Method and system for providing a magnetic tunneling junction using spin-orbit interaction based switching and memories utilizing the magnetic tunneling junction

• US 9,076,537 B2
• Filed: 08/26/2012
• Issued: 07/07/2015
• Est. Priority Date: 08/26/2012
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Khvalkovskiy, Alexey Vasilyevitch, Apalkov, Dmytro
• Primary Examiner(s): Ho, Hoai V
• Assistant Examiner(s): HUERTA, PABLO S
• Application Number:
  US13/594,824
• Publication Number:
  US 20140056060A1
• Time in Patent Office: 1,045 Days
• Field of Search: 365/158
• US Class Current: 1/1
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• 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 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 11/18 using Hall-effect devices
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details

Abstract

A magnetic memory is described. The magnetic memory includes magnetic junctions and at least one spin-orbit interaction (SO) active layer. Each of the magnetic junctions includes a data storage layer that is magnetic. The SO active layer(s) are adjacent to the data storage layer of the magnetic junction. The at SO active layer(s) are configured to exert a SO torque on the data storage layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer. The data storage layer is configured to be switchable using at least the SO torque.

Claims

1. A magnetic memory comprising:

a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the data storage layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer, the at least one SO active layer also configured to exert no SO torque on the data storage layer in the absence of the current;

the data storage layer being configured to be switchable using at least the SO torque.

2. The magnetic memory of claim 1 wherein each of the plurality of magnetic junctions further includes a reference layer and a nonmagnetic spacer layer, the nonmagnetic spacer layer residing between the data storage layer and the reference layer, the data storage layer being a free layer.

3. The magnetic memory of claim 1 further comprising:

a spin diffusion insertion layer for each of the at least one SO active layer, the spin diffusion insertion layer being between the data storage layer and the at least one SO active layer.

5. The magnetic memory of claim 1 wherein the at least one SO active layer is selected from a first SO layer of A and a second SO layer of M doped by B, where A includes at least one of Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Cd, In, Sb, Te, Hf, Ta, amorphous β

-Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, and At where M includes at least one of Al, Ti, V, Cr, Mn, Cu, Zn, Ag, Hf, Ta, W, Re, Pt, Au, Hg, Pb, Si, Ga, GaMn and GaAs, and B includes at least one of V, Cr, Mn, Fe, Co, Ni, P, S, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb.

6. The magnetic memory of claim 1 wherein the at least one SO active layer includes at least one of Cu, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Lu, Hf, Ta, amorphous β

-Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb.

7. The magnetic memory of claim 6 wherein the SO active layer adjoins the data storage layer, wherein the data storage layer includes at least one of Co, Fe, Ni, Mn, and wherein the magnetic junction includes an insulating layer adjoining the data storage layer, wherein the insulating layer adjoining the data storage layer includes at least one of an aluminum oxide and magnesium oxide.

8. The magnetic memory of claim 1 wherein the at least one SO active layer extends over at least two of the plurality of magnetic junctions.

9. The magnetic memory of claim 8 wherein the at least one SO active layer is an SO active word line.

11. The magnetic memory of claim 1 further comprising:

at least one word line corresponding to the plurality of magnetic junctions, the at least one SO active layer residing between the data storage layer and the at least one word line.

12. The magnetic memory of claim 11 wherein the at least one word line includes at least one aperture corresponding to each of the at least one SO active layer.

16. The magnetic memory of claim 1 wherein the data storage layer is further configured to be switchable using a write current passed through the magnetic junction.

17. The magnetic memory of claim 16 wherein the data storage layer has a quiescent magnetic moment in a first direction and the at least one SO active layer generates a SO polarization in a second direction substantially perpendicular to the first direction.

18. The magnetic memory of claim 17 wherein the magnetic moment of the data storage layer is substantially perpendicular to plane.

19. The magnetic memory of claim 16 wherein the current through the at least one SO active layer is a first current pulse, the write current is a second current pulse, and wherein the first current pulse does not start after the second current pulse.

