JP2002367112A - Method for manufacturing thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the corrosion of a high-saturation magnetic flux density layer when the upper surface of the high-saturation magnetic flux density layer formed by plating is made flat in the manufacturing of a thin film magnetic head having a high-saturation magnetic flux density layer made of a magnetic material containing Co and made flat for its upper surface. SOLUTION: At least one of steps of forming the power and upper magnetic pole layers of a thin film magnetic head includes a step of forming a substrate film 51, a step of forming a high-saturation magnetic flux density layer 53 on the substrate film 51 by plating, a step of removing the unnecessary part of the substrate film 51 by ion milling, a step of forming a nonmagnetic layer to cover the high-saturation magnetic flux density layer 53, and a step of making flat the high-saturation magnetic flux density layer 53 and the upper surface of the nonmagnetic layer by chemical and mechanical polishing. In the ion milling, in order to set an angle between a normal to the upper surface of the substrate film 51 and an ion irradiating direction equal to/higher than 45 deg., the substrate film 51 and the side face of the high-saturation magnetic flux density layer 53 are irradiated with ions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a thin-film magnetic head having at least an inductive electromagnetic transducer.

[0002]

2. Description of the Related Art In recent years, as the areal recording density of a hard disk drive has been improved, the performance of a thin film magnetic head has been required to be improved. The thin-film magnetic head has a structure in which a recording head having an inductive electromagnetic transducer for writing and a reproducing head having a magnetoresistive element for reading (hereinafter, also referred to as an MR (Magneto-resistive) element) are stacked. Composite thin film magnetic heads are widely used.

A recording head is provided between a lower magnetic pole layer and an upper magnetic pole layer each including a magnetic pole part facing each other on the air bearing surface side, and a magnetic recording medium provided between a magnetic pole part of the lower magnetic pole layer and a magnetic pole part of the upper magnetic pole layer. A gap layer; and a thin-film coil provided at least partially insulated from the lower pole layer and the upper pole layer.

In order to cope with a higher recording density in a recording head, it is required to reduce a magnetic path length, a magnetic pole width for defining a recording track width, and improve recording characteristics. However, when the magnetic pole width is reduced, the recording characteristics, for example, the overwrite characteristics, which are characteristics in the case of overwriting, deteriorate. Therefore, as the magnetic pole width decreases, the recording characteristics need to be further improved.

Conventionally, NiFe (permalloy) has often been used as a material for the upper magnetic pole layer and the lower magnetic pole layer. However, recently, in order to realize the recording characteristics corresponding to the higher recording density as described above, as a material for the upper magnetic pole layer and the lower magnetic pole layer, a high saturation magnetic flux density material having a larger saturation magnetic flux density than NiFe, for example, 1.8T saturation magnetic flux density
The above high saturation magnetic flux density materials have come to be used.

In the recording head, since a part of the coil is arranged inside the magnetic path, it is necessary to reduce the pitch of the coil winding in order to reduce the magnetic path length. For that purpose, it is necessary to form the coil with high precision. When the recording track width is defined by the upper magnetic pole layer, it is necessary to form the upper magnetic pole layer with high precision in order to reduce the recording track width. Therefore, in order to manufacture a thin-film magnetic head corresponding to high recording density, a step of forming a coil and an upper magnetic pole layer is important. Note that both the coil and the upper magnetic pole layer are formed by using a thin film forming technique including photolithography. In this case, the coil and the upper magnetic pole layer can be easily and accurately formed when the base of the coil and the upper magnetic pole layer is flat. Therefore, for example, Japanese Patent Application Laid-Open
JP-A-21524, JP-A-8-96327, JP-A-9-134504, JP-A-2000-1950
No. 13, JP-A-11-328630, a non-magnetic layer (insulating layer) is formed so as to cover the lower magnetic pole layer after the lower magnetic pole layer is formed, and the non-magnetic layer is polished. By flattening, it is common to flatten the base of the coil and the upper magnetic pole layer.

Here, an example of the steps from the formation of the lower pole layer to the planarization will be briefly described. In this step,
First, a base film serving as a plating electrode is formed on the base of the lower magnetic pole layer by, for example, a sputtering method, a photoresist layer is formed on the base film, and the photoresist layer is formed by a photolithography process. By patterning, a frame (outer frame) for plating is formed. This frame has an opening at the position where the lower pole layer is to be formed. Then, using this frame, electrolytic plating is performed using the previously formed base film as an electrode to form a lower pole layer on the base film. Then, the frame is removed. Next, unnecessary portions of the underlayer other than the portion existing under the lower magnetic pole layer are removed by dry etching such as ion milling. Next, a non-magnetic layer made of a non-magnetic and non-conductive material such as alumina (Al ₂ O ₃ ) is formed by, for example, a sputtering method so as to cover the base film and the lower magnetic pole layer. Next, the nonmagnetic layer is polished by, for example, chemical mechanical polishing until the lower magnetic pole layer is exposed, and the upper surfaces of the lower magnetic pole layer and the nonmagnetic layer are flattened.

[0008]

As described above, recently, in order to realize recording characteristics corresponding to a higher recording density, a high saturation magnetic flux density material is used as a material of the upper magnetic pole layer and the lower magnetic pole layer. It has become. As such a high saturation magnetic flux density material, CoNiFe or FeCo
Magnetic materials containing are often used.

However, a high saturation magnetic flux density material containing Co has lower corrosion resistance than NiFe. Therefore, for example, when a high saturation magnetic flux density material containing Co is used as the material of the lower magnetic pole layer, corrosion occurs in the lower magnetic pole layer in the step of flattening the upper surfaces of the lower magnetic pole layer and the nonmagnetic layer by chemical mechanical polishing. This causes a problem that the yield of the thin film magnetic head is reduced.

