WO2009116167A1 - Magnetic head, magnetic storage device, and magnetic head manufacturing method - Google Patents

Abstract

[PROBLEMS] Provided is a magnetic head manufacturing method for suppressing the excessive protrusion of an element against the rise in an environment temperature in the operation of a magnetic disc device and controlling the levitation amount irrespective of the environment temperature. [MEANS FOR SOLVING PROBLEMS] A magnetic head comprises a substrate, a first magnetic layer provided on the substrate, a first insulating layer which is provided on the first magnetic layer and which has a magnetic and electric insulating property, a coil layer which is provided on the first insulating layer and which can generate a magnetic field, a second insulating layer which is provided in such a manner that the coil layer is covered and which has the magnetic and electric insulating property, a low thermal expansion layer which is provided on the second insulating layer and the thermal expansion rate of which is lower than that of the second insulating layer, and a second magnetic layer which covers the low thermal expansion layer in such a manner that the layer is magnetically connected with the first magnetic layer.

Description

Magnetic head, magnetic storage device, and method of manufacturing magnetic head

The present invention relates to a magnetic head capable of changing the protruding amount of an element portion due to thermal expansion accompanying heating, a magnetic storage device including the magnetic head, and a method of manufacturing the same, and more particularly to an element in a high temperature environment. The present invention relates to a magnetic head capable of suppressing excessive protrusion, a magnetic storage device including the magnetic head, and a manufacturing method thereof.

In order to realize a high recording density of a magnetic disk device, the distance between the recording surface of the magnetic disk and the element portion of the magnetic head, that is, the so-called flying height of the magnetic head tends to be small. In recent years, a flying height of the order of 10 nm has been realized.

When the flying height of the magnetic head decreases, there is a problem that the magnetic head easily collides with minute protrusions on the surface of the magnetic disk, causing damage to the magnetic disk and the magnetic head. Further, since there is a dimensional tolerance in the size of the magnetic head, there is a problem that the flying height cannot be set low beyond the tolerance range in consideration of contact with the medium.

As a method to solve this problem, a magnetic head is equipped with a built-in heater, and the flying height is adjusted by utilizing the phenomenon that the surface (floating surface) facing the recording medium protrudes due to the thermal expansion of the magnetic head when the heater is energized. Controls have been proposed (for example, Patent Documents 1 to 3). However, the protruding amount of the element portion tends to become excessive due to an increase in temperature of the element and its peripheral portion (so-called environmental temperature) during operation of the magnetic disk device. For this reason, it is difficult to control the flying height regardless of temperature conditions.
JP 2003-303405 A JP 2004-192665 A Japanese Patent Laying-Open No. 2005-078706

(Problems to be solved by the invention)
The present invention provides a method for manufacturing a magnetic head capable of suppressing excessive protrusion of elements against an increase in environmental temperature during operation of a magnetic disk device and controlling the flying height regardless of the environmental temperature.
(Means for solving the problem)
According to one aspect of the invention,
Forming a first magnetic layer on a substrate;
Forming a first insulating layer having magnetic and electrical insulation on the first magnetic layer;
Forming a coil layer capable of generating a magnetic field on the first insulating layer;
Forming a second insulating layer having magnetic and electrical insulation so as to cover the coil layer;
Planarizing the second insulating layer;
Forming a low thermal expansion layer having a lower coefficient of thermal expansion than the second insulating layer on the second insulating layer;
Forming a mask layer on the low thermal expansion layer;
Patterning the mask layer by physical etching;
Removing the portion of the low thermal expansion layer where the mask layer is not formed;
And a step of providing a second magnetic layer magnetically connected to the first magnetic layer so as to cover the low thermal expansion layer.

(The invention's effect)
According to the magnetic head manufacturing method of the present invention, when a magnetic disk device incorporating the obtained magnetic head is used, the flying height can be controlled regardless of the environmental temperature.

1 is a plan view showing a schematic configuration of a magnetic disk device including a magnetic head of the present invention. 1 is a cross-sectional view in a direction perpendicular to a surface (floating surface) facing a storage medium, showing a schematic configuration of a magnetic head that is a first embodiment of a magnetic head of the present invention; It is a cross-sectional schematic diagram which shows another embodiment of the magnetic head of this invention. It is a cross-sectional schematic diagram which shows another embodiment of the magnetic head of this invention. It is a cross-sectional schematic diagram which shows another embodiment of the magnetic head of this invention. FIG. 5 is a schematic cross-sectional view for explaining the manufacturing process of the magnetic head according to the embodiment of FIG. 2. FIG. 5 is a schematic cross-sectional view for explaining the manufacturing process of the magnetic head according to the embodiment of FIG. 2. FIG. 5 is a schematic cross-sectional view for explaining the manufacturing process of the magnetic head according to the embodiment of FIG. 2. FIG. 8 is a conceptual schematic diagram for explaining the cross-sectional shape of the magnetic head before and after ion milling.

