Magnetic elements with spin engineered insertion layers and MRAM devices using the magnetic elements

• US 7,369,427 B2
• Filed: 09/09/2004
• Issued: 05/06/2008
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Samsung Semiconductor Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Grandis, Inc. (Samsung Electronics Co. Ltd.)
• Inventors: Nguyen, Paul P., Huai, Yiming, Diao, Zhitao, Pakala, Mahendra, Valet, Thierry
• Primary Examiner(s): Elms; Richard T.
• Assistant Examiner(s): Bernstein; Allison P.
• Application Number:
  US10/938,219
• Publication Number:
  US 20060049472A1
• Time in Patent Office: 1,335 Days
• Field of Search: 365/158, 365/171, 365/173, 257/421
• US Class Current: 365/158
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: H01F 10/30 characterised by the composition of the intermediate layers , e.g. seed, buffer, template, diffusion preventing, cap layers H01F10/06 and H01F10/32 take precedence
• CPC Class Codes: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• CPC Class Codes: H01F 41/302 for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices spin-exchange-coupled multilayers H01F10/32
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

A method and system include providing a pinned layer, a free layer, and a spacer layer between the pinned and free layers. The spacer layer is nonmagnetic. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element. In one aspect, the method and system include providing a spin engineered layer adjacent to the free layer. The spin engineered layer is configured to more strongly scatter majority electrons than minority electrons. In another aspect, at least one of the pinned, free, and spacer layers is a spin engineered layer having an internal spin engineered layer configured to more strongly scatter majority electrons than minority electrons. In this aspect, the magnetic element may include another pinned layer and a barrier layer between the free and pinned layers.

Claims

1. A magnetic element comprising:

a pinned layer;

a spacer layer, the spacer layer being nonmagnetic;

a free layer, the spacer layer residing between the pinned layer and the free layer; and

a spin engineered layer adjacent to the free layer, the spin engineered layer being configured to more strongly scatter majority electrons than minority electrons;

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element;

and

wherein the free layer is a simple free layer and the magnetic element includes only a single pinned layer, the single pinned layer being the pinned layer, the magnetic element including ferromagnetic layers only in at least one of the pinned layer, the free layer, and the spin engineered layer.

2. The magnetic element of claim 1 wherein the spin engineered layer includes at least one of Ru, Os, Ir, Re, Mn, Cr, Mo, and W.

3. The magnetic element of claim 1 wherein the spin engineered layer includes only at least one of RuX and Co(Fe)X, where X includes at least one of Ru, Os, Ir, Rh, Re, Mn, Cr, and V.

4. The magnetic element of claim 3 wherein the percentage of X is between zero and thirty atomic percent.

5. The magnetic element of claim 1 wherein the spin engineered layer has a thickness of at least five Angstroms and less than or equal to one hundred Angstroms.

6. The magnetic element of claim 1 wherein the free layer includes at least one of Co, Ni, and Fe.

7. The magnetic element of claim 6 wherein the free layer includes Co(Fe)Y, where Y includes B, Cu, Ta, Hf, Nb, Zr or a combination of two of B, Cu, Ta, Hr, Nb, and Zr.

8. The magnetic element of claim 1 wherein the pinned layer includes at least one of Co, Ni, and Fe.

9. The magnetic element of claim 8 wherein the pinned layer includes a first ferromagnetic layer and a second ferromagnetic layer that are ferromagnetically coupled.

10. The magnetic element of claim 9 wherein the first ferromagnetic layer includes Co(Fe)X, where X includes at least one of Ru, Os, Ir, Rh, Re, Mn, Cr, and V.

11. The magnetic element of claim 10 wherein the second ferromagnetic layer is separated from the first ferromagnetic layer by an intermediate layer.

12. The magnetic element of claim 11 wherein the intermediate layer includes Ru, RuX, or Co(Fe)X, where X is at least one of Ru, Os, Ir, Rh, Re, Mn, Cr, and V.

13. The magnetic element of claim 1 further comprising an antiferromagnetic layer, the pinned layer residing between the antiferromagnetic layer and the spacer layer, the antiferromagnetic layer for pinning a magnetization of the pinned layer.

14. The magnetic element of claim 13 wherein the pinned layer further includes a Co(Fe)X layer and a ferromagnetic layer, where X is at least one of Ru, Os, Ir, Rh, Re, Mn, Cr, and V.

