MAGNETIC MEMORY DEVICE AND METHOD OF FABRICATING THE SAME

Abstract

A magnetic memory device includes a pinning layer, a pinned layer, an insulation layer, which are sequentially stacked on a semiconductor substrate. The magnetic memory device further includes a free layer disposed on the insulation layer, a capping layer disposed on the free layer and an MR (magnetoresistance) enhancing layer interposed between the free layer and the capping layer. The MR enhancing layer is formed of at least one anti-ferromagnetic material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present can be understood in more detail from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross sectional view of a magnetic tunnel junction (MTJ) of a conventional magnetic random access memory (MRAM);

FIG. 2 is a cross sectional view of a magnetic tunnel junction (MTJ) of an MRAM according to an exemplary embodiment of the present invention;

FIG. 3 is a graph of simulation results showing a magnetoresistance (MR) ratio with respect to the thickness of an MR enhancing layer according to an exemplary embodiment of the present invention;

FIG. 4 is a graph of simulation results showing a switch field with respect to the thickness of the MR enhancing layer according to an exemplary embodiment of the present invention; and

FIG. 5 is a cross sectional view of a spin-torque-transfer-type magnetic memory device.

Claims

1. A magnetic device comprising: a pinning layer, a pinned layer, and an insulation layer sequentially stacked on a semiconductor substrate;a free layer disposed on the insulation layer;a capping layer disposed on the free layer; andan MR (magnetoresistance) enhancing layer interposed between the free layer and the capping layer,wherein the MR enhancing layer is formed of at least one anti-ferromagnetic material.

2. The device of claim 1, wherein the MR enhancing layer is formed to a thickness of about 1 to about 80 Å.

3. The device of claim 1, wherein the MR enhancing layer is formed of at least one material selected from the group consisting of iridium (Ir), platinum (Pt), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), chromium (Cr) and a combination thereof.

4. The device of claim 3, wherein the MR enhancing layer is formed of at least one material selected from the group consisting of iridium manganese (IrMn), platinum manganese (PtMn), iron manganese (FeMn), manganese oxide (MnO), manganese sulfide (MnS), manganese telluride (MnTe), manganese fluoride (MnF2), iron fluoride (FeF2), iron chloride (FeCl2), iron oxide (FeO), cobalt chloride (CoCl2), cobalt oxide (CoO), nickel chloride (NiCl2), nickel oxide (NiO), and chromium (Cr).

5. The device of claim 1, wherein the MR enhancing layer is formed to a thickness of about 3 to about 10 Å using at least one material selected from the group consisting of iridium manganese (IrMn), platinum manganese (PtMn), and iron manganese (FeMn).

6. The device of claim 1, wherein the MR enhancing layer is formed to such a thickness so as to prevent AFC (anti-ferromagnetic coupling) from occurring between the MR enhancing layer and the free layer.

7. The device of claim 1, wherein the free layer is formed of at least one material selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), magnesium (Mg), gadolinium (Gd), dysprosium (Dy), chromium (Cr), europium (Eu), yttrium (Y) and a combination thereof.

8. The device of claim 1, wherein the free layer is formed of at least one material selected from the group consisting of cobalt iron boron (CoFeB), iron (Fe), cobalt (Co), nickel (Ni), gadolinium (Gd), dysprosium (Dy), cobalt iron CoFe, nickel iron (NiFe), manganese arsenide (MnAs), manganese bismuth (MnBi), manganese antimony (MnSb), chromium oxide (CrO2), manganese ferrite (MnOFe2O3), iron ferrite (FeOFe2O3), nickel ferrite (NiOFe2O3), copper ferrite (CuOFe2O3), magnesium ferrite (MgOFe2O3), europium oxide (EuO), and yttrium-iron-garnet (Y3Fe5O12).

9. The device of claim 1, wherein the capping layer is formed of a conductive material including tantalum (Ta).

10. A method of fabricating a magnetic memory device, comprising: forming a lower electrode on a semiconductor substrate;forming an MTJ (magnetic tunnel junction) layer on the lower electrode, the MTJ layer including a pinning layer, a pinned layer, an insulation layer, a free layer, an MR (magnetoresistance) enhancing layer, and a capping layer that are stacked sequentially; andforming an MTJ pattern on the lower electrode by patterning the MTJ layer,wherein the MR enhancing layer is formed using at least one anti-ferromagnetic material to a thickness of about 1 to about 80 Å.

11. The method of claim 10, wherein the MR enhancing layer is formed to such a thickness so as to prevent anti-ferromagnetic coupling (AFC) from occurring between the MR enhancing layer and the free layer.

12. The method of claim 11, wherein the MR enhancing layer is formed to a thickness of about 3 to about 10 Å.

13. The method of claim 10, wherein the MR enhancing layer is formed using one of an atomic layer deposition (ALD) technique or a chemical vapor deposition (CVD) technique.

14. The method of claim 10, wherein the MR enhancing layer is formed of at least one material selected from the group consisting of iridium (Ir), platinum (Pt), iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), chromium (Cr) and a combination thereof.

15. The method of claim 14, wherein the MR enhancing layer is formed of at least one material selected from the group consisting of iridium manganese (IrMn), platinum manganese (PtMn), iron manganese (FeMn), manganese oxide (MnO), manganese sulfide (MnS), manganese telluride (MnTe), manganese fluroide (MnF)2, iron fluoride (FeF2), iron chloride (FeCl2), iron oxide (FeO), cobalt chloride (CoCl2), cobalt oxide (CoO), nickel chloride (NiCl2), nickel oxide (NiO), and chromium (Cr).

16. The method of claim 10, wherein the free layer is formed of at least one material selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), cobalt (Cu), magnesium (Mg), gadolinium (Gd), dysprosium (Dy), chromium (Cr), europium (Eu), yttrium (Y) and a combination thereof.

17. The method of claim 16, wherein the free layer is formed of at least one material selected from the group consisting of cobalt iron boron (CoFeB), iron (Fe), cobalt (Co), nickel (Ni), gadolinium (Gd), dysprosium (Dy), cobalt iron (CoFe), nickel iron (NiFe), manganese arsenide (MnAs), manganese bismuth MnBi, manganese antimony (MnSb), chromium oxide (CrO2), manganese ferrite (MnOFe2O3), iron ferrite (FeOFe2O3), nickel ferrite (NiOFe2O3), copper ferrite (CuOFe2O3), magnesium ferrite (MgOFe2O3), europium oxide (EuO), and yttrium-iron-garnet (Y3Fe5O12).

18. The method of claim 10, wherein the capping layer is formed of tantalum (Ta).

19. The method of claim 10, further comprising thermally treating the MTJ layer at a temperature of about 250 to 400° C. after the forming of the MTJ layer.