JPH11250415A - Thin film magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a thin film magnetic head capable of suppressing the leakage of magnetic flux from the leading edge of an upper pole holding a pole chip for forming a narrow track between the upper pole itself and a write gap and quickly removing dust or the like intruded between the air bearing face of a slider and a recording medium and a method for easily and inexpensively manufacturing the thin film magnetic head. SOLUTION: The leading edge of a 4th magnetic layer 16 constituting the upper pole exposed to the air bearing face 18 of the slider 31 is retreated from the air bearing face 18 by etching for forming a rail on the air bearing face 18 of the slider 31 to improve floating. Then a groove 32 connected to the leading edge of the retreated 4th magnetic layer 16 is formed on the surface of an overcoat layer 17 so as to reach the trailing edge end face of the slider 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thin-film magnetic head and a method of manufacturing the same, and more particularly to an inductive thin-film magnetic head for writing and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, as the areal recording density of a hard disk device has been improved, the performance of a thin-film magnetic head has also been required to be improved. The thin-film magnetic head has a structure in which a recording head for writing and a reproducing head for reading are stacked, and a magnetoresistive element is widely used for improving the performance of the reproducing head. As such a magnetoresistive element, a normal anisotropic magnetoresistance (AM
R: Anisotropic Magneto Resistive effect has been used in the past, but giant magnetoresistance (GMR: Giant Magneto Resi) whose resistance change rate is several times larger than this
Stive) effects have also been developed. In this specification, the AMR element and the GMR element are collectively referred to as a magnetoresistive reproducing element or an MR reproducing element.

By using an AMR element, a surface recording density of several gigabits / inch ² can be realized.
The use of the GMR element can further increase the areal recording density. By increasing the areal recording density in this manner, a hard disk device having a large capacity of 10 Gbytes or more can be realized. One of the factors that determine the performance of a read head including such a magnetoresistive read element is the height of the magnetoresistive read element (MR Heigh
t: MR height). The MR height is the distance measured from the air bearing surface of the magnetoresistive reproducing element whose end surface is exposed to the air bearing surface. In the process of manufacturing a thin-film magnetic head, the polishing when the air bearing surface is formed by polishing is performed. The desired MR height is obtained by controlling the amount.

On the other hand, as the performance of the reproducing head is improved, the performance of the recording head is also required to be improved. To increase the areal recording density, it is necessary to increase the track density in the magnetic recording medium. For this purpose, it is necessary to reduce the width of a write gap on the air bearing surface from a few microns to a submicron order, and semiconductor processing technology is used to achieve this.

One of the factors that determine the performance of a thin-film magnetic head for writing is a throat height (T).
H). The throat height is the distance of the magnetic pole portion from the air bearing surface to the edge of the insulating layer that electrically separates the thin-film coil, and it is desired that the distance be as short as possible. This reduction in throat height is also determined by the amount of polishing from the air bearing surface. Therefore, in order to improve the performance of the combined thin film magnetic recording / reproducing head, it is important to form the recording head and the reproducing head in a well-balanced manner.

1 to 9 show the procedure of manufacturing a conventional standard thin film magnetic head in the order of steps. In each figure, A is a sectional view of the entire thin film magnetic head, and B is a sectional view of a magnetic pole portion.
10 to 12 are a sectional view of the completed conventional thin film magnetic head, a sectional view of a magnetic pole portion, and a plan view of the entire thin film magnetic head, respectively. In this example, the thin-film magnetic head is a composite type in which an inductive type thin-film magnetic head for writing and an MR reproducing element for reading are stacked.

First, as shown in FIG. 1, alumina (Al ₂ O 3) is formed on a substrate 1 made of, for example, AlTiC (AlTiC).
An insulating layer 2 of O ₃ ) is deposited to a thickness of about 5 to 10 μm. Next, as shown in FIG. 2, a lower shield 3 having a magnetic shielding effect for protecting the MR reproducing element of the reproducing head from the influence of an external magnetic field is formed with a thickness of, for example, 3 μm. Thereafter, as shown in FIG. 3, as a first shield gap layer 4, alumina is sputter-deposited with a thickness of 100 to 150 nm, and then a magnetoresistive layer made of a material having a magnetoresistive effect constituting an MR reproducing element. 5 is formed to a thickness of several tens of nm, and is formed into a desired shape by highly accurate mask alignment. Subsequently, as shown in FIG. 4, alumina is sputter-deposited with a thickness of 100 to 150 nm as a second shield gap layer 6, and a magnetoresistive layer 5 is formed in the first and second shield gap layers 4 and 6. Buried.

