Methods of manufacturing a magnetoresistive random access memory device

Patent metadata

Field	Value
Publication number	US-9577183-B2
Application number	US-201514611717-A
Country	US
Kind code	B2
Filing date	Feb 2, 2015
Priority date	Apr 3, 2014
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

In a method of manufacturing a MRAM device, a lower electrode is formed on a substrate. A first magnetic layer, a tunnel barrier layer, and a second magnetic layer are sequentially formed on the lower electrode layer. An etching mask is formed on the second magnetic layer. An ion beam etching process in which a first ion beam and a second ion beam are simultaneously emitted onto the substrate is performed to form a MTJ structure including a first magnetic layer pattern, a tunnel layer pattern, and a second magnetic layer pattern from the first magnetic layer, the tunnel barrier layer, and the second magnetic layer, respectively, the MTJ structure has no by-products remaining after the ion beam etching process is performed.

First claim

What is claimed is:

1. A method of manufacturing a magnetoresistive random access memory (MRAM) device, the method comprising:
forming a lower electrode on a substrate;
forming a first magnetic layer, a tunnel barrier layer, and a second magnetic layer sequentially on the lower electrode layer;
forming an etching mask on the second magnetic layer; and
performing an ion beam etching process in which a first ion beam and a second ion beam are simultaneously emitted onto the substrate to form a magnetic tunnel junction (MTJ) structure including a first magnetic layer pattern, a tunnel layer pattern, and a second magnetic layer pattern from the first magnetic layer, the tunnel barrier layer, and the second magnetic layer, respectively,
wherein the MTJ structure has no by-products remaining after the ion beam etching process is performed,
wherein the first ion beam is emitted from a first ion beam source and has a first incident angle,
wherein the second ion beam is emitted from a second ion beam source and has a second incident angle,
wherein one of the first ion beam source and the second ion beam source is movable, and the other of the first ion beam source and the second ion beam source is fixed, and
wherein the first incident angle and the second incident angle are adjusted by moving the one of the first ion beam source and the second ion beam source so that the MTJ structure has no by-products remaining.

2. The method of claim 1 , wherein the first incident angle and the second incident angle are different from each other.

3. The method of claim 2 , wherein the first incident angle is about 60° to about 90°, and the second incident angle is about 20° to about 50°.

4. The method of claim 1 , wherein the performing the ion beam etching process comprises:
tilting the substrate to adjust the first incident angle and the second incident angle.

5. The method of claim 1 , wherein the performing the ion beam etching process comprises adjusting the first incident angle and the second incident angle, and
wherein the adjusting the first incident angle and the second incident angle comprises:
tilting the substrate so that the second ion beam is incident on the substrate at the adjusted second incident angle; and
moving the first ion beam source so that the first ion beam is incident on the tilted substrate at the adjusted first incident angle.

6. The method of claim 1 , further comprising:
forming a first electrode layer between the lower electrode and the first magnetic layer,
wherein the first electrode layer is etched to form a first electrode by the ion beam etching process.

7. The method of claim 1 , wherein in the ion beam etching process, the first ion beam etches the second magnetic layer, the tunnel barrier layer, and the first magnetic layer, and the second ion beam removes the by-products on the MTJ structure.

8. The method of claim 1 , further comprising:
forming a capping layer and an upper electrode layer between the second magnetic layer and the etching mask.

9. The method of claim 8 , further comprising:
etching the capping layer and the upper electrode layer by a reactive ion etching process or the ion beam etching process.

10. The method of claim 1 , further comprising:
etching the first magnetic layer, the tunnel barrier layer, and the second magnetic layer by the ion beam etching process using at least one of the first ion beam and the second ion beam to form a preliminary magnetic tunnel junction (MTJ) structure which comprises the by-products on a sidewall of the preliminary MTJ structure, after forming the etching mask.

11. The method of claim 10 , wherein the first ion beam and the second ion beam are emitted onto the preliminary MTJ structure, and
wherein the first incident angle is about 60° to about 90°, and the second incident angle is about 20° to about 50°.

12. The method of claim 10 , wherein the first ion beam and the second ion beam are incident on the preliminary MTJ structure, and each of the first incident angle and the second incident angle is about 20° to about 50°.

13. A method of manufacturing a magnetoresistive random access memory (MRAM) device, the method comprising:
forming a metal-oxide-semiconductor (MOS) transistor having an impurity region on a substrate;
forming an insulating interlayer on the substrate to cover the MOS transistor;
forming a lower electrode through the insulating interlayer layer, the lower electrode contacting the impurity region of the MOS transistor;
forming a first magnetic layer, a tunnel barrier layer, and a second magnetic layer sequentially on the lower electrode and the insulating interlayer layer;
forming an etching mask on the second magnetic layer;
performing an ion beam etching process in which a first ion beam and a second ion beam are simultaneously emitted onto the substrate to form a magnetic tunnel junction (MTJ) structure including a first magnetic layer pattern, a tunnel layer pattern, and a second magnetic layer pattern from the first magnetic layer, the tunnel barrier layer and the second magnetic layer, respectively,
wherein the MTJ structure has no by-products remaining after the ion beam etching process is performed,
wherein the first ion beam is emitted from a first ion beam source and has a first incident angle,
wherein the second ion beam is emitted from a second ion beam source and has a second incident angle; and
forming a wiring electrically connected to the second magnetic layer,
wherein one of the first ion beam source and the second ion beam source is movable, and the other of the first ion beam source and the second ion beam source is fixed, and
wherein the first incident angle and the second incident angle are adjusted by moving the one of the first ion beam source and the second ion beam source so that the MTJ structure has no by-products remaining.

14. The method of claim 13 , wherein the first incident angle and the second incident angle are different from each other.

15. A method of performing an ion beam etching process, the method comprising:
performing a first ion beam etching process in which a first ion beam is emitted on a substrate, a lower electrode disposed on the substrate, and an etching target layer disposed on the lower electrode such that by-products are deposited onto a sidewall of a pattern structure;
performing a second ion beam etching process in which a second ion beam is emitted on the substrate, the lower electrode disposed on the substrate, and the etching target layer disposed on the lower electrode; and
forming a magnetic tunnel junction (MTJ) structure comprising the pattern structure after the first ion beam etching process and the second ion beam etching process are performed,
wherein the MTJ structure has no by-products remaining after the first ion beam etching process and the second ion beam etching process are performed
wherein one of a first ion beam source which emits the first ion beam and a second ion beam source which emits the second ion beam is movable, and the other of the first ion beam source and the second ion beam source is fixed, and
wherein the first ion beam and the second ion beam are adjusted by moving the one of the first ion beam source and the second ion beam source so that the MTJ structure has no by-products remaining.

16. The method of claim 15 , wherein the first ion beam has a different incident angle than the second ion beam.

17. The method of claim 15 , wherein the first ion beam etching process forms the pattern structure from the etching target layer.

1

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Kyoung-Sun
• Kim Woo-Jin
• Tokashiki Ken

Classifications

• H01L43/12 Primary

  Electricity · mapped topic

• H01L27/228

  Electricity · mapped topic

• G11C11/161 Primary

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• H10N50/01 Primary

  Manufacture or treatment · CPC title

• H10B61/22

  of the field-effect transistor [FET] type · CPC title