Perpendicular magnetic recording (PMR) writer with one or more spin flipping elements in the gap

Patent metadata

Field	Value
Publication number	US-10325618-B1
Application number	US-201816037197-A
Country	US
Kind code	B1
Filing date	Jul 17, 2018
Priority date	Jul 17, 2018
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

A perpendicular magnetic recording writer has a main pole (MP) with a write gap formed between the MP trailing side and a trailing shield, a side gap between each MP side and a side shield, and a leading gap between the MP leading side and a leading shield. A flux guiding element is formed in at least one gap and comprises an inner non-spin preserving layer adjoining the MP, a middle flux guiding layer (FGL), and an outer spin preserving layer. A key feature is that the FGL has a magnetization that may be aligned anti-parallel to a gap field during a write process when a current of sufficient magnitude is applied from the adjacent shield towards the MP thereby increasing reluctance in the gap and forcing additional flux out of the MP at the air bearing surface to enhance writability on a magnetic recording medium.

First claim

We claim:

1. A perpendicular magnetic recording (PMR) writer, comprising:
(a) a main pole with a leading side and a trailing side, the leading side adjoins a leading gap at an air bearing surface (ABS), and the trailing side has a track width and adjoins a write gap at the ABS, and is formed on a first plane that is orthogonal to the ABS;
(b) a side gap which contacts a side of the main pole formed between the trailing side and leading side on each side of a center plane that bisects the main pole in a direction orthogonal to the ABS and the first plane;
(c) the leading gap that adjoins a bottom portion of each side gap and contacts the leading side of the main pole;
(d) a shield structure comprising a first trailing shield (TS) on the write gap, a side shield contacting each side gap, and a leading shield adjoining a bottom surface of the leading gap at a second plane that is parallel to the first plane; and
(e) at least one flux guiding element that is formed in one of the write gap, side gaps, or leading gap; and wherein the at least one flux guiding element extends to a height that is about a throat height of the first TS, and comprises:
(1) an inner non-spin preserving layer that contacts the main pole;
(2) a middle flux guiding layer (FGL) having a magnetization aligned parallel to a gap field from the main pole during a write process, and wherein the PMR writer is configured so that the FGL magnetization flips to an opposite direction when a current I b of sufficient magnitude is applied in a direction from the shield structure towards the main pole; and
(3) an outer spin preserving layer that adjoins one of the first TS, side shields, and leading shield.

2. The PMR writer of claim 1 wherein the at least one flux guiding element is formed in the write gap, and has a thickness equal to a write gap thickness, and a width essentially equal to the track width.

3. The PMR writer of claim 2 wherein a second flux guiding element is formed in each side gap between the first plane and the leading gap.

4. The PMR writer of claim 2 wherein a second flux guiding element is formed in each side gap and extends from a top end at the first plane to a bottom end at the second plane such that only a portion of the leading gap remains below the main pole leading side.

5. The PMR writer of claim 2 wherein a second flux guiding element is formed in each side gap and extends from a top end at the first plane to a bottom end at the second plane and fills each side gap and the leading gap.

6. The PMR writer of claim 2 wherein a second flux guiding element is formed in each side gap, and a third flux guiding element is formed in the leading gap, and wherein spin preserving layers in the second and third flux guiding elements form a conformal spin preserving layer (SPL) on the side shields, and leading shield, respectively, and wherein FGL in the second and third flux guiding elements form a conformal FGL on the conformal SPL, and non-SPL in the second and third flux guiding elements form a conformal non-SPL on the conformal FGL.

7. The PMR writer of claim 1 wherein the at least one flux guiding element has a thickness from about 5 nm to 30 nm.

8. The PMR writer of claim 1 wherein the non-spin preserving layer is a dielectric layer that is one of Ta, W, Pt, Ru, Ti, Ir, Rh, or Pd.

