Tuning perpendicular magnetic anisotropy of Heusler compound in MRAM devices

Patent metadata

Field	Value
Publication number	US-12317508-B2
Application number	US-202117450691-A
Country	US
Kind code	B2
Filing date	Oct 13, 2021
Priority date	Oct 13, 2021
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

A device is provided. The device includes a multi-layered structure that is non-magnetic at room temperature, the multi-layered structure comprising alternating layers of Co and E, wherein E comprises at least one other element selected from the group consisting of Ge, Ga, Sn and Al, wherein a composition of the multi-layered structure is represented by Co 1−x E x , with x being in a range from 0.42 to 0.55. The device also includes a combined layer provided in contact with the multi-layered structure, the combined layer including an insertion layer comprising Co or Fe or Mn or Al in contact with a Heusler compound.

First claim

What is claimed is:

1. A device, comprising:
a multi-layered structure that is non-magnetic at room temperature, the multi-layered structure comprising alternating layers of Co and E, wherein E comprises at least one other element selected from the group consisting of Ge, Ga, Sn and Al, wherein a composition of the multi-layered structure is represented by Co 1−x E x , with x being in a range from 0.42 to 0.55; and
a combined layer in contact with the multi-layered structure, the combined layer including an insertion layer in contact with a Heusler compound, the insertion layer consisting of an element selected from the group consisting of Co, Fe, Mn and Al.

2. The device of claim 1 , wherein the combined layer is a first magnetic layer that forms part of a magnetic tunnel junction.

3. The device of claim 2 , wherein a magnetic moment of the first magnetic layer is substantially perpendicular to an interface between the multi-layered structure and the first magnetic layer.

4. The device of claim 2 , wherein the first magnetic layer has a thickness of less than 5 nm.

5. The device of claim 1 , wherein the insertion layer has a thickness of less than or equal to 3 Å.

6. The device of claim 1 , wherein the Heusler compound is a binary Heusler.

7. The device of claim 6 , wherein the Heusler compound includes one or more of Mn 3.3−x Ge, Mn 3.3−x Sn, and Mn 3.3−y Sb, with x being in a range from 0 to 0.8 for Mn 3.3−x Ge and Mn 3.3−x Sn and with y being in a range from 0 to 1.3 for Mn 3.3−y Sb.

8. The device of claim 1 , wherein Co within the multi-layered structure is replaced by a CoIr alloy and/or E includes an alloy selected from the group consisting of AlSn, AlGa, AlGe, AlGaGe, AlGaSn, AlGeSn, and AlGaGeSn.

9. The device of claim 1 , further comprising a substrate underlying the multi-layered structure.

10. The device of claim 9 , wherein a Mn x N or VN layer is interposed between the substrate and the multi-layered structure.

11. The device of claim 2 , further comprising a tunnel barrier layer overlying the first magnetic layer, thereby permitting current to pass through both the tunnel barrier layer and the first magnetic layer.

12. The device of claim 11 , comprising a second magnetic layer provided in contact with the tunnel barrier layer.

13. The device of claim 11 , wherein the tunnel barrier layer comprises MgO.

14. The device of claim 11 , wherein the tunnel barrier layer comprises Mg 1−z Al 2+(2/3)z O 4 , wherein −0.5<z<0.5.

15. A method, comprising:
using a device as a memory element, the device including:
a multi-layered structure that is non-magnetic at room temperature, the multi-layered structure comprising alternating layers of Co and E, wherein E comprises at least one other element selected from the group consisting of Ge, Ga, Sn and Al, wherein a composition of the multi-layered structure is represented by Co 1−x Ex, with x being in a range from 0.45 to 0.55; and
a combined layer in contact with the multi-layered structure, the combined layer including an insertion layer in contact with a Heusler compound, the insertion layer consisting of an element selected from the group consisting of Co, Fe, Mn and Al.

16. The method of claim 15 , wherein the memory element is a racetrack memory device.

17. A magnetic tunnel junction device, comprising:
a substrate;
a multi-layered structure that is non-magnetic at room temperature, the multi-layered structure comprising alternating layers of Co and E, wherein E comprises at least one other element selected from the group consisting of Ge, Ga, Sn and Al, wherein a composition of the multi-layered structure is represented by Co 1−x E x , with x being in a range from 0.42 to 0.55; and
a first magnetic layer in contact with the multi-layered structure, the first magnetic layer including an insertion layer in contact with a Heusler compound, consisting of an element selected from the group consisting of Co, Fe, Mn and Al;
a tunnel barrier layer on the first magnetic layer; and
a second magnetic layer on the tunnel barrier layer.

18. The magnetic tunnel junction device of claim 17 , further comprising a synthetic anti-ferromagnetic layer on the second magnetic layer.

19. The magnetic tunnel junction device of claim 18 , wherein the first magnetic layer has a magnetic moment that is switchable, and the second magnetic layer has a magnetic moment that is fixed.

20. The magnetic tunnel junction device of claim 18 , wherein the first magnetic layer has a magnetic moment that is fixed, and the second magnetic layer has a magnetic moment that is switchable.

21. The magnetic tunnel junction device of claim 17 , wherein the Heusler compound includes one or more of Mn 3.3−x Ge, Mn 3.3−x Sn, and Mn 3.3−y Sb, with x being in a range from 0 to 0.8 for Mn 3.3−x Ge and Mn 3.3−x Sn and with y being in a range from 0 to 1.3 for Mn 3.3−y Sb.

Assignees

• IBM
• Samsung Electronics Co Ltd

Inventors

• Samant Mahesh
• Filippou Panagiotis Charilaos
• Ferrante Yari
• Garg Chirag
• Jeong Jaewoo
• Ikhtiar

Classifications

• H10N50/85

  Materials of the active region · CPC title

• H10N50/80

  Constructional details · CPC title

• H01F10/3254

  the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ] · CPC title

• H01F10/3272

  by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets · CPC title

• H01F41/307

  insulating or semiconductive spacer · CPC title