METHOD AND SYSTEM FOR PROVIDING MAGNETIC TUNNELING JUNCTION ELEMENTS HAVING IMPROVED PERFORMANCE THROUGH CAPPING LAYER INDUCED PERPENDICULAR ANISOTROPY AND MEMORIES USING SUCH MAGNETIC ELEMENTS

• US 20120155156A1
• Filed: 02/25/2011
• Published: 06/21/2012
• Est. Priority Date: 08/10/2009
• Status: Active Grant

• Current Assignee: Samsung Semiconductor Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Grandis, Inc. (Samsung Electronics Co. Ltd.)
• Inventors: Watts, Steven M., Diao, Zhitao, Tang, Xueti, Moon, Kiseok, Krounbi, Mohamad Towfik
• Granted Patent: US 10,446,209 B2
• Time in Patent Office: Days
• 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: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3286 Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
• CPC Class Codes: H01F 41/307 insulating or semiconductive spacer
• CPC Class Codes: H01F 41/325 applying a noble metal capping on a spin-exchange-coupled multilayer, e.g. spin filter deposition
• CPC Class Codes: H01F 41/34 in patterns, e.g. by lithography

Abstract

A method and system for providing a magnetic element and a magnetic memory utilizing the magnetic element are described. The magnetic element is used in a magnetic device that includes a contact electrically coupled to the magnetic element. The method and system include providing pinned, nonmagnetic spacer, and free layers. The free layer has an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is less than the out-of-plane demagnetization energy. The nonmagnetic spacer layer is between the pinned and free layers. The method and system also include providing a perpendicular capping layer adjoining the free layer and the contact. The perpendicular capping layer induces at least part of the perpendicular magnetic anisotropy in the free layer. The magnetic element is configured to allow the free layer to be switched between magnetic states when a write current is passed through the magnetic element.

Claims

1. A magnetic element for use in a magnetic device including a contact electrically coupled to the magnetic element, the magnetic element comprising:

a pinned layer;

a nonmagnetic spacer layer;

a free layer having an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is greater than the out-of-plane demagnetization energy, the nonmagnetic spacer layer residing between the pinned layer and the free layer; and

a perpendicular capping layer adjoining the free layer and the contact, the perpendicular capping layer inducing at least a portion of the perpendicular magnetic anisotropy in the free layer;

wherein the magnetic element is configured to allow the free layer to be switched between a plurality of stable magnetic states when a write current is passed through the magnetic element.

2. The magnetic element of claim 1 wherein the nonmagnetic spacer layer is a tunneling barrier layer.

3. The magnetic element of claim 2 wherein the perpendicular capping layer induces the perpendicular magnetic anisotropy without substantially changing an in-plane magnetic anisotropy of the free layer.

4. The magnetic element of claim 3 wherein the perpendicular capping layer includes at least one of an oxide layer and a nitride layer.

5. The magnetic element of claim 4 wherein the perpendicular capping layer has a thickness of not more than 1.5 nm and the free layer has a thickness of not more than 2 nm.

6. The magnetic element of claim 4 wherein the perpendicular capping layer further includes at least one of MgO, NiO, aluminum oxide, silicon oxide, AlN, SiN, TaN, TiN, RuO₂ and indium tin oxide.

7. The magnetic element of claim 3 wherein the perpendicular capping layer is metallic.

8. The magnetic element of claim 7 wherein the perpendicular capping layer includes at least one of Al, Cu, Mg, Ru, Au, Cr, Pt, Pd, Ta or W.

9. The magnetic element of claim 3 wherein the perpendicular capping layer is at least one of a bilayer and a trilayer.

10. The magnetic element of claim 1 further comprising:

an additional pinned layer, the perpendicular capping layer being between the free layer and the additional pinned layer.

11. The magnetic element of claim 1 wherein the magnetic element resides on a substrate and wherein the perpendicular capping layer is between the free layer and the substrate.

12. The magnetic element of claim 1 wherein the magnetic element resides on a substrate and wherein the free layer is between the perpendicular capping layer and the substrate.

16. The magnetic element of claim 1 wherein the magnetic element resides on a substrate and wherein the free layer is between the perpendicular capping layer and the substrate.