Explanation of symbols

3 Lower shield layer 4 Gap film 5 Magnetoresistive element 6 Upper shield layer 7 Substrate 8, 8a, 8b, 8c, 8d Coil 9 Insulating layer 10A, 10B Connection layer 11 Main magnetic pole layer 12 Insulating layer 13, 13a, 13b, 13c , 13d, 13e Resin layer 14 Trailing shield layer 15 Return yoke layer 16 Air bearing surface 17 Insulating layer 18 Low thermal expansion layer 19 Mask layer 21 Resist layer 23 Residue 30 Heater 100 Hard disk drive (HDD)
101 housing 102 spindle motor 103 storage medium (magnetic disk)
104 Head Gimbal Assembly 105 Shaft 106 Carriage Arm 107 Actuator 108 Magnetic Head 109 Disk Rotation Direction 111 Recording Head Unit 112 Playback Head Unit 207 Substrate 208a, 208b, 208c, 208d Coil 209 Insulating Layer 210A, 210B Connection Layer 211 Main Pole Layer 212 Insulating layer 213 Resist layer 214 Trailing shield layer 215 Return yoke layer 218 Low thermal expansion layer 219 Mask layer 221 Resist layer 222 Residue

Hereinafter, the configuration of a preferred embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a schematic configuration of a magnetic disk device (hard disk drive: HDD), which is an example of a magnetic storage device including a magnetic head according to the present embodiment. Hereinafter, the same components as those described above are denoted by the same reference numerals.

In FIG. 1, the HDD 100 has a housing 101. In the housing 101, a storage medium (magnetic disk) 103 mounted on the spindle motor 102 and a head gimbal assembly 104 mounted with a magnetic head 108 facing the storage medium 103 are arranged. The magnetic head 108 floats on the storage medium by an element portion (not shown) capable of applying a magnetic field for recording information on the storage medium 103 and an air flow generated by the rotation of the storage medium. And a slider (not shown) having a function. The element portion and the slider are arranged to face the storage medium 103. The head gimbal assembly 104 on which the magnetic head 108 is mounted is fixed to the tip of the carriage arm 106 that can swing around the shaft 105. The storage medium 103 includes a magnetic film (not shown). By applying a magnetic field generated from the element portion to the storage medium 103, information can be magnetically recorded on the storage medium 103. If the magnetic head 108 further includes an element capable of reading the magnetic information recorded on the storage medium 103, the information on the storage medium 103 can be reproduced.

During operation of the HDD 100, the storage medium 103 rotates in the direction of the arrow 109, the carriage arm 106 is driven to swing by the actuator 107, and the magnetic head 108 is positioned on a desired recording track of the storage medium 103. With these operations, the magnetic head 108 can write information to the storage medium 103 or read information from the storage medium 103.
-Magnetic head-
FIG. 2 shows a schematic configuration of the magnetic head according to the first embodiment of the magnetic head of the present invention, which is perpendicular to the surface facing the storage medium (floating surface 16) and perpendicular to the diameter direction of the recording medium. A sectional view of the surface is shown. Here, an outline of a magnetic head 108 having a recording head portion 111 composed of a single magnetic pole type perpendicular magnetic head and a reproducing head portion 112 for reproducing information recorded at an arbitrary position of a recording layer on the storage medium 103. A typical structure is shown.

In the following description, the X-axis direction is the diameter direction of the recording medium, the Y-axis direction is the direction away from the recording medium, and the Z-axis is the stacking direction of each layer stacked on the substrate (hereinafter referred to as “substrate”). And the moving direction of the medium relative to the magnetic head. The X axis, the Y axis, and the Z axis are perpendicular to each other. Further, the distance in the X-axis direction is expressed as “width”, the distance in the Y-axis direction as “length”, and the distance in the Z-axis direction as “thickness”. In the magnetic head, the side closer to the air bearing surface (air bearing surface: ABS) in the Y-axis direction is referred to as the “air bearing surface side”, and the side away from the air bearing surface is referred to as the “height side”. These notation contents are the same also in FIG.

