MAGNETIC MEMORY DEVICES INCLUDING IN-PLANE CURRENT LAYERS AND METHODS OF FABRICATING THE SAME

• US 20160181512A1
• Filed: 12/02/2015
• Published: 06/23/2016
• Est. Priority Date: 12/17/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ahn, Sungmin, Ryu, Jisu
• Granted Patent: US 9,882,120 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A magnetic memory device can include an upper electrode, a lower electrode and a Magnetic Tunnel Junction (MTJ). The MTJ can include a reference magnetic pattern configured to generate a fixed magnetization and a free magnetic pattern on the reference magnetic pattern configured to generate a switchable magnetization that switches direction between parallel and anti-parallel to the fixed magnetization. A metal pattern can be on the free magnetic pattern and can be configured to conduct an in-plane current and a perpendicular-to-plane to/from the upper electrode.

Claims

1. A magnetic memory device, comprising:

a lower electrode;

a magnetic tunnel junction on the lower electrode; and

a capping electrode on the magnetic tunnel junction,

wherein the magnetic tunnel junction comprises;

a reference magnetic pattern having a fixed magnetization direction;

a free magnetic pattern having a switchable magnetization direction;

a tunnel barrier pattern between the reference magnetic pattern and the free magnetic pattern;

a sub oxide pattern on the free magnetic pattern; and

a metal pattern between the sub oxide pattern and the free magnetic pattern, and

the fixed and switchable magnetization directions are substantially perpendicular to top surfaces of the reference and free magnetic pattern defining the magnetic tunnel junction.

2. The device of claim 1, wherein the metal pattern comprises at least one of a transition metal and a rare-earth metal.

3. The device of claim 1, wherein the metal pattern has a thickness ranging from about 0.5 to about 2 nm.

4. The device of claim 1, wherein the capping electrode is asymmetrically centered at a position that is offset from a center of the magnetic tunnel junction.

5. The device of claim 4, wherein the capping electrode is disposed to expose at least a portion of an upper surface of the sub oxide pattern.

6. The device of claim 1, wherein the magnetic tunnel junction has first and second maximum widths, respectively, measured in first and second directions parallel to the top surfaces of the magnetic patterns and the first and second directions are perpendicular to each other, and

the first maximum width is greater than the second maximum width.

7. The device of claim 6, wherein the capping electrode is disposed at an edge of the magnetic tunnel junction in the first direction.

8. The device of claim 6, wherein the capping electrode has a width that is less than the second maximum width.

9-12. -12. (canceled)

13. A magnetic memory device, comprising:

a magnetic tunnel junction; and

a capping electrode on the magnetic tunnel junction,

wherein the magnetic tunnel junction comprises a metal pattern adjacent to the capping electrode, and

the capping electrode is asymmetrically disposed at a position that is offset from a center of the magnetic tunnel junction defined by an axis passing through upper and lower surfaces of the magnetic tunnel junction.

14-24. -24. (canceled)

25. A magnetic memory device, comprising:

an upper electrode;

a lower electrode;

a Magnetic Tunnel Junction (MJT) including;

a reference magnetic pattern configured to generate a fixed magnetization;

a free magnetic pattern on the reference magnetic pattern configured to generate a switchable magnetization that switches direction between parallel and anti-parallel to the fixed magnetization; and

a metal pattern on the free magnetic pattern configured to conduct an in-plane current and a perpendicular-to-plane to/from the upper electrode.

26. The device of claim 25 wherein the metal pattern is directly on the free magnetic pattern.

27. The device of claim 26 wherein the metal pattern has a total thickness of about 0.5 nm to about 2 nm.

28. The device of claim 27 wherein the MJT switches between a high resistance state and a low resistance state responsive to a spin-orbit interaction generated by the in-plane current conducted in the metal pattern.

29. The device of claim 25 wherein a center of the upper electrode is laterally offset from a center of the MJT.

30. The device of claim 29 wherein the upper electrode is vertically aligned to a side wall of the MJT to conduct the in-plane current laterally away from the upper electrode across the metal pattern.

31. The device of claim 25 further comprising:

a sub oxide pattern between the upper electrode and the metal pattern.

32. The device of claim 25 wherein the MJT has an elliptical cross-section and upper electrode has a circular cross-section in a direction orthogonal to the fixed magnetization and to the switchable magnetization.

33. The device of claim 32 wherein the fixed magnetization and the switchable magnetization are perpendicular to the elliptical cross-section of the MJT.

34. The device of claim 31 wherein the sub oxide pattern has a total thickness of about 0.5 Å

to about 30 Å

.

35. The device of claim 25 wherein the metal pattern comprises a heavy metal pattern.