Spin transfer torque switching of a magnetic layer with volume uniaxial magnetic crystalline anistotropy

Patent metadata

Field	Value
Publication number	US-11005029-B2
Application number	US-201816146728-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Sep 28, 2018
Publication date	May 11, 2021
Grant date	May 11, 2021

Abstract

A device is disclosed. The device includes a first magnetic layer and a tunnel barrier. The first magnetic layer has a volume uniaxial magnetic crystalline anisotropy. The magnetic moment of the first layer is substantially perpendicular to the first layer. The tunnel barrier is in proximity to the first magnetic layer. The orientation of the magnetic moment of the first magnetic layer is reversed by spin transfer torque induced by current passing between and through the first magnetic layer and the tunnel barrier.

First claim

The invention claimed is:

1. A device, comprising:
a first layer including Mn and N forming Mn x N, wherein 2.5≤x≤4.0;
at least one templating layer including Co and at least one of Ga, Ge, Sn and Al, the at least one templating layer being directly on the first layer such that the first layer is closer to a substrate than the at least one templating layer;
a first magnetic layer having a volume uniaxial magnetic crystalline anisotropy, wherein the magnetic moment of the first magnetic layer is stable substantially perpendicular to the first magnetic layer, the first magnetic layer being on the at least one templating layer such that the first magnetic layer is in physical contact with the at least one templating layer, the first magnetic layer having a thickness of not more than twelve Angstroms and including a Heusler compound; and
a tunnel barrier in proximity to the first magnetic layer, wherein the orientation of the magnetic moment of the first magnetic layer is reversible using spin transfer torque induced by current passing between and through the first magnetic layer and the tunnel barrier.

2. The device of claim 1 , wherein the first magnetic layer is the Heusler compound.

3. The device of claim 2 , wherein the Heusler compound is selected from the group consisting of Mn x Ge, Mn x Sn, Mn x Sb, and combinations thereof, where x is in the range 2.5-3.5.

4. The device of claim 2 , wherein the Heusler compound is a ternary tetragonal Heusler.

5. The device of claim 4 , wherein the ternary Heusler is selected from the group consisting of Mn 2 CoSn, Mn 2 CoSb, Mn 2 OsSn, and Mn 2 RuSn.

6. The device of claim 5 , wherein the ternary Heusler includes Mn 2 CoSn.

7. The device of claim 1 , comprising a second magnetic layer in proximity with the tunnel barrier.

8. The device of claim 7 , wherein the tunnel barrier is MgO.

9. The device of claim 7 , wherein the tunnel barrier is an insulator that lattice matches the first magnetic layer and allows for spin filtering, the tunnel barrier including Mg 1-x Al 2-x O 4 , wherein −0.5<x<0.5.

10. The device of claim 7 wherein the device is a non-volatile memory element.

11. The device of claim 1 , wherein the Heusler compound includes Mn.

12. The device of claim 11 , wherein the Heusler compound is a binary Heusler compound.

13. A method, comprising:
switching an orientation of a magnetization of a first magnetic layer by passing a current through a device, across a tunnel barrier, the device including a first layer including Mn and N forming Mn x N, wherein 2.5≤x≤4.0, at least one templating layer being directly on the first layer such that the first layer is closer to a substrate than the at least one templating layer, the first magnetic layer on the at least one templating layer such that the first magnetic layer is in physical contact with the at least one templating layer, the tunnel barrier layer and a second magnetic layer, the at least one templating layer including Co and Ga, Ge, Sn and Al, the first magnetic layer having a volume uniaxial magnetic crystalline anisotropy, wherein the magnetic moment of the first magnetic layer is stable substantially perpendicular to the first magnetic layer, the tunnel barrier being in proximity to the first magnetic layer, the tunnel barrier being between the first magnetic layer and the second magnetic layer, the orientation of the magnetic moment of the first magnetic layer being reversed using spin transfer torque induced by the current passing between and through the first magnetic layer and the tunnel barrier, the second magnetic layer being in proximity with the tunnel barrier, the first magnetic layer having a thickness of not more than twelve Angstroms and including a Heusler compound.

14. The method of claim 13 , wherein the Heusler compound includes Mn.

15. The method of claim 14 , wherein the Heusler compound is a binary Heusler compound.

16. A device, comprising:
a substrate;
a Mn x N layer overlying the substrate, wherein 2.5≤x≤4;
a templating structure including Co and at least one of Ga, Ge, Sn and Al, the templating structure directly overlying the Mn x N layer;
a first magnetic layer that includes a Heusler compound, the magnetic layer being in physical contact with the templating structure, wherein the first magnetic layer has a magnetic moment that is stable perpendicular to the first magnetic layer and switchable by spin transfer torque, the first magnetic layer having a thickness of not more than twelve Angstroms;
a tunnel barrier overlying the first magnetic layer; and
a second magnetic layer in contact with the tunnel barrier.

17. The device of claim 16 , comprising a capping layer in contact with the second magnetic layer.

18. The device of claim 16 , wherein the first magnetic layer includes Mn and an element selected from the group consisting of Sn, Sb, and Ge.

19. The device of claim 16 , wherein the first magnetic layer further includes Co.

20. A device, comprising:
a substrate;
a Mn x N layer overlying the substrate, wherein 2.5≤x≤4;
a templating structure including Co and at least one of Ga, Ge, Sn and Al, the templating structure directly overlying the Mn x N layer;
a first magnetic layer that includes a Heusler compound, the magnetic layer being in physical contact with the templating structure, wherein the first magnetic layer has a magnetic moment that is stable perpendicular to the first magnetic layer and switchable using spin transfer torque, the first magnetic layer having a thickness of not more than twelve Angstroms;
a tunnel barrier overlying the first magnetic layer; and
a second magnetic layer in contact with the tunnel barrier.

Assignees

• Samsung Electronics Co Ltd
• IBM

Inventors

• Jeong Jaewoo
• Samant Mahesh G
• Parkin Stuart S P
• Ferrante Yari

Classifications

• G11C19/0841

  using electric current · CPC title

• G11C11/161 Primary

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

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title

• H10N50/10 Primary

  Magnetoresistive devices · CPC title

• H10N50/85 Primary

  Materials of the active region · CPC title