The same problem as described above occurs when a high saturation magnetic flux density material containing Co is used as the material of the upper magnetic pole layer. For example, when the upper pole layer has a pole portion layer including a pole portion defining a track width and a yoke portion layer forming a yoke portion, the upper pole layer may be formed by the following steps. That is, in this step, first, the magnetic pole partial layer is formed, then the non-magnetic layer is formed so as to cover the magnetic pole partial layer, and then the non-magnetic layer is exposed by chemical mechanical polishing until the magnetic pole partial layer is exposed. Is polished and planarized, and then a yoke partial layer is formed on the planarized pole partial layer and non-magnetic layer. When a high saturation magnetic flux density material containing Co is used as the material of the pole portion layer, corrosion occurs in the pole portion layer in the step of flattening the top surfaces of the pole portion layer and the non-magnetic layer by chemical mechanical polishing, There is a problem that the yield of the thin film magnetic head is reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a thin film magnetic head having a high saturation magnetic flux density layer made of a magnetic material containing Co and having a flat upper surface. Accordingly, it is an object of the present invention to provide a method of manufacturing a thin film magnetic head capable of preventing corrosion of a high saturation magnetic flux density layer when flattening the upper surface of a high saturation magnetic flux density layer formed by plating.

[0012]

A method of manufacturing a thin film magnetic head according to the present invention includes a medium facing surface facing a recording medium, and magnetic pole portions magnetically connected to each other on the medium facing surface side. First and second magnetic layers each including at least one layer; a gap layer provided between a magnetic pole portion of the first magnetic layer and a magnetic pole portion of the second magnetic layer; A thin-film coil provided between the first and second magnetic layers while being insulated from the first and second magnetic layers; and at least one of the first magnetic layer and the second magnetic layer Is a method of manufacturing a thin film magnetic head having a high saturation magnetic flux density layer made of a magnetic material containing Co.

According to the method of manufacturing a thin film magnetic head of the present invention, a step of forming a first magnetic layer, a step of forming a gap layer on the first magnetic layer, and a step of forming a second magnetic layer on the gap layer A step of forming a first magnetic layer and a step of forming a second magnetic layer, wherein at least one of the step of forming a first magnetic layer and the step of forming a second magnetic layer is a step of forming a conductive base film. And a step of forming a high saturation magnetic flux density layer on the base film by plating, and after forming the high saturation magnetic flux density layer,
A step of removing unnecessary portions of the base film by ion milling, a step of forming a non-magnetic layer covering the high saturation magnetic flux density layer, and a non-magnetic layer until the high saturation magnetic flux density layer is exposed by chemical mechanical polishing. Polishing the upper surface of the high saturation magnetic flux density layer and the non-magnetic layer, and removing unnecessary portions of the underlayer by irradiating the upper surface of the underlayer with normal lines and ions. 45 ° angle with the direction
As described above, the upper surface of the base film and the side surface of the high saturation magnetic flux density layer are irradiated with ions.

According to the method of manufacturing a thin film magnetic head of the present invention,
In the step of removing unnecessary portions of the base film by ion milling, so that the angle between the normal to the top surface of the base film and the ion irradiation direction is 45 ° or more.
The upper surface of the base film and the side surfaces of the high saturation magnetic flux density layer are irradiated with ions. This prevents the substance separated from the base film by ion milling from re-adhering to the side surface of the high saturation magnetic flux density layer. As a result, corrosion of the high saturation magnetic flux density layer when the upper surfaces of the high saturation magnetic flux density layer and the nonmagnetic layer are flattened by chemical mechanical polishing is prevented.

In the method of manufacturing a thin film magnetic head according to the present invention, the magnetic material containing Co may have a saturation magnetic flux density of 1.8 T or more.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, an outline of a method of manufacturing a thin-film magnetic head according to an embodiment of the present invention will be described with reference to FIGS. 1 to 6, (a) shows a cross section perpendicular to the air bearing surface, and (b) shows a cross section of a magnetic pole portion parallel to the air bearing surface.

In the method of manufacturing a thin-film magnetic head according to this embodiment, first, as shown in FIG. 1, a sputtering is performed on a substrate 1 made of a ceramic material such as AlTiC (Al ₂ O ₃ .TiC). An insulating layer 2 made of an insulating material such as alumina is formed to a thickness of, for example, 1 to 5 μm by a method or the like. Next, a lower shield layer 3 for a reproducing head made of a magnetic material such as NiFe is formed on the insulating layer 2 by sputtering or plating, for example, to a thickness of about 3 μm.
m.

Next, a lower shield gap film 4 made of an insulating material such as alumina is formed to a thickness of, for example, 10 to 200 nm on the lower shield layer 3 by a sputtering method or the like. Next, the MR element 5 for reproduction is formed on the lower shield gap film 4 by a sputtering method or the like.
Is formed, for example, to a thickness of several tens nm. As the MR element 5, an element using a magnetosensitive film exhibiting a magnetoresistance effect, such as an AMR (anisotropic magnetoresistance effect) element, a GMR (giant magnetoresistance effect) element, or a TMR (tunnel magnetoresistance effect) element is used. be able to.

Next, on the lower shield gap film 4,
A pair of electrode layers 6 electrically connected to the MR element 5 are formed to a thickness of several tens nm by a sputtering method or the like. Next, the lower shield gap film 4 and the MR element 5
An upper shield gap film 7 made of an insulating material such as alumina is formed on the
It is formed to a thickness of 0 to 200 nm.

Each layer constituting the above-mentioned reproducing head is patterned by a general etching method using a resist pattern, a lift-off method, or a method using both of them.

