The 1-Mb and 4-Mb commercial toggle magnetoresistive random-access memories（MRAMs） with 0.13 μm and 0.18-μm complementary metal–oxide–semiconductor（CMOS） process respectively and different magnetic tunneling j...The 1-Mb and 4-Mb commercial toggle magnetoresistive random-access memories（MRAMs） with 0.13 μm and 0.18-μm complementary metal–oxide–semiconductor（CMOS） process respectively and different magnetic tunneling junctions（MTJs） are irradiated with a Cobalt-60 gamma source. The electrical functions of devices during the irradiation and the room temperature annealing behavior are measured. Electrical failures are observed until the dose accumulates to 120-krad（Si） in 4-Mb MRAM while the 1-Mb MRAM keeps normal. Thus, the 0.13-μm process circuit exhibits better radiation tolerance than the 0.18-μm process circuit. However, a small quantity of read bit-errors randomly occurs only in 1-Mb MRAM during the irradiation while their electrical function is normal. It indicates that the store states of MTJ may be influenced by gamma radiation, although the electrical transport and magnetic properties are inherently immune to the radiation. We propose that the magnetic Compton scattering in the interaction of gamma ray with magnetic free layer may be the origin of the read bit-errors. Our results are useful for MRAM toward space application.展开更多
With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on ...With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.展开更多
A magnetoresistive random-access memory(MRAM) device was irradiated by ^(60) Co c-rays and an electron beam.The synergistic effect of this on the MRAM was tested with an additional magnetic field during irradiation,fr...A magnetoresistive random-access memory(MRAM) device was irradiated by ^(60) Co c-rays and an electron beam.The synergistic effect of this on the MRAM was tested with an additional magnetic field during irradiation,from which the total ionizing dose(TID) and the synergistic damage mechanism of MRAM were analyzed.In addition,DC,AC,and functional parameters of the memory were tested under irradiation and annealing via a very large-scale integrated circuit test system.The radiation-sensitive parameters were obtained through analyzing the data.Because of the magnetic field applied on the MRAM while testing the synergistic effects,shallow trench isolation leakage and Frenkel–Poole emission due to synergistic effects were smaller than that of TID,and hence radiation damage of the synergistic effects was also lower.展开更多
基于自旋电子学的磁性随机存储器(Magnetic Random Access Memory,MRAM)具有非易失性、可无限擦写、低功耗和快速写入等优点,从而有望成为下一代通用存储器.在MRAM家族中,根据磁写入方式和磁媒介的不同,人们提出了自旋转移力矩(Spin Tra...基于自旋电子学的磁性随机存储器(Magnetic Random Access Memory,MRAM)具有非易失性、可无限擦写、低功耗和快速写入等优点,从而有望成为下一代通用存储器.在MRAM家族中,根据磁写入方式和磁媒介的不同,人们提出了自旋转移力矩(Spin Transfer Torque,STT)、自旋轨道力矩(Spin Orbit Torque,SOT)、电压控制型(如电控磁各向异性(Voltage Controlled Magnetic Anisotropy,VCMA)型和电控SOT(Voltage Gated-SOT,VG-SOT)型)、磁畴壁(Domain Wall,DW)和磁斯格明子(Magnetic Skyrmion)型等不同类型的各具特色的MRAM,共同推动着磁存储技术的多元化发展.近年来STT-MRAM商用芯片的成功问世进一步推动了MRAM器件的研究与应用.本文首先简要介绍了存储器技术的历史,然后介绍了MRAM的基本工作原理、从MRAM中读取和写入信息背后的技术、材料和不同的物理机制以及潜在的挑战问题.接下来介绍了近些年发展的新型的磁写入机制的进展.本文末尾讨论了一些可能有助于行业超越传统MRAM的技术,最后是总结和展望.展开更多
The fabrication of a dynamic threshold-2T0C(DT-2T0C) DRAM cell incorporating a ZnO charge-trap layer in the write transistor has been successfully achieved, addressing the negative hold voltage(V_(HOLD)) issue of conv...The fabrication of a dynamic threshold-2T0C(DT-2T0C) DRAM cell incorporating a ZnO charge-trap layer in the write transistor has been successfully achieved, addressing the negative hold voltage(V_(HOLD)) issue of conventional 2T0C DRAM cells using oxide channel layers. The proposed device facilitates dynamic modulation of turn-on voltage(V_(ON)) through an additional SET operation, allowing V_(ON) to shift above 0 V. The retention time in SET operation was extended to 10^(4) s by optimizing the tunneling layer deposition conditions. The device characterization revealed a significant correlation between V_(ON) and both the WRITE speed and the retention properties of the DT-2T0C, verifying the trade-off between WRITE time and retention time. A long retention time over 1000 s was achieved, even under VHOLD of 0 V.展开更多