The magnetic head 108 according to the present embodiment is mounted as a magnetic recording device in a magnetic recording apparatus such as a hard disk drive. The magnetic head 108 is, for example, a composite head capable of performing both recording and reproduction functions, and is formed on a substrate (not shown) made of a ceramic material such as AlTiC (Al ₂ O ₃ TiC). For example, an insulating layer (not shown) made of aluminum oxide (Al ₂ O ₃ ; hereinafter simply referred to as “alumina”) and a magnetoresistive effect (MR) on the recording medium A reproducing head portion 112 capable of reproducing arbitrary information on the recording surface, a recording head portion 111 capable of recording information at an arbitrary position on the recording surface on the recording medium by a perpendicular recording method, and an overcoat layer made of, for example, alumina (Not shown) are stacked in this order. The magnetic head of the present invention may have a configuration in which, for example, an insulating layer, a recording head portion, and an overcoat layer are laminated in this order on a substrate.

The reproducing head portion 112 has, for example, a configuration in which the lower shield layer 3, the gap film 4, and the upper shield layer 6 are laminated in this order. In the gap film 4, a magnetoresistive effect element (Magnetorescence effect element, hereinafter abbreviated as MR element) 5 is embedded so that one end face is exposed on the air bearing surface 16.

The lower shield layer 3 and the upper shield layer 6 mainly shield the MR element 5 from the surroundings. The lower shield layer 3 and the upper shield layer 6 are made of, for example, a magnetic material such as a nickel iron alloy (NiFe (hereinafter simply referred to as “permalloy (trade name)”); Ni: 80 wt%, Fe: 20 wt%). Their thickness is about 1.0 μm to 2.0 μm.

The gap film 4 magnetically and electrically separates the MR element 5 from the lower shield layer 3 and the upper shield layer 6. The gap film 4 is made of, for example, a nonmagnetic nonconductive material such as alumina and has a thickness of about 0.1 μm to 0.2 μm.

As the MR element 5, for example, an element using a magnetosensitive film exhibiting a magnetoresistive effect such as a giant magnetoresistive effect (GMR; Giant Magneto-resistive) or a tunnel magnetoresistive effect (TMR; Tunneling Magneto-resistive) can be used. .

Furthermore, an insulating layer 9 is formed on the upper shield layer 6 of the reproducing head portion 112. The insulating layer 9 is made of a nonmagnetic nonconductive material such as alumina. A heater 30 is embedded in the insulating layer 9. The heater 30 heats the reproducing head unit 112 and the recording head unit 111 to expand them and project them to the air bearing surface side. As the heater 30, for example, a resistance heater can be used. The resistance heater is made of, for example, titanium tungsten (TiW), tungsten (W), or nickel copper (NiCu). By controlling the electric power supplied to the resistance heater, the resistance heater generates heat. Depending on the heat, the protruding amount of the reproducing head portion 112 (especially the MR element 5) and the recording head portion 111 (especially the main magnetic pole layer 11 described later) can be controlled. In the magnetic disk device, by controlling the protrusion amount, the flying height can be controlled to be suitable for reproduction and recording.

The recording head unit 111 includes, for example, the main magnetic pole layer 11, the trailing shield layer 14, the connection layers 10A and 10B, the coils 8a to 8d (hereinafter may be collectively referred to as the coil 8), and the resin layers 13a to 13e (hereinafter referred to as the “coil 8”). , A resist yoke 13, and a return yoke layer 15, insulating layers 12 and 17, a low thermal expansion layer 18, and a mask layer 19.

The main magnetic pole layer 11, the connection layer 10B, the return yoke layer 15, the connection layer 10A, and the trailing shield layer 14 are each made of a magnetic material and are magnetically connected. The coil 8 and a portion made of a magnetic material are shielded magnetically and electrically by the insulating layers 12 and 17 and the resin layer 13. The low thermal expansion layer 18 and the mask layer 19 are located between the insulating layer 17 and the return yoke layer 15. The coil 8, the resist 13, and the connection layer 10A are polished on the surface far from the substrate, and are located on substantially the same plane.

The coil layers 8a to 8d mainly generate a magnetic flux for recording. The coil layers 8a to 8d are made of, for example, a conductive material such as copper (Cu). The thickness of the coil layer is, for example, about 1 to 3 μm. A coil located on the height side of the connection layer 10B is not shown.

The main magnetic pole layer 11 mainly contains magnetic flux generated in the coil layers 8A and 8B and emits the magnetic flux toward a magnetic disk (not shown). The main magnetic pole layer 11 is normally exposed on the air bearing surface 16 side. The main magnetic pole layer 11 includes, for example, an iron cobalt alloy (FeCo), an iron-based alloy (Fe-M; M is a metal element of 4A, 5A, 6A, 3B, and 4B), or nitrides of these alloys. The thickness is about 0.1 μm to 0.5 μm. Here, the main magnetic pole layer 11 corresponds to a specific example of “first magnetic layer” in the invention.

