A novel SPRAM (SPin-transfer torque RAM) with a synthetic ferrimagnetic free layer for higher immunity to read disturbance and reducing write-current dispersion

被引:23
作者
Miura, K. [1 ]
Kawahara, I. [2 ]
Takemura, R. [2 ]
Hayakawa, J. [1 ,3 ]
Ikeda, S. [3 ]
Sasaki, R. [3 ]
Takahashi, H. [1 ,2 ]
Matsuoka, H. [1 ]
Ohno, H. [3 ]
机构
[1] Hitachi Ltd, Adv Res Lab, Kokubunji, Tokyo 1858601, Japan
[2] Hitachi Ltd, Cent Res Lab, Kokubunji, Tokyo 1858601, Japan
[3] Tohoku Univ, Lab Nanoelect & Spintron, Res Inst Elect Commun, Aoba Ku, Sendai, Miyagi 9808577, Japan
来源
2007 SYMPOSIUM ON VLSI TECHNOLOGY, DIGEST OF TECHNICAL PAPERS | 2007年
关键词
D O I
10.1109/VLSIT.2007.4339706
中图分类号
TM [电工技术]; TN [电子技术、通信技术];
学科分类号
0808 ; 0809 ;
摘要
A novel SPRAM (SPin-transfer torque RAM) consisting of MgO-barrier-based magnetic tunnel junctions (MTJs) with a synthetic ferrimagnetic (SyF) structure in a free layer was demonstrated for both higher immunity to read disturbance and a sufficient margin between the read and write currents. Since magnetization of the free layer becomes stable against thermal fluctuation with increasing thermal-stability factor E/k(B)T, the SyF free layer of the MTJs realized a magnetic information retention of over 10 years due to its high E/k(B)T of 67. Furthermore, it was found that the SyF free layer has an advantage of reducing dispersion of write-current density J(c), which is necessary for securing an adequate margin between the read and write currents.
引用
收藏
页码:234 / +
页数:2
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