Next, on the upper shield gap film 7,
An upper shield layer and lower magnetic pole layer (hereinafter, referred to as a lower magnetic pole layer) 8 made of a magnetic material and used for both the read head and the write head is formed to a thickness of, for example, 3 to 4 μm.

In the present embodiment, the lower magnetic pole layer 8 is made of Co.
And is formed of a magnetic material having a saturation magnetic flux density of 1.8 T or more. As such a magnetic material, for example, a magnetic material containing CoNiFe or FeCo is used. The lower magnetic pole layer 8 is formed by a plating method. The upper surface of the lower magnetic pole layer 8 is formed on the upper surface of the non-magnetic layer 21 around the lower magnetic pole layer 8 by chemical mechanical polishing.
Is flattened together with the upper surface. The nonmagnetic layer 21 is, for example,
It is formed of an inorganic insulating material such as alumina. The lower magnetic pole layer 8 corresponds to the high saturation magnetic flux density layer in the present invention.

Instead of the lower magnetic pole layer 8, an upper shield layer, a separation layer made of a non-magnetic material such as alumina formed on the upper shield layer by sputtering or the like, and The formed lower magnetic layer may be provided.

Next, as shown in FIG.
A recording gap layer 9 made of an insulating material such as alumina by sputtering or the like.
It is formed to a thickness of 0 nm. Next, in order to form a magnetic path, the recording gap layer 9 is partially etched at a central portion of a thin film coil described later to form a contact hole 9a.

Next, a first layer portion 10 of a thin film coil made of, for example, copper (Cu) is formed on the recording gap layer 9 to a thickness of, for example, 2 to 3 μm. In FIG. 2A, reference numeral 10a denotes a connection portion of the first layer portion 10 which is connected to a second layer portion 15 of a thin-film coil described later. The first layer portion 10 is wound around the contact hole 9a.

Next, as shown in FIG. 3, an organic insulating material such as a photoresist, which has fluidity when heated, is used to cover the first layer portion 10 of the thin-film coil and the recording gap layer 9 therearound. The insulating layer 11 is formed in a predetermined pattern. Next, heat treatment is performed at a predetermined temperature to flatten the surface of the insulating layer 11. By this heat treatment, the insulating layer 1
Each of the outer and inner peripheral edge portions of 1 has a rounded slope shape.

Next, the recording gap layer 9 and the insulating layer 11 are formed in a region of the insulating layer 11 from the slope portion on the air bearing surface 20 side (left side in FIG. 3A) to the air bearing surface 20 side. The track width defining layer 12a of the upper magnetic pole layer 12 is formed of a magnetic material for a recording head. The upper magnetic pole layer 12 is composed of the track width defining layer 12a, a connecting portion layer 12b and a yoke portion layer 12c described later.

In the present embodiment, the track width defining layer 12
a is formed of a magnetic material containing Co and having a saturation magnetic flux density of 1.8 T or more. As such a magnetic material, for example, a magnetic material containing CoNiFe or FeCo is used. The track width defining layer 12a is formed by plating.

The track width defining layer 12 a is formed on the recording gap layer 9, and has a tip portion 12 a _{1 serving as} a magnetic pole portion of the upper magnetic pole layer 12 and an air bearing surface 20 of the insulating layer 11.
It is formed on the sloped portion of the side, and a connecting portion 12a ₂ which is connected to the yoke portion layer 12c. Tip 12a ₁
Is equal to the recording track width. That is,
Tip 12a ₁ defines the write track width.

When the track width defining layer 12a is formed, a connecting portion layer 12b made of a magnetic material is simultaneously formed on the contact hole 9a, and the connecting portion 10a is formed.
A connection layer 13 made of a magnetic material is formed thereon. The connection portion layer 12b forms a portion of the upper pole layer 12 that is magnetically connected to the lower pole layer 8.

Next, at the periphery of the track width defining layer 12a, using the track width defining layer 12a as a mask, at least a part of the recording gap layer 9 and the magnetic pole portion of the lower magnetic pole layer 8 on the recording gap layer 9 side is etched. For example, reactive ion etching is used to etch the recording gap layer 9, and ion milling is used to etch the lower pole layer 8, for example. As shown in FIG. 3B, each side wall of at least a part of the magnetic pole portion of the upper magnetic pole layer 12 (the tip portion 12a ₁ of the track width defining layer 12a), the write gap layer 9 and the magnetic pole portion of the lower magnetic pole layer 8 Are vertically formed in a self-aligned manner, which is called a trim structure.

Next, as shown in FIG. 4, a nonmagnetic layer 14 made of an inorganic insulating material such as alumina is formed to a thickness of, for example, 3 to 4 μm. Next, the non-magnetic layer 14
By a chemical mechanical polishing, the track width defining layer 12a,
Polishing and flattening are performed until the surfaces of the connection partial layer 12b and the connection layer 13 are exposed. As described above, the upper surface of the track width defining layer 12a is planarized by chemical mechanical polishing together with the upper surface of the non-magnetic layer 14 disposed around the track width defining layer 12a. The track width defining layer 12a corresponds to the high saturation magnetic flux density layer in the present invention.

Next, as shown in FIG. 5, a second layer portion 15 of a thin film coil made of, for example, copper (Cu) is formed on the planarized nonmagnetic layer 14 to a thickness of, for example, 2 to 3 μm. Form. In FIG. 5A, reference numeral 15 a denotes a connection portion of the second layer portion 15 which is connected to the connection portion 10 a of the first layer portion 10 of the thin-film coil via the connection layer 13. The second layer portion 15 is wound around the connection partial layer 12b.

