Methods for patterning a magnetic sensing layer

Patent metadata

Field	Value
Publication number	US-10593869-B2
Application number	US-201615219694-A
Country	US
Kind code	B2
Filing date	Jul 26, 2016
Priority date	Jul 26, 2016
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

The present disclosure is directed towards a method for patterning a magnetic sensing layer. The method includes disposing a protective layer on a first of a substrate, disposing a first insulating layer on a first surface of protective layer. An opening is formed in the first insulating layer to expose the first surface of the protective layer. A magnetic sensing layer is disposed over the first insulating layer and a predetermined portion of the first surface of the protective layer within the opening. A second insulating layer can be disposed over the magnetic sensing layer. The second insulation layer and the magnetic sensing layer can be removed from the first insulation layer. Thus, the opening includes the magnetic sensing layer and the second insulation layer after the removal of the second insulation layer and magnetic sensing layer from the first insulation layer.

First claim

What is claimed:

1. A method for patterning a magnetic sensing layer, the method comprising:
disposing an insulating protective layer directly on a first surface of a substrate, the substrate having first and second opposing surfaces;
disposing a first insulating layer directly on a first surface of the insulating protective layer;
forming an opening in the first insulating layer to expose the first surface of the protective layer;
disposing a magnetic sensing layer over at least portions of the first insulating layer and a predetermined portion of the first surface of the insulating protective layer within the opening such that the magnetic sensing layer is in direct contact with the predetermined portion of the insulating protective layer spaced apart from wall portions of the first insulating layer within the opening;
disposing a second insulating over the magnetic sensing layer and at least portions of the first insulating layer such that the second insulating layer is in direct contact with the magnetic sensing layer disposed over the predetermined portion of the first surface of the protective layer and portions of the first surface of the protective layer; and
removing the second insulation layer and the magnetic sensing layer from the first insulation layer.

2. The method of claim 1 further comprising forming one or more vias through the protective layer to provide for a connection to the first surface of the substrate.

3. The method of claim 1 wherein disposing the magnetic sensing layer over a predetermined portion of the first surface of the substrate comprises depositing at least one of a giant magnetoresistance (GMR) layer, a tunnel magnetoresistance (TMR) layer, or a magnetic tunnel junction (MTJ) layer over the first surface of the substrate.

4. The method of claim 1 wherein disposing the magnetic sensing layer over a predetermined portion of the first surface of the protective layer comprises depositing a giant magnetoresistance (GMR) layer having at least one layer that includes at least one of:
a platinum;
a platinum alloy; or
a manganese platinum alloy.

5. The method of claim 1 wherein disposing the magnetic sensing layer over a predetermined portion of the first surface of the protective layer comprises depositing a giant magnetoresistance (GMR) layer having at least one layer that includes a manganese platinum alloy.

6. The method of claim 1 , further comprising forming a footing region within the opening.

7. The method of claim 1 , further comprising removing the second insulation layer using chemical-mechanical polishing.

8. The method of claim 1 , further comprising forming the magnetic sensing layer as at least one of: a stack layer in combination with at least one of a synthetic antiferromagnet (SAF) layer or a double pinned layer.

9. The method of claim 1 , further comprising disposing the second insulating layer using at least one of chemical vapor deposition or plasma chemical vapor deposition.

10. The method of claim 1 , further comprising filling a volume defined by the opening within the first insulating layer with the second insulating layer.

11. The method of claim 1 , further comprising forming a giant magnetoresistance (GMR) element, an anisotropic magnetoresistance (AMR) element, a tunnel magnetoresistance (TMR) element, or a magnetic tunnel junction (MTJ) element.

12. The method of claim 1 , wherein the first insulating layer comprises silicon oxide, silicon dioxide, silicon nitride, alumina or a combination of them.

13. The method of claim 1 , wherein the second insulating layer comprises silicon oxide, silicon dioxide, silicon nitride, alumina or a combination of them.

14. The method of claim 1 , wherein the protective layer comprises silicon oxide, silicon dioxide, silicon nitride, alumina, aluminum oxide or a combination of them.

15. The method of claim 1 , wherein the protective layer has a different etch rate from the first insulating layer.

16. The method of claim 1 , wherein the protective layer includes one type of material.

17. A magnetoresistance element comprising:
a substrate having first and second opposing surfaces;
an insulating protective layer disposed over and in direct contact with the first surface of the substrate;
a first insulating layer disposed over and in direct contact with a first surface of the insulating protective layer;
an opening formed in the first insulating layer to expose the first surface of the insulating protective layer;
a magnetic sensing layer disposed within the opening and in direct contact with a predetermined portion of the first surface of the insulating protective layer;
a second insulating layer disposed over the magnetic sensing layer within the opening, wherein the second insulating layer is disposed such that the second insulating layer is in direct contact with the magnetic sensing layer disposed over the predetermined portion of the first surface of the protective layer and portions of the first surface of the protective layer.

18. The magnetoresistance element of claim 17 , wherein the first insulating layer has a thickness in a range of about 25 nm to about 700 nm.

19. The magnetoresistance element of claim 17 , wherein the first insulating layer comprises silicon oxide, silicon dioxide, silicon nitride, alumina or a combination of them.

20. The magnetoresistance element of claim 17 , wherein a first edge of the opening forms a first wall of the opening and a second edge of the opening forms a second wall of the opening.

21. The magnetoresistance element of claim 20 , wherein the first wall and the second wall of the opening have a slope profile ranging from about 45 degrees to about 90 degrees.

22. The magnetoresistance element of claim 20 , wherein a depth of the opening is defined by a height of the first edge relative to the first surface of the protective layer and a height of the second edge relative to the first surface of the substrate.

23. The magnetoresistance element of claim 20 , wherein the predetermined portion of the first surface of the protective layer covered by the magnetic sensing layer corresponds to a slope profile of the first wall and the second wall of the opening.

24. The magnetoresistance element of claim 17 , wherein a central width or a central diameter of the opening ranges from about 0.5 μm to about 10 μm.

25. The magnetoresistance element of claim 17 , wherein the magnetic sensing layer is formed as a stack layer in combination with at least one of a synthetic antiferromagnet (SAF) layer or a double pinned layer.

26. The magnetoresistance element of claim 17 , wherein the second insulating layer has a thickness ranging from about 0.5 μm to about 5 μm.

27. The magnetoresistance element of claim 17 , wherein the second insulating layer fills a volume defined by the opening within the first insulating layer.

28. The magnetoresistance element of claim 17 , wherein the second insulating layer comprises silicon oxide, silicon dioxide, silicon nitride, alumina or a combination of them.

29. The magnetoresistance element of claim 17 , wherein the opening comprises the magnetic sensing layer and the second insulation layer after the removal of the second insulation layer and magnetic sensing layer from the first insulation layer.

30. The magnetoresistance element of claim 17 , further c

Assignees

• Allegro Microsystems Llc

Inventors

• Wong Harianto
• Taylor William P

Classifications

• G01R33/09

  Magnetoresistive devices · CPC title

• G01R33/098

  comprising tunnel junctions, e.g. tunnel magnetoresistance sensors · CPC title

• G01R33/0023 Primary

  Electronic aspects, e.g. circuits for stimulation, evaluation, control; Treating the measured signals; calibration (G01R33/0017 takes precedence) · CPC title

• H01L43/08 Primary

  Electricity · mapped topic

• H01L43/12

  Electricity · mapped topic