Magnetoresistive devices and methods of fabricating magnetoresistive devices

1. A method of manufacturing a magnetoresistive device, the method comprising:

forming a first magnetic region, an intermediate region, and a second magnetic region of a magnetoresistive stack above a via;

removing at least a portion of the second magnetic region using a first etch;

removing at least a portion of the intermediate region and at least a portion of the first magnetic region using a second etch;

removing at least a portion of material redeposited on the magnetoresistive stack using a third etch;

rendering at least a portion of the redeposited material remaining on the magnetoresistive stack electrically non-conductive, wherein rendering at least a portion of the redeposited material remaining on the magnetoresistive stack electrically non-conductive includes:

oxidizing at least a first portion of redeposited material remaining on the magnetoresistive stack;

removing the oxidized first portion;

oxidizing at least a second portion of the redeposited material remaining on the magnetoresistive stack; and

removing the oxidized second portion.

2. The method of claim 1 , further comprising, after rendering at least the portion of the redeposited material remaining on the magnetoresistive stack electrically non-conductive, forming an encapsulation material on the magnetoresistive stack.

3. The method of claim 1 , wherein the first etch is one of a reactive ion etch (RIE) and an ion beam etch (IBE), and the second etch is the other of the RIE and the IBE.

4. The method of claim 1 , wherein the first magnetic region is a free magnetic region and the second magnetic region is a fixed magnetic region.

5. The method of claim 4 , wherein the second magnetic region is formed on the intermediate region and the intermediate region is formed on the first magnetic region.

6. The method of claim 1 , wherein the third etch is an ion beam etch (IBE) or reactive ion etch (RIE).

7. The method of claim 1 , wherein the first etch is a reactive ion etch (RIE) and the second etch is an ion beam etch (IBE) at an angle of approximately 35° to approximately 55°.

8. The method of claim 1 , wherein rendering at least the portion of the redeposited material remaining on the magnetoresistive stack electrically non-conductive includes oxidizing at least the portion of the redeposited material remaining on the magnetoresistive stack, the oxidizing including exposing the magnetoresistive stack to a mixture of oxygen (O 2 ) and argon (Ar).

9. The method of claim 8 , wherein a molar ratio of O 2 to Ar is approximately 1:3 to approximately 1:10.

10. The method of claim 1 , wherein the magnetoresistive stack is a first magnetoresistive stack, and the method further comprises forming a second magnetoresistive stack, wherein a pitch between the first magnetoresistive stack and the second magnetoresistive stack is less than or equal to approximately 70 nm.

11. A method of manufacturing a magnetoresistive device, the method comprising:

forming a first magnetic region, an intermediate region, and a second magnetic region of a magnetoresistive stack above a via;

removing at least a portion of the second magnetic region using a first etch, wherein the first etch is an ion beam etch (IBE);

removing at least a portion of the intermediate region and at least a portion of the first magnetic region using a second etch, wherein the second etch is a reactive ion etch (RIE);

trimming at least a portion of redeposited material on the magnetoresistive stack, wherein trimming at least a portion of redeposited material on the magnetoresistive stack includes:

removing at least a portion of material redeposited on the magnetoresistive stack using a third etch; and

rendering at least a portion of the redeposited material remaining on the magnetoresistive stack electrically non-conductive by exposing the magnetoresistive stack to a mixture of oxygen (O 2 ) and argon (Ar).

12. The method of claim 11 , wherein the first etch exposes a surface of the intermediate region and the second etch exposes a surface of an interlayer dielectric.

13. The method of claim 11 , wherein the first etch is at an angle of approximately 35° to approximately 55°.

14. The method of claim 11 , wherein the redeposited material are formed during the first etch and/or the second etch.

15. The method of claim 11 , wherein the magnetoresistive stack is a first magnetoresistive stack, and the method further comprises forming a second magnetoresistive stack, wherein a pitch between the first magnetoresistive stack and the second magnetoresistive stack is less than or equal to approximately 70 nm.

16. A method of manufacturing a magnetoresistive device, the method comprising:

forming a free magnetic region, an intermediate region, and a fixed magnetic region of a magnetoresistive stack;

performing a first etch of a two-step etch process, wherein the first etch removes at least a portion of the fixed magnetic region;

performing a second etch of the two-step etch process, wherein the second etch removes at least a portion of the intermediate region and at least a portion of the free magnetic region;

removing a first redeposited material using an ion beam etch (IBE), wherein the first redeposited material is formed during the first etch, the second etch, or both; and

rendering at least the portion of the redeposited material remaining on the magnetoresistive stack electrically non-conductive by exposing the magnetoresistive stack to a mixture of oxygen (O 2 ) and argon (Ar).

17. The method of claim 16 , further comprising, before forming the free magnetic region, the intermediate region, and the fixed magnetic region of the magnetoresistive stack:

forming an interlayer dielectric;

forming a trench in the interlayer dielectric; and

depositing a conductive material in the trench to form a via,

wherein the via is coaxial to the magnetoresistive stack and a width of the via is less than a width of the magnetoresistive stack.

18. The method of claim 16 , further comprising:

oxidizing a second redeposited material, wherein the second redeposited material was formed during the first etch, the second etch, or both.

19. The method of claim 16 , wherein the first etch or the second etch is an angled ion beam etch at an angle of approximately 35° to approximately 55°.

20. The method of claim 16 , wherein the mixture has a molar ratio of O 2 to Ar of approximately 1:3 to approximately 1:10.