# US 10,770,214 B2 · Spin-orbit-torque magnetization rotational element, spin-orbit-torque magnetoresistance effect element, and magnetic memory

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- Number: US 10,770,214 B2
- Document ID: US10770214B2
- Status: Granted
- Kind: B2
- Application number: 16/292,840
- Filed: 2019-03-05
- Published: 2019-09-19
- Granted: 2020-09-08
- Earliest claimed: 2018-03-16
- Assignees: TDK Corporation
- Applicants: TDK Corporation
- Inventors: Yohei Shiokawa
- Web page: https://patentgrep.com/patent/US10770214B2

## CPC

- H01F 10/329: {Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect}
- G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell}
- G11C 11/1659: {Cell access}
- H01F 10/3254: {the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]}
- H10B 61/10: {comprising components having two electrodes, e.g. diodes or MIM elements}
- H10N 50/10: Magnetoresistive devices
- H10N 50/80: Constructional details
- H10N 70/231: {based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect}
- H10N 70/826: {adapted for essentially vertical current flow, e.g. sandwich or pillar type devices}
- H10N 70/841: {Electrodes}
- H10N 70/8825: {Selenides, e.g. GeSe}
- H10N 70/8828: {Tellurides, e.g. GeSbTe}
- G11C 11/1673: {Reading or sensing circuits or methods}
- G11C 11/1675: {Writing or programming circuits or methods}
- H10N 70/8833: {Binary metal oxides, e.g. TaOx}
- H10N 70/8836: {Complex metal oxides, e.g. perovskites, spinels}
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H10B: ELECTRONIC MEMORY DEVICES
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

A spin-orbit-torque magnetization rotational element includes: a spin-orbit-torque wiring extending in a first direction; a first ferromagnetic layer laminated on one surface of the spin-orbit-torque wiring; and a first electrode and a second electrode connected to the spin-orbit-torque wiring at positions sandwiching the first ferromagnetic layer in a plan view, wherein at least one of the first electrode and the second electrode includes therein a switching layer configured to shift between a high resistance state and a low resistance state with a predetermined threshold voltage as a boundary to allow an electric current to flow bidirectionally.

## Claims

### Claim 1

A spin-orbit-torque magnetization rotational element comprising:
a spin-orbit-torque wiring extending in a first direction;
a first ferromagnetic layer laminated on one surface of the spin-orbit-torque wiring in a second direction that crosses the first direction; and
a first electrode and a second electrode connected to the spin-orbit-torque wiring at positions sandwiching the first ferromagnetic layer in a plan view in the second direction, wherein:
at least one of the first electrode and the second electrode includes a switching layer configured to shift between a high resistance state and a low resistance state with a predetermined threshold voltage as a boundary to allow an electric current to flow bidirectionally;
the switching layer is arranged to cross the second direction;
relationships of (i) and (ii) are satisfied:
Vr/Ic<Rr+RON (i)
RSOT+2RON<Vw/Ic (ii)
Rr being a resistance value of the spin-orbit-torque wiring between the first electrode or the second electrode energized in reading and the first ferromagnetic layer,
Ron being a resistance value of the switching layer of the first electrode or the second electrode energized in reading in the low resistance state,
RSOT being a resistance value of the spin-orbit-torque wiring,
Vw being a voltage applied between the first electrode energized in writing and the second electrode in writing,
Vr being a voltage applied between the first electrode or the second electrode energized in reading; and the first ferromagnetic layer in reading, and
Ic being a critical threshold current required for a magnetization to be rotated in the first ferromagnetic layer; and
the switching layer is an alloy containing a chalcogen element and an additional element selected from the group consisting of aluminum, magnesium, boron, yttrium and rare earth element.

### Claim 2 (depends on 1)

The spin-orbit-torque magnetization rotational element according to claim 1, wherein the first electrode and the second electrode include the switching layer therein.

### Claim 3 (depends on 2)

The spin-orbit-torque magnetization rotational element according to claim 2, wherein a threshold voltage of the switching layer of the first electrode is different from a threshold voltage of the switching layer of the second electrode.

### Claim 4 (depends on 1)

The spin-orbit-torque magnetization rotational element according to claim 1, wherein the switching layer is an oxide that contains a transition metal capable of undergoing a metal-insulator transition.

### Claim 5 (depends on 2)

The spin-orbit-torque magnetization rotational element according to claim 2, wherein the switching layer is an oxide that contains a transition metal capable of undergoing a metal-insulator transition.

### Claim 6 (depends on 3)

The spin-orbit-torque magnetization rotational element according to claim 3, wherein the switching layer is an oxide that contains a transition metal capable of undergoing a metal-insulator transition.

### Claim 7 (depends on 1)

A spin-orbit-torque magnetoresistance effect element comprising:
the spin-orbit-torque magnetization rotational element according to claim 1;
a second ferromagnetic layer facing the first ferromagnetic layer; and
a nonmagnetic layer positioned between the first ferromagnetic layer and the second ferromagnetic layer.

### Claim 8 (depends on 7)

A magnetic memory comprising a plurality of the spin-orbit-torque magnetoresistance effect elements according to claim 7.