Perpendicular magnetic recording (PMR) writer with minimized internal flux shunting

Patent metadata

Field	Value
Publication number	US-9299367-B1
Application number	US-201514813887-A
Country	US
Kind code	B1
Filing date	Jul 30, 2015
Priority date	Jul 30, 2015
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A perpendicular magnetic recording (PMR) writer is disclosed wherein a 19-24 kG hot seed layer is formed between a gap layer and a 10-19 kG magnetic layer in a partially wrapped around shield structure involving side shields and trailing shield to reduce internal flux shunting, improve writability, and enable side gap and write gap dimensions 5-10 nm smaller than typical writers for conventional and shingled magnetic recording. Side shields have a bottom surface formed along a plane that is parallel to the main pole leading edge, and at a down-track distance from 50 nm above to 100 nm below the leading edge. Cross-track and down-track field gradients are improved by fully coupling the trailing shield and side shield hot seed layers. Also, side shield hot seed layers have a height <0.15 micron and less than the 10-19 kG side shield layer height to reduce internal flux shunting.

First claim

We claim:

1. A perpendicular magnetic recording (PMR) writer, comprising:
(a) a main pole with a leading edge at an air bearing surface (ABS) and formed at a first plane, and a trailing edge at the ABS and formed at a second plane where the first and second planes are parallel to each other and are orthogonal to the ABS and to a center plane formed equidistant between two main pole sides that connect the leading edge and trailing edge;
(b) a gap layer surrounding the main pole at the ABS and comprising a write gap that contacts the trailing edge and has a first cross-track width, and a side gap layer adjoining the main pole sides and leading edge;
(c) a composite side shield, comprising;
(1) a 19-24 kG magnetic (first hot seed) layer on each side of the center plane with an inner sidewall adjoining a portion of the side gap layer above a third plane that is formed between and parallel to the first and second planes, the third plane is a first down-track distance from the first plane, and the first hot seed layer has outer sidewall adjoining a first 10-19 kG magnetic layer; and
(2) the first 10-19 kG magnetic layer wherein each of the first 10-19 kG magnetic layer and first hot seed layer have a top surface at the second plane and a bottom surface at the third plane; and

(d) a composite trailing shield, comprising:
(1) a second 19-24 kG hot seed layer adjoining a top surface and sides of the write gap, the second hot seed layer has an outer sidewall formed coplanar with an outer sidewall of the first hot seed layer on each side of the center plane and a bottom surface that contacts and essentially covers the top surface of the first hot seed layer at the second plane; and
(2) a second 10-19 kG magnetic layer that adjoins a top surface and outer sidewalls of the second hot seed layer, and contacts the first 10-19 kG magnetic layer at the second plane.

2. The PMR writer of claim 1 wherein each of the first and second hot seed layers has a cross-track width of about 10 to 150 nm at the second plane.

3. The PMR writer of claim 1 wherein the outer sidewalls of the first and second hot seed layers form an angle of 90±15 degrees with respect to the third plane.

4. The PMR writer of claim 1 wherein the first down-track distance is from 0 to about 50 nm.

5. The PMR writer of claim 1 wherein the first hot seed layer has a front side at the ABS and a back side that is a first height (h 1 ) from the ABS in a direction parallel to the center plane, and the first 10-19 kG magnetic layer has a front side at the ABS and a back side at a second height (h 2 ) from the ABS where h 2 >h 1 .

6. The PMR writer of claim 5 wherein h 1 is from 10 to 150 nm.

7. The PMR writer of claim 5 wherein the inner sidewall of the first hot seed layer is a second cross-track width from a nearest main pole side and is formed substantially parallel thereto, and the outer sidewall of the first hot seed layer is greater than the second cross-track width from the nearest main pole side.

8. The PMR writer of claim 1 wherein the main pole has a tapered trailing side including the trailing edge at the ABS and the second hot seed layer has a first portion at the ABS and with a side facing the main pole tapered trailing side and separated therefrom by a second down-track thickness, and the second hot seed layer has a second portion adjoining a back side of the first portion at a third height from the ABS wherein the second portion has a side facing the main pole tapered trailing side that is greater than the second down-track thickness from the main pole tapered trailing side.