Next, as shown in FIG. 5, a first magnetic layer 7 made of permalloy is formed to a thickness of 3 μm. The first magnetic layer 7 and the lower shield layer 3 together with the MR
In this specification, since not only has the function of an upper shield layer for magnetically shielding the reproducing element but also has the function of a lower pole of a thin-film magnetic head for writing formed on the MR reproducing element. This magnetic layer is referred to as a first magnetic layer.

Next, a write gap layer 8 made of a non-magnetic material, for example, alumina is formed on the first magnetic layer 7 by about 20 nm.
After being formed to a thickness of 0 nm, for example, permalloy (Ni: 80 wt.
%, Fe: 20 wt%) or a second magnetic layer 9 made of a high saturation magnetic flux density material such as iron nitride (FeN), and is formed into a desired shape by highly accurate mask alignment. The second magnetic layer 9 formed into a predetermined shape is called a pole tip, and the width W defines a track width. Therefore, it is necessary to reduce the width W of the pole tip in order to realize a high areal recording density. At this time, if the first magnetic layer 7 constituting the lower pole of the induction type thin-film magnetic head and the dummy pattern 9 'for connecting the third magnetic layer constituting the upper pole described later are formed simultaneously, Polishing or Chemical Mechanical Polishing (C)
Opening of the through hole after MP) can be facilitated.

Then, in order to prevent the effective write track width from spreading, that is, to prevent the magnetic flux from spreading in the first magnetic layer 7 at the time of writing data, the second magnetic layer forming the pole tip is formed. The surfaces of the write gap layer 8 and the first magnetic layer 7 around the layer 9 are etched by ion beam etching such as ion milling. FIG. 5 shows this state, and this structure is called a trim (Trim), and this portion becomes the magnetic pole portion of the lower pole constituted by the first magnetic layer 7.

Next, as shown in FIG. 6, after forming an insulating layer, for example, an alumina film 10 to a thickness of about 3 μm, the whole is flattened by, for example, CMP. Thereafter, an insulating layer 11 made of a photoresist is formed into a predetermined pattern by high-precision mask alignment, and then a first-layer thin-film coil 12 made of, for example, copper is formed on the insulating layer.

Subsequently, as shown in FIG.
After the insulating layer 13 made of photoresist is formed on the substrate 2 again by high-precision mask alignment, it is baked at a temperature of, for example, 250 to 300 ° C. to flatten the surface.

Further, as shown in FIG.
3 on the flattened surface of the second thin film coil 1
4 is formed. Next, the second-layer thin-film coil 14 is formed.
After the insulating layer 15 made of photoresist is formed on the substrate by high-precision mask alignment, baking is performed at, for example, 250 ° C. to flatten the surface again. As described above, the reason why the insulating layers 11, 13 and 15 are formed by high-precision mask alignment is that the throat height and the MR height are defined with the edge on the magnetic pole portion side of the insulating layer 11 as a reference position, and these insulating layers are formed. This is because the apex angle is defined by the contour of the layer.

Next, as shown in FIG. 9, a second magnetic layer (pole chip) 9 and insulating layers 11, 13 and 15 are formed.
A third magnetic layer 16 made of, for example, permalloy is selectively formed with a thickness of 3 μm according to a desired pattern. The third magnetic layer 16 constitutes an upper pole, and is in contact with the first magnetic layer 7 via the dummy pattern 9 ′ at a rear position away from the magnetic pole portion, thereby forming the first magnetic layer and the first magnetic layer. The structure is such that the thin film coils 12 and 14 pass through a closed magnetic path constituted by the second and third magnetic layers. Further, an overcoat layer 17 made of alumina is deposited on the exposed surface of the third magnetic layer 16.

Finally, the side surface on which the magnetoresistive layer 5 and the gap layer 8 are formed is polished to form an air bearing surface (ABS) 18 facing the magnetic recording medium.
In the process of forming the air bearing surface 18, the magnetoresistive layer 5 is also polished, and the MR reproducing element 19 is obtained. Thus, the above-described throat height TH and MR height are determined. This is shown in FIG. In an actual thin-film magnetic head, pads for making electrical connection to the thin-film coils 12, 14 and the MR reproducing element 19 are formed, but are omitted in the drawing.

