Magnetoresistance effect element

Patent metadata

Field	Value
Publication number	US-12364168-B2
Application number	US-202217746178-A
Country	US
Kind code	B2
Filing date	May 17, 2022
Priority date	Jun 28, 2018
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer. The tunnel barrier layer is a stacked body including one or more first oxide layers having a spinel structure and one or more second oxide layers having a spinel structure with a composition which is different from a composition of the first oxide layer.

First claim

What is claimed is:

1. A magnetoresistance effect element, comprising:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer,
wherein the tunnel barrier layer is a stacked body including one or more first oxide layers and one or more second oxide layers with a composition which is different from a composition of the first oxide layer,
at least one of the first oxide layer or the second oxide layer has a disordered spinel structure,
the first oxide layer includes an oxide containing a metal or an alloy which is expressed by General Formula (I),
A 1-x B x   (I)

the second oxide layer includes an oxide containing a metal or an alloy which is expressed by General Formula (II),
A 1-y B y   (II), and wherein,

in General Formula (I) and General Formula (II),
A's are independently Mg or Zn,
B's are independently at least one type of metal selected from the group consisting of Al, Ga, and In, and
x satisfies 0<x<0.5 and y satisfies 0.5<y≤1, and |y−x|≥0.005,

wherein the tunnel barrier layer is a stacked body which includes two first oxide layers and in which the second oxide layer is interposed between the two first oxide layers.

2. The magnetoresistance effect element according to claim 1 , wherein the first ferromagnetic layer is formed on a substrate, the first oxide layer is stacked on a surface of the first ferromagnetic layer opposite to the substrate, and the second oxide layer is stacked on a surface of the first oxide layer opposite to the first ferromagnetic layer.

3. The magnetoresistance effect element according to claim 1 , wherein a thickness of the first oxide layer is thinner than a thickness of the second oxide layer.

4. The magnetoresistance effect element according to claim 1 , wherein a thickness of the tunnel barrier layer is equal to or less than 3 nm.

5. The magnetoresistance effect element according to claim 1 , wherein both the first oxide layer and the second oxide layer have a spinel structure.

6. The magnetoresistance effect element according to claim 1 , wherein both the first oxide layer and the second oxide layer have a disordered spinel structure.

7. The magnetoresistance effect element according to claim 1 , wherein
B's are independently at least one type of metal selected from the group consisting of Ga and In.

8. The magnetoresistance effect element according to claim 1 , wherein
in General Formula (I), A is Mg or Zn, B is at least one type of metal selected from the group consisting of Ga and In, and x and y satisfy 0<x≤1, 0<y≤1, and |y−x|≥0.005.

9. The magnetoresistance effect element according to claim 1 , wherein
in General Formula (II), A is Mg or Zn, B is at least one type of metal selected from the group consisting of Ga and In, and x and y satisfy 0<x≤1, 0<y≤1, and |y−x|≥0.005.

10. A method of manufacturing the magnetoresistance effect element according to claim 1 including: a first ferromagnetic layer; a second ferromagnetic layer; and a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer, the tunnel barrier layer being a stacked body including one or more first oxide layers and one or more second oxide layers with a composition which is different from a composition of the first oxide layer, the method comprising: performing a heat treatment after stacking each of the first and second oxide layers.

11. A magnetoresistance effect element, comprising:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a tunnel barrier layer that is interposed between the first ferromagnetic layer and the second ferromagnetic layer,
wherein the tunnel barrier layer is a stacked body including one or more first oxide layers and one or more second oxide layers with a composition which is different from a composition of the first oxide layer,
at least one of the first oxide layer or the second oxide layer has a disordered spinel structure,
the first oxide layer includes an oxide containing a metal or an alloy which is expressed by General Formula (I),
A 1-x B x   (I)

the second oxide layer includes an oxide containing a metal or an alloy which is expressed by General Formula (II),
A 1-y B y   (II), and wherein,

in General Formula (I) and General Formula (II),
A's are independently Mg or Zn,
B's are independently at least one type of metal selected from the group consisting of Al, Ga, and In, and
x satisfies 0<x<0.5 and y satisfies 0.5<y≤1, and |y−x|≥0.005,

wherein a thickness of the first oxide layer is thinner than a thickness of the second oxide layer.

12. The magnetoresistance effect element according to claim 11 , wherein the first ferromagnetic layer is formed on a substrate, the first oxide layer is stacked on a surface of the first ferromagnetic layer opposite to the substrate, and the second oxide layer is stacked on a surface of the first oxide layer opposite to the first ferromagnetic layer.

13. The magnetoresistance effect element according to claim 11 , wherein the tunnel barrier layer is a stacked body which includes two first oxide layers and in which the second oxide layer is interposed between the two first oxide layers.

14. The magnetoresistance effect element according to claim 11 , wherein a thickness of the tunnel barrier layer is equal to or less than 3 nm.

15. The magnetoresistance effect element according to claim 11 , wherein both the first oxide layer and the second oxide layer have a spinel structure.

16. The magnetoresistance effect element according to claim 11 , wherein both the first oxide layer and the second oxide layer have a disordered spinel structure.

17. The magnetoresistance effect element according to claim 11 , wherein B's are independently at least one type of metal selected from the group consisting of Ga and In.

18. The magnetoresistance effect element according to claim 11 , wherein in General Formula (I), A is Mg or Zn, B is at least one type of metal selected from the group consisting of Ga and In, and x and y satisfy 0<x≤1, 0<y≤1, and |y−x|≥0.005.

19. The magnetoresistance effect element according to claim 11 , wherein in General Formula (II), A is Mg or Zn, B is at least one type of metal selected from the group consisting of Ga and In, and x and y satisfy 0<x≤1, 0<y≤1, and |y−x|≥0.005.

Assignees

• Tdk Corp

Inventors

• Ichikawa Shinto
• Nakada Katsuyuki
• Sasaki Tomoyuki

Classifications

• H10N50/10

  Magnetoresistive devices · CPC title

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title

• H01F10/324

  Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer · CPC title

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title

• B82Y25/00

  Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance · CPC title