Magneto-resistance effect element and magnetic memory

• US 7,663,171 B2
• Filed: 09/19/2005
• Issued: 02/16/2010
• Est. Priority Date: 03/22/2005
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Saito, Yoshiaki, Inokuchi, Tomoaki, Sugiyama, Hideyuki
• Primary Examiner(s): LE, THAO P
• Application Number:
  US11/228,326
• Publication Number:
  US 20060227465A1
• Time in Patent Office: 1,611 Days
• Field of Search: 257/422, 257/295, 257/421, 257/427, 257/E27.104, 257/E29.164, 365/158
• US Class Current: 257/295
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H01F 10/3231 via a non-magnetic spacer
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• CPC Class Codes: H01F 10/3281 only by use of asymmetry of the magnetic film pair itself, i.e. so-called pseudospin valve [PSV] structure, e.g. NiFe/Cu/Co
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

It is possible to reduce a current required for spin injection writing. A magneto-resistance effect element includes: a first magnetization pinned layer; a magnetization free layer; a tunnel barrier layer; a second magnetization pinned layer whose direction of magnetization is pinned to be substantially anti-parallel to the direction of magnetization of the first magnetization pinned layer, and; a non-magnetic layer. When the second magnetization pinned layer is made of ferromagnetic material including Co, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Zr, Hf, Rh, Ag, and Au; when the second magnetization pinned layer is made of ferromagnetic material including Fe, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Rh, Pt, Ir, Al, Ag, and Au; and when the second magnetization pinned layer is made of ferromagnetic material including Ni, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Zr, Hf, Au, and Ag.

Claims

1. A magneto-resistance effect element comprising:

a first magnetization pinned layer whose direction of magnetization is fixed;

a magnetization free layer whose direction of magnetization is variable;

a tunnel barrier layer which is provided between the first magnetization pinned layer and the magnetization free layer;

a second magnetization pinned layer which is provided on the opposite side of the magnetization free layer from the tunnel barrier layer and whose direction of magnetization is pinned to be substantially anti-parallel to the direction of magnetization of the first magnetization pinned layer, and;

a non-magnetic layer which is provided between the magnetization free layer and the second magnetization pinned layer,

a direction of magnetization of the magnetization free layer being made variable when a current is caused to flow between the first magnetization pinned layer and the second magnetization pinned layer,

wherein when the second magnetization pinned layer is made of Fe-rich ferromagnetic material, material for the non-magnetic layer is metal including at least one element selected from the group consisting of Pt, Ir, and Al; and

wherein the magnetization free layer is

a layer having at least two ferromagnetic particles where the at least two ferromagnetic particles are isolated from each other by dielectric or insulator, or

a layer having a first portion of a column-shaped ferromagnetic material and a second portion of dielectric or insulator surrounding the ferromagnetic material.

2. A magnetic memory comprising:

a memory cell having the magneto-resistance effect element according to claim 1;

a first wiring electrically connected with one end of the magneto-resistance effect element; and

a second wiring electrically connected with the other end of the magneto-resistance effect element.

3. The magneto-resistance effect element according to claim 1, wherein the magnetization free layer is a layer having at least two ferromagnetic particles where the at least two ferromagnetic particles are isolated from each other by dielectric or insulator.

4. The magneto-resistance effect element according to claim 1, wherein the magnetization free layer is a layer having a first portion of a column-shaped ferromagnetic material and a second portion of dielectric or insulator surrounding the ferromagnetic material.

5. The magneto-resistance effect element according to claim 1, wherein the second magnetization pinned layer is made of Fe-rich ferromagnetic material, and the material for the non-magnetic layer is metal including at least one element selected from the group consisting of Pt, Ir, and Al.

6. The magneto-resistance effect element according to claim 5, wherein the material for the non-magnetic layer is metal including Pt.

7. The magneto-resistance effect element according to claim 5, wherein the material for the non-magnetic layer is metal including Ir.

8. The magneto-resistance effect element according to claim 5, wherein the material for the non-magnetic layer is metal including Al.

9. The magneto-resistance effect element according to claim 5, wherein the magnetization free layer is a layer having at least two ferromagnetic particles where the at least two ferromagnetic particles are isolated from each other by dielectric or insulator.

10. The magneto-resistance effect element according to claim 5, wherein the magnetization free layer is a layer having a first portion of a column-shaped ferromagnetic material and a second portion of dielectric or insulator surrounding the ferromagnetic material.