High moment side shield design for area density improvement of perpendicular magnetic recording (PMR) writer

• US 9,361,912 B1
• Filed: 04/20/2015
• Issued: 06/07/2016
• Est. Priority Date: 04/20/2015
• Status: Active Grant

• Current Assignee: Headway Technologies Incorporated, TDK Corporation
• Original Assignee: Headway Technologies Incorporated, TDK Corporation
• Inventors: Liu, Yue, Yamaguchi, Atsushi, Tang, Yuhui, Lee, Jiun-Ting, Wei, Yaguang, Liu, Xiaomin, Ukita, Hideyuki, Dovek, Moris, Nishiyama, Michitaka
• Primary Examiner(s): Miller, Brian
• Application Number:
  US14/690,693
• Time in Patent Office: 414 Days
• Field of Search: 360/125.3
• US Class Current: 1/1
• CPC Class Codes: G11B 5/00826 comprising a plurality of single poles or gaps or groups thereof operative at the same time
• CPC Class Codes: G11B 5/11 Shielding of head against electric or magnetic fields
• CPC Class Codes: G11B 5/1278 specially adapted for magnetisations perpendicular to the surface of the record carrier
• CPC Class Codes: G11B 5/187 Structure or manufacture of the surface of the head in physical contact with, or immediately adjacent to the recording medium; Pole pieces; Gap features G11B5/265, G11B5/29 , G11B5/31 take precedence
• CPC Class Codes: G11B 5/1871 Shaping or contouring of the transducing or guiding surface
• CPC Class Codes: G11B 5/23 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 Class Codes: G11B 5/3116 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 Class Codes: G11B 5/315 Shield layers on both sides of the main pole, e.g. in perpendicular magnetic heads
• CPC Class Codes: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
• CPC Class Codes: G11B 5/3912 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 Class Codes: G11B 5/6082 Design of the air bearing surface

Abstract

A PMR writer is disclosed wherein a hot seed layer (HS) made of a 19-24 kilogauss (kG) magnetic material is formed between a side gap and a 10-16 kG magnetic layer in the side shields, and between a 16-19 kG magnetic layer and the leading gap in the leading shield to improve Hy_grad and Hy_grad_x while maintaining write-ability. The HS is from 10 to 100 nm thick and has a first side facing the write pole with a height of ≦0.15 micron, and a second side facing a main pole flared side that may extend to a full side shield height of ≦0.5 micron. First and second sides may form a continuous curve or the a double tapered design where first and second sides have different angles with respect to a center plane. The side shield design described herein is especially beneficial for side gaps of 20-60 nm.

Claims

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 lead gap at an air bearing surface (ABS) and the trailing side adjoins a write gap at 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;

(c) a lead gap that is connected to an end of each side gap and contacts the leading side of the main pole; and

(d) a side shield and leading shield structure comprising;

(1) a hot seed layer made of a 19-24 kilogauss (kG) magnetic material having a side that faces the main pole wherein a first portion thereof adjoins the lead gap and a second portion contacts the side gap on each side of the center plane; and

(2) a first magnetic layer made of a 10-16 kG magnetic material that adjoins the first portion on a side thereof which faces away from the main pole and together with the hot seed layer first portion forms a composite leading shield; and

(3) a second magnetic layer made of a 10-16 kG magnetic material that adjoins each second portion on a side thereof that faces away from the main pole and with the hot seed layer second portion forms a composite side shield.

2. The PMR writer of claim 1 wherein the hot seed layer has a thickness from about 10 to 100 nm.

3. The PMR writer of claim 1 wherein the second portion of the hot seed layer has a full side shield height, or has a height less than that of second magnetic layer in the composite side shield.

4. The PMR writer of claim 1 wherein the main pole leading side and trailing side each have a tapered portion with a front end at the ABS, the leading side tapered portion extends a first height (h1) from the ABS, and the trailing side tapered portion extends to a third height from the ABS such that a back end of each tapered portion is a greater distance than the front end from a second plane that is orthogonal to the center plane and the ABS.

5. The PMR writer of claim 4 wherein the first portion of the hot seed layer adjoins a trailing side of the first magnetic layer, has a side facing the tapered portion of the main pole trailing side, and extends to a first end that is less than or equal to h1 from the ABS, the first magnetic layer that adjoins the hot seed layer first portion extends to a first height from the ABS.

6. The PMR writer of claim 5 wherein the first portion of the hot seed layer further comprises a section with a side aligned parallel to the second plane and with a front end contacting the first end at the first height (h1), and a back end at a second height (h2) from the ABS where h2>

h1.

7. The PMR writer of claim 6 wherein h2 is less than about 1 micron.

8. The PMR writer of claim 1 wherein the second portion of the hot seed layer is double tapered such that a first side thereof facing a write pole portion of the main pole is formed at a first angle α

1 with respect to the center plane, and a second side of the second portion that faces a flared side of the main pole is formed at a second angle α

2 with respect to the center plane where α

2>

α

1.

9. The PMR writer of claim 8 wherein the first side of the hot seed layer second portion extends from the ABS to a height of ≦

0.15 micron, and the second side extends from an end of the first side to a side of the side shield structure that is ≦

0.5 micron from the ABS.

10. The PMR writer of claim 1 further comprised of a write gap that adjoins the trailing side of the main pole and contacts a top surface of the side gap and a top surface of the side shield structure on each side of the center plane, and a composite trailing shield comprising;

(a) a second hot seed layer made of a 19-24 kG magnetic material that contacts a trailing side of the write gap that faces away from the main pole, and has a cross-track width essentially the same as a cross-track width of the write gap; and

(b) a third magnetic layer made of a 16-19 kG magnetic material that adjoins a trailing side and side surfaces of the second hot seed layer, and contacts a portion of a top surface of the second magnetic layer in the composite side shields.