Next, an insulating layer 16 made of an organic insulating material having fluidity when heated, such as a photoresist, is covered with a predetermined pattern so as to cover the second layer portion 15 of the thin-film coil and the nonmagnetic layer 14 around the second layer portion 15. Formed. Next, the insulating layer 1
In order to flatten the surface of No. 6, heat treatment is performed at a predetermined temperature.
By this heat treatment, each of the outer and inner peripheral edge portions of the insulating layer 16 has a rounded slope shape.

Next, as shown in FIG. 6, the track width defining layer 12a, the non-magnetic layers 14, 16 and the connecting partial layer 12
A yoke portion layer 12c that forms a yoke portion of the upper magnetic pole layer 12 is formed on the recording layer b using a magnetic material for a recording head such as NiFe. The end of the yoke portion layer 12c on the air bearing surface 20 side is arranged at a position away from the air bearing surface 20. Also, the yoke partial layer 12c
Are connected to the lower magnetic pole layer 8 via the connection partial layer 12b.

Next, an overcoat layer 17 made of, for example, alumina is formed so as to cover the whole. Finally, the slider including the above layers is machined to form the air bearing surface 20 of the thin-film magnetic head including the recording head and the reproducing head, thereby completing the thin-film magnetic head.

The thin-film magnetic head according to the present embodiment manufactured as described above has a medium facing surface (air bearing surface 20) facing a recording medium, a reproducing head, and a recording head (inductive electromagnetic transducer). Have. In the reproducing head, the MR element 5 and the air bearing surface 20 side are partially M
It has a lower shield layer 3 and an upper shield layer (lower pole layer 8) for shielding the MR element 5, which are arranged to face each other with the R element 5 interposed therebetween.

The recording heads are magnetically connected to each other,
A lower magnetic pole layer 8 and an upper magnetic pole layer 12 each including at least one layer and including a magnetic pole part facing each other on the air bearing surface 20 side, and a magnetic pole part of the lower magnetic pole layer 8 and a magnetic pole part of the upper magnetic pole layer 12. It has a recording gap layer 9 provided therebetween, and thin film coils 10 and 15 at least partially disposed between the lower magnetic pole layer 8 and the upper magnetic pole layer 12 while being insulated therefrom. ing.
In the thin-film magnetic head according to the present embodiment, as shown in FIG.
The length up to the end on the air bearing surface 20 side is the throat height TH. The throat height refers to the length (height) from the end on the air bearing surface side to the end on the opposite side of the portion where the two magnetic pole layers face each other via the recording gap layer.

In the present embodiment, the lower magnetic pole layer 8 corresponds to the first magnetic layer in the present invention, and the upper magnetic pole layer 12 corresponds to the second magnetic layer in the present invention.

Next, a method of forming a high saturation magnetic flux density layer in the present embodiment will be described in detail with reference to FIGS. The high saturation magnetic flux density layer 53 in the following description may be the lower magnetic pole layer 8 or the track width defining layer 12a of the upper magnetic pole layer 12.

In the method of forming the high saturation magnetic flux density layer according to the present embodiment, first, as shown in FIG. A conductive base film 51 serving as an electrode for plating is formed. When the high saturation magnetic flux density layer 53 is the lower magnetic pole layer 8, the base 50 is the upper shield gap film 7. When the high saturation magnetic flux density layer 53 is the track width defining layer 12a, the base 50 is the recording gap layer 9 and the insulating layer 11. As the material of the base film 51, for example, NiFe may be used, or the same material as the material of the high saturation magnetic flux density layer 53 to be formed, for example, a magnetic material containing CoNiFe or FeCo may be used. Further, the base film 51 may be a laminate of two or more layers made of different materials. In this case, the lowermost layer of the base film 51 may be an adhesive layer for improving the adhesion between the layer above and the base 50. As a material of the adhesive layer, for example, Ti is used.

Next, as shown in FIG. 8, a photoresist layer is formed on the base film 51, and the photoresist layer is patterned by a photolithography process.
A plating frame (outer frame) 52 is formed. The frame 52 has an opening at a position where the high saturation magnetic flux density layer 53 is to be formed.

Next, as shown in FIG.
Then, electrolytic plating is performed using the base film 51 formed earlier as an electrode to form a high saturation magnetic flux density layer 53 on the base film 51. As a material of the high saturation magnetic flux density layer 53, a magnetic material containing Co and having a saturation magnetic flux density of 1.8 T or more, for example, a magnetic material containing CoNiFe or FeCo is used. After that, the frame 52 is removed.

Next, as shown in FIG. 10, the high saturation magnetic flux density layer 5 of the underlying film 51 is formed by ion milling.
Unnecessary parts other than the part under 3 are removed. In the present embodiment, in the ion milling, the base film 51 is formed.
The upper surface of the base film 51 and the side surfaces of the high saturation magnetic flux density layer 53 are irradiated with ions so that the angle between the normal line to the upper surface of the substrate and the irradiation direction of the ions is 45 ° or more. This prevents the substance separated from the base film 51 by ion milling from re-adhering to the side surface of the high saturation magnetic flux density layer 53. FIG. 11 shows a state after unnecessary portions of the base film 51 have been removed.

Next, as shown in FIG. 12, a non-magnetic layer made of a non-magnetic and non-conductive material such as alumina is applied so as to cover the base film 51 and the high saturation magnetic flux density layer 53 by, for example, a sputtering method. 54 are formed.

Next, as shown in FIG. 13, the nonmagnetic layer 54 is polished by chemical mechanical polishing until the high saturation magnetic flux density layer 53 is exposed, and the high saturation magnetic flux density layer 53 and the nonmagnetic layer 54 are polished. Flatten the top surface.

