Memory cells have always been an important element of information technology.With emerging technologies like big data and cloud computing,the scale and complexity of data storage has reached an unprecedented peak with...Memory cells have always been an important element of information technology.With emerging technologies like big data and cloud computing,the scale and complexity of data storage has reached an unprecedented peak with a much higher requirement for memory technology.As is well known,better data storage is mostly achieved by miniaturization.However,as the size of the memory device is reduced,a series of problems,such as drain gate-induced leakage,greatly hinder the performance of memory units.To meet the increasing demands of information technology,novel and high-performance memory is urgently needed.Fortunately,emerging memory technologies are expected to improve memory performance and drive the information revolution.This review will focus on the progress of several emerging memory technologies,including two-dimensional material-based memories,resistance random access memory(RRAM),magnetic random access memory(MRAM),and phasechange random access memory(PCRAM).Advantages,mechanisms,and applications of these diverse memory technologies will be discussed in this review.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
存内计算(CIM,Computing in Memory)是一种为缓解“内存墙”和“功耗墙”而出现的新兴架构。因CPU处理器和存储器速度发展不均衡性,冯·诺依曼架构这类中央处理器与存储器分离的结构逐渐失去其优越性。存内计算提出以计算和存储相...存内计算(CIM,Computing in Memory)是一种为缓解“内存墙”和“功耗墙”而出现的新兴架构。因CPU处理器和存储器速度发展不均衡性,冯·诺依曼架构这类中央处理器与存储器分离的结构逐渐失去其优越性。存内计算提出以计算和存储相结合的方式来减少数据的搬移,极大地提升了计算效率。MRAM作为最有潜力的新一代非易失存储器件,被视为构建高效存内计算架构的有力候选者。以MRAM为基础构建的存内计算根据计算过程的不同可分为MRAM模拟存内计算和MRAM数字存内计算。数字存内计算又可以根据数字逻辑产生的方式分为MRAM写入式存内计算、MRAM读取式存内计算以及MRAM近存计算。MRAM模拟存内计算利用高并行度摊销能耗,在单位面积上,吞吐量和能效都具有数字存内计算无法比拟的优势,但也因其易受PVT影响等特征在实际应用中有所限制。MRAM数字存内计算实现方式多样,写入式存内计算几乎消除了存储器外的数据搬移,虽然当前工艺下的MRAM所需的翻转能耗和时延过大,导致该方式一直停留在仿真阶段,但不妨碍该存内计算是缓解“内存墙”最有效的手段之一;读取式存内计算严重依赖于读取放大器的功能设计,在相关领域有所发展,但所受限制较大;近存计算是当前MRAM非易失器件和CMOS电路在计算速度和计算能效差异较大的情况下,融合两者优势的优解,在实际应用中具有巨大的益处。展开更多
Nano-ring-type magnetic tunnel junctions （NR-MTJs） with the layer structure of Ta（5）/Ir22Mn78（10）/ Co75Fe25（2）/Ru（0.75）/CoooFe20B20（3）/Al（0.6）-oxide/Co60Fe20B20（2.5）/Ta（3）/Ru（5） （thickness unit：...Nano-ring-type magnetic tunnel junctions （NR-MTJs） with the layer structure of Ta（5）/Ir22Mn78（10）/ Co75Fe25（2）/Ru（0.75）/CoooFe20B20（3）/Al（0.6）-oxide/Co60Fe20B20（2.5）/Ta（3）/Ru（5） （thickness unit： nm） were nano-fabricated on the Si（100）/SiO2 substrate using magnetron sputtering deposition combined with the optical lithography, electron beam lithography （EBL） and Ar ion-beam etching techniques. The smaller NR-MTJs with the inner- and outer-diameter of around 50 and 100 nm and also their corresponding NR-MTJ arrays were nano-patterned. The tunnelling magnetoresistance （TMR ＆ R） versus driving current （I） loops for a spin-polarized current switching were measured, and the TMR ratio of around 35% at room temperature were observed. The critical values of switching current for the free Co60Fe20B20 layer relative to the reference Co6oFe2oB2o layer between parallel and anti-parallel magnetization states were between 0.50 and 0.75 mA in such NR-MTJs. It is suggested that the applicable MRAM fabrication with the density and capacity higher than 256 Mbit/inch2 even 6 Gbite/inch2 are possible using both I NR-MTJ＋1 transistor structure and current switching mechanism based on based on our fabricated 4×4 MRAM demo devices.展开更多