13. A magnetic memory comprising:

a plurality of magnetic storage cells, each of the plurality of magnetic storage cells including a plurality of contacts and at least one magnetic element, each of the at least one magnetic element including a pinned layer, a free layer, a nonmagnetic spacer layer between the pinned layer and the free layer, and a perpendicular capping layer, the free layer having an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy, the out-of-plane demagnetization energy being less than the perpendicular anisotropy energy, the nonmagnetic spacer layer residing between the pinned layer and the free layer, the free layer including CoFe and having a thickness of not more than 2 nm, the perpendicular capping layer adjoining the free layer and a contact of the plurality of contacts, the perpendicular capping layer inducing the perpendicular magnetic anisotropy in the free layer, the magnetic element being configured to allow the free layer to be switched between a plurality of stable magnetic states when a write current is passed through the magnetic element by the contacts;

a plurality of word lines coupled with the plurality of magnetic storage cells; and

a plurality of bit lines coupled with the plurality of storage cells.

14. The magnetic memory of claim 13 wherein each of the at least one magnetic element further includes:

an additional pinned layer, the perpendicular capping layer being between the free layer and the additional pinned layer.

15. The magnetic memory of claim 13 wherein the magnetic element resides on a substrate and wherein the perpendicular capping layer is between the free layer and the substrate.

17. A magnetic element for use in a magnetic device including a contact electrically coupled to the magnetic element, the magnetic element comprising:

a first pinned layer;

a nonmagnetic spacer layer;

a free layer having an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is greater than the out-of-plane demagnetization energy, the nonmagnetic spacer layer residing between the first pinned layer and the free layer;

a perpendicular spacer layer adjoining the free layer, the free layer residing between the perpendicular spacer layer and the nonmagnetic spacer layer, the perpendicular spacer layer inducing at least a portion of the perpendicular magnetic anisotropy in the free layer and being nonmagnetic, the perpendicular spacer layer including at least one of a doped nitride layer and a doped oxide layer; and

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

wherein the magnetic element is configured to allow the free layer to be switched between a plurality of stable magnetic states when a write current is passed through the magnetic element.

18. The magnetic element of claim 17 wherein the perpendicular spacer layer induces the perpendicular anisotropy energy.

19. A method for providing magnetic element for use in a magnetic device including a contact electrically coupled to the magnetic element, the method comprising:

providing a pinned layer;

providing a nonmagnetic spacer layer;

providing a free layer having an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is greater than the out-of-plane demagnetization energy, the nonmagnetic spacer layer residing between the pinned layer and the free layer; and

providing a perpendicular capping layer adjoining the free layer and the contact, the perpendicular capping layer inducing at least a portion of the perpendicular magnetic anisotropy in the free layer;

wherein the magnetic element is configured to allow the free layer to be switched between a plurality of stable magnetic states when a write current is passed through the magnetic element.

20. The method of claim 19 wherein the step of providing the perpendicular capping layer further induces:

depositing a nonmagnetic metal layer; and

oxidizing the nonmagnetic metal layer.

21. The method of claim 20 wherein the steps of depositing the nonmagnetic metal layer and oxidizing the nonmagnetic metal layer form a portion of the perpendicular capping layer, and wherein the step of providing the perpendicular capping layer further induces:

depositing an additional nonmagnetic metal layer on the portion of the perpendicular capping layer; and

oxidizing the additional nonmagnetic metal layer.

24. The method of claim 20 wherein the steps of depositing the nonmagnetic metal layer and oxidizing the nonmagnetic metal layer form a portion of the perpendicular spacer layer, and wherein the step of providing the perpendicular spacer layer further induces:

depositing an additional nonmagnetic metal layer on the portion of the perpendicular spacer layer; and

oxidizing the additional nonmagnetic metal layer.

22. A method for providing magnetic element for use in a magnetic device including a contact electrically coupled to the magnetic element, the method comprising:

providing a first pinned layer;

providing a nonmagnetic spacer layer;

providing a free layer having an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is greater than the out-of-plane demagnetization energy, the nonmagnetic spacer layer residing between the first pinned layer and the free layer;

providing a perpendicular spacer layer adjoining the free layer, the free layer residing between the perpendicular spacer layer and the nonmagnetic spacer layer, the perpendicular spacer layer inducing at least a portion of the perpendicular magnetic anisotropy in the free layer and being nonmagnetic, the perpendicular spacer layer including at least one of a doped nitride layer and a doped oxide layer; and

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

wherein the magnetic element is configured to allow the free layer to be switched between a plurality of stable magnetic states when a write current is passed through the magnetic element.

23. The method of claim 22 wherein the step of providing the perpendicular spacer layer further induces:

depositing a nonmagnetic metal layer; and

oxidizing the nonmagnetic metal layer.