2021 Fiscal Year Final Research Report
Study on new read-disturbance mechanism and its solution in Spin-Orbit Torque RAM
Project/Area Number |
19K04536
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 21060:Electron device and electronic equipment-related
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Research Institution | Tokyo University of Science |
Principal Investigator |
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | MRAM / ディスターブ低減 / SOT-MRAM / 両方向読み出し |
Outline of Final Research Achievements |
In order to realize the proposed bidirectional reading method SOT-RAM (which can reduce the disturbance by about 10 times), we investigated the material parameter dependence, element size dependence, and memory cell array resistance dependence. We were able to confirm the reduction of the proposed method for any material parameter and element shape. In addition, from the magnetization state analysis including the magnetization vortex, it was found that the spin current acts on the left and right magnetization of the free layer, and the magnetizations antagonize each other across the magnetization vortex to reduce the disturbance. Furthermore, in the array structure, the effect of different current path resistance depending on the location of the memory cell was investigated. As a result, it was found that sufficient disrupt reduction can be obtained even if up to about 1000 wires are connected to common wiring.
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Free Research Field |
電子デバイス・電子機器
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Academic Significance and Societal Importance of the Research Achievements |
持続可能なIoT時代に必須の理想的な不揮発性RAMとして、MRAMの開発が進んでいる。SOT-RAMは高速で耐久性、安定性に優れた次世代MRAMである。また、MRAMを採用することでコンピュータの構成要素をスタンバイ状態ではオフにして必要な時に瞬時に起動するノーマリーオフコンピューティングを実現できることから、より高速で信頼性が高く、エネルギー効率の優れたデバイスの開発につながる。このように、次世代の磁気メモリとして注目されるSOT-RAMに固有の課題を見出し、解決案を提示した本研究は、SOT-RAMの製品化に必須の技術であり、今後の応用が期待される。
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