磁随机存取存储器(magnetoresistive random access memory,MRAM)以其高能效和快速的数据存储能力在大数据时代备受关注^([1,2]).在MRAM单元中,数据通过两个铁磁层磁化状态的平行和反平行排列以低电阻态和高电阻态形式存储在磁隧道结(ma...磁随机存取存储器(magnetoresistive random access memory,MRAM)以其高能效和快速的数据存储能力在大数据时代备受关注^([1,2]).在MRAM单元中,数据通过两个铁磁层磁化状态的平行和反平行排列以低电阻态和高电阻态形式存储在磁隧道结(magnetic tunnel junction,MTJ)中^([3,4]).展开更多
We have successfully demonstrated a 1 Kb spin-orbit torque(SOT)magnetic random-access memory(MRAM)multiplexer(MUX)array with remarkable performance.The 1 Kb MUX array exhibits an in-die function yield of over 99.6%.Ad...We have successfully demonstrated a 1 Kb spin-orbit torque(SOT)magnetic random-access memory(MRAM)multiplexer(MUX)array with remarkable performance.The 1 Kb MUX array exhibits an in-die function yield of over 99.6%.Additionally,it provides a sufficient readout window,with a TMR/RP_sigma%value of 21.4.Moreover,the SOT magnetic tunnel junctions(MTJs)in the array show write error rates as low as 10^(-6)without any ballooning effects or back-hopping behaviors,ensuring the write stability and reliability.This array achieves write operations in 20 ns and 1.2 V for an industrial-level temperature range from-40 to 125℃.Overall,the demonstrated array shows competitive specifications compared to the state-of-the-art works.Our work paves the way for the industrial-scale production of SOT-MRAM,moving this technology beyond R&D and towards widespread adoption.展开更多
基金This work was supported by the National Natural Science Foundation of China(61622401,61851402,and 61734003)National Key Research and Development Program(2017YFB0405600)+1 种基金Shanghai Education Development Foundation and Shanghai Municipal Education Commission Shuguang Program(18SG01)P.Z.also acknowledges support from Shanghai Municipal Science and Technology Commission(grant no.18JC1410300).
文摘Memory cells have always been an important element of information technology.With emerging technologies like big data and cloud computing,the scale and complexity of data storage has reached an unprecedented peak with a much higher requirement for memory technology.As is well known,better data storage is mostly achieved by miniaturization.However,as the size of the memory device is reduced,a series of problems,such as drain gate-induced leakage,greatly hinder the performance of memory units.To meet the increasing demands of information technology,novel and high-performance memory is urgently needed.Fortunately,emerging memory technologies are expected to improve memory performance and drive the information revolution.This review will focus on the progress of several emerging memory technologies,including two-dimensional material-based memories,resistance random access memory(RRAM),magnetic random access memory(MRAM),and phasechange random access memory(PCRAM).Advantages,mechanisms,and applications of these diverse memory technologies will be discussed in this review.
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.