As shown in FIG. 10, the thin film coils 12,
The angle θ formed between the line segment S connecting the corners of the side surfaces of the insulating layers 11, 13, and 15 that insulates and separates 14 from the upper surface of the third magnetic layer 16
(ApexAngle) is also an important factor that determines the performance of the thin-film magnetic head, together with the above-described throat height TH and MR height.

As shown in FIG. 12, the width W of the second magnetic layer 9 constituting the pole tip is narrow, and the width of the track recorded on the magnetic recording medium is defined by this width. Therefore, in order to realize a high areal recording density, it is necessary to make the width W as narrow as possible.

Conventionally, a particular problem in forming a thin-film magnetic head is that, after the coil is formed, a coil protrusion covered with a photoresist insulating layer, particularly its inclined portion (Ap).
ex) It is difficult to finely form the upper pole (yoke pole) formed along the ex. That is, conventionally, when forming the upper pole, after plating a material for the upper pole such as permalloy on the coil protrusion having a height of about 7 to 10 μm, a photoresist is applied in a thickness of 3 to 4 μm, After that, a predetermined pattern was formed using photolithography technology.

Here, assuming that a minimum resist film thickness of 3 μm to be patterned by the resist on the convex portion of the mountain-shaped coil is required, a photoresist having a thickness of about 8 to 10 μm is applied below the inclined portion. Will be. On the other hand, the upper pole formed on the surface of the coil protrusion having such a height difference of about 10 μm and the light gap layer formed on the flat surface is formed of a photoresist insulating layer (for example, 11 and 13 in FIG. 7). It is necessary to form a narrow track of the recording head near the edge of
It must be patterned to m width. Therefore, 8 ~
It becomes necessary to form a pattern having a width of 1 μm using a photoresist film having a thickness of 10 μm.

However, even if an attempt is made to form a pattern having a width as small as about 1 μm with a photoresist film as thick as 8 to 10 μm, pattern distortion due to light reflected by light at the time of photolithographic exposure occurs, Since the resolution is reduced due to the large film thickness, it is extremely difficult to accurately form a narrow top pole for forming a narrow track.

Therefore, as shown in the above-mentioned conventional example, after the second magnetic layer 9 constituting the pole chip capable of forming a narrow track width of the recording head is formed on the write gap 8, this pole chip A structure has been proposed in which a third magnetic layer 16 constituting an upper pole is connected. In this way, by forming the pole tip 9 for determining the track width and the third magnetic layer 16 constituting the upper pole for inducing magnetic flux into two, the writing of the track having a width as narrow as about 1 μm is performed. And the efficiency of use of magnetic flux is increased.

[0022]

However, the thin-film magnetic head formed as described above, particularly the recording head, still has the following problems. That is, the third magnetic layer 1 constituting the upper pole
6 is exposed on the air bearing surface 18, a part of the magnetic flux generated by the thin film coil does not pass through the second magnetic layer 9 constituting the pole tip, and the second magnetic layer From the front end surface of the magnetic recording medium. Such a tendency is more remarkable because the distance between the air bearing surface of the thin-film magnetic head and the magnetic recording medium is becoming narrower. In this case, as shown in FIG. 11, the width of the front end face of the third magnetic layer 16 is wider than the width W of the second magnetic layer 9, so that the leakage from the front end face of the third magnetic layer 16 is prevented. The width of the magnetic flux is widened, the width of the recording track is widened, and there is a disadvantage of causing interference with an adjacent track. As a result, the significance of providing a pole tip is lost. Further, if the magnetic flux leaks from the tip end surface exposed on the air bearing surface 18 of the third magnetic layer 16 as described above, the use efficiency of the magnetic flux is reduced and the efficiency of the thin film magnetic head is deteriorated. is there.

When a magnetic storage device such as a hard disk is constituted by the above-described thin film magnetic head,
An element called a slider is formed by cutting and polishing a base on which necessary members are formed. This slider has a flat shape as a whole, and one main surface is used as an air bearing surface, and recording and reproduction are performed with this air bearing surface facing the surface of the magnetic recording medium. During operation, the air bearing surface of the slider is spaced apart from the surface of the recording medium by a small distance, so that the slider is floating. With the improvement in areal recording density, the above-mentioned interval is becoming narrower, and recently, several tens n
m. As described above, when the distance between the air bearing surface of the slider and the surface of the magnetic recording medium is reduced, if foreign matter such as dust enters between them, the magnetic characteristics fluctuate and normal operation cannot be performed. In particular, there is a drawback that when a contaminant enters the write gap portion of the inductive type thin film magnetic head, the write characteristics and the read characteristics are greatly reduced.

