# US 8,465,658 B2 · Method of forming main pole of thermally-assisted magnetic recording head

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- Number: US 8,465,658 B2
- Document ID: US8465658B2
- Status: Granted
- Kind: B2
- Application number: 13/110,442
- Filed: 2011-05-18
- Published: 2012-11-22
- Granted: 2013-06-18
- Earliest claimed: 2011-05-18
- Assignees: Headway Technologies, Inc.
- Applicants: Hironori Araki; Yoshitaka Sasaki; Hiroyuki Ito; Kazuki Sato; Shigeki Tanemura; Yukinori Ikegawa
- Inventors: Hironori Araki; Yoshitaka Sasaki; Hiroyuki Ito; Kazuki Sato; Shigeki Tanemura; Yukinori Ikegawa
- Web page: https://patentgrep.com/patent/US8465658B2

## CPC

- 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}
- 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)}
- G11B 2005/0021: {Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal}
- Y10T 29/4902: Electromagnet, transformer or inductor
- Y10T 29/49021: Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T 29/49032: Fabricating head structure or component thereof
- Y10T 29/49043: Depositing magnetic layer or coating
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

In a method of forming a main pole, an initial accommodation layer is etched by RIE using a first etching mask having a first opening, whereby a groove is formed in the initial accommodation layer. Next, a part of the initial accommodation layer including the groove is etched by RIE using a second etching mask having a second opening, so that the groove becomes an accommodation part. The main pole is then formed in the accommodation part. The first etching mask has first and second sidewalls that face the first opening and are opposed to each other at a first distance in a track width direction. The second etching mask has third and fourth sidewalls that face the second opening and are opposed to each other at a second distance greater than the first distance.

## Claims

### Claim 1

A method of forming a main pole of a thermally-assisted magnetic recording head, the thermally-assisted magnetic recording head comprising:
a medium facing surface that faces a recording medium;
the main pole that produces a write magnetic field for writing data on the recording medium;
an accommodation layer including an accommodation part that accommodates the main pole;
a waveguide having a core and a clad, the core allowing light to propagate therethrough;
a plasmon generator having a near-field light generating part located in the medium facing surface, the plasmon generator being configured so that a plasmon is excited based on the light propagating through the core, and the near-field light generating part generates near-field light based on the plasmon; and
a substrate having a top surface, wherein:
the main pole, the accommodation layer, the waveguide, and the plasmon generator are disposed above the top surface of the substrate;
the core has an end face that faces toward the medium facing surface and that is located away from the medium facing surface, the core being located farther from the top surface of the substrate than is the plasmon generator;
the main pole has a front end face located in the medium facing surface and a rear end face opposite to the front end face, the main pole being interposed between the end face of the core and the medium facing surface;
the accommodation layer has a wall face that faces the accommodation part and that defines the shape of the rear end face of the main pole; and
the front end face of the main pole has a first end closer to the top surface of the substrate and a second end farther from the top surface of the substrate, the first end being smaller than the second end in width in a track width direction,
the method of forming the main pole comprising:
a step of forming an initial accommodation layer having a top surface;
a step of forming a first etching mask on the top surface of the initial accommodation layer, the first etching mask having a first opening;
a first etching step of etching the initial accommodation layer by reactive ion etching using the first etching mask to thereby form a groove in the initial accommodation layer;
a step of forming a second etching mask on the top surface of the initial accommodating layer after the first etching step, the second etching mask having a second opening;
a second etching step of etching a part of the initial accommodation layer including the groove by reactive ion etching using the second etching mask so that the initial accommodation layer becomes the accommodation layer and the groove becomes the accommodation part; and
a step of forming the main pole in the accommodation part, wherein:
the first etching mask has first and second sidewalls that face the first opening, the first and second sidewalls being opposed to each other and being at a first distance from each other in the track width direction;
the second etching mask has third and fourth sidewalls that face the second opening, the third and fourth sidewalls being opposed to each other and being at a second distance from each other in the track width direction, the second distance being greater than the first distance; and
in any cross section of the accommodation part parallel to the medium facing surface, an end closest to the top surface of the substrate is smaller in width in the track width direction than an end farthest from the top surface of the substrate.

### Claim 2 (depends on 1)

The method of forming the main pole of the thermally-assisted magnetic recording head according to claim 1, further comprising a step of forming a third etching mask on the top surface of the initial accommodation layer before the step of forming the first etching mask, the third etching mask being intended for defining a position of the wall face of the accommodation layer, wherein:
the first etching step etches the initial accommodation layer using the first etching mask and the third etching mask; and
the second etching step etches the initial accommodation layer using the second etching mask and the third etching mask.