Mn基二元合金Mn_(x)Ga和Mn_(x)Al等因其超大的垂直磁各向异性能、较高的自旋极化度和较小的磁阻尼因子等特点,成为制备高密度磁随机存储器(Magnetic Random Access Memory,MRAM)的理想电极材料,在过去十多年中受到了特别关注.本文概述...Mn基二元合金Mn_(x)Ga和Mn_(x)Al等因其超大的垂直磁各向异性能、较高的自旋极化度和较小的磁阻尼因子等特点,成为制备高密度磁随机存储器(Magnetic Random Access Memory,MRAM)的理想电极材料,在过去十多年中受到了特别关注.本文概述了垂直磁化Mn基二元合金薄膜的晶格结构、磁学性质及其在磁性隧道结和自旋轨道力矩效应器件中应用的研究进展.首先,详细讨论了L1_(0)-Mn_(x)Ga,D0_(22)-Mn_(x)Ga和L1_(0)-Mn_(x)Al薄膜的晶格结构、外延生长方法、磁学特性以及交换耦合行为,着重分析了生长条件对材料垂直磁各向异性、磁阻尼因子和自旋极化率等关键参数的影响.然后,总结了基于Mn_(x)Ga和Mn_(x)Al的磁性隧道结相关研究,包括隧穿磁电阻效应的实验与理论分析,探讨了通过引入Heusler合金缓冲层或金属插层等界面工程提升隧穿磁电阻效应的技术方案,并分析了晶格失配和界面缺陷对器件性能的制约.阐述了Mn基二元合金中自旋轨道力矩驱动的磁化翻转现象,特别是在D0_(22)-Mn_(3)Ga/Pt,L1_(0)-MnGa/FeMn等相关双层膜中观察到的无场磁化翻转行为,揭示了界面耦合和材料设计对降低临界翻转电流密度和提高翻转效率的关键作用.最后,对垂直磁化的Mn_(x)Ga,Mn_(x)Al材料在MRAM中的应用前景进行了展望.展开更多
We report on the design and performance of a fiber laser system with adaptive acousto-optic macropulse control for a novel photocathode laser driver with 3D ellipsoidal pulse shaping. The laser system incorporates a t...We report on the design and performance of a fiber laser system with adaptive acousto-optic macropulse control for a novel photocathode laser driver with 3D ellipsoidal pulse shaping. The laser system incorporates a threestage fiber amplifier with an integrated acousto-optical modulator. A digital electronic control system with feedback combines the functions of the arbitrary micropulse selection and modulation resulting in macropulse envelope profiling. As a benefit, a narrow temporal transparency window of the modulator, comparable to a laser pulse repetition period, effectively improves temporal contrast. In experiments, we demonstrated rectangular laser pulse train profiling at the output of a three-cascade Yb-doped fiber amplifier.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61404161)
文摘The 1-Mb and 4-Mb commercial toggle magnetoresistive random-access memories（MRAMs） with 0.13 μm and 0.18-μm complementary metal–oxide–semiconductor（CMOS） process respectively and different magnetic tunneling junctions（MTJs） are irradiated with a Cobalt-60 gamma source. The electrical functions of devices during the irradiation and the room temperature annealing behavior are measured. Electrical failures are observed until the dose accumulates to 120-krad（Si） in 4-Mb MRAM while the 1-Mb MRAM keeps normal. Thus, the 0.13-μm process circuit exhibits better radiation tolerance than the 0.18-μm process circuit. However, a small quantity of read bit-errors randomly occurs only in 1-Mb MRAM during the irradiation while their electrical function is normal. It indicates that the store states of MTJ may be influenced by gamma radiation, although the electrical transport and magnetic properties are inherently immune to the radiation. We propose that the magnetic Compton scattering in the interaction of gamma ray with magnetic free layer may be the origin of the read bit-errors. Our results are useful for MRAM toward space application.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60921062)
文摘With the progress of the semiconductor industry,the resistive random-access memory（RAM） has drawn increasing attention.The discovery of the memristor has brought much attention to this study.Research has focused on the resistive switching characteristics of different materials and the analysis of resistive switching mechanisms.We discuss the resistive switching mechanisms of different materials in this paper and analyze the differences of those mechanisms from the view point of circuitry to establish their respective circuit models.Finally,simulations are presented.We give the prospect of using different materials in resistive RAM on account of their resistive switching mechanisms,which are applied to explain their resistive switchings.
基金supported by the National Natural Science Foundation of China(No.11705276)the West Light Foundation of the Chinese Academy of Sciences(No.CAS-LWC-2017-2)
文摘A magnetoresistive random-access memory(MRAM) device was irradiated by ^(60) Co c-rays and an electron beam.The synergistic effect of this on the MRAM was tested with an additional magnetic field during irradiation,from which the total ionizing dose(TID) and the synergistic damage mechanism of MRAM were analyzed.In addition,DC,AC,and functional parameters of the memory were tested under irradiation and annealing via a very large-scale integrated circuit test system.The radiation-sensitive parameters were obtained through analyzing the data.Because of the magnetic field applied on the MRAM while testing the synergistic effects,shallow trench isolation leakage and Frenkel–Poole emission due to synergistic effects were smaller than that of TID,and hence radiation damage of the synergistic effects was also lower.
