Magnetoresistive element and magnetoresistive memory

• US 8,803,267 B2
• Filed: 09/18/2012
• Issued: 08/12/2014
• Est. Priority Date: 03/21/2012
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kitagawa, Eiji, Daibou, Tadaomi, Kato, Yushi
• Primary Examiner(s): Such, Matthew W
• Assistant Examiner(s): Kilpatrick, Warren H
• Application Number:
  US13/621,998
• Publication Number:
  US 20130249026A1
• Time in Patent Office: 693 Days
• Field of Search: 257/421, 365/365
• US Class Current: 257/421
• CPC Class Codes: H01F 10/123 having a L10 crystallographic structure, e.g. [Co,Fe][Pt,Pd] thin films
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3286 Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
• CPC Class Codes: H01F 10/3295 Spin-exchange coupled multilayers wherein the magnetic pinned or free layers are laminated without anti-parallel coupling within the pinned and free layers
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

According to one embodiment, a magnetoresistive element includes a first magnetic film having a variable magnetization direction, a second magnetic film having an invariable magnetization direction, and a magnesium oxide film provided between the first magnetic film and the second magnetic film and being in contact with both the first magnetic film and the second magnetic film, and doped with at least one element selected from a first group consisting of copper, silver, and gold.

Claims

1. A magnetoresistive element comprising:

a first magnetic film having a variable magnetization direction;

a second magnetic film having an invariable magnetization direction; and

a magnesium oxide film provided between the first magnetic film and the second magnetic film and doped with at least one element selected from a first group consisting of gallium and indium.

2. The element according to claim 1, wherein a concentration of the one element selected from the first group in the magnesium oxide film is not more than 10 at %.

3. The element according to claim 1, wherein the magnesium oxide film is further doped with at least one element selected from a second group consisting of copper, silver, and gold.

4. The element according to claim 1, wherein a band gap of the magnesium oxide film is smaller than 7.8 eV.

5. The element according to claim 1, wherein the magnesium oxide film has a preferred orientation along an fcc (001) plane and a plane equivalent to the fcc (001) plane.

6. The element according to claim 1, wherein each of the first magnetic film and the second magnetic film has a magnetization perpendicular to film surfaces of the first magnetic film and the second magnetic film.

7. The element according to claim 1, wherein each of the first magnetic film and the second magnetic film has a magnetization parallel to film surfaces of the first magnetic film and the second magnetic film.

8. The element according to claim 1, wherein

the first magnetic film includes a first interface layer being in contact with the magnesium oxide film and containing at least two of cobalt, iron, and boron, and

the second magnetic film includes a second interface layer being in contact with the magnesium oxide film and containing at least two of cobalt, iron, and boron.

9. A magnetoresistive memory comprising

a memory cell including the magnetoresistive element according to claim 1.

10. The element according to claim 1, wherein the magnesium oxide film is further doped with at least one element selected from a second group consisting of aluminum and boron.