20. The magnetic memory of claim 1 wherein the at least one SO active layer includes at least one of Z, or at least one surface alloy of A/B residing on a (111) surface of a host material B, or material Q, or a combination thereof, A includes at least one of Cu, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb, and B includes at least one of Si, Zn, Cu, Ag, Au, W, Zn, Cr, Pt, Pd;

alloys A/B include substitutional Bi/Ag, substitutional Pb/Ag, substitutional Sb/Ag, substitutional Bi/Si, substitutional Ag/Pt, substitutional Pb/Ge, substitutional Bi/Cu, Z includes at least one of Cu, Zn, Ga, Ge, As, Se, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, I, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, At, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Q includes at least one of InGaAs, HgCdTe, a LaAlO₃/SrTiO₃ bilayer, and LaTiO₃/SrTiO₃ bilayer.

21. The magnetic memory of claim 1 wherein the data storage layer has an easy axis and the at least one SO active layer generates a SO field having a polarization along the easy axis.

22. The magnetic memory of claim 21 wherein the data storage layer is configured to be switched if the SO field and a spin transfer field are aligned.

23. The magnetic memory of claim 21 wherein the data storage layer is configured to be switched by the SO field and a heating current driven through the data storage layer.

24. The magnetic memory of claim 21 wherein the data storage layer is configured to be switched by the SO field and an anisotropy control voltage applied to data storage layer, the anisotropy control voltage configured to change a magnetic anisotropy of the data storage layer.

26. The magnetic memory of claim 21 further comprising:

a plurality of heating elements corresponding to the plurality of magnetic elements and being adjacent to the at least one SO active layer, each of the plurality of heating elements configured to heat the at least one SO active layer in a region corresponding to at least one magnetic element of the plurality of magnetic elements that is not to be written, the at least one SO active layer generating the SO field at a portion of the plurality of heating elements that is not heating the at least one SO active layer.

4. A magnetic memory comprising:

a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the data storage layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer;

a spin diffusion insertion layer for each of the at least one SO active layer, the spin diffusion insertion layer being between the data storage layer and the at least one SO active layer;

wherein the spin diffusion layer includes at least one of a metal layer, an insulating layer having a resistance area of less than 2Ω

-μ

m², and a multilayer including a first layer and a second layer, the first layer including a first material, the second layer including a second material different from the first material; and

wherein the data storage layer is configured to be switchable using at least the SO torque.

10. A magnetic memory comprising:

a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the data storage layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer;

the data storage layer being configured to be switchable using at least the SO torque;

wherein the at least one SO active layer is an SO active word line; and

wherein a portion of the SO active layer adjacent to each of the plurality of magnetic junctions has a first thickness and a first width, the SO active layer having a second thickness and a second width between two of the plurality of magnetic junctions, a first product of the first thickness and the first width being less than a second product of the second width and the second thickness.

13. A magnetic memory comprising:

a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the data storage layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer, the at least one SO active layer further including

at least one spin polarized current injector for polarizing a plurality of spins of a plurality of charge carriers for the current; and

at least one conductive layer having a high spin diffusion length, the at least one conductive layer being between the at least one spin polarized current injector and the plurality of magnetic junctions; and

wherein the data storage layer is configured to be switchable using at least the SO torque.

14. The magnetic memory of claim 13 wherein the spin diffusion length is at least 100 nm.

15. The magnetic memory of claim 14 wherein the spin diffusion length is at least one micron.

25. A magnetic memory comprising:

a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the data storage layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer;

a plurality of variable resistive elements corresponding to the plurality of magnetic elements and being adjacent to the at least one SO active layer, each of the plurality of variable resistive elements configured to have a low resistance state and shunt the current from the at least one SO active layer in a first region corresponding to at least one magnetic element of the plurality of magnetic elements that is not to be written, each of the plurality of variable resistive elements configured to have a high resistance state in a second region corresponding to at least another magnetic element of the plurality of magnetic elements that is to be written, the at least one SO active layer generating the SO field in the second region;

wherein the data storage layer is configured to be switchable using at least the SO torque; and

wherein the data storage layer has an easy axis and the at least one SO active layer generates a SO field having a polarization along the easy axis.