An object of the present invention is to solve the above-mentioned problem advantageously, and to prevent a magnetic flux from leaking from the front end surface of the third magnetic layer, to realize a pole tip for realizing a narrow track. The thin-film magnet that can exhibit its effects effectively and can quickly discharge dust that has entered between the write gap of the inductive thin-film magnetic head and the magnetic recording medium that appears on the air bearing surface of the slider. It is intended to provide a head. Another object of the present invention is to propose a method capable of easily and inexpensively manufacturing a thin film magnetic head having the above-described characteristics.

[0025]

A thin-film magnetic head according to the present invention opposes a first magnetic layer having a magnetic pole portion exposed on an air bearing surface of a slider, a magnetic recording medium, and defines a width of a recording track. A second magnetic layer forming an air bearing surface together with an end surface of the magnetic pole portion forming a pole tip having a width, and an end surface of the magnetic pole portion together with an end surface of the magnetic pole portion of the first magnetic layer; A third magnetic layer in contact with the layer on the side opposite to the first magnetic layer side and magnetically coupled to the first magnetic layer at a rear position away from the air bearing surface; and at least the magnetic pole portion First in
A gap layer made of a nonmagnetic material interposed between the magnetic pole portion of the magnetic layer and the magnetic pole portion of the second magnetic layer, and a magnetic flux for writing to a magnetic recording medium is generated on the air bearing surface. A thin-film coil having a portion disposed between the first magnetic layer and the second and third magnetic layers with an insulating layer interposed therebetween; and the first, second and third magnetic layers and the gap layer. And an overcoat layer provided so as to cover the insulating layer, and a base supporting the first, second, and third magnetic layers, the gap layer, the insulating layer, the thin-film coil, and the overcoat layer. A thin-film magnetic head, wherein a tip end surface of the third magnetic layer is retreated from an air bearing surface, and the retreated tip end surface is exposed to an air bearing surface through an opening formed in the overcoat layer. Features Is shall.

In such a thin-film magnetic head according to the present invention, the tip surface of the third magnetic layer constituting the upper pole is receded from the air bearing surface facing the magnetic recording medium. The distance between the leading end surface of the layer and the recording medium becomes longer, so that the leakage of magnetic flux can be effectively suppressed, and the possibility that the foreign matter remains between them becomes smaller. Further, in the embodiment in which a groove that is continuous with the leading end surface of the receded third magnetic layer and extends to the trailing end surface of the slider is formed on the surface constituting the air bearing surface of the overcoat layer, the write gap The contaminants that have entered between the recording medium and the
Since it is quickly removed, the possibility that the magnetic recording characteristics are degraded by contaminants is further reduced.

In the thin film magnetic head according to the present invention,
The groove formed on the surface of the overcoat layer extends to the end surface on the trailing side of the slider, and the shape as viewed from the direction perpendicular to the air bearing surface extends from the front end surface of the second magnetic layer toward the end surface of the slider. It is preferable that the opening be expanded. With such a configuration, the effect of removing the foreign substances is further improved.

The present invention further provides a first magnetic layer having a magnetic pole portion exposed on an air bearing surface of a slider, and a magnetic pole constituting a pole tip facing a magnetic recording medium and having a width defining a recording track width. A second magnetic layer having an air bearing surface together with an end surface of the magnetic pole portion of the first magnetic layer;
Contacting the magnetic layer on the side opposite to the first magnetic layer side,
A third magnetic layer magnetically coupled to the first magnetic layer at a position rearward from the air bearing surface, and a magnetic pole portion of the first magnetic layer and a magnetic pole portion of the second magnetic layer at least in the magnetic pole portion A first magnetic layer, a second magnetic layer, and a third magnetic layer so as to generate a magnetic flux for writing to a magnetic recording medium on the air bearing surface. A thin-film coil having a portion disposed with an insulating layer interposed therebetween; and an overcoat layer disposed to cover the first, second, and third magnetic layers, the gap layer, and the insulating layer. , The first and second
And a substrate supporting a third magnetic layer, a gap layer, an insulating layer, a thin-film coil, and an overcoat layer, the method comprising the steps of: The present invention is characterized in that the leading end surface that appears is selectively etched to retreat the leading end surface of the third magnetic layer from the air bearing surface. In the manufacturing method according to the present invention, the tip surface of the third magnetic layer is selectively etched and the tip surface of the third magnetic layer is recessed from the air bearing surface, so that the tip surface is continuously connected to the tip surface of the third magnetic layer. A groove extending to the trailing end surface of the slider can be formed on the surface of the overcoat layer.

