# US 8,772,887 B2 · Magnetic device

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- Number: US 8,772,887 B2
- Document ID: US8772887B2
- Status: Granted
- Kind: B2
- Application number: 13/475,520
- Filed: 2012-05-18
- Published: 2012-11-22
- Granted: 2014-07-08
- Earliest claimed: 2011-05-19
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Woo-Chang Lim; Jang-Eun Lee; Se-Chung Oh; Woo-Jin Kim; Young-Hyun Kim; Jeong-Heon Park
- Inventors: Woo-Chang Lim; Jang-Eun Lee; Se-Chung Oh; Woo-Jin Kim; Young-Hyun Kim; Jeong-Heon Park
- Web page: https://patentgrep.com/patent/US8772887B2

## CPC

- H10N 50/10: Magnetoresistive devices
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

A magnetic tunnel junction element is provided. The magnetic tunnel junction element has first magnetic layer and second magnetic layer formed adjacent, e.g., on lower and upper portions of an insulating layer, respectively and each having a perpendicular magnetic anisotropy, a magnetic field adjustment layer formed on the second magnetic layer and having a perpendicular magnetic anisotropy, and a bather layer formed between the magnetic field adjustment layer and the second magnetic layer. The second magnetic layer and the magnetic field adjustment layer are magnetically decoupled from each other.

## Claims

### Claim 1

A magnetic device comprising:
a first magnetic layer and a second magnetic layer adjacent lower and upper portions of an insulating layer, respectively, and the first magnetic layer and the second magnetic layer each having a perpendicular magnetic anisotropy;
a magnetic field adjustment layer overlying the second magnetic layer and having a perpendicular magnetic anisotropy; and
a barrier layer formed between the magnetic field adjustment layer and the second magnetic layer, said barrier layer comprising a metal alloy containing a metal selected from the group consisting of tantalum (Ta), ruthenium (Ru), titanium (Ti), palladium (Pd), platinum (Pt), magnesium (Mg), and aluminum (Al), and having a thickness between about 20 to 50Å;
wherein the second magnetic layer and the magnetic field adjustment layer are magnetically decoupled from each other.

### Claim 2 (depends on 1)

The magnetic device of claim 1, wherein the thickness of the second magnetic layer is equal to or larger than about 15Å.

### Claim 3 (depends on 1)

The magnetic device of claim 1, wherein the magnetic field adjustment layer comprises a third magnetic layer, a fourth magnetic layer, and a nonmagnetic layer formed between the third magnetic layer and the fourth magnetic layer, and the third magnetic layer and the fourth magnetic layer are anti-ferromagnetically coupled to each other.

### Claim 4 (depends on 3)

The magnetic device of claim 3, wherein the fourth magnetic layer is formed to be thicker than the third magnetic layer.

### Claim 5 (depends on 3)

The magnetic device of claim 3, wherein the third magnetic layer and the fourth magnetic layer have a structure in which a ferromagnetic metal and a nonmagnetic metal are alternately laminated.

### Claim 6 (depends on 1)

The magnetic device of claim 1, wherein an overall magnetization direction of the magnetic field adjustment layer and a magnetization direction of the first magnetic layer are anti-parallel to each other.

### Claim 7 (depends on 1)

The magnetic device of claim 1, wherein a seed layer, which includes a single metal selected from the group consisting of tantalum (Ta), ruthenium (Ru), titanium (Ti), palladium (Pd), platinum (Pt), magnesium (Mg), aluminum (Al) and their alloy, is formed adjacent to the first magnetic layer.

### Claim 8 (depends on 7)

The magnetic device of claim 7, further comprising a fifth magnetic layer having a perpendicular magnetic anisotropy and substantially the same magnetization direction as the first magnetic layer, said fifth magnetic layer formed adjacent the seed layer and on an opposite side of the seed layer as the first magnetic layer.

### Claim 9

A magnetic device comprising:
a first magnetic layer and a second magnetic layer disposed on opposite sides of an insulating layer, said first and second magnetic layers each having a perpendicular magnetic isotropy;
a seed layer formed adjacent the first magnetic layer;
a magnetic field adjustment layer arranged above the second magnetic layer and also having a perpendicular magnetic isotropy; and
a barrier layer formed between the magnetic field adjustment layer and the second magnetic layer, said barrier layer comprising a metal selected from the group consisting of tantalum (Ta), ruthenium (Ru), titanium (Ti), palladium (Pd), platinum (Pt), magnesium (Mg), and aluminum (Al), and having a thickness between about 20 to 50Å,
wherein the barrier layer comprises a metal alloy.

### Claim 10 (depends on 9)

The magnetic device of claim 9, wherein the thickness of the second magnetic layer is equal to or larger than about 15Å.

### Claim 11 (depends on 9)

The magnetic device of claim 9, wherein the magnetic field adjustment layer comprises a third magnetic layer, a fourth magnetic layer, and a nonmagnetic layer formed between the third magnetic layer and the fourth magnetic layer, and wherein the third magnetic layer and the fourth magnetic layer are anti-ferromagnetically coupled to each other.

### Claim 12 (depends on 11)

The magnetic device of claim 11, wherein the fourth magnetic layer is thicker than the third magnetic layer.

### Claim 13 (depends on 11)

The magnetic device of claim 11, wherein the third magnetic layer and the fourth magnetic layer have a structure in which a ferromagnetic metal and a nonmagnetic metal are alternately laminated.

### Claim 14 (depends on 9)

The magnetic device of claim 9, wherein an overall magnetization direction of the magnetic field adjustment layer and a magnetization direction of the first magnetic layer are anti-parallel to each other.

### Claim 15 (depends on 9)

The magnetic device of claim 9, wherein the seed layer includes a single metal selected from the group consisting of tantalum (Ta), ruthenium (Ru), titanium (Ti), palladium (Pd), platinum (Pt), magnesium (Mg), aluminum (Al) and their alloys.

### Claim 16 (depends on 9)

The magnetic device of claim 9, further comprising a fifth magnetic layer having a perpendicular magnetic anisotropy and substantially the same magnetization direction as the first magnetic layer, said fifth magnetic layer formed adjacent the seed layer and opposite the first magnetic layer.

### Claim 17

A magnetic device comprising:
a first magnetic layer and a second magnetic layer disposed on opposite sides of an insulating layer, said first and second magnetic layers each having a perpendicular magnetic isotropy;
a seed layer formed adjacent the first magnetic layer;
a magnetic field adjustment layer arranged above the second magnetic layer and also having a perpendicular magnetic isotropy, wherein the magnetic field adjustment layer comprises a third magnetic layer, a fourth magnetic layer, and a nonmagnetic layer formed between the third magnetic layer and the fourth magnetic layer, and wherein the third magnetic layer and the fourth magnetic layer are anti-ferromagnetically coupled to each other; and
a barrier layer formed between the magnetic field adjustment layer and the second magnetic layer, said barrier layer comprising a metal alloy including a metal selected from the group consisting of tantalum (Ta), ruthenium (Ru), titanium (Ti), palladium (Pd), platinum (Pt), magnesium (Mg), and aluminum (Al), and having a thickness between about 20 to 50Å;
a fifth magnetic layer having a perpendicular magnetic anisotropy and substantially the same magnetization direction as the first magnetic layer, said fifth magnetic layer formed adjacent the seed layer and on a side opposite the first magnetic layer.