基于自旋极化多铁隧道结的多值存储研究

项目名称： 基于自旋极化多铁隧道结的多值存储研究

项目编号： No.51472210

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 唐明华

作者单位： 湘潭大学

项目金额： 83万元

中文摘要： 多铁存储器同时具有铁电存储器和磁存储器的突出优点，其存储单元中最核心的多铁隧道结由于能同时对电荷和自旋进行编码，可以在一个存储单元上实现四个以上的多值存储状态，从而能成倍地提高信息存储密度、确保信息安全，已引起世界各国科学家和工程技术人员的高度关注。本申请项目拟利用脉冲激光沉积和磁控溅射方法制备一系列多铁隧道结及阵列，并对其微结构、磁电耦合性能、自旋输运机理、多值存储特性和热稳定性进行系统而深入的研究，用第一性原理计算对自旋电子输运机理进行分析和预测。在此基础上，用Cadence等集成电路设计软件对多铁隧道结阵列、读/写电路、灵敏放大电路等外围控制电路进行器件结构和工艺设计与仿真，建立基于多铁存储器的SPICE模型。采用0.13 μm的CMOS工艺制备出多铁隧道结存储器测试芯片，并进行多值存储功能验证及相关性能测试。研究成果可以为多铁隧道结多值存储器的真正实用化提供有益的理论和实验依据。

中文关键词： 多铁薄膜；磁电耦合；自旋极化；隧道结；多值存储

英文摘要： Multiferroic memories possess the excellent advantages of ferroelectric random access memory (FeRAM) and magnetoresistive random-access memory (MRAM) simultaneously (ferroelectric write and magnetic read operations), its key part in memory cell is the multiferroic tunnel junctions (MFTJs) which can encode the charge and spin at the same time to achieve multilevel data storage (more than four states, i.e. many folds), redouble information storage density greatly, ensure information security and has been increasingly focused by scientists and engineers all over the world. This application project is intended to carry out a systematic research on the microstructure, magnetoelectric coupling effect, spin transport mechanism, multilevel data storage property and the thermal stability of a series of MFTJs (Au/Co/Fe/BaTiO3/La0.7Sr0.3MnO3/SrTiO3(001)) and its array fabricated by pulsed laser deposition (PLD) combined with megnetron sputtering method. A first principles study is used to analyse and predict the spin electron trnsport mechanism of the MFTJs. On the basis of the above investigations, the array of MFTJs (4×4 cells, 2 bits/cell) and the peripheral control circuits, such as read/write circuits as well as sensing amplifiers etc, are designed and simulated by means of Cadence integrated circuit software and TCAD simulation, the SPICE model based multiferroic memories is also established. The MFTJ memory prototype chip is implemented in a 0.13 μm CMOS technology and the multilevel data storage functional verification and related characterization tests are performed in detail. Our study is expected to provide a beneficial theoretical and experimental scientific basis for developing multiferroic tunnel junction multistate memory with high performance and its practical large-scale applications.

英文关键词： multiferroic thin films;magnetoelectric coupling;spin-polarization;tunnel junctions;multilevel data storage