HfO2本征缺陷态对MRAM磁化翻转机理的理论研究

自旋转移力矩磁随机存储器（STT-MRAM）是通过电流驱动即自旋转移矩效应来诱导磁性薄膜的磁化翻转来实现存储的，是最有希望可以满足下一代高性能计算及需求的新型存储技术，但是目前仍然面临着存储密度低，磁矩翻转临界电流密度高等物理问题。本项目旨在研究高介电材料HfO2在不同氧空位的缺陷态对于MRAM磁化翻转的影响机理的理论研究。基于密度泛函理论的第一性原理计算HfO2各氧空位缺陷态的电子结构和光学性质，并逐步分析在器件中的优劣势影响情况，具体包括有HfO2的氧空位本征缺陷态的物理性质的研究，MRAM中铁磁薄膜的磁化翻转机制的物理研究，HfO2本征缺陷的铁磁性质对于磁化翻转机制的影响这三方面的内容。本项目所研究的缺陷态等物理参数对磁化翻转的影响机制，其理论计算结果可以为新型磁存储器的设计和应用提供指导和支持。

Spin transfer torque magnetic random access memory (STT-MRAM) is used to induce the magnetization flip of the magnetic thin film through current drive, that is, the spin transfer torque effect to achieve storage. And it is a new type technology of storage that is the most promising to meet the needs of next-generation high-performance computing. But it still faces physical problems such as low storage density and high critical current density for magnetic moment reversal. This project aims to study the theoretical study of the mechanism of the effect of the defect states of the high dielectric material HfO2 in different oxygen vacancies on the MRAM magnetization reversal. Calculate the electronic structure and optical properties of each oxygen vacancy defect state of HfO2 based on the first principles of density functional theory, and gradually analyze the influence of advantages and disadvantages in the device. The research contains the following three aspects, the research about the physical properties of the oxygen vacancy intrinsic defect state of HfO2, the magnetization reversal mechanism of the ferromagnetic film in MRAM, and the influence of the ferromagnetic properties of the intrinsic defects of HfO2 on the magnetization reversal mechanism. The theoretical calculation results of the defect state and other physical parameters studied in this project can provide guidance and support for the design and application of new magnetic memory.