27. A magnetic memory comprising:

a plurality of storage cells, each of the plurality of magnetic storage cells including at least one selection device and at least one magnetic junction, each of the at least one magnetic junction including a reference layer, a nonmagnetic spacer layer, and a free layer, the free layer being magnetic, the nonmagnetic spacer layer being between the reference layer and the free layer; and

at least one spin-orbit interaction (SO) active layer adjacent to the free layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the free layer due to an in-plane current passing through the at least one SO active layer, the at least one SO active layer also configured to exert no SO torque on the free storage layer in the absence of the in-plane current;

the free layer being configured to be switchable using the SO torque and a perpendicular write current driven through the at least one magnetic junction.

28. A magnetic memory comprising:

a plurality of storage cells, each of the plurality of magnetic storage cells including at least one selection device and at least one magnetic junction, each of the at least one magnetic junction including a reference layer, a nonmagnetic spacer layer, and a free layer, the free layer being magnetic, the nonmagnetic spacer layer being between the reference layer and the free layer; and

at least one spin-orbit interaction (SO) active layer adjacent to the free layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the free layer due to an in-plane current passing through the at least one SO active layer, the at least one SO active layer also configured to exert no SO torque on the free layer in the absence of the in-plane current;

the free layer being configured to be switchable using the SO torque.

29. A method for providing a magnetic memory comprising:

providing a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

providing at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the free layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer, the at least one SO active layer configured to exert no SO torque on the data storage layer in the absence of the current;

the data storage layer being configured to be switchable using at least the SO torque.

30. The method of claim 29 wherein each of the plurality of magnetic junctions further includes a reference layer and a nonmagnetic spacer layer, the nonmagnetic spacer layer residing between the data storage layer and the reference layer, the data storage layer being a free layer.

31. The method of claim 29 further comprising:

providing a spin diffusion insertion layer for each of the at least one SO active layer, the spin diffusion insertion layer being between the data storage layer and the at least one SO active layer.

32. The method of claim 29 wherein the at least one SO active layer extends over at least two of the plurality of magnetic junctions.

33. The method of claim 29 further comprising:

providing at least one word line corresponding to the plurality of magnetic junctions, the at least one SO active layer residing between the data storage layer and the at least one word line.

34. The method of claim 33 wherein the at least one word line includes at least one aperture corresponding to each of the at least on SO active layer.

36. The method of claim 29 wherein the data storage layer is further configured to be switchable using a write current passed through the magnetic junction.

37. The method of claim 36 wherein the data storage layer has a magnetic moment in a first direction and the at least one SO active layer generates a SO field in a second direction substantially perpendicular to the first direction.

38. The method of claim 37 wherein the magnetic moment of the data storage layer is substantially perpendicular to plane.

39. The method of claim 37 wherein the current through the at least one SO active layer is a first current pulse, the write current is a second current pulse, and wherein the first current pulse starts before the second current pulse.

40. The method of claim 29 wherein the data storage layer has an easy axis and the at least one SO active layer generates a SO field in along the easy axis.

42. The method of claim 40 wherein the step of driving the current through the at least one SO active layer includes driving a first current pulse through the at least one SO active layer and wherein the method further includes:

driving a second current pulse through a portion of the at least one magnetic junction after the first current pulse starts.

43. The method of claim 40 further comprising:

selecting at least one of the plurality of magnetic junctions for writing.

35. A method for providing a magnetic memory comprising:

providing a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic; and

providing at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the free layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer, the step of providing the SO active layer further including

providing at least one spin polarized current injector for polarizing a plurality of spins of a plurality of charge carriers for the current; and

providing at least one conductive layer having a high spin diffusion length, the at least one conductive layer being between the at least one spin polarized current injector and the plurality of magnetic junctions; and

wherein the data storage layer is configured to be switchable using at least the SO torque.

41. A method for programming a magnetic memory including a plurality of magnetic junctions, each of the plurality of magnetic junctions including a data storage layer, the data storage layer being magnetic the method comprising:

driving a current through at least one spin-orbit interaction (SO) active layer adjacent to the data storage layer of the magnetic junction, the at least one SO active layer configured to exert a SO torque on the free layer due to a current passing through the at least one SO active layer in a direction substantially perpendicular to a direction between the at least one SO active layer and the data storage layer of a magnetic junction of the plurality of magnetic junctions closest to the at least one SO active layer, the data storage layer being configured to be switchable using at least the SO torque;

wherein the SO active layer is configured to exert no SO torque on the data storage layer in the absence of the current.