### Claim 3 (depends on 1)

The method of forming the main pole of the thermally-assisted magnetic recording head according to claim 1, wherein the wall face of the accommodation layer forms an angle of 10° or less with respect to a direction perpendicular to the top surface of the substrate.

### Claim 4 (depends on 1)

The method of forming the main pole of the thermally-assisted magnetic recording head according to claim 1, wherein the accommodation layer also serves as the core.

### Claim 5 (depends on 1)

The method of forming the main pole of the thermally-assisted magnetic recording head according to claim 1, wherein the accommodation layer also serves as the clad.

### Claim 6

A method of manufacturing a thermally-assisted magnetic recording head, the thermally-assisted magnetic recording head comprising:
a medium facing surface that faces a recording medium;
a main pole that produces a write magnetic field for writing data on the recording medium;
an accommodation layer including an accommodation part that accommodates the main pole;
a waveguide having a core and a clad, the core allowing light to propagate therethrough;
a plasmon generator having a near-field light generating part located in the medium facing surface, the plasmon generator being configured so that a plasmon is excited based on the light propagating through the core, and the near-field light generating part generates near-field light based on the plasmon; and
a substrate having a top surface, wherein:
the main pole, the accommodation layer, the waveguide, and the plasmon generator are disposed above the top surface of the substrate;
the core has an end face that faces toward the medium facing surface and that is located away from the medium facing surface, the core being located farther from the top surface of the substrate than is the plasmon generator;
the main pole has a front end face located in the medium facing surface and a rear end face opposite to the front end face, the main pole being interposed between the end face of the core and the medium facing surface;
the accommodation layer has a wall face that faces the accommodation part and that defines the shape of the rear end face of the main pole; and
the front end face of the main pole has a first end closer to the top surface of the substrate and a second end farther from the top surface of the substrate, the first end being smaller than the second end in width in a track width direction,
the method of manufacturing the thermally-assisted magnetic recording head comprising the steps of:
forming the plasmon generator;
forming the waveguide after the plasmon generator is formed; and
forming the accommodation layer and the main pole after the plasmon generator is formed,
wherein the step of forming the accommodation layer and the main pole includes:
a step of forming an initial accommodation layer having a top surface;
a step of forming a first etching mask on the top surface of the initial accommodation layer, the first etching mask having a first opening;
a first etching step of etching the initial accommodation layer by reactive ion etching using the first etching mask to thereby form a groove in the initial accommodation layer;
a step of forming a second etching mask on the top surface of the initial accommodating layer after the first etching step, the second etching mask having a second opening;
a second etching step of etching a part of the initial accommodation layer including the groove by reactive ion etching using the second etching mask so that the initial accommodation layer becomes the accommodation layer and the groove becomes the accommodation part; and
a step of forming the main pole in the accommodation part, wherein:
the first etching mask has first and second sidewalls that face the first opening, the first and second sidewalls being opposed to each other and being at a first distance from each other in the track width direction;
the second etching mask has third and fourth sidewalls that face the second opening, the third and fourth sidewalls being opposed to each other and being at a second distance from each other in the track width direction, the second distance being greater than the first distance; and
in any cross section of the accommodation part parallel to the medium facing surface, an end closest to the top surface of the substrate is smaller in width in the track width direction than an end farthest from the top surface of the substrate.

### Claim 7 (depends on 6)

The method of manufacturing the thermally-assisted magnetic recording head according to claim 6, wherein:
the step of forming the accommodation layer and the main pole further includes a step of forming a third etching mask on the top surface of the initial accommodation layer before the step of forming the first etching mask, the third etching mask being intended for defining a position of the wall face of the accommodation layer;
the first etching step etches the initial accommodation layer using the first etching mask and the third etching mask; and
the second etching step etches the initial accommodation layer using the second etching mask and the third etching mask.

### Claim 8 (depends on 6)

The method of manufacturing the thermally-assisted magnetic recording head according to claim 6, wherein the wall face of the accommodation layer forms an angle of 10° or less with respect to a direction perpendicular to the top surface of the substrate.

### Claim 9 (depends on 6)

The method of manufacturing the thermally-assisted magnetic recording head according to claim 6, wherein the accommodation layer also serves as the core.

### Claim 10 (depends on 6)

The method of manufacturing the thermally-assisted magnetic recording head according to claim 6, wherein the accommodation layer also serves as the clad.