Magnetic element and memory device

Patent metadata

Field	Value
Publication number	US-10096771-B2
Application number	US-201615262403-A
Country	US
Kind code	B2
Filing date	Sep 12, 2016
Priority date	Sep 16, 2015
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

According to one embodiment, a magnetic element includes a first stacked unit and a third ferromagnetic layer. The first stacked unit includes first and second ferromagnetic layers, and a first non-magnetic layer. The first ferromagnetic layer has a first magnetization. The second ferromagnetic layer is separated from the first ferromagnetic layer in a first direction, and has a second magnetization. The first non-magnetic layer is provided between the first and second ferromagnetic layers. The third ferromagnetic layer is stacked with the first stacked unit in the first direction, and has a third magnetization. 2γNzMs is not less than 0.9 times of a magnetic resonance frequency (Hz) of the third ferromagnetic layer, when the second magnetization is Ms (emu/cc), a demagnetizing coefficient of the second ferromagnetic layer is Nz, and a gyro magnetic constant is γ (Hz/Oe).

First claim

What is claimed is:

1. A memory device comprising:
a magnetic element;
a first interconnection electrically connected to one end of the magnetic element;
a second interconnection electrically connected to other end of the magnetic element; and
a controller electrically connected to the magnetic element via the first interconnection and the second interconnection,
wherein the magnetic element comprises:
a first stacked unit comprising:
a first ferromagnetic layer having a first magnetization,
a second ferromagnetic layer separated from the first ferromagnetic layer in a first direction, the second ferromagnetic layer having a second magnetization, and
a first non-magnetic layer provided between the first ferromagnetic layer and the second ferromagnetic layer; and

a third ferromagnetic layer stacked with the first stacked unit in the first direction, the third ferromagnetic layer having a third magnetization,
wherein the third ferromagnetic layer comprises a first portion and a second portion, the first portion being provided between the second portion and the first stacked unit, a magnetic resonance frequency of the first portion being higher than a magnetic resonance frequency of the second portion, and a magnetization of the first portion and a magnetization of the second portion being antiferromagnetically coupled, and
wherein:
a component of the first direction of the first magnetization is larger than a component of a second direction perpendicular to the first direction of the first magnetization,
a component of the first direction of the second magnetization is smaller than a component of the second direction of the second magnetization, and
a component of the first direction of the third magnetization is larger than a component of the second direction of the third magnetization.

2. The memory device according to claim 1 , further comprising a transistor provided at least one of between the magnetic element and the first interconnection or between the magnetic element and the second interconnection.

3. The memory device according to claim 1 , wherein the third ferromagnetic layer comprises at least one selected from the group consisting of a first alloy and a Heuller alloy,
wherein
the Heuller alloy comprises at least one selected from the group consisting of Co, Mn, Fe, Ni, Cu, Rh, Ru and Pd, and
the first alloy comprises at least one selected from the group consisting of Co, Mn, Fe, Ni, Cu, Rh, Ru and Pd.

4. The memory device according to claim 1 , wherein the third ferromagnetic layer comprises at least one selected from the group consisting of Co 2 FeSi, Co 2 FeAl, Co 2 FeGa, Co 2 MnGe, Co 2 MnSn, Co 2 MnSi, Co 2 MnGa, Co 2 MnAl, Co 2 MnSb, Co 2 CrGa, Ni 2 MnIn, Ni 2 MnGa, Ni 2 MnSn, Ni 2 MnSb, Ni 2 FeGa, Pd 2 MnSb, Pd 2 MnSn, Cu 2 MnAl, Cu 2 MnSn, Cu 2 MnIn, Rh 2 MnGe, Rh 2 MnPb, Rh 2 MnSn, Pd 2 MnGe, Rh 2 FeSn, Ru 2 FeSn, and Rh 2 FeSb.

5. The memory device according to claim 1 , wherein
the third ferromagnetic layer comprises at least one selected from the group consisting of Co 2 HfSn, Co 2 ZrSn, Co 2 HfAl, Co 2 ZrAl, Co 2 HfGa, Co 2 TiSi, Co 2 TiGe, Co 2 TiSn, Co 2 TiGa, Co 2 TiAl, Co 2 VGa, Co 2 VAl, Co 2 TaAl, Co 2 NbGa, Co 2 NbAl, Co 2 VSn, Co 2 NbSn, Co 2 CrAl, Rh 2 NiSn, Rh 2 NiGe, Mn 2 WSn, Fe 2 MnSi, and Fe 2 MnAl.

