Magnetic memory element and memory apparatus having multiple magnetization directions

• US 9,331,270 B2
• Filed: 07/14/2014
• Issued: 05/03/2016
• Est. Priority Date: 11/30/2011
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Higo, Yutaka, Hosomi, Masanori, Ohmori, Hiroyuki, Bessho, Kazuhiro, Asayama, Tetsuya, Yamane, Kazutaka, Uchida, Hiroyuki
• Primary Examiner(s): Valentine, Jami M
• Application Number:
  US14/330,748
• Publication Number:
  US 20140319633A1
• Time in Patent Office: 659 Days
• Field of Search: 257/20, 257/414, 257421-427, 257/E29.323, 438/3, 365157-158, 365171-173, 360327-326
• US Class Current: 1/1
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H01L 29/82 controllable by variation of the magnetic field applied to the device
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• 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

A memory element includes a layered structure: a memory layer having a magnetization direction changed depending on information, the magnetization direction being changed by applying a current in a lamination direction of the layered structure to record the information in the memory layer, including a first ferromagnetic layer having a magnetization direction that is inclined from a direction perpendicular to a film face, a bonding layer laminated on the first ferromagnetic layer, and a second ferromagnetic layer laminated on the bonding layer and bonded to the first ferromagnetic layer via the bonding layer, having a magnetization direction that is inclined from the direction perpendicular to the film face, a magnetization-fixed layer having a fixed magnetization direction, an intermediate layer that is provided between the memory layer and the magnetization-fixed layer, and is contacted with the first ferromagnetic layer, and a cap layer that is contacted with the second ferromagnetic layer.

Claims

1. A memory element, comprising a layered structure including:

a memory layer having a magnetization direction configured to be changed by in response to a current applied in a lamination direction of the layered structure to record information in the memory layer and at least including;

a first ferromagnetic layer,

a bonding layer laminated on the first ferromagnetic layer, and

a second ferromagnetic layer laminated on the bonding layer;

a fixed-magnetization layer having a fixed magnetization direction parallel to the lamination direction, the lamination direction being a direction perpendicular to a film face of the fixed-magnetization layer; and

an intermediate layer provided between the memory layer and the fixed-magnetization layer,

wherein a magnetization direction in an equilibrium state of the first ferromagnetic layer and a magnetization direction in an equilibrium state of the second ferromagnetic layer are respectively at a first and second predetermined angle relative to the fixed magnetization direction, wherein the first and second predetermined angles are more than 0 degrees and less than 180 degrees relative to the fixed magnetization direction, and the first predetermined angle is different in magnitude from the second predetermined angle.

2. The memory element according to claim 1, wherein

the magnetization direction of the first ferromagnetic layer is closer to a direction parallel to the lamination direction than to a direction perpendicular to the lamination direction, and

the magnetization direction of the second ferromagnetic layer is closer to a direction perpendicular to the lamination direction than to a direction parallel to the lamination direction.

3. The memory element according to claim 2, wherein

the angle formed by the magnetization direction of the first ferromagnetic layer and the direction perpendicular to the lamination direction is greater than the angle formed by the magnetization direction of the second ferromagnetic layer and the direction perpendicular to the lamination direction.

4. The memory element according to claim 1, wherein

the magnetization direction of the first ferromagnetic layer is closer to a direction perpendicular to the lamination direction than to a direction parallel to the lamination direction, and

the magnetization direction of the second ferromagnetic layer is closer to a direction parallel to the lamination direction than to a direction perpendicular to the lamination direction.

5. The memory element according to claim 4, wherein

the angle formed by the magnetization direction of the first ferromagnetic layer and the direction perpendicular to the lamination direction is smaller than the angle formed by the magnetization direction of the second ferromagnetic layer and the direction perpendicular to the lamination direction.

6. The memory element according to claim 1, wherein the intermediate layer is a tunnel insulating layer.

7. The memory element according to claim 1, further comprising a cap layer including an oxide layer.

8. The memory element according to claim 1, wherein the first ferromagnetic layer and the second ferromagnetic layer respectively include a Co—

Fe—

B layer.

17. The memory element according to claim 1, wherein the magnetization direction of the first ferromagnetic layer is closer to the fixed magnetization direction than to a direction perpendicular to the fixed magnetization direction.

19. The memory element according to claim 1, wherein the equilibrium state is a state where no current is applied.

9. A memory apparatus, comprising:

a memory element having a layered structure including;

a memory layer having a magnetization direction configured to be changed by in response to a current applied in a lamination direction of the layered structure to record information in the memory layer and at least including;

a first ferromagnetic layer,

a bonding layer laminated on the first ferromagnetic layer, and

a second ferromagnetic layer laminated on the bonding layer;

a fixed-magnetization layer having a fixed magnetization direction parallel to the lamination direction, the lamination direction being a direction perpendicular to a film face of the fixed-magnetization layer; and

an intermediate layer provided between the memory layer and the fixed-magnetization layer,

wherein a magnetization direction in an equilibrium state of the first ferromagnetic layer and a magnetization direction in an equilibrium state of the second ferromagnetic layer are respectively at a first and second predetermined angle relative to the fixed magnetization direction, wherein the first and second predetermined angles are more than 0 degrees and less than 180 degrees relative to the fixed magnetization direction, and the first predetermined angle is different in magnitude from the second predetermined angle.

10. The memory apparatus according to claim 9, wherein

the magnetization direction of the first ferromagnetic layer is closer to a direction parallel to the lamination direction than to a direction perpendicular to the lamination direction, and

the magnetization direction of the second ferromagnetic layer is closer to a direction perpendicular to the lamination direction than to a direction parallel to the lamination direction.

11. The memory apparatus according to claim 10, wherein

the angle formed by the magnetization direction of the first ferromagnetic layer and the direction perpendicular to the lamination direction is greater than the angle formed by the magnetization direction of the second ferromagnetic layer and the direction perpendicular to the lamination direction.

12. The memory apparatus according to claim 9, wherein

the magnetization direction of the first ferromagnetic layer is closer to a direction perpendicular to the lamination direction than to a direction parallel to the lamination direction, and

the magnetization direction of the second ferromagnetic layer is closer to a direction parallel to the lamination direction than to a direction perpendicular to the lamination direction.

13. The memory apparatus according to claim 12, wherein

the angle formed by the magnetization direction of the first ferromagnetic layer and the direction perpendicular to the lamination direction is smaller than the angle formed by the magnetization direction of the second ferromagnetic layer and the direction perpendicular to the lamination direction.

14. The memory apparatus according to claim 9, wherein the intermediate layer is a tunnel insulating layer.

15. The memory apparatus according to claim 9, further comprising a cap layer including an oxide layer.

16. The memory apparatus according to claim 9, wherein the first ferromagnetic layer and the second ferromagnetic layer respectively include a Co—

Fe—

B layer.

18. The memory apparatus according to claim 9, wherein the magnetization direction of the first ferromagnetic layer is closer to the fixed magnetization direction than to a direction perpendicular to the fixed magnetization direction.

20. The memory apparatus according to claim 9, wherein the equilibrium state is a state where no current is applied.