Here, referring to FIG. 14 to FIG.
A comparative example for the method of forming a high saturation magnetic flux density layer in the present embodiment will be described. In the method of forming the high saturation magnetic flux density layer of this comparative example, first, as shown in FIG.
Underlayer 150 of high saturation magnetic flux density layer 153 to be formed
A base film 151 serving as a plating electrode is formed on the base film 151 by, for example, a sputtering method. A photoresist layer (not shown) is formed on the base film 151, and the photoresist layer is patterned by a photolithography process. Then, a frame (outer frame) for plating is formed. This frame has an opening at a position where the high saturation magnetic flux density layer 153 is to be formed. Then, using this frame, electrolytic plating is performed using the previously formed base film 151 as an electrode to form a high saturation magnetic flux density layer 153 on the base film 151. As a material of the high saturation magnetic flux density layer 153, a magnetic material containing Co and having a saturation magnetic flux density of 1.8 T or more, for example, a magnetic material containing CoNiFe or FeCo is used. Then, the frame is removed. The steps so far are the same as the method of forming the high saturation magnetic flux density layer in the present embodiment.

Next, in the comparative example, unnecessary portions of the base film 151 other than the portion existing under the high saturation magnetic flux density layer 153 are removed by ion milling. At this time, the irradiation direction of the ions is a direction perpendicular to the upper surface of the base film 151. When the underlying film 151 is removed by such ion milling, the underlying film 151 is removed by ion milling.
The substance separated from 51 adheres again to the side surface of the high saturation magnetic flux density layer 153.

FIG. 15 shows a state after an unnecessary portion of the base film 151 has been removed. As shown in FIG. 15, on the side surface of the high saturation magnetic flux density layer 153, a re-adhesion film 161 formed by re-adhesion of a substance separated from the base film 151 by ion milling is formed.

In the comparative example, as shown in FIG. 16, a non-magnetic and non-conductive material such as alumina is used to cover the base film 151 and the high saturation magnetic flux density layer 153 by, for example, a sputtering method. A non-magnetic layer 154 is formed.

In the comparative example, as shown in FIG. 17, the nonmagnetic layer 154 is polished by chemical mechanical polishing until the high saturation magnetic flux density layer 153 is exposed. The upper surface of the magnetic layer 154 is flattened.

In the method of forming the high saturation magnetic flux density layer of the comparative example, the high saturation magnetic flux density layer 1 is formed by chemical mechanical polishing.
In the step of flattening the upper surface of the non-magnetic layer 53 and the non-magnetic layer 154, corrosion occurs in the high saturation magnetic flux density layer 153.

As shown in FIG. 17, the present inventor has found that the corrosion of the high saturation magnetic flux density layer 153 is mainly caused near the upper surface of the high saturation magnetic flux density layer 153 and near the boundary with the reattachment film 161. Found to occur in parts. In FIG. 17, reference numeral 162 indicates a corroded portion of the high saturation magnetic flux density layer 153. In addition, the present inventor has found that the occurrence of corrosion of the high saturation magnetic flux density
It was found that not only the material described above, but also the redeposition film 161 was involved. Hereinafter, an experiment performed for investigating a cause of corrosion of the high saturation magnetic flux density layer 153 will be described.

In this experiment, a plating layer was formed by the following four methods. The basic method of forming the plating layer is the same as the method of forming the high saturation magnetic flux density layer 53 in the present embodiment or the method of forming the high saturation magnetic flux density layer 153 of the comparative example. In the first method, NiFe having a saturation magnetic flux density of 1.4 T is used as the material of the base film, the same NiFe is used as the material of the plating layer, and ion milling is performed to remove unnecessary portions of the base film. Was set to a direction perpendicular to the upper surface of the base film. In the second method, CoNiF having a saturation magnetic flux density of 1.8 T is used as a material of the base film.
e, the same CoNiFe was used as the material of the plating layer, and the direction of ion irradiation when removing unnecessary portions of the underlayer by ion milling was set to a direction perpendicular to the upper surface of the underlayer. In the third method, Ni is used as the material of the underlayer.
Fe was used, CoNiFe was used as the material of the plating layer, and the ion irradiation direction when removing unnecessary portions of the underlayer by ion milling was set to a direction perpendicular to the upper surface of the underlayer. In the fourth method, NiF is used as the material of the underlayer.
e, using CoNiFe as the material of the plating layer,
When removing unnecessary portions of the base film by ion milling, the upper surface of the base film and the side surfaces of the plating layer are formed so that the angle between the normal to the top surface of the base film and the irradiation direction of ions is 45 °. Irradiated with ions.

In the experiment, the plating layers formed by the above first to fourth methods were respectively covered with a nonmagnetic layer, and the nonmagnetic layer was polished by chemical mechanical polishing until the plating layer was exposed. The upper surfaces of the layer and the nonmagnetic layer were flattened.

In the experiment, next, the flattened surface of the plating layer formed by the first to fourth methods was observed with a scanning electron microscope. 18 to 21 respectively
FIG. 4 is a simplified view of an image of a flattened surface of a plating layer formed by the first to fourth methods, which is taken by a scanning electron microscope. 18 to 21, reference numeral 173 denotes a plating layer, reference numeral 181 denotes a re-adhesion film formed by re-adhering a substance separated from the base film by ion milling, and reference numeral 182 denotes a corroded portion of the plating layer 173. Is shown. Note that, as shown in FIG. 18, it is difficult to visually distinguish the plating layer 173 formed by the first method from the re-adhesion film 181. However, FIG.
As shown in FIG. 9 or FIG. 20, since the redeposition film 181 is formed on the side surface of the plating layer 173 formed by the second or third method, the plating layer formed by the first method is formed. It is clear that the redeposition film 181 is also formed on the side surface of the 173.