9. The PMR writer of claim 1 wherein the FGL is comprised of a multilayer of magnetic materials that is one or more of Ni x Fe 100-x , Co y Fe 100-y , Co z Ni 100-z , or alloys thereof with one or more additional elements that are B, Mo, Pt, Pd, W, and Cr where each of x, y, and z are from 0 to 100 atomic %.

10. The PMR writer of claim 1 wherein the spin preserving layer is a conductive layer that is one of Cu, Ag, Au, Al, or Cr.

11. The PMR writer of claim 1 wherein the magnitude of I b is greater than a critical current I c , where I c drives the FGL magnetization into an oscillatory state while maintaining the FGL magnetization substantially in the direction of the gap field.

12. The PMR writer of claim 1 wherein I b has a current density that is in a range of 1×10 −7 Amp/cm 2 to 1×10 −9 Amp/cm 2 .

13. A head gimbal assembly (HGA), comprising:
(a) a slider on which the PMR writer of claim 1 is formed; and
(b) a suspension that has a flexure to which the slider is joined, a load beam with one end connected to the flexure, and a base plate connected to the other end of the load beam.

14. A magnetic recording apparatus, comprising:
(a) the HGA of claim 13 ;
(b) a magnetic recording medium positioned opposite to the slider;
(c) a spindle motor that rotates and drives the magnetic recording medium; and
(d) a device that supports the slider, and that positions the slider relative to the magnetic recording medium.

15. A method of forming a perpendicular magnetic recording (PMR) writer wherein at least one of the gaps surrounding a main pole has a flux guiding element therein, comprising:
(a) providing a shield structure comprised of a leading shield and a side shield layer on the leading shield wherein the side shield layer has an opening bounded by two inner sides of the side shield layer and a portion of the leading shield top surface, and the two inner sides are equidistant from a center plane;
(b) depositing a conformal first flux guiding element on the two inner sides and the portion of leading shield top surface, and wherein the conformal first flux guiding element comprises:
(1) a lower first spin preserving layer;
(2) a middle first flux guiding layer (FGL); and
(3) an upper first non-spin preserving layer wherein the conformal first flux guiding element is configured so that a magnetization in the middle first FGL flips to a direction antiparallel to a side gap field (H SG ) and to a leading gap field (H LG ) when a current I b of sufficient magnitude is applied in a direction from each side shield layer and the leading shield towards the main pole;

(c) depositing the main pole (MP) having two sides and a bottom surface (leading side) on the upper first non-spin preserving layer; and
(d) performing a first chemical mechanical polish (CMP) process to form a top surface on the main pole that is coplanar with a top surface of the side shield layer on each side of the center plane.

16. The method of claim 15 further comprising:
(a) providing a tapered top surface on the main pole with a process comprised of an ion beam etch and a photoresist masking layer;
(b) depositing a gap magnetic layer (GML) stack of layers on the tapered MP top surface and on each side shield layer top surface wherein the GML stack comprises:
(1) a lower second non-spin preserving layer;
(2) a middle second flux guiding layer (FGL); and
(3) an upper second spin preserving layer;

(c) patterning the GML stack such that a portion thereof is retained on the MP top surface thereby forming a second flux guiding element having sides at the air bearing surface plane that are separated by a cross-track dimension essentially equal to a track width, and that is configured so that a magnetization in the middle second FGL flips to a direction antiparallel to a write gap field (H WG ) when a current I b of sufficient magnitude is applied in a direction from a trailing shield towards the main pole;
(d) depositing a write gap that adjoins the sides of the second flux guiding element; and
(e) performing a second CMP process such that the write gap has a thickness equal to that of the second flux guiding element.

17. The method of claim 16 wherein each of the conformal first flux guiding element and secon

Assignees

• Headway Tech Inc

Inventors

• Wu Yan
• Tang Yuhui
• Chen Wenyu
• Liu Ying

Classifications

• G11B5/11 Primary

  Shielding of head against electric or magnetic fields · CPC title

• G11B5/1278

  specially adapted for magnetisations perpendicular to the surface of the record carrier · CPC title