The trailing shield layer 14 mainly reduces the magnetic field gradient of the write magnetic field of the main magnetic pole layer when the magnetic flux emitted from the main magnetic pole layer 11 is circulated to the return yoke 9 via a hard disk (not shown). Responsible for steep functions. The trailing shield layer 14 also has a function of magnetically shielding the main magnetic pole layer 11 from the surroundings. The trailing shield layer 14 is normally exposed on the air bearing surface 16 side. The trailing shield layer 14 is made of a magnetic material such as permalloy (Ni: 80 wt%, Fe: 20 wt%), and has a thickness of about 1.0 μm to 2.0 μm. Here, the trailing shield layer 14 corresponds to a specific example of a “third magnetic layer” in the present invention.

The return yoke layer 15 has a function of circulating the magnetic flux emitted from the main magnetic pole layer 11 through the hard disk (not shown) in the recording head unit 111. The return yoke layer 15 is made of, for example, a magnetic material such as permalloy (Ni: 80 wt%, Fe: 20 wt%), and has a thickness of about 1.0 μm to 4.0 μm. The return yoke layer 15 corresponds to a specific example of “second magnetic layer” in the invention.

The resin layers 13a to 13e are made of, for example, a photoresist (photosensitive resin) that exhibits fluidity when heated. In the resin layers 13a to 13e, ceramics such as alumina may be disposed instead of the resin layers 13a to 13e. Here, the resin layers 13a to 13e correspond to a specific example of the “second insulating layer” in the present invention. The thickness of the resin layer 13 is, for example, about 1 to 3 μm.

The insulating layers 12 and 17 are made of a nonmagnetic nonconductive material such as alumina or silicon oxide (SiO ₂ ), and have a thickness of about 0.1 μm to 1.0 μm. Here, the insulating layers 12 and 17 correspond to specific examples of “first insulating layer” and “second insulating layer” in the present invention, respectively.

The connection layer 10A is for magnetically connecting the return yoke layer 15 and the trailing shield 14, and is usually located on the air bearing surface side of the coil layer 8. The connection layer 10 </ b> B is for magnetically coupling the return yoke layer 15 and the main magnetic pole layer 11, and is usually located on the height side of the coil layer 8. The connection layers 10A and 10B are made of a magnetic material such as permalloy (Ni: 80% by weight, Fe: 20% by weight).

The low thermal expansion layer 18 is larger than the magnetic material constituting the main magnetic pole layer 11 and the return yoke layer 15, the nonmagnetic nonconductive material such as the insulating layers 12 and 17, the resin layer 13, and the thermal expansion coefficient of the coil 8. It is composed of a material having a small coefficient of thermal expansion. For example, SiC (silicon carbide), Si ₃ N ₄ (silicon nitride), SiO ₂ (silicon oxide), AlN (aluminum nitride), or W (tungsten) is used as such a material.

The mask layer 19 is a layer provided for processing the low thermal expansion layer 18 and the insulating layer 17 by etching or the like in order to process the connection layer 10A and the connection layer 10B so that they can be magnetically connected by the return yoke layer 15. It is. The mask layer 19 is provided on the low thermal expansion layer 18. The mask layer 19 is a material having an etching rate smaller than the etching rates of the low thermal expansion layer 18 and the insulating layer 17, that is, a material having a high selectivity ([low thermal expansion layer etching rate] / [mask layer etching rate]). It is preferable from the point which forms a low thermal expansion layer and an insulating layer accurately. For example, Cr is preferably used as the mask layer 19. The thickness of the mask layer 19 is about 0.1 to 0.3 μm. The mask layer 19 may be removed by any means after the low thermal expansion layer 18 and the insulating layer 17 are processed into a desired shape, but may be left as in the present embodiment.

An overcoat layer (not shown) is provided on the upper surface of the recording head unit 111 to protect the reproducing head unit 112 and the recording head unit 111. The material constituting the overcoat layer is not particularly limited. The overcoat layer can be made of alumina, for example.

When the magnetic head 108 of FIG. 2 is arranged on a magnetic disk and information is to be recorded on the recording layer on the recording medium, a predetermined magnetic flux is generated by passing a current through the coil 8 near the main magnetic pole layer 11. The magnetic flux generated by the coil 8 passes through the main magnetic pole layer 11 and flows from the air bearing surface 16 to the surface of the recording medium (not shown). The magnetic field flowing into the recording layer flows out into the magnetic flux and flows into the trailing shield layer 14, the connection layer 10 </ b> A, and the return yoke layer 15. The main magnetic pole layer 11, the recording medium (not shown), the trailing shield 14, the connection layer 10A, the return yoke 15, and the connection layer 10B form a magnetic circuit. Using this magnetic circuit, magnetization (information) in a direction perpendicular to the recording medium surface of the recording medium can be recorded on the recording layer.