9. The PMR writer of claim 1 wherein the inner sidewall of each first hot seed layer is formed at an angle of 0 to 30 degrees with respect to the center plane.

10. The PMR writer of claim 1 wherein the write gap has a first cross-track width of 50 to 150 nm, and a thickness from 10 to 20 nm at the ABS.

11. A perpendicular magnetic recording (PMR) writer, comprising:
(a) a main pole with a leading edge at an air bearing surface (ABS) and formed at a first plane, and a trailing edge at the ABS and formed along a second plane where the first and second planes are parallel to each other and are orthogonal to the ABS and a center plane formed equidistant between two main pole sides;
(b) a gap layer surrounding the main pole at the ABS and comprising a write gap that contacts the trailing edge and has a first cross-track width greater than a track width of the trailing edge, and a side gap layer adjoining the main pole sides and leading edge, the side gap layer has a first down-track thickness below the leading edge;
(c) a composite side shield at the ABS and comprising;
(1) a 19-24 kG magnetic (first hot seed) layer on each side of the center plane with an inner sidewall adjoining the side gap layer above a third plane that is formed parallel to the first plane, and less than or equal to the first down-track distance below the first plane, and the first hot seed layer has an outer sidewall adjoining a first 10-19 kG magnetic layer; and
(2) the first 10-19 kG magnetic layer wherein each of the first 10-19 kG magnetic layer and first hot seed layer have a top surface at the second plane and a bottom surface at the third plane; and

(d) a composite trailing shield at the ABS and comprising:
(1) a second hot seed layer made of a 19-24 kG material formed on a top surface and sides of the write gap, the second hot seed layer has an outer sidewall formed coplanar with an outer sidewall of the first hot seed layer on each side of the center plane, and a bottom surface that contacts and essentially covers the top surface of the first hot seed layer at the second plane; and
(2) a second magnetic layer made of a 10-19 kG material that adjoins a top surface and outer sidewalls of the second hot seed layer, and contacts the first 10-19 kG magnetic layer at the second plane.

12. The PMR writer of claim 11 wherein each of the first and second hot seed layers have a cross-track width of about 10 to 150 nm at the second plane.

13. The PMR writer of claim 11 wherein the outer sidewalls of the first and second hot seed layers form an angle of 90±15 degrees with respect to the third plane.

14. The PMR writer of claim 11 wherein the first down-track distance is greater than 0 nm, and is less than or equal to 100 nm.

15. The PMR writer of claim 11 wherein the first hot seed layer has a front side at the ABS and a back side at a first height (h 1 ) from the ABS in a direction parallel to the center plane, and the first 10-19 kG magnetic layer has a front side at the ABS and a back side at a second height (h 2 ) from the ABS where h 2 >h 1 .

16. The PMR writer of claim 15 wherein h 1 is from 10 to 150 nm.

17. The PMR writer of claim 15 wherein the inner sidewall of the first hot seed layer is a second cross-track width from a nearest main pole side and is formed substantially parallel thereto, and the outer sidewall of the first hot seed layer is greater than the second cross-track width from the nearest main pole side.

18. The PMR writer of claim 11 wherein the main pole has a tapered trailing side including the trailing edge at the ABS, and the second hot seed layer has a first portion at the ABS and with a side facing the main pole tapered trailing side and separated therefrom by a second down-track thickness, and the second hot seed layer has a second portion adjoining a back side of the first portion at a third height from the ABS wherein the second portion has a side facing the main pole tapered trailing side that is greater tha

Assignees

• Headway Technologies Inc

Inventors

• Tang Yuhui
• Wei Yaguang
• Liu Yue
• Lee Jiun-Ting
• Dovek Moris

Classifications

• G11B5/1278 Primary

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

• G11B5/127 Primary

  Structure or manufacture of heads, e.g. inductive · CPC title

• G11B5/23

  Gap features {(G11B5/1871, G11B5/1875, G11B5/265, G11B5/29, G11B5/488 and subgroups, G11B5/4907 and subgroups, G11B5/4969 and subgroups take precedence)} · CPC title

• G11B5/315

  Shield layers on both sides of the main pole, e.g. in perpendicular magnetic heads · CPC title

• G11B5/3116

  Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks (G11B5/3113, G11B5/245 take precedence) · CPC title