# US 6,718,623 B2 · Magnetoresistive device and method of manufacturing same, and thin-film magnetic head and method of manufacturing same

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- Number: US 6,718,623 B2
- Document ID: US6718623B2
- Status: Granted
- Kind: B2
- Application number: 10/146,924
- Filed: 2002-05-17
- Published: 2003-11-20
- Granted: 2004-04-13
- Earliest claimed: 2002-05-17
- Assignees: Headway Technologies, Inc.; SAE Magnetics (H.K.) Ltd.
- Inventors: Yoshitaka Sasaki; Takehiro Kamigama
- Web page: https://patentgrep.com/patent/US6718623B2

## CPC

- G11B 5/3903: {using magnetic thin film layers or their effects, the films being part of integrated structures}
- B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
- B82Y 25/00: Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
- H10N 50/01: Manufacture or treatment
- H10N 50/10: Magnetoresistive devices
- 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 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 2005/3996: {large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices}
- Y10T 29/49044: Plural magnetic deposition layers
- Y10T 29/49052: by etching
- 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)
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A reproducing head of a thin-film magnetic head incorporates an MR element, a pair of bias field applying layers located to be adjacent to the side portions of the MR element, and a pair of electrode layers that are located on the bias field applying layers and overlap the MR element. The electrode layers each have a first layer that is laid over part of the top surface of the MR element via a protection layer, and a second layer that overlaps the first layer. In the method of manufacturing the reproducing head, after forming the protection layer on an element-to-be film to make the MR element, a first electrode-to-be film to make the first layers is formed continuously without interposing a step of exposing the protection layer to the air.

## Claims

### Claim 1

A method of manufacturing a magnetoresistive device comprising:
a magnetoresistive element having two surfaces that face toward opposite directions and two side portions;
a pair of bias field applying layers that are adjacent to the side portions of the magnetoresistive element and apply a bias magnetic field to the magnetoresistive element;
a pair of electrode layers that feed a current used for signal detection to the magnetoresistive element, each of the electrode layers being adjacent to one of surfaces of each of the bias field applying layers and overlapping one of the surfaces of the magnetoresistive element; and
a protection layer for protecting the magnetoresistive element, the protection layer being located between the one of the surfaces of the magnetoresistive element and the electrode layers,
wherein each of the electrode layers includes: a first layer laid over part of the one of the surfaces of the magnetoresistive element via the protection layer; and a second layer electrically connected to the first layer, the method comprising the steps of:
forming an element-to-be film that is to be the magnetoresistive element;
forming the protection layer on the element-to-be film;
forming a first electrode-to-be film that is to be the first layers of the electrode layers on the protection layer;
forming the bias field applying layers; and
forming the second layers of the electrode layers after the step of forming the bias field applying layers, wherein:
in the step of forming the first electrode-to-be film, the first electrode-to-be film is formed continuously after the step of forming the protection layer, without interposing a step of exposing the protection layer to the air.

### Claim 2 (depends on 1)

A method of manufacturing a magnetoresistive device according to claim 1, further comprising, after the step of forming the first electrode-to-be film, the steps of:
forming a mask on the first electrode-to-be film, for patterning the first electrode-to-be film, the protection layer, and the element-to-be film by etching; and
patterning the first electrode-to-be film, the protection layer, and the element-to-be film by etching using the mask.

### Claim 3 (depends on 2)

A method of manufacturing a magnetoresistive device according to claim 2, wherein the bias field applying layers are formed with the mask left unremoved in the step of forming the bias field applying layers.

### Claim 4 (depends on 3)

A method of manufacturing a magnetoresistive device according to claim 3, wherein the second layers are formed with the mask left unremoved in the step of forming the second layers.

### Claim 5 (depends on 1)

A method of manufacturing a magnetoresistive device according to claim 1, wherein the second layers are formed to overlap the first layers.

### Claim 6 (depends on 5)

A method of manufacturing a magnetoresistive device according to claim 5, further comprising the step of patterning the first electrode-to-be film by etching using the second layers as masks, in order to make the first layers.

### Claim 7 (depends on 5)

A method of manufacturing a magnetoresistive device according to claim 5, further comprising the step of forming a coating layer to cover the second layers, and the step of patterning the first electrode-to-be film by etching using the coating layer as a mask, in order to make the first layers.

### Claim 8 (depends on 1)

A method of manufacturing a magnetoresistive device according to claim 1, further comprising the step of selectively removing portions of the bias field applying layers located on the first electrode-to-be film, between the step of forming the bias field applying layers and the step of forming the second layers.

### Claim 9

A method of manufacturing a thin-film magnetic head comprising:
a medium facing surface that faces toward a recording medium;
a magnetoresistive element located near the medium-facing surface and having two surfaces that face toward opposite directions and two side portions;
a pair of bias field applying layers that are adjacent to the side portions of the magnetoresistive element and apply a bias magnetic field to the magnetoresistive element;
a pair of electrode layers that feed a current used for signal detection to the magnetoresistive element, each of the electrode layers being adjacent to one of surfaces of each of the bias field applying layers and overlapping one of the surfaces of the magnetoresistive element; and
a protection layer for protecting the magnetoresistive element, the protection layer being located between the one of the surfaces of the magnetoresistive element and the electrode layers,
wherein each of the electrode layers includes: a first layer laid over part of the one of the surfaces of the magnetoresistive element via the protection layer; and a second layer electrically connected to the first layer, the method comprising the steps of:
forming an element-to-be film that is to be the magnetoresistive element;
forming the protection layer on the element-to-be film;
forming a first electrode-to-be film that is to be the first layers of the electrode layers on the protection layer;
forming the bias field applying layers; and
forming the second layers of the electrode layers after the step of forming the bias field applying layers, wherein:
in the step of forming the first electrode-to-be film, the first electrode-to-be film is formed continuously after the step of forming the protection layer, without interposing a step of exposing the protection layer to the air.

### Claim 10 (depends on 9)

A method of manufacturing a thin-film magnetic head according to claim 9, further comprising, after the step of forming the first electrode-to-be film, the steps of:
forming a mask on the first electrode-to-be film, for patterning the first electrode-to-be film, the protection layer, and the element-to-be film by etching; and
patterning the first electrode-to-be film, the protection layer, and the element-to-be film by etching using the mask.

### Claim 11 (depends on 10)

A method of manufacturing a thin-film magnetic head according to claim 10, wherein the bias field applying layers are formed with the mask left unremoved in the step of forming the bias field applying layers.

### Claim 12 (depends on 11)

A method of manufacturing a thin-film magnetic head according to claim 11, wherein the second layers are formed with the mask left unremoved in the step of forming the second layers.

### Claim 13 (depends on 9)

A method of manufacturing a thin-film magnetic head according to claim 9, wherein the second layers are formed to overlap the first layers.

### Claim 14 (depends on 13)

A method of manufacturing a thin-film magnetic head according to claim 13, further comprising the step of patterning the first electrode-to-be film by etching using the second layers as masks, in order to make the first layers.

### Claim 15 (depends on 13)

A method of manufacturing a thin-film magnetic head according to claim 13, further comprising the step of forming a coating layer to cover the second layers, and the step of patterning the first electrode-to-be film by etching using the coating layer as a mask, in order to make the first layers.

### Claim 16 (depends on 9)

A method of manufacturing a thin-film magnetic head according to claim 9, further comprising the step of selectively removing portions of the bias field applying layers located on the first electrode-to-be film, between the step of forming the bias field applying layers and the step of forming the second layers.