6. The memory device according to claim 1 , wherein
the first portion comprises at least one selected from the group consisting of Co 2 HfSn, Co 2 ZrSn, Co 2 HfAl, Co 2 ZrAl, CoFeMnSi, Co 2 HfGa, Co 2 TiSi, Co 2 TiGe, Co 2 TiSn, Co 2 TiGa, Co 2 TiAl, Co 2 VGa, Co 2 VAl, Co 2 TaAl, Co 2 NbGa, Co 2 NbAl, Co 2 VSn, Co 2 NbSn, Co 2 CrAl, Rh 2 NiSn, Rh 2 NiGe, Mn 2 WSn, Fe 2 MnSi, and Fe 2 MnAl, and
the second portion comprises at least one selected from the group consisting of Co 2 FeSi, Co 2 FeAl, Co 2 FeGa, Co 2 MnGe, Co 2 MnSn, Co 2 MnSi, Co 2 MnGa, Co 2 MnAl, Co 2 MnSb, Co 2 CrGa, Ni 2 MnIn, Ni 2 MnGa, Ni 2 MnSn, Ni 2 MnSb, Ni 2 FeGa, Pd 2 MnSb, Pd 2 MnSn, Cu 2 MnAl, Cu 2 MnSn, Cu 2 MnIn, Rh 2 MnGe, Rh 2 MnPb, Rh 2 MnSn, Pd 2 MnGe, Rh 2 FeSn, Ru 2 FeSn, and Rh 2 FeSb.

7. The memory device according to claim 1 , wherein
the magnetic resonance frequency of the first portion is not less than 20 GHz, and
the magnetic resonance frequency of the second portion is less than 20 GHz.

8. The memory device according to claim 1 , wherein
a component of magnetization of the first portion parallel to the first direction is larger than a component of the magnetization of the first portion perpendicular to the first direction, and
a component of magnetization of the second portion parallel to the first direction is larger than a component of the magnetization of the second portion perpendicular to the first direction.

9. The memory device according to claim 1 , further comprising:
a second non-magnetic layer provided between the second ferromagnetic layer and the third ferromagnetic layer.

10. The memory device according to claim 9 , wherein the second non-magnetic layer is conductive.

11. The memory device according to claim 9 , further comprising:
an insulating layer provided between the third ferromagnetic layer and the second non-magnetic layer.

12. The memory device according to claim 1 , further comprising:
a fourth ferromagnetic layer stacked with the third ferromagnetic layer in the first direction;
the first interconnection electrically connected to the first ferromagnetic layer; and
the second interconnection electrically connected to the fourth ferromagnetic layer.

13. The memory device according to claim 12 , further comprising:
a third non-magnetic layer provided between the third ferromagnetic layer and the fourth ferromagnetic layer.

14. The memory device according to claim 1 , further comprising:
a fourth ferromagnetic layer stacked with the third ferromagnetic layer in the first direction, and having a fourth magnetization,
wherein a component of the first direction of the fourth magnetization is larger than a component of the second direction of the fourth magnetization.

15. The memory device according to claim 14 , wherein
the third ferromagnetic layer is disposed between the first ferromagnetic layer and the fourth ferromagnetic layer, and
the second ferromagnetic layer is disposed between the first ferromagnetic layer and the third ferromagnetic layer.

16. The memory device according to claim 1 , wherein
a length of the third ferromagnetic layer in a direction perpendicular to the first direction is not more than 25 nanometers.

17. The memory device according to claim 1 , further comprising:
a conductive layer, at least a portion of the conductive layer facing at least a portion of a side surface of the first stacked unit.

18. The memory device according to claim 1 , wherein the second ferromagnetic layer is disposed between the first ferromagnetic layer and the third ferromagnetic layer.

19. The memory device according to claim 1 , wherein 2γNzMs is between 0.9 and 0.96 times of the magnetic resonance frequency of the third ferromagnetic layer when the second magnetization of the second ferromagnetic layer is Ms, a demagnetizing coefficient of the second ferromagnetic layer is Nz, and a gyro magnetic constant is γ.

20. The memory device according to claim 1 , wherein the first portion is in physical contact with the second portion.

Assignees

• Toshiba Kk

Inventors

• Saida Daisuke

Classifications

• H01L43/08

  Electricity · mapped topic

• G11C11/1673

  Reading or sensing circuits or methods · CPC title

• G11B5/3906

  Details related to the use of magnetic thin film layers or to their effects · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title

• G11C11/161

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