As shown in FIG. 18, when NiFe was used as the material of the plating layer 173, the plating layer 173 did not corrode even if the redeposition film 181 was formed. In contrast, as shown in FIGS. 19 and 20,
When CoNiFe was used as the material of the plating layer 173, corrosion of the plating layer 173 occurred. In FIG. 19 and FIG. 20, the corroded portion 182 occurs not in the outer periphery of the structure including the plating layer 173 and the redeposition film 181, but in a portion about 10 to 20 nm inside from the outer periphery of this structure. Therefore, the corroded portion 182 is formed by the redeposition film 181.
, That is, at a portion near the boundary between the plating layer 173 and the redeposition film 181. Corrosion of the plating layer 173 is caused by the same method as that of the second method except that the material of the base film is the same as that of the plating layer 173 using CoNiFe.
However, even when the material of the base film was NiFe different from the material of the plating layer 173 as in the third method, the problem occurred.

The reason why the plating layer 173 does not corrode when NiFe is used as the material of the plating layer 173 and the plating layer 173 corrodes when CoNiFe is used as the material of the plating layer 173 is as follows. It is considered as follows. That is, in chemical mechanical polishing, a workpiece is mechanically polished by a slurry and a polishing cloth. The slurry contains an abrasive (abrasive grains) and a working liquid for dispersing the abrasive. Therefore, depending on the combination of the type of the processing liquid and the material of the processing target, the processing target can be chemically etched by a chemical reaction between the processing liquid and the processing target. Here, when comparing the progress speed of the mechanical polishing and the progress speed of the chemical etching in the direction from the surface to the inside of the workpiece, if the progress speed of the mechanical polishing is higher, the workpiece is Does not occur, but if the rate of progress of chemical etching is higher, corrosion of the workpiece occurs. When NiFe is used as the material of the plating layer 173, it is considered that corrosion of the plating layer 173 does not occur because the mechanical polishing proceeds at a higher speed. On the other hand, when CoNiFe is used as the material of the plating layer 173 and the redeposition film 181 is present, the chemical etching proceeds at a higher rate, and the plating layer 1
It is considered that corrosion of 73 occurs.

The reason that the corrosion of the plating layer 173 occurs in the vicinity of the boundary with the redeposition film 181 is that a difference in ionization tendency between the plating layer 173 and the redeposition film 181 causes a potential difference between the two. Is considered to promote chemical etching. Material of base film is plating layer 17
No. 3 even if it is the same CoNiFe as the material of the plating layer 173
Is caused by the fact that the physical properties of the redeposition film 181 are not exactly the same as those of the underlying film.

On the other hand, as shown in FIG.
Even when CoNiFe is used as the material 73, the angle between the normal to the upper surface of the base film and the direction of ion irradiation is 45 ° when unnecessary portions of the base film are removed by ion milling. As described above, when the upper surface of the base film and the side surfaces of the plating layer 173 were irradiated with ions, no re-adhesion film was formed and the plating layer 173 did not corrode. In another experiment, the angle between the normal to the upper surface of the base film and the ion irradiation direction was set to 45 degrees.
° or more, the formation of the redeposition film and the plating layer 1
It was found that the corrosion of No. 73 could be prevented. in this way,
Even if CoNiFe is used as the material of the plating layer 173, if the formation of a re-adhesion film during ion milling is prevented, the plating layer 173 during chemical mechanical polishing can be used.
It has been found that corrosion of steel can be prevented.

As described above, in the present embodiment,
At least one of the step of forming the lower pole layer 8 and the step of forming the upper pole layer 12 includes a step of forming a conductive base film 51 and a step of forming a high saturation magnetic flux density layer 53 on the base film 51 by plating. Forming step and high saturation magnetic flux density layer 5
Removing the unnecessary portion of the base film 51 by ion milling after the formation of the high saturation magnetic flux density layer 5;
Forming the non-magnetic layer 54 covering the third magnetic layer 3 and polishing the non-magnetic layer 54 by chemical mechanical polishing until the high-saturation magnetic flux density layer 53 is exposed. Flattening. Further, in this embodiment, in the step of removing unnecessary portions of the base film 51 by ion milling, the angle between the normal to the upper surface of the base film 51 and the ion irradiation direction is 45 degrees.
Irradiation is performed on the side surfaces of the base film 51 and the high saturation magnetic flux density layer 53 so that the angle is equal to or more than 0 °. This allows
The substance separated from the base film 51 by the ion milling is prevented from re-adhering to the side surface of the high saturation magnetic flux density layer 53. As a result, according to the present embodiment, high saturation magnetic flux density layer 53 and non-magnetic layer 54 are formed by chemical mechanical polishing.
Can be prevented from corroding the high saturation magnetic flux density layer 53 when the upper surface of the thin film magnetic head is flattened, and the yield of the thin film magnetic head can be improved.

According to the present embodiment, the nonmagnetic layer 2 disposed on the upper surface of the lower magnetic pole layer 8 and around the lower magnetic pole layer 8
1 is flattened, and the first surface of the thin-film coil is placed on these flattened surfaces via the recording gap layer 9.
The layer portion 10 and the track width defining layer 12a can be formed with high accuracy. As a result, according to the present embodiment,
It is possible to reduce the magnetic path length of the recording head by reducing the pitch of the windings of the thin-film coil 10 and to reduce the recording track width. Therefore, according to the present embodiment, it is possible to manufacture a thin film magnetic head corresponding to a higher recording density with a high yield.