Each of the above layers uses, for example, an existing thin film process including a film forming technique such as plating or sputtering, a patterning technique using a photolithography method or an etching method, and a polishing technique such as machining or polishing, It can manufacture by laminating | stacking on the board | substrate (not shown) which consists of ceramic materials in order toward the upper layer from the lower layer of FIG. Details of the method of manufacturing the magnetic head will be described later.

In the magnetic head of this embodiment, the thermal expansion coefficient of each layer from the main magnetic pole layer 11 to the insulating layer 17 is smaller than that of the low thermal expansion layer 18. The main magnetic pole layer 11 is in contact with and in close contact with the low thermal expansion layer 18 via the insulating layer 12, the coil 8, the resin layer 13, and the insulating layer 17. The adhesion between the layers is obtained by lamination using the existing thin film process. When the temperature of two closely-bonded layers with different coefficients of thermal expansion is raised, the force (action) at which the surface of the layer with the larger thermal expansion coefficient (closed interface) expands in the direction parallel to the surface is the thermal expansion. It is impeded by the opposite force (reaction) exerted by the surface of the layer with the smaller modulus. The low thermal expansion layer 18 having a relatively small thermal expansion coefficient is in close contact with the insulating layer 17, thereby suppressing protrusion of the insulating layer 17 toward the air bearing surface 16 in a scene where the environmental temperature rises. The insulating layer 17 whose protrusion is suppressed is in close contact with the coil 8 and the resin layer 13, thereby suppressing the coil 8 and the resin layer 13 from protruding toward the air bearing surface 16 in a scene where the environmental temperature rises. Similarly, the coil 8 and the resin layer 13 whose protrusion is suppressed are in close contact with the insulating layer 12, thereby suppressing the insulating layer 12 from protruding toward the air bearing surface 16 in a scene where the environmental temperature rises. Similarly, the insulating layer 12 whose protrusion is suppressed is in close contact with the main magnetic pole layer 11, thereby suppressing the main magnetic pole layer 11 from protruding toward the air bearing surface 16 when the environmental temperature rises. Thus, the low thermal expansion layer 18 functions to suppress displacement in the direction in which the air bearing surface 16 side from the main magnetic pole layer 11 to the insulating layer 17 protrudes.

The thickness of the low thermal expansion layer 18 is preferably a thickness capable of suppressing protrusion of each layer from the main magnetic pole layer 11 to the insulating layer 17. For example, the low thermal expansion layer 18 is made of SiC. In some cases, it is 1.0 to 5.0 μm. The fact that the thickness of the low thermal expansion layer 18 is thicker than the total thickness of the insulating layer 17, the resin layer 13, the insulating layer 12, and the main magnetic pole layer 11 can effectively suppress the protrusion in a scene where the environmental temperature rises. To preferred.

According to the magnetic head of this embodiment, the main magnetic pole layer 11 is difficult to protrude due to a small amount of heat from other than the heater 30. Therefore, in the magnetic disk apparatus equipped with the magnetic head of the present embodiment, even if the interval (so-called flying height) between the recording surface of the magnetic disk and the air bearing surface side of the main magnetic pole layer 11 is set narrow from the viewpoint of improving the recording density. In the scene where the environmental temperature rises, it is possible to prevent the air bearing surface side of the recording head unit 111 from colliding with the recording medium.

Further, when the magnetic head of the present embodiment is used in a magnetic disk apparatus, the heater 30 heats the main magnetic pole layer 11 to a temperature higher than the environmental temperature, so that the main amount necessary for controlling the flying height is increased. The protrusion amount of the pole layer 11 is obtained. At this time, the amount of protrusion (that is, control of the flying height) can be controlled with high accuracy without complicatedly controlling the energization amount of the heater 30 in consideration of heat from other than the heater 30. Therefore, such a magnetic disk device can perform stable writing on the recording medium.

If the low thermal expansion layer 18 is omitted, the return yoke 15, the insulating layers 12 and 17, the coil 8, the resin layer 13 and the like are largely displaced by thermal expansion due to the increase in environmental temperature. Due to this thermal expansion, even if the heater 30 is not heated, the main magnetic pole layer 11 also protrudes from the air bearing surface side. The amount of protrusion caused by the change in environmental temperature is added to the amount of protrusion due to heating of the heater 30. For this reason, the accuracy of control of the protrusion amount decreases, and the probability of collision between the magnetic head and the recording medium increases.

