Memory element and memory device

• US 10,665,775 B2
• Filed: 10/22/2018
• Issued: 05/26/2020
• Est. Priority Date: 09/06/2010
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamane, Kazutaka, Hosomi, Masanori, Ohmori, Hiroyuki, Bessho, Kazuhiro, Higo, Yutaka, Uchida, Hiroyuki, Asayama, Tetsuya
• Primary Examiner(s): Ahmad, Khaja
• Application Number:
  US16/166,761
• Publication Number:
  US 20190058114A1
• Time in Patent Office: 582 Days
• Field of Search: None
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

There is disclosed an information storage element including a first layer including a ferromagnetic layer with a magnetization direction perpendicular to a film face; an insulation layer coupled to the first layer; and a second layer coupled to the insulation layer opposite the first layer, the second layer including a fixed magnetization so as to be capable of serving as a reference of the first layer. The first layer is capable of storing information according to a magnetization state of a magnetic material, and the magnetization state is configured to be changed by a spin injection. A magnitude of an effective diamagnetic field which the first layer receives is smaller than a saturated magnetization amount of the first layer.

Claims

1. A storage element comprising:

a first layer having a magnetization state of a first magnetic material;

a second layer having a fixed magnetization state of a second magnetic material;

an intermediate layer including a nonmagnetic material and being interposed between the first layer and the second layer;

wherein the first layer is configured to store information according to the magnetization state of the first magnetic material,

wherein a magnitude of an effective diamagnetic field which the first layer receives is smaller than a saturated magnetization amount of the first layer,

wherein the storage element has a size of about 70 nmϕ

or less, and the first magnetic material includes a Co, Fe and B alloy having a Fe atomic % of at least 60, and

wherein a ratio of Co and Fe in the first magnetic material is 7 to 3.

2. The storage element according to claim 1, wherein the magnetization state of the first magnetic material is configured to be changed by a current.

3. The storage element according to claim 1, wherein the second magnetic material includes Co, Fe, and B.

4. The storage element according to claim 1, wherein the intermediate layer includes at least one of magnesium oxide, aluminum oxide, aluminum nitride, SiO₂, Bi₂O₃, MgF₂, CaF, SrTiO₂, AlLaO₃, and AlNO.

5. The storage element according to claim 1, further comprising a cap layer.

6. The storage element according to claim 5, wherein the cap layer includes Ru or Ta.

7. The storage element according to claim 6, wherein the cap layer includes a laminated film including a first Ta film, a second Ta film, and a Ru film formed between the first and second Ta films.

8. The storage element according to claim 1, further comprising an underlying layer.

9. The storage element according to claim 8, wherein the underlying layer includes Ru or Ta.

10. The storage device according to claim 9, wherein the underlying layer includes a laminated film of a Ta film and a Ru film.

11. The storage device according to claim 1, wherein a film thickness of the second layer is greater than a film thickness of the first layer.

12. The storage device according to claim 1, wherein a damping constant of the second layer is greater than a damping constant of the first layer.

13. The storage device according to claim 1, wherein the second layer has a laminated ferri-pin structure including two ferromagnetic layers and a non-magnetic layer.

14. The storage device according to claim 13, further comprising an anti-ferromagnetic layer applied to the laminated ferri-pin structure.

15. The storage device according to claim 1, wherein a magnetization direction of the first magnetic material is perpendicular to a substrate of the storage device.

16. A memory device, comprising:

an storage element that retains information through a magnetization state of a magnetic material; and

two kinds of interconnects that intersect each other,

wherein the storage element includes

a first layer having a magnetization state of a first magnetic material;

a second layer having a fixed magnetization state of a second magnetic material; and

an intermediate layer including a nonmagnetic material and being interposed between the first layer and the second layer;

wherein a magnitude of an effective diamagnetic field which the first layer receives is smaller than a saturated magnetization amount of the first layer,

wherein the storage element has a size of about 70 nmϕ

or less, and the first magnetic material includes a Co, Fe and B alloy having a Fe atomic % of at least 60, and

wherein a ratio of Co and Fe in the first magnetic material is 7 to 3.