# US 12,010,926 B2 · Magnetic tunnel junction (MTJ) device and manufacturing method thereof

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- Number: US 12,010,926 B2
- Document ID: US12010926B2
- Status: Granted
- Kind: B2
- Application number: 18/138,137
- Filed: 2023-04-24
- Published: 2023-08-17
- Granted: 2024-06-11
- Earliest claimed: 2020-08-14
- Assignees: United Microelectronics Corp.
- Applicants: United Microelectronics Corp.
- Inventors: Chih-Wei Kuo
- Web page: https://patentgrep.com/patent/US12010926B2

## CPC

- H10N 50/80: Constructional details
- H10B 61/00: Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
- H10N 50/01: Manufacture or treatment
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B: ELECTRONIC MEMORY DEVICES

## Abstract

A method of manufacturing a magnetic tunnel junction (MTJ) device, including steps of forming a dielectric layer comprising a metal line therein on a substrate, forming a magnetic tunneling junction element over the metal line, depositing a silicon nitride cap layer conformally covering the magnetic tunneling junction element and the dielectric layer, depositing a tantalum containing cap layer conformally covering the silicon nitride cap layer, removing parts of the tantalum containing cap layer and the silicon nitride cap layer, and disposing a metal plug directly on the magnetic tunneling junction element.

## Claims

### Claim 1

A method of manufacturing a magnetic tunnel junction (MTJ) device, comprising:
forming a dielectric layer comprising a metal line therein on a substrate;
forming a magnetic tunneling junction element over the metal line;
depositing a silicon nitride cap layer conformally covering the magnetic tunneling junction element and the dielectric layer;
depositing a tantalum containing cap layer conformally covering the silicon nitride cap layer;
removing parts of the tantalum containing cap layer and the silicon nitride cap layer to form silicon nitride spacers on sidewalls of the magnetic tunnel junction element and tantalum containing spacers on the silicon nitride spacers, wherein the tantalum containing spacers comprises a top part covering parts of a top surface of the magnetic tunnel junction element and a side part covering the sidewalls of the magnetic tunnel junction element, and the silicon nitride spacer is between the tantalum containing spacer and the magnetic tunnel junction element; and
disposing a metal plug directly on the magnetic tunneling junction element.

### Claim 2 (depends on 1)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 1, further comprising:
performing an atomic layer deposition process to conformally cover an oxide layer on the dielectric layer beside the magnetic tunnel junction element.

### Claim 3 (depends on 1)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 1, further comprising:
performing a deposition process and then a planarization process to cover a first dielectric material beside the magnetic tunnel junction element blanketly.

### Claim 4 (depends on 3)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 3, wherein the first dielectric material comprises a MRAM area and a logic area, wherein the magnetic tunneling junction element is in the MRAM area.

### Claim 5 (depends on 4)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 4, further comprising:
forming a first metal plug in the first dielectric material of the logic area.

### Claim 6 (depends on 5)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 5, further comprising:
depositing a second dielectric material on the first dielectric material and the magnetic tunneling junction element.

### Claim 7 (depends on 6)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 6, further comprising:
depositing a metal plug and a second metal plug in the second dielectric material, wherein the metal plug is directly on the magnetic tunneling junction element and a second metal plug is directly on the first metal plug.

### Claim 8 (depends on 7)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 7, wherein the metal plug is disposed by etching the second dielectric material, to form a through hole in the second dielectric material, and then filling the metal plug in the second dielectric material.

### Claim 9 (depends on 8)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 8, wherein the second dielectric material is etched by a fluorine containing dry etching process.

### Claim 10 (depends on 9)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 9, wherein the parts of the tantalum containing cap layer and the silicon nitride cap layer are removed by the over-etching of the dry etching process.

### Claim 11 (depends on 1)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 1, wherein the tantalum containing cap layer is deposited by an atomic layer deposition process.

### Claim 12 (depends on 11)

The method of manufacturing a magnetic tunnel junction (MTJ) device according to claim 11, wherein the tantalum containing cap layer comprises a tantalum cap layer or a tantalum nitride cap layer.