15. The magnetic element of claim 13 wherein the pinned layer further includes a first ferromagnetic layer, an intermediate layer, and a second ferromagnetic layer, wherein the first and second ferromagnetic layers are ferromagnetically coupled.

16. The magnetic element of claim 15 wherein the intermediate layer includes Ru, RuX, or Co(Fe)X, where X is at least one of Ru, Os, Ir, Rh, Re, Mn, Cr, and V.

17. A magnetic element comprising:

a pinned layer;

a spacer layer, the spacer layer being nonmagnetic;

a free layer, the spacer layer residing between the pinned layer and the free layer;

wherein at least one of the pinned layer, the spacer layer, and the free layer includes an internal spin engineered layer configured to more strongly scatter majority electrons than minority electrons, the internal spin engineered layer including at least one of a single metal, RuX, and CoFeY, wherein X includes at least one of Os, Ir, Rh, Re, Mn, Cr, and V, Y includes at least one of Ru, Os, Ir, Rh, Re, Mn, Cr, and V and wherein the metal includes at least one of Os, Ir, Re, Mn, Mo, and W; and

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element;

wherein the free layer includes the internal spin engineered layer.

18. The magnetic element of claim 17 wherein the free layer includes a ferromagnetic layer and an internal spin engineered layer configured to more strongly scatter majority electrons than minority electrons.

19. The magnetic element of claim 18 wherein the internal spin engineered layer consists of Co(Fe)Ru.

20. A magnetic element comprising:

a pinned layer;

a spacer layer, the spacer layer being nonmagnetic;

a free layer, the spacer layer residing between the pinned layer and the free layer;

wherein the free layer includes an internal spin engineered layer configured to more strongly scatter majority electrons than minority electrons, a ferromagnetic layer adjacent to the spacer layer, and a Cu layer, at least one of the internal spin engineered layer residing between the Cu layer and the ferromagnetic layer and the Cu layer residing between the ferromagnetic layer and the spin engineered layer, the internal spin engineered layer including Co(Fe)Ru or at least one bilayer of Co/Ru, the ferromagnetic layer residing between the internal spin engineered layer and the spacer layer, the free layer consisting of the Cu layer, the ferromagnetic layer, and the spin engineered layer;

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.

21. A magnetic element comprising:

a pinned layer;

a spacer layer, the spacer layer being nonmagnetic and being a spin engineered layer configured to more strongly scatter majority electrons than minority electrons;

a free layer, the spacer layer residing between the pinned layer and the free layer;

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.

22. The magnetic element of claim 21 further comprising:

an additional spacer layer; and

an additional pinned layer, the additional spacer layer residing between the additional pinned layer and the free layer.

23. The magnetic element of claim 22 wherein the additional spacer layer is an additional spin engineered layer configured to more strongly scatter majority electrons than minority electrons.

24. A magnetic element comprising:

a spin engineered pinned layer;

a barrier layer;

a free layer, the barrier layer residing between the spin engineered pinned layer and the free layer;

a spin engineered spacer layer, the free layer residing between the barrier layer and the spin engineered spacer layer; and

a pinned layer, the spin engineered spacer layer residing between the free layer and the pinned layer;

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.

25. A method for fabricating magnetic element comprising:

providing a pinned layer;

providing a spacer layer, the spacer layer being nonmagnetic;

providing a free layer, the spacer layer residing between the pinned layer and the free layer;

providing a spin engineered layer adjacent to the free layer, the spin engineered layer being configured to more strongly scatter majority electrons than minority electrons;

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element; and

wherein the free layer is a simple free layer and the magnetic element includes only a single pinned layer, the single pinned layer being the pinned layer, the magnetic element including ferromagnetic layers only in at least one of the pinned layer, the free layer, and the spin engineered layer.

26. A method for fabricating a magnetic element comprising:

providing a spin engineered pinned layer;

providing a barrier layer;

providing a free layer, the barrier layer residing between the spin engineered pinned layer and the free layer;

providing a spin engineered spacer layer, the free layer residing between the barrier layer and the spin engineered spacer layer; and

providing a pinned layer, the spin engineered spacer layer residing between the free layer and the pinned layer;

wherein the magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.