3 to 5 are cross-sectional schematic views showing other embodiments of the magnetic head of the present invention. In the magnetic head of the above embodiment, the trailing shield layer 14 and the connection layers 10A and 10B are provided. However, for example, as shown in FIG. 3, the trailing shield 14 and the connection layer 10A may not be provided. Moreover, the trailing shield 14 and the connection layers 10A and 10B may not be provided as shown in FIG. Further, as shown in FIG. 5, the reproducing head unit 112 may not be provided. Each of the magnetic heads shown in FIGS. 3 to 5 has a flat plane on which the upper surface of the coil 8 is located, and an insulating layer 17, a low thermal expansion layer 18, and a mask layer 19 are provided on the plane. By providing the mask layer 19 on a flat plane, the mask layer 19 can be processed into a desired shape by ion milling. Details will be described in a method of manufacturing a magnetic head described later.
-Magnetic head manufacturing method-
6 to 8 are cross-sectional views for explaining the manufacturing process of the magnetic head according to the embodiment of FIG. Here, a cross-sectional view in a direction perpendicular to the substrate is shown in the laminate obtained in the course of manufacture.

First, as shown in FIG. 6A, an insulating layer 9 is formed on a substrate 7. Examples of the method for forming the insulating layer 9 include a method of forming a film of alumina or silicon oxide by sputtering. Note that a reproducing head portion (not shown) may be provided on the substrate 7, but the description thereof is omitted in this specification.

Next, as shown in FIG. 6B, the main magnetic pole layer 11 is formed on the insulating layer 9. Examples of the method of forming the main magnetic pole layer 11 include a method of forming a magnetic material made of a CoFe magnetic material having a high saturation magnetic flux density by sputtering. Further, in order to form the main magnetic pole layer 11 having a predetermined core width (length on the air bearing surface 16 in a direction perpendicular to the paper surface (X-axis direction)), further etching may be performed. As this etching, it is possible to use a focused ion beam etching (Focused. Ion Beam: FIB) or an ion beam etching technique called ion milling.

Next, as shown in FIG. 6C, an insulating layer 12 is formed by sputtering alumina or silicon oxide at the positions where the coils 8a to 8d and the trailing shield 14 are to be formed. As for the thickness of the insulating layer 12, the portion where the trailing shield 14 is desired to be formed is usually thinner than the other portions.

Next, as shown in FIG. 6D, the coils 8a to 8d, the trailing shield layer 14, and the connection layer 10A 'are formed on the insulating layer 12. Further, the connecting portion 10B 'is formed at a position where the insulating layer 12 of the main magnetic pole 11 is not formed (usually, a position away from the air bearing surface). The coils 8a to 8d are wound around the connection layer 10B 'so as to pass between the main magnetic pole layer 11 and the return yoke layer 15. A coil located on the height side of the connection layer 10B 'is not shown.

Next, as shown in FIG. 7A, a resin layer 13z is formed between the windings of the coils 8a to 8d formed on the insulating layer 12. The resin layer 13z can be formed by applying a photoresist having fluidity at the time of formation. The upper surface of the resin layer 13z is normally convex. The resin layer 13z is non-conductive and non-magnetic.

Next, as shown in FIG. 7B, the upper part of the resin layer 13z and the connection portions 10A ′ and 10B ′ is used by using a chemical mechanical polishing method (also referred to as a CMP method (Chemical and Mechanical Polishing Method)). Polish and process so that the upper surface is flat. The upper surfaces of the coils 8a to 8d, the resin layers 13a to 13e, and the connecting portion 10A, whose upper surfaces are exposed by this polishing, are located on substantially the same plane. By this polishing, the surface of each layer becomes flat when the insulating layer 17a, the low thermal expansion layer 18a, and the mask layer 19a are formed in a later step. In the present embodiment, the coil is exposed on the upper surface, but the coil may not be exposed on the upper surface as long as the upper surface is flat. When the coil is not exposed on the upper surface, the insulating layer 17 may not be provided in a later process.

Next, as shown in FIG. 7C, an insulating layer 17a, a low thermal expansion layer 18a, and a mask layer 19a are formed on the flattened coils 8a to 8d, the resin layers 13a to 13e, and the upper surfaces of the connection portions 10A and 10B. Form in order. Each of these is processed in a subsequent process, whereby the insulating layer 17, the low thermal expansion layer 18, and the mask layer 19 in the description of the embodiment of the magnetic head of the present invention are obtained. As described above, the insulating layer 17a can be made of alumina, for example. As described above, the low thermal expansion layer 18a can be made of, for example, SiC (silicon carbide), Si ₃ N ₄ (silicon nitride), SiO ₂ (silicon oxide), AlN (aluminum nitride), and W (tungsten). The mask layer 19a can be made of, for example, Cr (chrome). The low thermal expansion layer 18a can be formed by, for example, a sputtering method. Since the upper surface of FIG. 7B is flat, the upper surfaces of these layers are flat.