文摘基于自旋电子学的磁性随机存储器(Magnetic Random Access Memory,MRAM)具有非易失性、可无限擦写、低功耗和快速写入等优点,从而有望成为下一代通用存储器.在MRAM家族中,根据磁写入方式和磁媒介的不同,人们提出了自旋转移力矩(Spin Transfer Torque,STT)、自旋轨道力矩(Spin Orbit Torque,SOT)、电压控制型(如电控磁各向异性(Voltage Controlled Magnetic Anisotropy,VCMA)型和电控SOT(Voltage Gated-SOT,VG-SOT)型)、磁畴壁(Domain Wall,DW)和磁斯格明子(Magnetic Skyrmion)型等不同类型的各具特色的MRAM,共同推动着磁存储技术的多元化发展.近年来STT-MRAM商用芯片的成功问世进一步推动了MRAM器件的研究与应用.本文首先简要介绍了存储器技术的历史,然后介绍了MRAM的基本工作原理、从MRAM中读取和写入信息背后的技术、材料和不同的物理机制以及潜在的挑战问题.接下来介绍了近些年发展的新型的磁写入机制的进展.本文末尾讨论了一些可能有助于行业超越传统MRAM的技术,最后是总结和展望.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (RS-2024-00334190)。
文摘The fabrication of a dynamic threshold-2T0C(DT-2T0C) DRAM cell incorporating a ZnO charge-trap layer in the write transistor has been successfully achieved, addressing the negative hold voltage(V_(HOLD)) issue of conventional 2T0C DRAM cells using oxide channel layers. The proposed device facilitates dynamic modulation of turn-on voltage(V_(ON)) through an additional SET operation, allowing V_(ON) to shift above 0 V. The retention time in SET operation was extended to 10^(4) s by optimizing the tunneling layer deposition conditions. The device characterization revealed a significant correlation between V_(ON) and both the WRITE speed and the retention properties of the DT-2T0C, verifying the trade-off between WRITE time and retention time. A long retention time over 1000 s was achieved, even under VHOLD of 0 V.
文摘Mn基二元合金Mn_(x)Ga和Mn_(x)Al等因其超大的垂直磁各向异性能、较高的自旋极化度和较小的磁阻尼因子等特点,成为制备高密度磁随机存储器(Magnetic Random Access Memory,MRAM)的理想电极材料,在过去十多年中受到了特别关注.本文概述了垂直磁化Mn基二元合金薄膜的晶格结构、磁学性质及其在磁性隧道结和自旋轨道力矩效应器件中应用的研究进展.首先,详细讨论了L1_(0)-Mn_(x)Ga,D0_(22)-Mn_(x)Ga和L1_(0)-Mn_(x)Al薄膜的晶格结构、外延生长方法、磁学特性以及交换耦合行为,着重分析了生长条件对材料垂直磁各向异性、磁阻尼因子和自旋极化率等关键参数的影响.然后,总结了基于Mn_(x)Ga和Mn_(x)Al的磁性隧道结相关研究,包括隧穿磁电阻效应的实验与理论分析,探讨了通过引入Heusler合金缓冲层或金属插层等界面工程提升隧穿磁电阻效应的技术方案,并分析了晶格失配和界面缺陷对器件性能的制约.阐述了Mn基二元合金中自旋轨道力矩驱动的磁化翻转现象,特别是在D0_(22)-Mn_(3)Ga/Pt,L1_(0)-MnGa/FeMn等相关双层膜中观察到的无场磁化翻转行为,揭示了界面耦合和材料设计对降低临界翻转电流密度和提高翻转效率的关键作用.最后,对垂直磁化的Mn_(x)Ga,Mn_(x)Al材料在MRAM中的应用前景进行了展望.
基金Russian Foundation for Basic Research(RFBR)(15-07-03719)Russian Science Foundation(RSF)(16-19-10448)Ministry of Education and Science of the Russian Federation(Minobrnauka)(14.Z50.31.0007,K2-2015-077)
文摘We report on the design and performance of a fiber laser system with adaptive acousto-optic macropulse control for a novel photocathode laser driver with 3D ellipsoidal pulse shaping. The laser system incorporates a threestage fiber amplifier with an integrated acousto-optical modulator. A digital electronic control system with feedback combines the functions of the arbitrary micropulse selection and modulation resulting in macropulse envelope profiling. As a benefit, a narrow temporal transparency window of the modulator, comparable to a laser pulse repetition period, effectively improves temporal contrast. In experiments, we demonstrated rectangular laser pulse train profiling at the output of a three-cascade Yb-doped fiber amplifier.
