Spin-orbit torque(SOT)has been considered as one of the promising technologies for the next-generation magnetic random access memory(MRAM).So far,SOT has been widely utilized for inducing various modes of magnetizatio...Spin-orbit torque(SOT)has been considered as one of the promising technologies for the next-generation magnetic random access memory(MRAM).So far,SOT has been widely utilized for inducing various modes of magnetization switching.However,it is a challenge that so many multiple modes of magnetization switching are integrated together.Here we propose a method of implementing both unipolar switching and bipolar switching of the perpendicular magnetization within a single SOT device.The mode of switching can be easily changed by tuning the amplitude of the applied current.We show that the field-like torque plays an important role in switching process.The field-like torque induces the precession of the magnetization in the case of unipolar switching,however,the field-like torque helps to generate an effective zcomponent torque in the case of bipolar switching.In addition,the influence of key parameters on the mode of switching is discussed,including the field-like torque strength,the bias field,and the current density.Our proposal can be used to design novel reconfigurable logic circuits in the near future.展开更多
基于自旋转移矩的磁性随机存储器(Spin Transfer Torque-Based Magnetoresistive RAM,STT-MRAM)具有非易失性、可无限擦写和快速写入等优点而有望成为下一代低功耗通用存储器.尤其是近年来STT-MRAM商用芯片的成功问世进一步推动了该器...基于自旋转移矩的磁性随机存储器(Spin Transfer Torque-Based Magnetoresistive RAM,STT-MRAM)具有非易失性、可无限擦写和快速写入等优点而有望成为下一代低功耗通用存储器.尤其是近年来STT-MRAM商用芯片的成功问世进一步推动了该器件的研究与应用.本文首先阐述了MRAM的基本原理与发展历程,着重介绍了写入技术的演变以及磁各向异性的改善.然后总结了近期在3个领域的研究成果:(1)学术界开展了大量研究以探讨制备工艺和器件结构等因素对界面垂直磁各向异性的影响;(2)CoFeB-MgO双界面结构被提出,该结构在不增大写入电流的前提下增强了磁隧道结的热稳定性势垒;(3)新兴的自旋轨道矩写入方式引起了广泛的关注,该技术有望解决传统自旋转移矩所面临的速度瓶颈和势垒击穿风险.最后,本文扼要地介绍了STT-MRAM在芯片设计领域的最新进展.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62171013 and 61704005)the National Key Research and Development Program of China(Grant Nos.2021YFB3601303,2021YFB3601304,and 2021YFB3601300)+1 种基金the Beijing Municipal Science and Technology Project,China(Grant No.Z201100004220002)the Fundamental Research Funds for the Central Universities,China(Grant No.YWF-21-BJ-J-1043)。
文摘Spin-orbit torque(SOT)has been considered as one of the promising technologies for the next-generation magnetic random access memory(MRAM).So far,SOT has been widely utilized for inducing various modes of magnetization switching.However,it is a challenge that so many multiple modes of magnetization switching are integrated together.Here we propose a method of implementing both unipolar switching and bipolar switching of the perpendicular magnetization within a single SOT device.The mode of switching can be easily changed by tuning the amplitude of the applied current.We show that the field-like torque plays an important role in switching process.The field-like torque induces the precession of the magnetization in the case of unipolar switching,however,the field-like torque helps to generate an effective zcomponent torque in the case of bipolar switching.In addition,the influence of key parameters on the mode of switching is discussed,including the field-like torque strength,the bias field,and the current density.Our proposal can be used to design novel reconfigurable logic circuits in the near future.
文摘基于自旋转移矩的磁性随机存储器(Spin Transfer Torque-Based Magnetoresistive RAM,STT-MRAM)具有非易失性、可无限擦写和快速写入等优点而有望成为下一代低功耗通用存储器.尤其是近年来STT-MRAM商用芯片的成功问世进一步推动了该器件的研究与应用.本文首先阐述了MRAM的基本原理与发展历程,着重介绍了写入技术的演变以及磁各向异性的改善.然后总结了近期在3个领域的研究成果:(1)学术界开展了大量研究以探讨制备工艺和器件结构等因素对界面垂直磁各向异性的影响;(2)CoFeB-MgO双界面结构被提出,该结构在不增大写入电流的前提下增强了磁隧道结的热稳定性势垒;(3)新兴的自旋轨道矩写入方式引起了广泛的关注,该技术有望解决传统自旋转移矩所面临的速度瓶颈和势垒击穿风险.最后,本文扼要地介绍了STT-MRAM在芯片设计领域的最新进展.
