Magnetoresistance effect element

Patent metadata

Field	Value
Publication number	US-11944018-B2
Application number	US-202217858200-A
Country	US
Kind code	B2
Filing date	Jul 6, 2022
Priority date	Jul 15, 2021
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

A magnetoresistance effect element of the present disclosure includes a first Ru alloy layer, a first ferromagnetic layer, a non-magnetic metal layer, and a second ferromagnetic layer in order, wherein the first Ru alloy layer contains one or more Ru alloys represented by the following general formula (1),RuαX1-α  (1)where, in the general formula (1), the symbol X represents one or more elements selected from the group consisting of Be, B, Ti, Y, Zr, Nb, Mo, Rh, In, Sn, La, Ce, Nd, Sm, Gd, Dy, Er, Ta, W, Re, Os, and Ir, and the symbol α represents a number satisfying 0.5<α<1, the first ferromagnetic layer contains a Heusler alloy, and the second ferromagnetic layer contains a Heusler alloy.

First claim

What is claimed is:

1. A magnetoresistance effect element comprising a first Ru alloy layer, a first ferromagnetic layer, a non-magnetic metal layer, and a second ferromagnetic layer in order,
wherein the first Ru alloy layer contains one or more Ru alloys represented by the following general formula (1),
Ru α X 1-α   (1)

where, in the general formula (1), the symbol X represents one or more elements selected from the group consisting of Be, B, Ti, Y, Zr, Nb, Mo, Rh, In, Sn, La, Ce, Nd, Sm, Gd, Dy, Er, Ta, W, Re, Os, and Ir, and the symbol α represents a number satisfying 0.5<α<1,
the first ferromagnetic layer contains a Heusler alloy, and
the second ferromagnetic layer contains a Heusler alloy.

2. The magnetoresistance effect element according to claim 1 , wherein the symbol X in the general formula (1) represents one or more elements selected from the group consisting of B, Ti, Zr, Nb, Mo, Rh, Ta, W, Re, Os, and Ir.

3. The magnetoresistance effect element according to claim 1 , wherein a Ru content of the Ru alloy contained in the first Ru alloy layer changes in an in-plane direction or a laminating direction of the first Ru alloy layer.

4. The magnetoresistance effect element according to claim 1 , wherein a Ru content of the Ru alloy contained in the first Ru alloy layer continuously changes in the laminating direction of the first Ru alloy layer.

5. The magnetoresistance effect element according to claim 1 , wherein a Ru content of the Ru alloy contained in the first Ru alloy layer increases from a surface of the first Ru alloy layer on the first ferromagnetic layer side toward a surface of the first Ru alloy layer on a side opposite to the first ferromagnetic layer side.

6. The magnetoresistance effect element according to claim 1 , wherein at least one of the Heusler alloy contained in the first ferromagnetic layer and the Heusler alloy contained in the second ferromagnetic layer contains one or more Heusler alloys represented by the following general formula (2),
Co 2 (Fe 1-β ,M1 β )M2  (2)

where, in the general formula (2), the symbol M1 represents Mn or Ti, the symbol M2 represents one or more elements selected from the group consisting of Si, Al, Ga, Ge, and Sn, and the symbol β represents a number satisfying 0≤β≤1.

7. The magnetoresistance effect element according to claim 6 , wherein the Heusler alloy is one or more alloys selected from the group consisting of Co 2 Fe(GaGe), Co 2 (MnFe)Ge, and Co 2 (FeMn)(GaGe).

8. The magnetoresistance effect element according to claim 6 , wherein the first ferromagnetic layer contains the Heusler alloy represented by the general formula (2), and the Heusler alloy contained in a surface of the first ferromagnetic layer on the first Ru alloy layer side has a large amount of Co and Fe as compared with the Heusler alloy contained in a surface thereof on a side opposite to the first Ru alloy layer side.

9. The magnetoresistance effect element according to claim 6 , wherein the second ferromagnetic layer contains the Heusler alloy represented by the general formula (2), and the Heusler alloy contained in an interface of the second ferromagnetic layer on a side opposite to the non-magnetic metal layer side has a large amount of Co and Fe as compared with the Heusler alloy contained in an interface of the second ferromagnetic layer on the non-magnetic metal layer side.

10. The magnetoresistance effect element according to claim 1 , wherein a CoFeB layer or a CoFe layer is provided between the first ferromagnetic layer and the first Ru alloy layer.

11. The magnetoresistance effect element according to claim 1 , wherein a second Ru alloy layer is provided on a surface of the second ferromagnetic layer on a side opposite to the non-magnetic metal layer, and the second Ru alloy layer contains one or more Ru alloys represented by the general formula (1).

12. The magnetoresistance effect element according to claim 11 , wherein a CoFeB layer or a CoFe layer is provided between the second ferromagnetic layer and the second Ru alloy layer.

13. The magnetoresistance effect element according to claim 1 , wherein the non-magnetic metal layer contains Ag or a Ag alloy.

Assignees

• Tdk Corp

Inventors

• INUBUSHI Kazuumi
• Nakada Katsuyuki
• Ichikawa Shinto

Classifications

• H10N50/85 Primary

  Materials of the active region · CPC title

• H10N50/10 Primary

  Magnetoresistive devices · CPC title

• G11B5/372

  in magnetic thin films · CPC title

• G11C11/161

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• H03B15/006

  using spin transfer effects or giant magnetoresistance · CPC title