SELF-COMPENSATION OF STRAY FIELD OF PERPENDICULAR MAGNETIC ELEMENTS

• US 20160043304A1
• Filed: 08/07/2014
• Published: 02/11/2016
• Est. Priority Date: 08/07/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: CHEN, Wei-Chuan, ZHU, Xiaochun, LI, Xia, LU, Yu, PARK, Chando, KANG, Seung Hyuk
• Granted Patent: US 10,043,967 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H10N 50/01 Manufacture or treatment
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

A perpendicular magnetic tunnel junction (pMTJ) device includes a perpendicular reference layer, a tunnel barrier layer on a surface of the perpendicular reference layer, and a perpendicular free layer on a surface of the tunnel barrier layer. The pMTJ device also includes a dielectric passivation layer on the tunnel barrier layer and surrounding the perpendicular free layer. The pMTJ device further includes a high permeability material on the dielectric passivation layer that is configured to be magnetized by the perpendicular reference layer and to provide a stray field to the perpendicular free layer that compensates for a stray field from the perpendicular reference layer.

Claims

1. A perpendicular magnetic tunnel junction (pMTJ) device, comprising:

a perpendicular reference layer;

a tunnel barrier layer on a surface of the perpendicular reference layer;

a perpendicular free layer on the surface of the tunnel barrier layer;

a dielectric passivation layer on the tunnel barrier layer and surrounding the perpendicular free layer; and

a high permeability material on the dielectric passivation layer configured to be magnetized by the perpendicular reference layer and to provide a stray field to the perpendicular free layer that compensates for the stray field from the perpendicular reference layer.

2. The pMTJ device of claim 1, in which the perpendicular reference layer comprises a single layer.

3. The pMTJ device of claim 1, in which the perpendicular reference layer comprises a synthetic antiferromagnetic (SAF) layer.

4. The pMTJ device of claim 1, in which the high permeability material comprises Mu-metal, nickel iron (NiFe)-based materials, iron-based materials, ferrite, permalloys, oxygen doping and nitride doping.

5. The pMTJ device of claim 1, in which the perpendicular reference layer extends laterally outside the perpendicular free layer.

6. The pMTJ device of claim 1, in which the dielectric passivation layer comprises silicon nitride (SiN), silicon oxynitride (SiON or SiO_xN_y), aluminum oxide (AlO_x), and silicon oxide (SiO_x).

7. The pMTJ device of claim 1 integrated into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.

8. A perpendicular magnetic tunnel junction (pMTJ) device, comprising:

a perpendicular reference layer;

a tunnel barrier layer on a surface of the perpendicular reference layer;

a perpendicular free layer on the surface of the tunnel barrier layer;

a dielectric passivation layer on the tunnel barrier layer and surrounding the perpendicular free layer; and

means for providing a stray field to the perpendicular free layer that compensates for the stray field from the perpendicular reference layer.

9. The pMTJ device of claim 8, in which the perpendicular reference layer comprises a single layer.

10. The pMTJ device of claim 8, in which the perpendicular reference layer comprises a synthetic antiferromagnetic (SAF) layer.

11. The pMTJ device of claim 8, in which the providing means comprises Mu-metal, nickel iron (NiFe)-based materials, iron-based materials, ferrite, permalloys, oxygen doping and nitride doping.

12. The pMTJ device of claim 8, in which the perpendicular reference layer extends laterally outside the perpendicular free layer.

13. The pMTJ device of claim 8, in which the dielectric passivation layer comprises silicon nitride (SiN), silicon oxynitride (SiON or SiO_xN_y), aluminum oxide (AlO_x), and silicon oxide (SiO_x).

14. The pMTJ device of claim 8 integrated into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.

15. A method of fabricating a perpendicular magnetic tunnel junction (pMTJ) device, comprising:

depositing a magnetic tunnel junction (MTJ) stack;

etching a portion of the MTJ stack to a tunnel barrier layer;

depositing a dielectric passivation layer on the tunnel barrier layer; and

depositing a high permeability material on the dielectric passivation layer.

16. The method of claim 15, further comprising:

exposing a top electrode of the MTJ stack; and

depositing a conductive material on the top electrode.

17. The method of claim 15, further comprising depositing an inter-metal dielectric (IMD) on the high permeability material.

18. The method of claim 15, in which etching the portion comprises etching a free layer and a top electrode to have a smaller cross section than the tunnel barrier layer and a pinned layer.

19. The method of claim 15, in which depositing comprises depositing a synthetic antiferromagnetic (SAF) pin layer.

20. The method of claim 15, further comprising integrating the pMTJ device into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.

21. A computer program product for fabricating a perpendicular magnetic tunnel junction (pMTJ) device, comprising:

a non-transitory computer-readable medium having non-transitory program code recorded thereon, the program code comprising;

program code to deposit a magnetic tunnel junction (MTJ) stack;

program code to etch a portion of the MTJ stack to a tunnel barrier layer;

program code to deposit a dielectric passivation layer on the tunnel barrier layer; and

program code to deposit a high permeability material on the dielectric passivation layer.

22. The computer program product of claim 21, in which the program code further comprises:

program code to expose a top electrode of the MTJ stack; and

program code to deposit a conductive material on the top electrode.

23. The computer program product of claim 21, in which the program code further comprises program code to deposit an inter-metal dielectric (IMD) on the high permeability material.

24. The computer program product of claim 21, in which the program code to etch the portion comprises program code to etch a free layer and a top electrode to have a smaller cross section than the tunnel barrier layer and a pinned layer.

25. The computer program product of claim 21, in which the program code to deposit comprises program code to deposit a synthetic antiferromagnetic (SAF) pin layer.

26. The computer program product of claim 21, in which the program code further comprises program code to integrate the pMTJ device into a mobile phone, a set top box, a music player, a video player, an entertainment unit, a navigation device, a computer, a hand-held personal communication systems (PCS) unit, a portable data unit, and/or a fixed location data unit.