The magnetic head manufacturing method of the present invention includes a step of forming a second insulating layer having magnetic and electrical insulation so as to cover the coil layer and to have a flat upper surface. Good. For example, a recess is formed in the insulating layer 12, a coil is embedded in the recess using a sputtering method or a plating method, an alumina layer is then formed as a second insulating layer by a sputtering method, and the upper surface of the alumina layer is further subjected to CMP. You may grind by.

Next, in order to process the low thermal expansion layer 18a and the insulating layer 17a into desired shapes, the mask layer 19a is patterned by physical etching. As physical etching, it is possible to use an ion beam etching called ion milling or a focused ion beam (Focused. Ion Beam: FIB) technique. Hereinafter, a method of processing the mask layer 19a by ion milling will be described.

First, a resist layer 21 is formed as shown in FIG. The resist layer 21 has a fluidity when formed like a photoresist, and is applied with a material that can be cured by irradiation with light, electron beam, or the like, and then light is irradiated to a desired position and further developed. Is obtained. The resist layer 21 is formed to shield a part of the mask layer 19a from ions during ion milling. Next, the portion of the mask layer 19a where the resist 21 is not formed is removed by physical etching to obtain the mask layer 19 as shown in FIG.

FIG. 9 is a conceptual schematic diagram for explaining the cross-sectional shape of the magnetic head before and after ion milling. FIG. 9A is a schematic cross-sectional view showing the insulating layer 17a, the low thermal expansion layer 18a, the mask layer 19a, and the resist layer 21 before ion milling. The direction in which the constituent material of the mask radiates is the most at 180 ° with respect to the incident direction of ions, and is smaller as it approaches the 90 ° direction (according to the so-called cosine law). According to the method of manufacturing the magnetic head of this embodiment, as shown in FIG. 9A, the flat low thermal expansion layer 18a and the mask layer 19a are formed. When ions are incident on the mask layer 19a during ion milling, the constituent material of the mask layer 19a is the radiation direction of the mask layer 19a (in FIG. 9A) with respect to the direction of ion incidence (arrow a in FIG. 9A). The angle formed by the arrow b) (θ in FIG. 9A) scatters in the direction of 90 ° to 270 °. FIG. 9B is a schematic cross-sectional view showing the insulating layer 17a, the low thermal expansion layer 18a, the mask layer 19 and the resist layer 21 after ion milling. FIG. 9C is a schematic cross-sectional view showing the insulating layer 17a, the low thermal expansion layer 18a, and the mask layer 19 after the resist layer 21 is further removed. The region where the constituent material of the mask layer 19a scattered by ion milling can be reattached is on the side surface of the mask layer 19 (19b in FIG. 9B) or the side surface of the resist layer 21 (region 21a in FIG. 9B). Limited. The mask layer 19 is as thin as 0.1 to 0.3 μm, and is positioned in a direction of approximately 90 ° with respect to the incident direction of ions to the mask layer 19a. Few. Further, the residue 23 generated by reattaching to the side surface 21a of the resist layer is peeled off together with the resist layer 21 as shown in FIG. 9C when the resist layer 21 is peeled off in the next step. As described above, the mask layer 19 having a desired shape is obtained. Therefore, the low thermal expansion layer 18a and the insulating layer 17a can be precisely patterned in a patterning process described later. In this step, a part of the low thermal expansion layer 18a may be removed.

Then, the resist layer 21 is peeled off as shown in FIG. The stripping means is not particularly limited. For example, a wet process using a solvent capable of dissolving the resist layer 21 may be used, or a dry process in which ashing (ashing) is performed with oxygen plasma is used. It may be used. In the case of using a wet process, it is particularly preferable that ultrasonic cleaning is simultaneously performed when the resist layer 21 is dissolved from the viewpoint of easy removal of the residue 23.

In the present embodiment, the patterned resist layer 21 is provided on the mask layer 19a and the mask layer 19 is formed by ion milling. However, the mask 19 may be formed using FIB. When physical etching using FIB is used, ions can be irradiated only at a desired position without providing a resist layer. Even in this case, since the region where the constituent material of the scattered mask layer 19a can be reattached is limited to the side surface of the mask layer 19, the mask layer 19 having a desired shape is obtained as in the case of physical etching by ion milling. It is done.

Next, the low thermal expansion layer 18a and the insulating layer 17a are patterned. That is, the portions of the low thermal expansion layer 18a and the insulating layer 17a that are not covered with the mask layer 19 are removed to form the low thermal expansion layer 18 and the insulating layer 17 as shown in FIG. The removing means is not particularly limited, but can be removed by RIE (Reactive Ion Etching), ion milling, or the like. By this removal, the connecting portions 10A and 10B are exposed on the upper surface of the obtained laminate.

