Title:
MAGNETIC MEMORY
Document Type and Number:
WIPO Patent Application WO/2010/100728
Kind Code:
A1
Abstract:
Provided is a magnetic random access memory employing spin torque magnetization reversal which is thermally stable during reading and achieves a reduction in current during writing. A magnetoresistive effect element formed by sequentially stacking a fixed layer, a nonmagnetic barrier layer, and a recording layer is used as a memory element, and the recording layer is composed of a laminated ferri-structure. The following expression is satisfied: Ms
2(t/w)>|Jex|>(2kBTΔ)/S where kB is a Boltzman constant, T is the operating temperature of the magnetic memory, S is an area parallel to the film plane of the magnetoresistive effect element, t and Ms are respectively the thickness and saturation magnetization of a ferromagnetic layer with a smaller thickness out of two ferromagnetic layers composing the laminated ferri-structure, w is the length of a shorter side of the recording layer, Δ is the thermal stability exponent of the magnetic memory, and Jex is exchange coupling energy applied between the two ferromagnetic layers of the recording layer.
Inventors:
ITO KENCHI (JP)
HAYAKAWA JUN (JP)
MIURA KATSUYA (JP)
YAMAMOTO HIROYUKI (JP)
HAYAKAWA JUN (JP)
MIURA KATSUYA (JP)
YAMAMOTO HIROYUKI (JP)
Application Number:
PCT/JP2009/054070
Publication Date:
September 10, 2010
Filing Date:
March 04, 2009
Export Citation:
Assignee:
HITACHI LTD (JP)
ITO KENCHI (JP)
HAYAKAWA JUN (JP)
MIURA KATSUYA (JP)
YAMAMOTO HIROYUKI (JP)
ITO KENCHI (JP)
HAYAKAWA JUN (JP)
MIURA KATSUYA (JP)
YAMAMOTO HIROYUKI (JP)
International Classes:
H01L43/08; H01L21/8246; H01L27/105; H01L29/82
Foreign References:
| JP2004193595A | 2004-07-08 | |||
| JP2007150265A | 2007-06-14 | |||
| JP2008311321A | 2008-12-25 | |||
| JP2008198900A | 2008-08-28 | |||
| JP2007281247A | 2007-10-25 | |||
| JP2007142393A | 2007-06-07 | |||
| JP2007317734A | 2007-12-06 | |||
| US5734605A | 1998-03-31 | |||
| JP2005294376A | 2005-10-20 | |||
| JP2007317734A | 2007-12-06 |
Other References:
PHYSICAL REVIEW LETTERS, vol. 84, no. 14, 2000, pages 2149 - 2152
APPLIED PHYSICS LETTERS, vol. 84, 2004, pages 2118 - 2120
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol. 159, 1996, pages LI-6
PHYSICAL REVIEW B, vol. 62, no. 1, pages 570 - 578
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol. 159, 1996, pages LL-6
See also references of EP 2405504A4
APPLIED PHYSICS LETTERS, vol. 84, 2004, pages 2118 - 2120
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol. 159, 1996, pages LI-6
PHYSICAL REVIEW B, vol. 62, no. 1, pages 570 - 578
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, vol. 159, 1996, pages LL-6
See also references of EP 2405504A4
Attorney, Agent or Firm:
HIRAKI, YUSUKE (JP)
Yusuke Hiraki (JP)
Yusuke Hiraki (JP)
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