Study on spin injection solid state magnetic memories

自旋注入固态磁存储器的研究

• 批准号: 16206031
• 负责人: TSUNASHIMA Shigeru
• 金额: $ 31.7万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16206031/
• 关键词: microfabrication; electron beam lithography; thermomagnetic recording; spin injection; amorphous alloy; etching method; Joule heating; critical current; リフトオフ法

In order to develop high speed, non-volatile, and thermally stable solid-state memory, this research studied thermal writing and spin injection writing on micro-fabricated amorphous magnetic thin films.TbFe amorphous thin films having a large perpendicular magnetic anisotropy and moderate Curie temperature were micro-fabricated by using electron beam lithography technique. In this study, thermomagnetic writing was performed by flowing current pulses into the micro-fabricated TbFe narrow path under a static magnetic field of 100 Oe. The successful writing on TbFe with a lateral size of 0.5 x 0.5 μm^2 was confirmed after the application of the current pulse of 0.14 mW and 100 nsec. The critical current density for the successful writing was increased with decreasing pulse duration, and the dependence on the pulse duration was reproduced by the numerical thermal simulation.It is necessary to exhibit high tunnel magneto-resistance (TMR) ratio in TbFe based magnetic tunnel junctions to utilize the TbFe memory layer as an element of the magnetic random access memory. We, therefore, tried to fabricate magnetic tunneling junctions having the structure of TbFe (20 nm) / CoFe (tnm) / Al-0 (1.6 nm) / CoFe (t nm) / TbFe (20 nm). By inserting thin CoFe layers at t = 1 nm, large TMR ratio of 12% was confirmed. Further improvement of the TMR ratio is expected by optimizing the deposition condition and the structure of the junction.

为了开发高速，非易失性和热稳定的固态记忆，这项研究研究了对微型无定形无定形的无形磁性薄膜的热写作和自旋注射写作。TBFE无定形薄膜具有大型垂直磁各向异性和适度的咖喱温度，并通过使用电子纤维图技术进行了微量处理。在这项研究中，通过将电流脉冲流入100 OE的静态磁场下，将电磁脉冲流入微型制造的TBFE狭窄路径中，进行热磁写作。在施加0.14 mW和100 NSEC的电流脉冲后，确认了在TBFE上的成功写作，横向大小为0.5 x0.5μm^2。随着脉冲持续时间的减少，成功写作的临界电流密度增加了，并且对脉冲持续时间的依赖性通过数值热模拟复制。在基于TBFE的磁性隧道连接中，必须在暴露高隧道磁力抗性（TMR）比率以利用TBFE记忆层作为TBFE记忆层作为磁性随机访问的元素，这是必要的。因此，我们试图制造具有TBFE（20 nm） / COFE（TNM） / AL-0（1.6 nm） / COFE（TNM） / TBFE（20 nm）的磁性隧道连接。通过在t = 1 nm处插入薄的COFE层，确认了12％的较大TMR比。通过优化连接的沉积条件和结构，预期TMR比的进一步改善。

项目成果

Thickness Dependence of Exchange Anisotropy for (001) Oriented Mn_<89>Pt_<11>/NiFe Bilayers

(001) 取向 Mn_<89>Pt_<11>/NiFe 双层交换各向异性的厚度依赖性

• 发表时间: 2007
• 期刊: J. Magn. Magn. Mat. 310・2-3
• 作者: D.Hippo;K.Urakawa;Y.Kawata;Y.Tsuchiya;H.Mizuta;N Koshida;S.Oda;K. Yamane;H.Yamaguchi;T.Kume et al.
• 通讯作者: T.Kume et al.

STM observation and magnetic anisotropy of MBE-Grown Fe/Pt superlattices with (111) and (001) orientations

(111) 和 (001) 取向 MBE 生长的 Fe/Pt 超晶格的 STM 观察和磁各向异性

• 发表时间: 2004
• 期刊: IEEE Trans.Magn. 95・11
• 作者: M.Takahashi;M.Tonouchi;S.Yamamoto
• 通讯作者: S.Yamamoto

Exchange anisotropy of (001) oriented Mn_<80>Ir_<20>/NiFe epitaxial bilayers

(001)取向Mn_<80>Ir_<20>/NiFe外延双层的交换各向异性

• 发表时间: 2004
• 期刊: J.Magn.Magn.Mat. 286
• 作者: I.A.Halin;S.Kawahito;T.Kume
• 通讯作者: T.Kume

固体メモリ装置

固态存储设备

• 发表时间: 2004

Simulation of thermomagnetic recording process using MFM method : effect of field gradient (Invited)

使用MFM方法模拟热磁记录过程：场梯度的影响（特邀）

• 发表时间: 2004
• 期刊: Trans. Magn. Soc. Jpn 4-2
• 作者: K. Kajikawa;K. Tomachi;N. Maema;M. Matsuo;S. Sato;K. Funaki;H. Kumakura;K. Tanaka;M. Okada;K. Nakamichi;Y. Kihara;T. Kamiya;I. Aoki;T.Kato et al.
• 通讯作者: T.Kato et al.