Magnetoresistive random access memory(MRAM)is a promising non-volatile memory technology that can be utilized as an energy and space-efficient storage and computing solution,particularly in cache functions within circ...Magnetoresistive random access memory(MRAM)is a promising non-volatile memory technology that can be utilized as an energy and space-efficient storage and computing solution,particularly in cache functions within circuits.Although MRAM has achieved mass production,its manufacturing process still remains challenging,resulting in only a few semiconductor companies dominating its production.In this review,we delve into the materials,processes,and devices used in MRAM,focusing on both the widely adopted spin transfer torque MRAM and the next-generation spin-orbit torque MRAM.We provide an overview of their operational mechanisms and manufacturing technologies.Furthermore,we outline the major hurdles faced in MRAM manufacturing and propose potential solutions in detail.Then,the applications of MRAM in artificial intelligent hardware are introduced.Finally,we present an outlook on the future development and applications of MRAM.展开更多
Magnetic tunnel junction(MTJ) based spin transfer torque magnetic random access memory(STT-MRAM) has been gaining tremendous momentum in high performance microcontroller(MCU) applications. As e Flash-replacement type ...Magnetic tunnel junction(MTJ) based spin transfer torque magnetic random access memory(STT-MRAM) has been gaining tremendous momentum in high performance microcontroller(MCU) applications. As e Flash-replacement type MRAM approaches mass production, there is an increasing demand for non-volatile RAM(nv RAM) technologies that offer fast write speed and high endurance. In this work, we demonstrate highly reliable 4 Mb nv RAM type MRAM suitable for industry and auto grade-1 applications. This nv RAM features retention over 10 years at 125 ℃, endurance of 1 × 10^(12)cycles with 20 ns write speed, making it ideal for applications requiring both high speed and broad temperature ranges. By employing innovative MTJ materials, process engineering, and a co-optimization of process and design, reliable read and write performance across the full temperature range between -40 to 125 ℃, and array yield that meets sub-1 ppm error rate was significantly improved from 0 to above 95%, a concrete step toward applications.展开更多
The magnetoresistive random access memory process makes a great contribution to threshold voltage deterioration of metal-oxide-silicon field-effect transistors,especially on p-type devices.Herein,a method was proposed...The magnetoresistive random access memory process makes a great contribution to threshold voltage deterioration of metal-oxide-silicon field-effect transistors,especially on p-type devices.Herein,a method was proposed to reduce the threshold voltage degradation by utilizing back-side stress.Through the deposition of tensile material on the back side,positive charges generated by silicon-hydrogen bond breakage were inhibited,resulting in a potential reduction in threshold voltage shift by up to 20%.In addition,it was found that the method could only relieve silicon-hydrogen bond breakage physically,thus failing to provide a complete cure.However,it holds significant potential for applications where additional thermal budget is undesired.Furthermore,it was also concluded that the method used in this work is irreversible,with its effect sustained to the chip package phase,and it ensures competitive reliability of the resulting magnetic tunnel junction devices.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
由于传统的磁盘甚至已广泛应用的Flash固态盘已无法很好地满足当前对存储器在集成度、读写速度、可靠性方面的需求,故须积极寻找新一代存储介质尝试与当前存储器混合使用甚至替代之.而磁阻随机存储器(magnetic random access memory,MR...由于传统的磁盘甚至已广泛应用的Flash固态盘已无法很好地满足当前对存储器在集成度、读写速度、可靠性方面的需求,故须积极寻找新一代存储介质尝试与当前存储器混合使用甚至替代之.而磁阻随机存储器(magnetic random access memory,MRAM)作为一种非易失性存储器,拥有静态随机存储器(satic random access memory,SRAM)的高速读取写入能力,以及动态随机存储器(dynamic random access memory,DRAM)的高集成度,同时比DRAM更低的能耗,并具有无限的读写次数,这些优秀的特性使得MRAM拥有很好的潜力成为下一代主流存储介质.为了对MRAM的读写性能、功耗等有深入的理解,设计并实现了一个MRAM测试平台,完成对MRAM读写性能测试和特性数据采集.该测试平台主要由MRAM控制器设计、MRAM特性数据采集、读写性能测试3个方面组成,由MRAM控制器对MRAM芯片进行读写完成读写性能测试,采集MRAM在读、写、空闲等状态下的特性数据.实验表明,MRAM具有良好的读写性能和低功耗,有条件成为下一代主流存储介质.展开更多
经常有人将磁阻RAM（MRAM，Magnetoresistive Random Access Memory）称作是非易失性存储器（nvRAM，Non—Volatile RAM）的关键性技术。作为一项非易失性存储器技术，MRAM可以在掉电时保留数据，并且不需要定期刷新。MRAM利用磁性材料...经常有人将磁阻RAM（MRAM，Magnetoresistive Random Access Memory）称作是非易失性存储器（nvRAM，Non—Volatile RAM）的关键性技术。作为一项非易失性存储器技术，MRAM可以在掉电时保留数据，并且不需要定期刷新。MRAM利用磁性材料和传统的硅电路在单个器件中提供了SRAM的高速度和闪存的非易失性，它的寿命几乎是没有限制的。MRAM器件可以用于高速缓冲器、配置内存和其官要求高辣、耐用和非易失性的商业应用。展开更多
利用磁阻效应的非易失性存储器MRAM最近开始复苏，全球很多存储器厂商正在加速开发采用自旋注入反磁化方式的新型MRAM（见图1）。在与磁存储相关的国际会议一第52届磁学与磁性材料年会（52nd Annual Conference on Magnetism and Magnet...利用磁阻效应的非易失性存储器MRAM最近开始复苏，全球很多存储器厂商正在加速开发采用自旋注入反磁化方式的新型MRAM（见图1）。在与磁存储相关的国际会议一第52届磁学与磁性材料年会（52nd Annual Conference on Magnetism and Magnetic Materials，MMM）上，多家厂商相继发布了多种技术方案，可以将自旋注入MRAM的制造工艺提升到45nm-32nm，展开更多
基金supported in part by the Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS)under Grant 2020118Beijing Nova Program under Grant 20230484358Beijing Superstring Academy of Memory Technology:under Grant No.E2DF06X003。
文摘Magnetoresistive random access memory(MRAM)is a promising non-volatile memory technology that can be utilized as an energy and space-efficient storage and computing solution,particularly in cache functions within circuits.Although MRAM has achieved mass production,its manufacturing process still remains challenging,resulting in only a few semiconductor companies dominating its production.In this review,we delve into the materials,processes,and devices used in MRAM,focusing on both the widely adopted spin transfer torque MRAM and the next-generation spin-orbit torque MRAM.We provide an overview of their operational mechanisms and manufacturing technologies.Furthermore,we outline the major hurdles faced in MRAM manufacturing and propose potential solutions in detail.Then,the applications of MRAM in artificial intelligent hardware are introduced.Finally,we present an outlook on the future development and applications of MRAM.
