非挥发性阻变存储器的无源集成方式研究

Resistance random acceess memory (RRAM) has become the current hot research area for next-generation nonvolatile application due to its advantages such as simple device structure, easy 3D stackablity, high operation speed, and low power consumption. For the practical application of RRAM, the crucial issue is to improve the anti-crosstalk performances.In this research project, we will investigate resistance switching and rectifying characteristics of NiO film, and further prepare the passive crossbar RRAM array with memroy and selector based on NiO and Li:NiO, respectively. We will also study the intrinsic physical origin of tranisition from memory effect to rectifying effect by Li doping, to further understand the microscopic physical mechanism of resistance switching effect and construct the physical model of the transition from memory to rectifying effect by Li doping. Under the theoretical guidance, we will improve the anti-crosstalk performances and establish the framwork and methodology for the research on the reliability of the passive RRAM. Our research project will help to calrify to physical mechanism of resistance swithing effect and understand integrated way of passive crossbar RRAM array with rectifying characteristic，and thereby provide the theoretical and expermental solution to the optimization of the device structure and function and the realization of high-density integration of RRAM.

阻变存储器因其结构简单、可三维堆叠、擦写速度快以及功耗低等优点，已成为非挥发性存储器领域的研究热点，而提高阻变存储器的抗串扰性能是当前亟需解决的技术关键和难点。本项目在研究NiO基薄膜器件阻变存储特性及整流特性的基础上，提出采用以NiO为存储器和以Li:NiO为选择器，制备阻变存储器的无源交叉阵列。通过研究NiO薄膜中Li的掺杂浓度与其阻变存储特性、整流特性之间的内在作用规律，深入理解阻变存储的微观机制并建立存储和整流特性转换的物理模型。在理论指导下提高器件的抗串扰性能，建立无源RRAM存储可靠性的研究方法。本课题的研究，将有助于澄清器件阻变存储特性的物理机制，加深基于整流特性的无源交叉RRAM阵列的集成方式认识，为优化器件的结构和功能、实现高密度集成的阻变存储器提供理论和实验依据。

基于过渡金属氧化物电致阻变特性的阻变存储器在未来具有广阔的应用潜力，是目前的热点研究领域。本项目从存储器材料的选择、器件制备工艺、器件结构、性能优化以及集成方式方面开展研究。首先，采用金属氧化物薄膜作为存储介质，通过改变金属氧化物电极的功函数方式调节电极与氧化物存储介质间的肖特基势垒高度，实现了具有高整流效应的阻变存储特性。这种整流效应可应用于交叉存储阵列，成为其高密度集的选择单元。此外，通过调控限制电流大小，研究了器件从偶极性、单极性至至阈值型阻变效应的转换过程的物理微观机制，并获得了稳定的阈值型阻变效应和一次性写入重复读取的存储特性，可分别用于解决集成器件因漏电流引起的信号串扰问题和永久性的数据存储。本项目研究工作的完成，不仅完善了阻变存储特性的调控方式、微观物理机制以及高密度交叉阵列集成方式等理论，也为阻变存储器的应用提供实验依据。