Magnetic device and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-9570670-B2
Application number	US-201313763464-A
Country	US
Kind code	B2
Filing date	Feb 8, 2013
Priority date	Jul 20, 2012
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

Provided are a magnetic memory device and a method of fabricating the same. The device may include a magnetic tunnel junction including a lower magnetic structure, an upper magnetic structure, and a tunnel barrier interposed therebetween. The tunnel barrier may have a width greater than that of the lower magnetic structure.

First claim

The invention claimed is:

1. A magnetic device, comprising:
a lower electrode;
a magnetic tunnel junction including a lower magnetic structure, a tunnel barrier, and an upper magnetic structure that are sequentially stacked in a first direction on the top surface of the lower electrode, wherein the tunnel barrier comprises a width that is greater than a width of the lower magnetic structure in a second direction that is substantially perpendicular to the first direction, wherein the tunnel barrier comprises a substantially quadrilateral cross section, and wherein a width of the lower electrode in the second direction is substantially smaller than a width of the lower magnetic structure in the second direction;
an upper electrode stacked in the first direction on the upper magnetic structure;
a capping layer conformally covering the magnetic tunnel junction and comprising single layer, the capping layer including a first portion extending in the first direction and a second portion extending in the second direction; and
a mold layer disposed between a sidewall of the lower magnetic structure and the first portion of the capping layer,
wherein a width of the upper electrode is smaller than the width of the lower magnetic structure in the second direction,
wherein the lower electrode is electrically connected between the lower magnetic structure and a selection element,
wherein the upper magnetic structure is electrically connected further away from the selection element than the lower magnetic structure,
wherein the first portion of the capping layer is in direct contact with a sidewall of the tunnel barrier and a sidewall of the upper magnetic structure, and
wherein the first portion of the capping layer is in directly contact with a sidewall of the mold layer.

2. The device of claim 1 , wherein each of the lower and upper magnetic structures has a multi-layered structure including a plurality of layers.

3. The device of claim 2 , wherein at least one of the layers of the lower magnetic structure has a generally ‘U’-shaped cross section, and wherein at least one of the layers of the upper magnetic structure has a generally ‘U’-shaped cross section.

4. The device of claim 1 , wherein at least one of the layers of the lower magnetic structure has a generally ‘U’-shaped cross section, and
each of the layers of the upper magnetic structure has a substantially quadrilateral cross section.

5. The device of claim 1 , wherein each of the layers of the lower magnetic structure has a substantially quadrilateral cross section, and wherein at least one of the layers of the upper magnetic structure has a generally ‘U’-shaped cross section.

6. The device of claim 1 , wherein each of the layers of the lower magnetic structure is a plate-shaped structure having a substantially quadrilateral cross section, and
each of the layers of the upper magnetic structure is a plate-shaped structure having a substantially quadrilateral cross section.

7. The device of claim 1 , wherein at least one of the layers of the lower magnetic structure comprises sidewall portions facing each other and a bottom portion connecting the sidewall portions, thereby having a generally ‘U’-shaped cross section, and the bottom portion is formed of a magnetic material, and the sidewall portions are substantially formed of an oxide of the magnetic material constituting the bottom portion.

8. The device of claim 1 , wherein the tunnel barrier has a width greater than that of the upper magnetic structure.

9. The device of claim 1 , wherein the tunnel barrier has substantially the same width as that of the upper magnetic structure.

10. The device of claim 1 , wherein a lower width of the tunnel barrier is greater than an upper width thereof, and
an upper width of the lower magnetic structure is greater than a lower width thereof.

11. The device of claim 1 , wherein a lower width of the tunnel barrier is greater than an upper width thereof.

12. The device of claim 11 , wherein an upper width of the upper magnetic structure is greater than a lower width thereof.

13. The device of claim 1 , wherein a distance between a sidewall of the tunnel barrier and a sidewall of the lower magnetic structure at one side of the tunnel barrier is different than at the other side of the tunnel barrier.

14. The device of claim 13 , wherein a distance between sidewalls of the tunnel barrier and the upper magnetic structure is substantially the same at both sides of the tunnel barrier.

15. The device of claim 1 , wherein one of the upper and lower magnetic structures comprises an antiferromagnetic material.

16. The device of claim 1 , wherein the tunnel barrier comprises a magnesium oxide layer or a pair of magnesium oxide layers separated by a metal-containing layer.

17. A magnetic device, comprising:
a lower electrode;
a magnetic tunnel junction including a lower magnetic structure, a tunnel barrier, and an upper magnetic structure, which are sequentially stacked in a first direction on the lower electrode;
a capping layer on the magnetic tunnel junction, the capping layer being directly in contact with a sidewall of the tunnel barrier and a sidewall of the upper magnetic structure; and
a mold layer disposed between a sidewall of the lower magnetic structure and the capping layer,
wherein the lower electrode is electrically connected between the lower magnetic structure and a selection element,
wherein the upper magnetic structure electrically connected further away from the selection element than the lower magnetic structure,
wherein the tunnel barrier has a width is greater than a width of the lower magnetic structure, in the second direction being substantially perpendicular from the first direction,
wherein a thickness of the capping layer on sidewalls of the tunnel barrier and the upper magnetic structure is substantially uniform, the thickness being measured along the second direction,
wherein the capping layer is spaced apart from the lower magnetic structure, and
wherein the tunnel barrier is in contact with the mold layer.

18. The device of claim 17 , wherein a width of the upper magnetic structure is smaller than the width of the tunnel barrier, in the second direction.

19. The device of claim 17 , wherein a width of the lower electrode is smaller than a width of the lower magnetic structure, in the second direction.

20. The device of claim 17 , further comprising an upper electrode penetrating the capping layer to contact with a top surface of the upper magnetic structure,
wherein the upper electrode has a width smaller than a width of the upper magnetic structure.

21. The device of claim 17 , wherein the capping layer extends on a sidewall of the mold layer.

22. The device of claim 17 , wherein a sidewall of the mold layer is vertically aligned with the sidewall of the tunnel barrier.

23. The device of claim 1 , wherein the capping layer has the lowermost surface located at substantially the same level as a bottom surface of the lower magnetic structure.

Assignees

• Park Chanjin
• Kim Woojin
• Kwon Hyungjoon
• Park Soonoh
• Park Jongchul
• Oh Sechung
• Samsung Electronics Co Ltd

Inventors

• Park Chanjin
• Kim Woojin
• Kwon Hyungjoon
• Park Soonoh
• Park Jongchul
• Oh Sechung

Classifications

• H01L43/02 Primary

  Electricity · mapped topic

• H01L43/12

  Electricity · mapped topic

• H01L43/08

  Electricity · mapped topic

• G11C11/1659 Primary

  Cell access · CPC title

• G11C11/15

  using multiple magnetic layers (G11C11/155 takes precedence) · CPC title