基金supported by National Science and Technology Major Project (2020AAA0109003)the support from Hangzhou Innovation Team Program (TD2022018)。
文摘Magnetic tunnel junction(MTJ) based spin transfer torque magnetic random access memory(STT-MRAM) has been gaining tremendous momentum in high performance microcontroller(MCU) applications. As e Flash-replacement type MRAM approaches mass production, there is an increasing demand for non-volatile RAM(nv RAM) technologies that offer fast write speed and high endurance. In this work, we demonstrate highly reliable 4 Mb nv RAM type MRAM suitable for industry and auto grade-1 applications. This nv RAM features retention over 10 years at 125 ℃, endurance of 1 × 10^(12)cycles with 20 ns write speed, making it ideal for applications requiring both high speed and broad temperature ranges. By employing innovative MTJ materials, process engineering, and a co-optimization of process and design, reliable read and write performance across the full temperature range between -40 to 125 ℃, and array yield that meets sub-1 ppm error rate was significantly improved from 0 to above 95%, a concrete step toward applications.
基金Project supported by the National Natural Science Foundation of China(Grant No.51672246)the National Key Research and Development Program of China(Grant Nos.2017YFA0304302 and 2020AAA0109003)the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C01002)。
文摘The magnetoresistive random access memory process makes a great contribution to threshold voltage deterioration of metal-oxide-silicon field-effect transistors,especially on p-type devices.Herein,a method was proposed to reduce the threshold voltage degradation by utilizing back-side stress.Through the deposition of tensile material on the back side,positive charges generated by silicon-hydrogen bond breakage were inhibited,resulting in a potential reduction in threshold voltage shift by up to 20%.In addition,it was found that the method could only relieve silicon-hydrogen bond breakage physically,thus failing to provide a complete cure.However,it holds significant potential for applications where additional thermal budget is undesired.Furthermore,it was also concluded that the method used in this work is irreversible,with its effect sustained to the chip package phase,and it ensures competitive reliability of the resulting magnetic tunnel junction devices.
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。
文摘由于传统的磁盘甚至已广泛应用的Flash固态盘已无法很好地满足当前对存储器在集成度、读写速度、可靠性方面的需求,故须积极寻找新一代存储介质尝试与当前存储器混合使用甚至替代之.而磁阻随机存储器(magnetic random access memory,MRAM)作为一种非易失性存储器,拥有静态随机存储器(satic random access memory,SRAM)的高速读取写入能力,以及动态随机存储器(dynamic random access memory,DRAM)的高集成度,同时比DRAM更低的能耗,并具有无限的读写次数,这些优秀的特性使得MRAM拥有很好的潜力成为下一代主流存储介质.为了对MRAM的读写性能、功耗等有深入的理解,设计并实现了一个MRAM测试平台,完成对MRAM读写性能测试和特性数据采集.该测试平台主要由MRAM控制器设计、MRAM特性数据采集、读写性能测试3个方面组成,由MRAM控制器对MRAM芯片进行读写完成读写性能测试,采集MRAM在读、写、空闲等状态下的特性数据.实验表明,MRAM具有良好的读写性能和低功耗,有条件成为下一代主流存储介质.
文摘经常有人将磁阻RAM（MRAM，Magnetoresistive Random Access Memory）称作是非易失性存储器（nvRAM，Non—Volatile RAM）的关键性技术。作为一项非易失性存储器技术，MRAM可以在掉电时保留数据，并且不需要定期刷新。MRAM利用磁性材料和传统的硅电路在单个器件中提供了SRAM的高速度和闪存的非易失性，它的寿命几乎是没有限制的。MRAM器件可以用于高速缓冲器、配置内存和其官要求高辣、耐用和非易失性的商业应用。
文摘利用磁阻效应的非易失性存储器MRAM最近开始复苏，全球很多存储器厂商正在加速开发采用自旋注入反磁化方式的新型MRAM（见图1）。在与磁存储相关的国际会议一第52届磁学与磁性材料年会（52nd Annual Conference on Magnetism and Magnetic Materials，MMM）上，多家厂商相继发布了多种技术方案，可以将自旋注入MRAM的制造工艺提升到45nm-32nm，
