# US 10,312,238 B2 · Manufacturing method of magnetic random access memory cell

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- Number: US 10,312,238 B2
- Document ID: US10312238B2
- Status: Granted
- Kind: B2
- Application number: 15/803,852
- Filed: 2017-11-06
- Published: 2019-05-09
- Granted: 2019-06-04
- Earliest claimed: 2017-11-06
- Assignees: United Microelectronics Corp.
- Applicants: United Microelectronics Corp.
- Inventors: Hsiao-Pang Chou; Yu-Ru Yang; Chih-Chien Liu; Chao-Ching Hsieh; Chun-Hsien Lin
- Web page: https://patentgrep.com/patent/US10312238B2

## CPC

- G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell}
- H10B 61/22: {of the field-effect transistor [FET] type}
- H10N 50/01: Manufacture or treatment
- H10N 50/10: Magnetoresistive devices
- H10N 50/80: Constructional details
- H10N 50/85: Materials of the active region
- H10W 20/43: Layouts of interconnections
- G11C: STATIC STORES (semiconductor memory devices H10B)
- H10B: ELECTRONIC MEMORY DEVICES
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A manufacturing method of a magnetic random access memory (MRAM) cell includes the following steps. A magnetic tunnel junction (MTJ) film stack is formed on an insulation layer. An aluminum mask layer is formed on the MTJ film stack. A hard mask layer is formed on the aluminum mask layer. An ion beam etching (IBE) process is performed with the aluminum mask layer and the hard mask layer as a mask. The MTJ film stack is patterned to be a patterned MTJ film stack by the IBE process, and at least apart of the aluminum mask layer is bombarded by the IBE process for forming an aluminum film on a sidewall of the patterned MTJ film stack. An oxidation treatment is performed, and the aluminum film is oxidized to be an aluminum oxide protection layer on the sidewall of the patterned MTJ film stack by the oxidation treatment.

## Claims

### Claim 1

A manufacturing method of a magnetic random access memory (MRAM) cell, comprising:
forming a magnetic tunnel junction (MTJ) film stack on an insulation layer;
forming an aluminum mask layer on the MTJ film stack;
forming a hard mask layer on the aluminum mask layer;
performing an ion beam etching (IBE) process with the aluminum mask layer and the hard mask layer as a mask, wherein the MTJ film stack is patterned to be a patterned MTJ film stack by the IBE process, and at least a part of the aluminum mask layer is bombarded by the IBE process for forming an aluminum film on a sidewall of the patterned MTJ film stack;
performing an oxidation treatment, wherein the aluminum film is oxidized to be an aluminum oxide protection layer on the sidewall of the patterned MTJ film stack by the oxidation treatment;
forming an interlayer dielectric covering the aluminum oxide protection layer and the patterned MTJ film stack; and
forming a connection structure penetrating the interlayer dielectric above the patterned MTJ film stack, wherein the connection structure is electrically connected to a topmost portion of the patterned MTJ film stack, and the aluminum mask layer is completely removed before the step of forming the connection structure.

### Claim 2 (depends on 1)

The manufacturing method of the MRAM cell according to claim 1, wherein an argon (Ar) bombardment is used in the IBE process for patterning the MTJ film stack.

### Claim 3 (depends on 2)

The manufacturing method of the MRAM cell according to claim 2, wherein the oxidation treatment is a part of the IBE process, and the oxidation treatment is performed after the Ar bombardment.

### Claim 4 (depends on 2)

The manufacturing method of the MRAM cell according to claim 2, wherein at least a part of the hard mask layer is removed by the Ar bombardment.

### Claim 5 (depends on 1)

The manufacturing method of the MRAM cell according to claim 1, wherein a part of the insulation layer is removed by the IBE process.

### Claim 6 (depends on 5)

The manufacturing method of the MRAM cell according to claim 5, wherein the aluminum film is further formed on a sidewall of the insulator layer under the patterned MTJ film stack.

### Claim 7 (depends on 1)

The manufacturing method of the MRAM cell according to claim 1, wherein the patterned MTJ film stack comprises:
a bottom electrode;
a pinned layer formed on the bottom electrode;
a first barrier layer formed on the pinned layer;
a free layer formed on the first barrier layer;
a second barrier layer formed on the free layer; and
a top electrode formed on the second barrier layer.

### Claim 8 (depends on 7)

The manufacturing method of the MRAM cell according to claim 7, further comprising:
forming a first connection structure in the insulation layer before the IBE process, wherein the first connection structure is electrically connected with the bottom electrode.

### Claim 9 (depends on 1)

The manufacturing method of the MRAM cell according to claim 1, wherein a part of the hard mask layer remains on the aluminum mask layer during the oxidation treatment.

### Claim 10 (depends on 1)

The manufacturing method of the MRAM cell according to claim 1, wherein at least a part of the aluminum mask layer is oxidized by the oxidation treatment.