Hereinafter, a head gimbal assembly and a hard disk drive to which the thin film magnetic head according to the present embodiment is applied will be described. First, referring to FIG. 22, slider 21 included in the head gimbal assembly
0 will be described. In the hard disk device, the slider 210 is arranged so as to face a hard disk which is a disk-shaped recording medium that is driven to rotate. The slider 210 includes a base 211 mainly including the substrate 1 and the overcoat layer 17 in FIG. The base 211 has a substantially hexahedral shape. One of the six surfaces of the base 211 faces the hard disk. On one surface, a rail portion 212 whose surface is an air bearing surface is formed. Rail part 212
A tapered portion or a step portion is formed near an end on the air inflow side (an upper right end in FIG. 22). When the hard disk rotates in the z direction in FIG. 22, an air flow that flows from the tapered portion or the step portion and passes between the hard disk and the slider 210 generates a lift in the slider 210 below the y direction in FIG. 22. The slider 210 flies above the surface of the hard disk by the lift. Note that FIG.
The x direction in 2 is the track cross direction of the hard disk. The air outlet side end of the slider 210 (FIG. 22)
(The lower left end in FIG. 1), the thin-film magnetic head 100 according to the present embodiment is formed.

Next, the head gimbal assembly 220 according to the present embodiment will be described with reference to FIG. The head gimbal assembly 220 includes a slider 210 and a suspension 221 that elastically supports the slider 210. Suspension 2
Reference numeral 21 denotes a plate-shaped load beam 222 made of, for example, stainless steel, and a flexure 223 provided at one end of the load beam 222 and joined to the slider 210 to give the slider 210 an appropriate degree of freedom.
And a base plate 224 provided at the other end of the load beam 222. Base plate 224
Is mounted on an arm 230 of an actuator for moving the slider 210 in the track cross direction x of the hard disk 300. The actuator has an arm 230 and a voice coil motor that drives the arm 230. Flexure 223
In the part where the slider 210 is attached,
A gimbal portion is provided for keeping the attitude of the slider 210 constant.

The head gimbal assembly 220 is attached to the arm 230 of the actuator. One in which the head gimbal assembly 220 is attached to one arm 230 is called a head arm assembly. Also,
A carriage having a plurality of arms with the head gimbal assembly 220 attached to each arm is called a head stack assembly.

FIG. 23 shows an example of the head arm assembly. In this head arm assembly, a head gimbal assembly 220 is attached to one end of an arm 230. A coil 231 that is a part of a voice coil motor is attached to the other end of the arm 230. A bearing 233 attached to a shaft 234 for rotatably supporting the arm 230 is provided at an intermediate portion of the arm 230.

Next, an example of a head stack assembly and a hard disk device according to the present embodiment will be described with reference to FIGS. 24 and 25. FIG. 24 is an explanatory view showing a main part of the hard disk drive, and FIG. 25 is a plan view of the hard disk drive. Head stack assembly 2
50 is a carriage 251 having a plurality of arms 252
have. A plurality of head gimbal assemblies 220 are attached to the plurality of arms 252 so as to be spaced apart from each other and arranged in a vertical direction. Carriage 25
1, a coil 253 which is a part of a voice coil motor is attached to the side opposite to the arm 252. The head stack assembly 250 is incorporated in a hard disk drive. The hard disk device has a plurality of hard disks 262 attached to a spindle motor 261. Two sliders 210 are arranged for each hard disk 262 so as to face each other with the hard disk 262 interposed therebetween. Further, the voice coil motor is connected to the coil 25 of the head stack assembly 250.
3 are provided at positions facing each other with the permanent magnet 263 interposed therebetween.

The head stack assembly 250 and the actuator except for the slider 210
And is positioned with respect to the hard disk 262.

In the hard disk drive of the present embodiment, the slider 210 is moved by the actuator in the direction across the tracks of the hard disk 262, and the slider 210 is positioned with respect to the hard disk 262. The thin-film magnetic head included in the slider 210 records information on the hard disk 262 by a recording head, and reproduces information recorded on the hard disk 262 by a reproducing head.

The present invention is not limited to the above embodiment, and various changes can be made. For example, in the embodiment, the lower magnetic pole layer 8 is constituted by one layer, but the lower magnetic pole layer 8 is divided into a yoke partial layer and a magnetic pole partial layer formed on the yoke partial layer. Is also good. In this case, at least one of the yoke partial layer and the magnetic pole partial layer may be the high saturation magnetic flux density layer in the present invention.

Further, in the above-described embodiment, the thin-film magnetic head having the structure in which the reading MR element is formed on the substrate side and the inductive electromagnetic transducer for writing is laminated thereon has been described. The order may be reversed.

That is, an inductive electromagnetic transducer for writing may be formed on the substrate side, and an MR element for reading may be formed thereon. In such a structure, for example, the magnetic film having the function of the upper magnetic pole layer shown in the above-described embodiment is formed on the substrate side as a lower magnetic pole layer, and the magnetic film having the above-described structure is opposed to the magnetic pole layer via a recording gap film. It can be realized by forming the magnetic film having the function of the lower magnetic pole layer shown in the embodiment as the upper magnetic pole layer.

The present invention can also be applied to a thin-film magnetic head exclusively for recording provided with only an inductive electromagnetic transducer, and a thin-film magnetic head for performing recording and reproduction by using an inductive electromagnetic transducer.

