铁磁纳米晶与非晶碳复合膜系的阻变特性及其应用研究

Materials with resistive switching (RS) phenomenon are considered to be the most promising substance for the development of high-capacity, high storage density, high reliability memory. To solve the scale limit issue, in this proposed project, we will take (Fe, Co) nanoparticles containing amorphous carbon composite film system as the main object of study. The RS characteristics of composite films will be mainly investigated, including under a given external field RS behavior varied with different size, shape, and volume percentage of the ferromagnetic nanoparticles. We will also pay attention to the relationship between Roff/Ron and external fields (temperature, electric field and magnetic field) in particular material systems, reveal the microscopic mechanism of RS phenomenon in the composite material, describe the switching characteristics of metal electrodes/composite film/metal electrode sandwich cell in detail. The expected research results are of great importance to understand the magnetoelectric effect, the electron-phonon interaction and the spin-phonon interaction in this material system, to shed light on the mechanism of RS and to clarify the origin of ferromagnetism in doped amorphous carbon films. They also have a good technical reference value in promoting the development of high-performance memory devices with independent intellectual property rights.

阻变材料被认为是最有希望用于开发新一代大容量、高存储密度、高可靠存储器的重要物质。为解决器件的尺度极限效应，本项目将以Fe/Co纳米颗粒和非晶碳组成的复合薄膜体系为主要研究对象，重点分析复合材料的电致电阻效应，包括给定外场条件下组变系数随铁磁纳米粒子的尺寸、形状和体积百分比的变化，特定材料体系的电阻变化的大小与温度、电场和磁场之间的关系；揭示引起复合材料电阻变化的微观机制；对金属电极/Fe或Co纳米颗粒和非晶碳复合薄膜/金属电极的开关特性与存储特征进行细致刻画。项目的预期研究成果对于理解该材料体系中的磁电耦合效应、电子-声子相互作用、自旋-声子相互作用，阐明电致电阻效应的物理机制、澄清掺杂非晶碳膜铁磁性的来源等基本科学问题具有重要意义，对促进具有自主知识产权的高性能存储器件的研发也有很好的技术参考价值。

与其它在阻变存储器中使用的材料相比，碳基材料具有许多优点，包括极佳的微缩性，低成本，高稳定性以及与标准CMOS工艺的兼容性。本项目将以Fe/Co掺杂非晶碳薄膜体系为主要研究对象，在掌握了薄膜特性与生长条件之间的内在联系的基础上，成功制备了Al/a-C:Co/FTO双极型和Pt/Al/a-C:Fe/Au/Ti反常双极型ReRAM存储单元。此外还设计了不同于传统三明治结构的平面型的阻变存储单元，在此结构器件中实现了较为稳定的阻变特性。分别研究了溅射时间、后处理条件和上电极对其阻变特性的影响，深入探讨了正常、反常和单边电致电阻效应的物理机制。研究结果对促进具有自主知识产权的高性能存储器件的研发也有很好的技术参考价值。