Magnetoresistive sensor having synthetic antiferromagnetic layer in top and bottom shields

Patent metadata

Field	Value
Publication number	US-9368136-B2
Application number	US-201414192388-A
Country	US
Kind code	B2
Filing date	Feb 27, 2014
Priority date	Feb 27, 2014
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

In accordance with one implementation of the described technology, an apparatus comprises a sensor structure including a top shield which includes a top shield synthetic antiferromagnetic layer and a bottom shield including a bottom shield synthetic antiferromagnetic layer, wherein the bottom synthetic antiferromagnetic shield layer acts as a seed layer structure.

First claim

What is claimed is:

1. An apparatus comprising:
a sensor structure, including a top shield including a top shield synthetic antiferromagnetic (SAF) layer and a bottom shield including a bottom shield SAF layer, wherein the bottom SAF shield layer acts as a seed layer that promotes crystal texture growth of an antiferromagnetic layer with a magnetic orientation pinned perpendicular to an air-bearing surface direction.

2. The apparatus of claim 1 , wherein the top SAF shield layer is an ex situ SAF layer.

3. The apparatus of claim 1 , wherein the bottom SAF shield layer is an in situ SAF layer.

4. The apparatus of claim 3 , wherein the in situ bottom SAF shield layer is a seed layer.

5. The apparatus of claim 1 , further comprising a magnetoresistive sensor element between the top shield SAF layer and bottom shield SAF layer, the magnetoresistive sensor element comprises a free layer, a barrier layer, a magnetic reference layer, a coupling spacer, a magnetic pinned layer, and an antiferromagnetic layer.

6. The apparatus of claim 1 , wherein the top shield SAF layer is an ex situ SAF layer and the bottom shield SAF layer is an in situ SAF layer, the in situ bottom shield SAF layer being a seed layer.

7. The apparatus of claim 6 , further comprising an antiferromagnetic layer of a polycrystalline composition adjacent to the bottom shield SAF layer.

8. The apparatus of claim 7 , wherein the antiferromagnetic layer includes at least one of platinum and manganese.

9. The apparatus of claim 1 , wherein the top shield SAF layer further comprises layers of at least one of nickel alloys and cobalt alloys.

10. The apparatus of claim 1 , wherein the bottom shield SAF layer further comprises layers of at least one of nickel alloys and cobalt alloys.

11. An apparatus comprising:
a sensor structure, including a top shield including a top shield synthetic antiferromagnetic (SAF) layer and a bottom shield including a bottom shield SAF layer, the top shield SAF layer is an ex situ top shield SAF layer and the bottom shield SAF layer is an in situ bottom shield SAF layer, wherein the bottom SAF shield layer acts as a seed layer that promotes crystal texture growth of an antiferromagnetic layer with a magnetic orientation pinned perpendicular to an air-bearing surface direction.

12. The apparatus of claim 11 , wherein the top shield SAF layer has magnetic anisotropy Hk greater than 300 Oe.

13. The apparatus of claim 12 , wherein the bottom shield SAF layer has magnetic anisotropy Hk greater than 300 Oe.

14. A magnetoresistive (MR) sensor comprising:
an MR stack configured between a top shield and bottom shield along a down-track direction;
a top shield synthetic antiferromagnetic (SAF) layer configured in the top shield; and
a bottom shield SAF layer configured in the bottom shield, wherein the bottom SAF shield layer acts as a seed layer with a magnetic orientation pinned perpendicular to an air-bearing surface direction.

15. The MR sensor of claim 14 , wherein the top shield SAF layer is configured using an ex situ process.

16. The MR sensor of claim 14 , wherein the bottom shield SAF layer is configured using an in situ process.

17. The MR sensor of claim 14 , wherein anisotropy Hk of the top shield SAF layer is greater than 300 Oe.

Assignees

• Seagate Technology Llc

Inventors

• Lu Zhengqi
• Hassett Daniel
• Mcelhinney Paula
• Xu Jiansheng

Classifications

• G11B2005/3996

  large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices · CPC title

• G11B5/3912 Primary

  Arrangements in which the active read-out elements are transducing in association with active magnetic shields, e.g. magnetically coupled shields (G11B5/3916 takes precedence) · CPC title

• G11B5/115

  Shielding devices arranged between heads or windings ({G11B5/265} , G11B5/29 take precedence) · CPC title

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title