文摘存内计算(CIM,Computing in Memory)是一种为缓解“内存墙”和“功耗墙”而出现的新兴架构。因CPU处理器和存储器速度发展不均衡性,冯·诺依曼架构这类中央处理器与存储器分离的结构逐渐失去其优越性。存内计算提出以计算和存储相结合的方式来减少数据的搬移,极大地提升了计算效率。MRAM作为最有潜力的新一代非易失存储器件,被视为构建高效存内计算架构的有力候选者。以MRAM为基础构建的存内计算根据计算过程的不同可分为MRAM模拟存内计算和MRAM数字存内计算。数字存内计算又可以根据数字逻辑产生的方式分为MRAM写入式存内计算、MRAM读取式存内计算以及MRAM近存计算。MRAM模拟存内计算利用高并行度摊销能耗,在单位面积上,吞吐量和能效都具有数字存内计算无法比拟的优势,但也因其易受PVT影响等特征在实际应用中有所限制。MRAM数字存内计算实现方式多样,写入式存内计算几乎消除了存储器外的数据搬移,虽然当前工艺下的MRAM所需的翻转能耗和时延过大,导致该方式一直停留在仿真阶段,但不妨碍该存内计算是缓解“内存墙”最有效的手段之一;读取式存内计算严重依赖于读取放大器的功能设计,在相关领域有所发展,但所受限制较大;近存计算是当前MRAM非易失器件和CMOS电路在计算速度和计算能效差异较大的情况下,融合两者优势的优解,在实际应用中具有巨大的益处。
基金the State Key Project of Fundamental Research of Ministry of Science and Technology （No. 2006CB932200） the National Natural Science Foundation of China （NSFC, No. 10574156）+2 种基金 the Knowledge Innovation Program of Chinese Aca.demy of Sciencesthe protial support of 0utstanding Young Researcher Foundation （Nos. 50325104 and 50528101） K.C.Wong Education Foundation, Hong Kong.
文摘Nano-ring-type magnetic tunnel junctions （NR-MTJs） with the layer structure of Ta（5）/Ir22Mn78（10）/ Co75Fe25（2）/Ru（0.75）/CoooFe20B20（3）/Al（0.6）-oxide/Co60Fe20B20（2.5）/Ta（3）/Ru（5） （thickness unit： nm） were nano-fabricated on the Si（100）/SiO2 substrate using magnetron sputtering deposition combined with the optical lithography, electron beam lithography （EBL） and Ar ion-beam etching techniques. The smaller NR-MTJs with the inner- and outer-diameter of around 50 and 100 nm and also their corresponding NR-MTJ arrays were nano-patterned. The tunnelling magnetoresistance （TMR ＆ R） versus driving current （I） loops for a spin-polarized current switching were measured, and the TMR ratio of around 35% at room temperature were observed. The critical values of switching current for the free Co60Fe20B20 layer relative to the reference Co6oFe2oB2o layer between parallel and anti-parallel magnetization states were between 0.50 and 0.75 mA in such NR-MTJs. It is suggested that the applicable MRAM fabrication with the density and capacity higher than 256 Mbit/inch2 even 6 Gbite/inch2 are possible using both I NR-MTJ＋1 transistor structure and current switching mechanism based on based on our fabricated 4×4 MRAM demo devices.
基金supported by the National Key Research and Development Program of China (Nos.2021YFB3601303,2021YFB3601304,2021YFB3601300,2022YFB4400200,2022YFB4400201,2022YFB4400203)the National Natural Science Foundation of China (Grant No.62171013)。
文摘We have successfully demonstrated a 1 Kb spin-orbit torque(SOT)magnetic random-access memory(MRAM)multiplexer(MUX)array with remarkable performance.The 1 Kb MUX array exhibits an in-die function yield of over 99.6%.Additionally,it provides a sufficient readout window,with a TMR/RP_sigma%value of 21.4.Moreover,the SOT magnetic tunnel junctions(MTJs)in the array show write error rates as low as 10^(-6)without any ballooning effects or back-hopping behaviors,ensuring the write stability and reliability.This array achieves write operations in 20 ns and 1.2 V for an industrial-level temperature range from-40 to 125℃.Overall,the demonstrated array shows competitive specifications compared to the state-of-the-art works.Our work paves the way for the industrial-scale production of SOT-MRAM,moving this technology beyond R&D and towards widespread adoption.