Next, as shown in FIG. 8D, a return yoke layer 15 capable of magnetically connecting the connection portions 10A and 10B exposed in the previous step is provided so as to cover the low thermal expansion layer 18. The return yoke layer 15 can be formed by a sputtering method or the like.

Next, an overcoat layer (not shown) is provided on the entire upper surface using a sputtering method, and the air bearing surface side is appropriately polished using a CMP method, whereby the magnetic head of this embodiment shown in FIG. obtain.

The magnetic head obtained by such a magnetic head manufacturing method can accurately control the amount of protrusion when the head is incorporated in a magnetic disk device. In such a method of manufacturing a magnetic head, a low thermal expansion layer and a mask layer are sequentially provided on the polished flat surface, and the mask layer is further patterned by physical etching. Since the material constituting the mask layer hardly adheres to the mask layer during the physical etching, the shape accuracy of the obtained mask layer is high. The accuracy of the pattern of the low thermal expansion layer processed using this mask layer is increased. For this reason, the accuracy of the shape of the low thermal expansion layer is improved, and the manufacturing yield of the magnetic head can be improved. Furthermore, when a magnetic disk device incorporating the obtained magnetic head is used, since contamination caused by peeling of the low thermal expansion layer is unlikely to occur, the recording or reproducing performance of the magnetic disk device can be maintained for a long time.

The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.

Claims (11)

Forming a first magnetic layer on a substrate;
Forming a first insulating layer having magnetic and electrical insulation on the first magnetic layer;
Forming a coil layer capable of generating a magnetic field on the first insulating layer;
Forming a second insulating layer having magnetic and electrical insulation so as to cover the coil layer;
Planarizing the second insulating layer;
Forming a low thermal expansion layer having a lower coefficient of thermal expansion than the second insulating layer on the second insulating layer;
Forming a mask layer on the low thermal expansion layer;
Patterning the mask layer by physical etching;
Removing the portion of the low thermal expansion layer where the mask layer is not formed;
And a step of providing a second magnetic layer magnetically connected to the first magnetic layer so as to cover the low thermal expansion layer. 2. The method of manufacturing a magnetic head according to claim 1, wherein, in the step of planarizing the second insulating layer, the upper surface of the second insulating layer is polished by chemical mechanical polishing. The step of forming the second insulating layer includes the step of providing a third insulating layer having magnetic and electrical insulation so as to cover the coil layer, and the chemical mechanical polishing of the upper surface of the third insulating layer. A step of exposing the coil layer by polishing, and a step of forming a fourth insulating layer having magnetic and electrical insulation on the upper surface where the coil layer is exposed,
The method of manufacturing a magnetic head according to claim 1, wherein: The patterning step includes forming a resist layer on the mask layer;
Removing a portion of the mask layer where the resist layer is not formed by physical etching;
The method of manufacturing a magnetic head according to claim 1, further comprising a step of removing the resist layer. 5. The method of manufacturing a magnetic head according to claim 4, wherein the step of removing the resist layer is performed by applying ultrasonic waves while the resist layer is immersed in a stripping solution. 2. The method of manufacturing a magnetic head according to claim 1, wherein the physical etching is ion milling. Providing a third magnetic layer on the first insulating layer;
2. The method of manufacturing a magnetic head according to claim 1, wherein the second magnetic layer is provided so that the first magnetic layer and the third magnetic layer are magnetically coupled. The method of manufacturing a magnetic head according to claim 1, wherein the mask layer is made of chromium. A substrate,
A first magnetic layer provided on the substrate;
A first insulating layer having magnetic and electrical insulation provided on the first magnetic layer;
A coil layer capable of generating a magnetic field provided on the first insulating layer;
A second insulating layer provided to cover the coil layer and having magnetic and electrical insulation;
A low thermal expansion layer provided on the second insulating layer and having a lower coefficient of thermal expansion than the second insulating layer;
A magnetic head comprising: a second magnetic layer covering the low thermal expansion layer so as to be magnetically connected to the first magnetic layer. The magnetic head according to claim 9, wherein the low thermal expansion layer is made of silicon carbide. A substrate,
A first magnetic layer provided on the substrate;
A first insulating layer having magnetic and electrical insulation provided on the first magnetic layer;
A coil layer capable of generating a magnetic field provided on the first insulating layer;
A second insulating layer provided to cover the coil layer and having magnetic and electrical insulation;
A low thermal expansion layer provided on the second insulating layer and having a lower coefficient of thermal expansion than the second insulating layer;
A magnetic head having a second magnetic layer covering the low thermal expansion layer so as to be magnetically connected to the first magnetic layer;
A magnetic storage device comprising: a magnetic storage medium facing the magnetic head, wherein the magnetic head is capable of magnetically recording information.

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