[0074]

As described above, in the method of manufacturing a thin-film magnetic head according to the present invention, at least one of the step of forming the first magnetic layer and the step of forming the second magnetic layer has a low conductivity. Forming a base film, forming a high saturation magnetic flux density layer on the base film by plating, and removing unnecessary portions of the base film by ion milling after forming the high saturation magnetic flux density layer Forming a non-magnetic layer covering the high saturation magnetic flux density layer, and polishing the non-magnetic layer by chemical mechanical polishing until the high saturation magnetic flux density layer is exposed. Flattening the upper surface. Further, in the present invention, in the step of removing unnecessary portions of the base film by ion milling, the base film may be formed so that the angle between the normal to the upper surface of the base film and the ion irradiation direction is 45 ° or more. In addition, ions are irradiated to the side surface of the high saturation magnetic flux density layer. This prevents the substance separated from the base film by ion milling from re-adhering to the side surface of the high saturation magnetic flux density layer. As a result, according to the present invention, it is possible to prevent corrosion of the high saturation magnetic flux density layer when the upper surfaces of the high saturation magnetic flux density layer and the nonmagnetic layer are flattened by chemical mechanical polishing.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically illustrating a method of manufacturing a thin-film magnetic head according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view for explaining a step following the step shown in FIG.

FIG. 3 is a cross-sectional view for explaining a step following the step shown in FIG. 2;

FIG. 4 is a cross-sectional view for explaining a step following the step shown in FIG. 3;

FIG. 5 is a cross-sectional view for explaining a step following the step shown in FIG. 4;

FIG. 6 is a cross-sectional view for explaining a step following the step shown in FIG. 5;

FIG. 7 is a cross-sectional view for explaining a method of forming a high saturation magnetic flux density layer in one embodiment of the present invention.

FIG. 8 is a cross-sectional view for explaining a step following the step shown in FIG. 7;

FIG. 9 is a cross-sectional view for explaining a step following the step shown in FIG. 8;

FIG. 10 is a cross-sectional view for explaining a step following the step shown in FIG. 9;

FIG. 11 is a cross-sectional view for explaining a step following the step shown in FIG. 10;

FIG. 12 is a cross-sectional view for explaining a step following the step shown in FIG. 11;

FIG. 13 is a cross-sectional view for explaining a step following the step shown in FIG. 12;

FIG. 14 is a cross-sectional view for explaining a comparative example with respect to a method of forming a high saturation magnetic flux density layer in one embodiment of the present invention.

FIG. 15 is a sectional view for illustrating a step following the step shown in FIG. 14;

FIG. 16 is a cross-sectional view for explaining a step following the step shown in FIG. 15;

FIG. 17 is a sectional view for illustrating a step following the step shown in FIG. 16;

FIG. 18 is an explanatory diagram showing the results of an experiment conducted to find out the cause of corrosion of the high saturation magnetic flux density layer.

FIG. 19 is an explanatory diagram showing the results of an experiment conducted to investigate the cause of corrosion of the high saturation magnetic flux density layer.

FIG. 20 is an explanatory diagram showing the results of an experiment conducted to investigate the cause of corrosion of the high saturation magnetic flux density layer.

FIG. 21 is an explanatory diagram showing the results of an experiment performed to find out the cause of corrosion of a high saturation magnetic flux density layer.

FIG. 22 is a perspective view showing a slider included in the head gimbal assembly according to one embodiment of the present invention.

FIG. 23 is a perspective view showing a head arm assembly including a head gimbal assembly according to one embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a main part of a hard disk device according to an embodiment of the present invention.

FIG. 25 is a plan view of a hard disk drive according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Insulating layer, 3 ... Lower shield layer, 5 ... MR
Element 8, lower magnetic pole layer, 9: recording gap layer, 10: first layer portion of thin film coil, 12: upper magnetic pole layer, 12a: track width defining layer, 12b: connecting partial layer, 12c: yoke partial layer, 14 ... Non-magnetic layer, 15: Second layer portion of thin-film coil, 21: Non-magnetic layer, 50: Underlayer, 51: Underlayer, 52
... frame, 53 ... high saturation magnetic flux density layer, 54 ... non-magnetic layer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuya Mino 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Reichi Kurumizawa 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Toshio Kubota 1-13-1 Nihonbashi, Chuo-ku, Tokyo F-term within TDK Corporation (reference) 5D033 AA01 BA03 BA07 BA12 BA61 DA03 DA04 DA08 DA31

Claims (2)

[Claims] 1. A first and a second magnetic layer including a medium facing surface facing a recording medium and magnetic pole portions magnetically coupled to each other and facing each other on the medium facing surface side, each including at least one layer. A layer, a gap layer provided between a magnetic pole part of the first magnetic layer and a magnetic pole part of the second magnetic layer, at least a part of which is between the first and second magnetic layers, A thin-film coil provided in a state insulated from the first and second magnetic layers, wherein at least one of the first magnetic layer and the second magnetic layer is made of a magnetic material containing Co. A method of manufacturing a thin-film magnetic head having a high saturation magnetic flux density layer, comprising: forming the first magnetic layer; forming the gap layer on the first magnetic layer; Forming the second magnetic layer on the layer And forming the thin film coil. At least one of the step of forming the first magnetic layer and the step of forming the second magnetic layer is a step of forming a conductive base film. Forming the high saturation magnetic flux density layer on the underlying film by plating, and removing unnecessary portions of the underlying film by ion milling after forming the high saturation magnetic flux density layer. Forming a non-magnetic layer covering the high-saturation magnetic flux density layer, and polishing the non-magnetic layer until the high-saturation magnetic flux density layer is exposed by chemical mechanical polishing, so that the high-saturation magnetic flux density layer and the Flattening the upper surface of the non-magnetic layer, wherein the step of removing unnecessary portions of the underlayer is performed at an angle of 45 ° or more between the normal to the upper surface of the underlayer and the ion irradiation direction. So that Method of manufacturing a thin film magnetic head is characterized in that ion irradiation to the side surface of the upper surface and the high saturation magnetic flux density layer of the base film. 2. The method according to claim 1, wherein the magnetic material containing Co has a saturation magnetic flux density of 1.8 T or more.