Magnetic Element Utilizing Protective Sidewall Passivation

• US 20100072566A1
• Filed: 09/24/2008
• Published: 03/25/2010
• Est. Priority Date: 09/24/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kang, Seung H., Yoon, Sei Seung
• Granted Patent: US 8,482,966 B2
• Time in Patent Office: Days
• US Class Current: 257/422
• CPC Class Codes: G01R 33/098 comprising tunnel junctions, e.g. tunnel magnetoresistance sensors
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

Exemplary embodiments of the invention are directed to magnetic elements including a passivation layer for isolation from other on-chip elements. One embodiment is directed to an apparatus comprising a magnetic tunnel junction (MTJ) element. The MTJ element comprises: a first ferromagnetic layer; a second ferromagnetic layer; an insulating layer disposed between the first and second ferromagnetic layers; and an MTJ passivation layer forming protective sidewalls disposed adjacent to the first ferromagnetic layer, the second ferromagnetic layer, and the insulating layer.

Claims

1. An apparatus comprising a magnetic tunnel junction (MTJ) element, comprising:

a first ferromagnetic layer;

a second ferromagnetic layer;

an insulating layer disposed between the first and second ferromagnetic layers; and

an MTJ passivation layer forming protective sidewalls disposed adjacent to the first ferromagnetic layer, the second ferromagnetic layer, and the insulating layer.

2. The apparatus of claim 1, wherein the MTJ passivation layer is formed of a dielectric material.

3. The apparatus of claim 2, wherein the MTJ passivation layer is formed of silicon carbide.

4. The apparatus of claim 1, wherein the MTJ passivation layer is formed of a given thickness in the range of about 5 nm to about 100 nm.

5. The apparatus of claim 1, further comprising:

an auxiliary shielding layer disposed adjacent to the MTJ passivation layer for magnetically shielding the MTJ element.

6. The apparatus of claim 5, wherein the auxiliary shielding layer is formed of a high permeability material.

7. The apparatus of claim 6, wherein the auxiliary shielding layer is formed of permalloy.

8. The apparatus of claim 1, further comprising:

an insulation layer disposed adjacent to the MTJ passivation layer.

9. The apparatus of claim 8, wherein the insulation layer is formed of a carbide, a nitride, or an oxide compound.

10. The apparatus of claim 1, further comprising:

an auxiliary shielding layer disposed adjacent to the MTJ passivation layer for magnetically shielding the MTJ element; and

an insulation layer disposed adjacent to the auxiliary shielding layer.

11. The apparatus of claim 1, further comprising:

a global passivation layer disposed between metal layers of the apparatus and formed of a carbide, a nitride, or an oxide compound.

12. The apparatus of claim 1, wherein the apparatus is a spin-transfer torque magnetic random access memory (STT-MRAM).

13. A method of forming a magnetic tunnel junction (MTJ) device including an MTJ element, comprising:

forming a first ferromagnetic layer;

forming a second ferromagnetic layer;

forming an insulating layer disposed between the first and second ferromagnetic layers; and

forming an MTJ passivation layer of protective sidewalls disposed adjacent to the first ferromagnetic layer, the second ferromagnetic layer, and the insulating layer.

14. The method of claim 13, wherein the MTJ passivation layer is formed of a dielectric material.

15. The method of claim 13, further comprising:

forming an auxiliary shielding layer adjacent to the MTJ passivation layer to magnetically shield the MTJ element.

16. The method of claim 15, wherein the auxiliary shielding layer is formed of a high permeability material.

17. The method of claim 13, further comprising:

forming an insulation layer adjacent to the MTJ passivation layer.

18. The method of claim 13, further comprising:

forming an auxiliary shielding layer adjacent to the MTJ passivation layer to magnetically shield the MTJ element; and

forming an insulation layer adjacent to the auxiliary shielding layer.

19. The method of claim 13, further comprising:

forming a global passivation layer of a carbide, a nitride, or an oxide compound between metal layers of the MTJ device.

20. An apparatus comprising a magnetic tunnel junction (MTJ) element, comprising:

a first ferromagnetic layer;

a second ferromagnetic layer;

an insulating layer disposed between the first and second ferromagnetic layers; and

MTJ passivation means disposed adjacent to the first ferromagnetic layer, the second ferromagnetic layer, and the insulating layer for at least partially isolating the MTJ element electrically and magnetically from interference.

21. The apparatus of claim 20, further comprising:

auxiliary shielding means disposed adjacent to the MTJ passivation layer for magnetically shielding the MTJ element.

22. The apparatus of claim 21, wherein the auxiliary shielding means has a high permeability.

23. The apparatus of claim 20, further comprising:

insulation means disposed adjacent to the MTJ passivation means.

24. The apparatus of claim 20, further comprising:

auxiliary shielding means disposed adjacent to the MTJ passivation layer for magnetically shielding the MTJ element; and

insulation means disposed adjacent to the auxiliary shielding means.

25. The apparatus of claim 20, further comprising:

global passivation means disposed between metal layers of the MTJ device.