IP Library Granted Patent US 10,658,576
Granted Patent B2
US 10,658,576 · App. 16/580,025 · Granted May 19, 2020

Magnetoresistive stack/structure and method of manufacturing same

Inventors: Sarin A. Deshpande (San Jose, CA); Kerry Joseph Nagel (Scottsdale, AZ); Chaitanya Mudivarthi (Sunnyvale, CA); Sanjeev Aggarwal (Scottsdale, AZ)
Assignee: Everspin Technologies, Inc.
H01L43/12H01L43/08
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Quick Facts
Patent No.
US 10,658,576
App. No.
16/580,025
Granted
May 19, 2020
Kind
B2
Abstract

A method of manufacturing a magnetoresistive stack/structure comprising (a) etching through a second magnetic region to (i) provide sidewalls of the second magnetic region and (ii) expose a surface of a dielectric layer, (b) depositing a first encapsulation layer on the sidewalls of the second magnetic region and over a surface of the dielectric layer, (c) thereafter: (i) etching the first encapsulation layer which is disposed over the dielectric layer using a first etch process, and (ii) etching re-deposited material using a second etch process, wherein, after such etching, a portion of the first encapsulation layer remains on the sidewalls of the second magnetic region, (d) etching (i) through the dielectric layer to form a tunnel barrier and provide sidewalls thereof and (ii) etching the first magnetic region to provide sidewalls thereof, and (e) depositing a second encapsulation layer on the sidewalls of the tunnel barrier and first magnetic region.

Claims (29)

1. A method of manufacturing a magnetoresistive structure including an intermediate layer disposed between a first magnetic region and a second magnetic region, comprising:

(a) etching through the second magnetic region to form exposed surfaces, wherein (i) the exposed surfaces include at least a portion of the intermediate layer, and (ii) after the etching, at least a portion of the exposed surfaces includes re-deposited material;

(b) forming a first encapsulation layer on the exposed surfaces after step (a);

(c) removing at least a portion of the re-deposited material after step (b);

(d) etching through the intermediate layer after step (c); and

(e) forming a second encapsulation layer after step (d).

2. The method of claim 1 , wherein the intermediate layer is a dielectric layer.

3. The method of claim 1 , wherein step (a) includes etching using a physical etch process.

4. The method of claim 1 , wherein step (a) and step (c) include etching using a physical etch process.

5. The method of claim 4 , wherein the physical etch process includes ion beam etching.

6. The method of claim 1 , wherein step (a) includes etching through a portion of the intermediate layer.

7. The method of claim 1 , further including terminating the etching in step (a) at the top of the intermediate layer.

8. The method of claim 1 , wherein step (b) includes forming an oxide or a nitride layer.

9. The method of claim 1 , wherein step (b) includes depositing one or more of a silicon oxide, a silicon nitride, or a tetraethylorthosilicate (TEOS).

10. The method of claim 1 , wherein step (e) includes depositing one or more of a silicon oxide, a silicon nitride, or a tetraethylorthosilicate (TEOS).

11. The method of claim 1 , wherein the first magnetic region and the second magnetic region include at least one of a synthetic antiferromagnetic structure (SAF) or a synthetic ferromagnetic structure (SyF).

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

13. 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.

14. The method of claim 1 , wherein the intermediate layer includes magnesium oxide (MgO).

15. A method of manufacturing a magnetoresistive structure including an intermediate layer disposed between a first magnetic region and a second magnetic region, comprising:

(a) etching through the second magnetic region to form exposed surfaces, wherein (i) the exposed surfaces include at least a portion of the intermediate layer, and (ii) after the etching, at least a portion of the exposed surfaces includes re-deposited material;

(b) depositing a first encapsulation layer on the exposed surfaces after step (a);

(c) etching at least a portion of the re-deposited material after step (b); and

(d) etching the intermediate layer after step (c).

16. The method of claim 15 , wherein the first encapsulation layer is one or more of a silicon oxide, a silicon nitride, or a tetraethylorthosilicate (TEOS).

17. The method of claim 15 , further including depositing a second encapsulation layer after step (d).

18. The method of claim 16 , wherein the second encapsulation layer is one or more of a silicon oxide, a silicon nitride, or a tetraethylorthosilicate (TEOS).

19. The method of claim 15 , wherein step (a), step (c), and step (d) include the same or different physical etch processes.

20. The method of claim 15 , further including terminating the etching in step (a) at the top of the intermediate layer.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 25, 2019
From: DESHPANDE, SARIN A.; NAGEL, KERRY JOSEPH; MUDIVARTHI, CHAITANYA; AGGARWAL, SANJEEV
To: EVERSPIN TECHNOLOGIES, INC.
Reel/Frame 050481/0212 →
Continuity (6)
Continuation 16050749 · Jul 31, 2018
Continuation 15727905 · Oct 9, 2017
Division 15013950 · Feb 2, 2016
Provisional Application 62249196 · Oct 31, 2015
Provisional Application 62111976 · Feb 4, 2015
Related Publication 20200020852A1 · Jan 16, 2020
Cited By (1)
US 12,369,495