Journal ArticleDOI
Magnetic tunnel junction device with perpendicular magnetization films for high-density magnetic random access memory
Naoki Nishimura,Tadahiko Hirai,Akio Koganei,Takashi Ikeda,Kazuhisa Okano,Yoshinobu Sekiguchi,Yoshiyuki Osada +6 more
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TLDR
In this paper, a magnetic tunnel junction device using perpendicular magnetization films designed for magnetic random access memory (MRAM) was presented, where stable and uniform magnetization states were observed in 0.3 μm×0.3Abstract:
We present here a magnetic tunnel junction device using perpendicular magnetization films designed for magnetic random access memory (MRAM). In order to achieve high-density MRAM, magnetic tunnel junction devices with a small area of low aspect ratio (length/width) is required. However, all MRAMs reported so far consist of in-plane magnetization films, which require an aspect ratio of 2 or more in order to reduce magnetization curling at the edge. Meanwhile, a perpendicular magnetic tunnel junction (pMTJ) can achieve an aspect ratio=1 because the low saturation magnetization does not cause magnetization curling. Magnetic-force microscope shows that stable and uniform magnetization states were observed in 0.3 μm×0.3 μm perpendicular magnetization film fabricated by focused-ion beam. In contrast, in-plane magnetization films clearly show the presence of magnetization vortices at 0.5 μm×0.5 μm, which show the impossibility of information storage. The PMTJ shows a magnetoresistive (MR) ratio larger than 50% w...read more
Citations
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Journal ArticleDOI
A perpendicular-anisotropy CoFeB–MgO magnetic tunnel junction
Shoji Ikeda,Katsuya Miura,Katsuya Miura,H. Yamamoto,H. Yamamoto,K. Mizunuma,Huadong Gan,M. Endo,Shun Kanai,Jun Hayakawa,Fumihiro Matsukura,Hideo Ohno +11 more
TL;DR: Inter interfacial perpendicular anisotropy between the ferromagnetic electrodes and the tunnel barrier of the MTJ is used by employing the material combination of CoFeB-MgO, a system widely adopted to produce a giant tunnel magnetoresistance ratio in MTJs with in-plane an isotropy.
Journal ArticleDOI
Electric-field-assisted switching in magnetic tunnel junctions
TL;DR: Electric-field-assisted reversible switching in CoFeB/MgO/CoFeB magnetic tunnel junctions with interfacial perpendicular magnetic anisotropy is reported, where the coercivity, the magnetic configuration and the tunnelling magnetoresistance can be manipulated by voltage pulses associated with much smaller current densities.
Journal ArticleDOI
Spintronics based random access memory: a review
Sabpreet Bhatti,Rachid Sbiaa,Atsufumi Hirohata,Hideo Ohno,Shunsuke Fukami,S. N. Piramanayagam +5 more
TL;DR: This article reviews spintronics based memories, in particular, magnetic random access memory (MRAM) in a systematic manner and discusses some of the future technologies that might help the industry to move beyond the conventional MRAM technology.
Journal ArticleDOI
Magnetic tunnel junctions
Jian-Gang Zhu,Chando Park +1 more
TL;DR: A brief overview of the development of magnetic tunnel junctions, introducing the underlying physics, is given in this paper, where read sensors in hard disk drives and memory elements in magnetoresistive random access memory are discussed.
Journal ArticleDOI
Towards the development of flexible non-volatile memories.
TL;DR: The flash memories, resistive random access memories and ferroelectric random access memory/ferroelectric field-effect transistor memories (FeRAM/FeFET) are considered as promising candidates for next generation non-volatile memory device.
References
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Journal ArticleDOI
Exchange-biased magnetic tunnel junctions and application to nonvolatile magnetic random access memory (invited)
Stuart S. P. Parkin,Kevin P. Roche,Mahesh G. Samant,P. M. Rice,Robert Beyers,Roy Edwin Scheuerlein,Eugene J. O'Sullivan,Stephen L. Brown,J. Bucchigano,D. W. Abraham,Yu Lu,M. Rooks,Philip L. Trouilloud,R. A. Wanner,William J. Gallagher +14 more
TL;DR: In this paper, exchange biased magnetic tunnel junction (MTJ) structures are shown to have useful properties for forming magnetic memory storage elements in a novel cross-point architecture, which exhibit very large magnetoresistive (MR) values exceeding 40% at room temperature, with specific resistance values ranging down to as little as ∼60 Ω(μm)2.
Journal ArticleDOI
Progress and outlook for MRAM technology
TL;DR: Progress on improving the material structures, memory bits, thermal stability of the bits, and competitive architectures for GMR and MTJ based MRAM memories as well as the potential of these memories in the commercial memory market are discussed.
Journal ArticleDOI
Switching field variation in patterned submicron magnetic film elements
Youfeng Zheng,Jian-Gang Zhu +1 more
TL;DR: In this article, a micromagnetic study of magnetic switching properties on sub-micron scale single layer and multilayer thin film elements is presented, and it is found that the switching field of these patterned film elements can strongly depend on these edge domain configurations.
Journal ArticleDOI
Domain configurations of nanostructured Permalloy elements
TL;DR: In this paper, the magnetization distributions of an array of small NiFe elements were studied using Lorentz transmission electron microscopy (LTEM) and magnetic force microscopy.
Journal ArticleDOI
Geometry dependence of magnetization vortices in patterned submicron NiFe elements
TL;DR: The dependence of the vortex exit field on lateral dimensions of Ni80Fe20 thin-film elements is measured in this paper, showing that in the limit where the lateral dimensions are much larger than the vortex core size, smaller structures are more prone to the formation of trapped vortices.