# US 9,437,810 B2 · Magnetoresistive element and magnetic memory

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- Number: US 9,437,810 B2
- Document ID: US9437810B2
- Status: Granted
- Kind: B2
- Application number: 14/193,340
- Filed: 2014-02-28
- Published: 2014-09-18
- Granted: 2016-09-06
- Earliest claimed: 2013-03-14
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Eiji Kitagawa; Takao Ochiai; Kay Yakushiji; Makoto Konoto; Hitoshi Kubota; Shinji Yuasa; Takayuki Nozaki; Akio Fukushima
- Web page: https://patentgrep.com/patent/US9437810B2

## CPC

- H10N 50/85: Materials of the active region
- H10B 61/22: {of the field-effect transistor [FET] type}
- H10N 50/10: Magnetoresistive devices
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B: ELECTRONIC MEMORY DEVICES

## Abstract

According to one embodiment, a magnetoresistive element includes a first magnetic layer having a variable magnetization direction; a second magnetic layer having an invariable magnetization direction; and a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer and including an MgFeO film, wherein the MgFeO film contains at least one element selected from a group consisting of Ti, V, Mn, and Cu.

## Claims

### Claim 1

A magnetoresistive element comprising:
a first magnetic layer;
an MgFeO layer; and
a second magnetic layer stacked in a first direction, the MgFeO layer disposed between the first and second magnetic layers; wherein
Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in the first direction, and
the MgFeO layer contains at least one element selected from a group consisting of Ti, V, Mn, and Cu.

### Claim 2 (depends on 1)

The element according to claim 1,
wherein at least one of the first and second magnetic layers includes Fe.

### Claim 3 (depends on 1)

The element according to claim 1,
wherein at least one of the first and second magnetic layers includes a same metal element as a metal element contained in the MgFeO layer.

### Claim 4 (depends on 1)

The element according to claim 1,
wherein at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer.

### Claim 5 (depends on 1)

The element according to claim 1,
wherein the MgFeO layer includes at least one of a fine crystal phase and an amorphous phase.

### Claim 6 (depends on 1)

The element according to claim 1,
wherein the MgFeO layer further includes boron.

### Claim 7 (depends on 1)

A magnetic memory comprising a memory cell including the magnetoresistive element according to claim 1.

### Claim 8

A magnetoresistive element comprising:
a first magnetic layer;
an MgFeO layer; and
a second magnetic layer stacked in a first direction, the MgFeO layer disposed between the first and second magnetic layers; wherein
Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in the first direction, and
the MgFeO layer contains boron.

### Claim 9 (depends on 8)

The element according to claim 8,
wherein at least one of the first and second magnetic layers includes Fe.

### Claim 10 (depends on 8)

The element according to claim 8, wherein at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer.

### Claim 11 (depends on 8)

The element according to claim 8,
wherein the MgFeO layer includes at least one of a fine crystal phase and an amorphous phase.

### Claim 12 (depends on 8)

A magnetic memory comprising a memory cell including the magnetoresistive element according to claim 8.

### Claim 13

A magnetoresistive element comprising:
a first magnetic layer having a variable magnetization direction;
a second magnetic layer having an invariable magnetization direction; and
a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer and including an MgFeO layer, wherein
Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in a thickness direction,
at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer, and
the MgFeO layer contains at least one element selected from a group consisting of Ti, V, Mn, and Cu.

### Claim 14

A magnetoresistive element comprising:
a first magnetic layer having a variable magnetization direction;
a second magnetic layer having an invariable magnetization direction; and
a tunnel barrier layer provided between the first magnetic layer and the second magnetic layer and including an MgFeO layer, wherein
Fe of the MgFeO layer is included at least in a central portion of the MgFeO layer in a thickness direction,
at least one of a concentration of Fe in a region between the first magnetic layer and the MgFeO layer and a concentration of Fe in a region between the second magnetic layer and the MgFeO layer is higher than a concentration of Fe at the central portion of the MgFeO layer, and
the MgFeO layer contains boron.