# US 12,114,510 B2 · SOT MRAM having dielectric interfacial layer and method forming same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,114,510 B2
- Document ID: US12114510B2
- Status: Granted
- Kind: B2
- Application number: 17/809,928
- Filed: 2022-06-30
- Published: 2022-10-13
- Granted: 2024-10-08
- Earliest claimed: 2019-05-17
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Wilman Tsai; MingYuan Song; Shy-Jay Lin
- Web page: https://patentgrep.com/patent/US12114510B2

## CPC

- H10B 61/00: Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
- G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell}
- H10N 50/01: Manufacture or treatment
- H10N 50/10: Magnetoresistive devices
- H10N 50/80: Constructional details
- G11C 11/1675: {Writing or programming circuits or methods}
- H10B: ELECTRONIC MEMORY DEVICES
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR

## Abstract

A device includes a spin orbit coupling layer and a Magnetic Tunnel Junction (MTJ) stack. The MTJ stack includes a dielectric layer over the spin orbit coupling layer, a free layer over the dielectric layer, a tunnel barrier layer over the free laver, and a reference layer over the tunnel barrier layer. The spin orbit coupling layer extends beyond edges of the MTJ stack in a first direction and a second direction opposite to the first direction.

## Claims

### Claim 1

A device comprising:
a dielectric seed layer having a crystalline structure;
a spin orbit coupling layer over the dielectric seed layer; and
a Magnetic Tunnel Junction (MTJ) stack comprising:
a dielectric layer over the spin orbit coupling layer;
a free layer over the dielectric layer;
a tunnel barrier layer over the free layer; and
a reference layer over the tunnel barrier layer, wherein the spin orbit coupling layer extends beyond edges of the MTJ stack in a first direction and a second direction opposite to the first direction.

### Claim 2 (depends on 1)

The device of claim 1, wherein the dielectric layer comprises a nitride or an oxide.

### Claim 3 (depends on 1)

The device of claim 1, wherein the free layer and the reference layer are formed of ferromagnetic materials.

### Claim 4 (depends on 1)

The device of claim 1, wherein the dielectric layer has a thickness allowing spin polarized carriers in the spin orbit coupling layer to tunnel through and flowing into the free layer.

### Claim 5 (depends on 1)

The device of claim 1, wherein the spin orbit coupling layer further extends laterally beyond edges of the MTJ stack in a third direction perpendicular to the first direction and the second direction.

### Claim 6 (depends on 1)

The device of claim 1, wherein the spin orbit coupling layer extends laterally beyond an edge of the MTJ stack.

### Claim 7 (depends on 1)

The device of claim 1, wherein the dielectric seed layer and the spin orbit coupling layer have edges vertically aligned to each other.

### Claim 8 (depends on 7)

The device of claim 7, wherein the dielectric seed layer comprises magnesium oxide.

### Claim 9

A device comprising:
a dielectric seed layer having a crystalline structure;
a metal layer over and contacting the dielectric seed layer;
a Magnetic Tunnel Junction (MTJ) over the metal layer, wherein the MTJ comprises:
a dielectric layer over the metal layer;
a free layer over the dielectric layer, wherein the dielectric layer has a thickness configured to allow spin polarized carriers in the metal layer to flow through the dielectric layer into the free layer;
a tunnel barrier layer over the free layer; and
a reference layer over the tunnel barrier layer; and
a dielectric capping layer on sidewalls of the MTJ, wherein the dielectric capping layer contacts edges of the dielectric layer, and extends on a top surface of the metal layer.

### Claim 10 (depends on 9)

The device of claim 9, wherein the dielectric seed layer comprises a material selected from the group consisting of MgO, HfOx, AlOx, AgOx, CuO, SrO, HfN, AlN, AgN, SrN, and combinations thereof.

### Claim 11 (depends on 10)

The device of claim 10, wherein the dielectric seed layer comprises magnesium oxide.

### Claim 12 (depends on 10)

The device of claim 10, wherein edges of the dielectric seed layer are vertically aligned to respective edges of the metal layer.

### Claim 13 (depends on 9)

The device of claim 9, wherein the free layer has an in-plane spin polarization direction.

### Claim 14 (depends on 9)

The device of claim 9, wherein the free layer has a perpendicular spin polarization direction.

### Claim 15 (depends on 9)

The device of claim 9, wherein the metal layer is selected from the group consisting of W, Ta, Pt, AuPt, W3Ta, BixSey, BiSeTe, and combinations thereof.

### Claim 16

A device comprising:
a first dielectric layer having a crystalline structure;
a metal layer over and contacting the first dielectric layer, wherein first edges of the first dielectric layer are vertically aligned to respective second edges of the metal layer;
a second dielectric layer over the metal layer, wherein the second dielectric layer has a thickness thin enough to allow spin polarized carriers to flow through;
a free layer over the second dielectric layer;
a tunnel barrier layer over the free layer; and
a reference layer over the tunnel barrier layer.

### Claim 17 (depends on 16)

The device of claim 16, wherein the second dielectric layer is thin enough to allow electrons to tunnel through.

### Claim 18 (depends on 16)

The device of claim 16, wherein the first dielectric layer comprises MgO.

### Claim 19 (depends on 18)

The device of claim 18, and wherein the first dielectric layer and the metal layer extend laterally beyond the free layer.

### Claim 20 (depends on 16)

The device of claim 16, wherein the free layer comprises a ferromagnetic material.