# US 2019/0355898 A1 · Magnetoresistance effect element

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- Number: US 2019/0355898 A1
- Document ID: US20190355898A1
- Status: Published application
- Kind: A1
- Application number: 16/412,727
- Filed: 2019-05-15
- Published: 2019-11-21
- Earliest claimed: 2018-05-16
- Assignees: TDK Corporation
- Applicants: TDK Corporation
- Inventors: Katsuyuki NAKADA
- Web page: https://patentgrep.com/patent/US20190355898A1

## CPC

- H10N 50/10: Magnetoresistive devices
- H10N 50/80: Constructional details
- H10N 50/85: Materials of the active region
- H10N 50/01: Manufacture or treatment
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

A magnetoresistance effect element includes: a first ferromagnetic layer; a second ferromagnetic layer; and a tunnel barrier layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer, wherein the tunnel barrier layer is an oxide having a spinel structure, and the tunnel barrier layer includes a magnetic element as an additional element.

## Claims

### Claim 1

A magnetoresistance effect element, comprising:
a first ferromagnetic layer;
a second ferromagnetic layer; and
a tunnel barrier layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer,
wherein the tunnel barrier layer is an oxide having a spinel structure, and the tunnel barrier layer includes a magnetic element as an additional element.

### Claim 2 (depends on 1)

The magnetoresistance effect element according to claim 1, wherein the magnetic element is one or more elements selected from a group consisting of Cr, Mn, Fe, Co, and Ni.

### Claim 3 (depends on 1)

The magnetoresistance effect element according to claim 1, wherein the magnetic element is one or more elements selected from a group consisting of Fe, Co, and Ni.

### Claim 4 (depends on 1)

The magnetoresistance effect element according to claim 1, wherein more of the magnetic element is present on interface sides between the tunnel barrier layer and the first ferromagnetic layer and the second ferromagnetic layer than at a center of the tunnel barrier layer in a laminating direction.

### Claim 5 (depends on 1)

The magnetoresistance effect element according to claim 1, wherein:
the tunnel barrier layer is an oxide having a spinel structure including an element A and an element B,
the element A is one or more elements selected from a group consisting of Mg and Zn, and
the element B is one or more elements selected from a group consisting of Al, In, and Ga.

### Claim 6 (depends on 5)

The magnetoresistance effect element according to claim 5, wherein an abundance ratio of the magnetic element with respect to the total number of atoms of the element A and the element B in the tunnel barrier layer is 0.3 at % or more and 3 at % or less.

### Claim 7 (depends on 5)

The magnetoresistance effect element according to claim 5, wherein:
the tunnel barrier layer is represented by a composition formula AαBβMxOγ, and
in the composition formula, A is the element A, B is the element B, M is a magnetic element, and α+β+x=1, β≠0, 0.35≤y≤1.7, 0.003≤x≤0.029.

### Claim 8 (depends on 1)

The magnetoresistance effect element according to claim 1, wherein an MR ratio at room temperature is 80% or more.

### Claim 9 (depends on 1)

The magnetoresistance effect element according to claim 1, wherein a ratio of the MR ratio at a temperature of 400 K to the MR ratio at room temperature is 0.9 or more.