through it, and the changeable V-I characteristics in physical tests make it difficult to accurately set the memristance to the target value. In this paper, the conductive mechanism of the memristor is analyzed, a method of continuously programming the memristance is proposed and simulated in a simulation program with integrated circuit emphasis, and its feasibility and compatibility, both in simu- lations and physical realizations, are demonstrated. This method is then utilized in a first-order active filter as an example to show its applications in programmable filters. This work also provides a practical tool for utilizing memristors as resistance programmable devices.