In carrying out the above-described manufacturing method according to the present invention, the tip surface of the third magnetic layer is retracted and the air bearing surface of the slider is etched by an etching process for forming a groove in the surface of the overcoat layer. It is preferable to simultaneously form rails of a predetermined shape in order to simplify the process. In this case, the etching rate for a material such as Altic which constitutes the base of the slider, the etching rate for a material such as non-magnetic and insulating alumina such as alumina which constitutes the overcoat layer, and the third magnetic layer The material is selected so that the ratio of the etching rate to the magnetic material such as permalloy is appropriately set, and the etching conditions are set so that the height of the rail formed on the slider is, for example, 3 to 4 μm. , The depth of the groove is, for example, 0.5
１1 μm.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. The thin film magnetic head according to the present invention may have only an inductive type thin film magnetic head, but is preferably a composite type thin film magnetic head combining a reading head such as a magnetoresistive effect type thin film magnetic head. It is. Therefore, in the following embodiment, such a composite type thin film magnetic head will be described. Further, of the steps of manufacturing the thin-film magnetic head according to the present invention, the steps up to forming the required members on the base are the same as the conventional steps. That is, the steps shown in FIGS. 1 to 9 are the same as those in the related art.

As shown in FIG. 9, AlTiC (AlTi)
An insulating layer 2 made of, for example, alumina is deposited to a thickness of about 5 to 10 .mu.m on a substrate 1 made of C), and a lower shield layer 3 is formed thereon to a thickness of 3 .mu.m. The layer 4 is sputter-deposited to a thickness of 100 to 150 nm, a magnetoresistive layer 5 constituting an MR reproducing element is formed thereon to a thickness of several tens of nm, and a second shield gap layer 6 made of alumina is formed. It is formed.

Further, a first magnetic layer 7 made of permalloy, which constitutes an upper pole for the MR element and also constitutes a lower pole of the inductive type thin film magnetic head, is formed to a thickness of 3 μm, and a light layer made of alumina is formed thereon. After forming the gap layer 8 to a thickness of about 200 nm, the permalloy (Ni:
A second magnetic layer 9 made of a high saturation magnetic flux density material such as 80 wt%, Fe: 20 wt%) or iron nitride (FeN) is formed, and a pole tip is formed in a desired shape by highly accurate mask alignment. Further, using the second magnetic layer 9 as a mask, the write gap layer 8 and the first magnetic layer 7 are etched by ion beam etching such as ion milling to form a trim structure.

Further, an insulating layer 10 made of alumina is formed to a thickness of about 3 μm, and the insulating layers 11 and 1 are formed thereon.
The thin film coils 12, 14 supported in a state of being insulated and separated by the third and third layers 15 are formed, and the second magnetic layer 9 and the insulating layers 11, 13 and 15 are further formed of permalloy constituting an upper pole. The third magnetic layer 16 is selectively formed with a thickness of 3 μm according to a desired pattern, and an overcoat layer 17 made of alumina is deposited on the exposed surface including the exposed surface of the third magnetic layer 16.

When mass-producing a composite thin-film magnetic head, a part necessary for the composite thin-film magnetic head is formed on a wafer constituting the base 1, and then the wafer is scribed to form a large number of composite thin-film magnetic heads. Are divided into bars in which are arranged, the side surfaces of each bar are polished to form an air bearing surface, and the bars are further divided to form individual sliders. FIG. 13 is a perspective view showing the slider 31 formed in this manner, and its air bearing surface 1 is shown.
8 shows an MR element 19 of a magnetoresistive thin film magnetic head.
And the edge of the write gap 8 of the inductive type thin film magnetic head appears.

The air bearing surface 18 of the slider 31
In order to give a desired floating characteristic, the rail is formed by etching, but in the present invention, at the time of etching for forming the rail, FIG.
15 is an overall perspective view, FIG. 15 is an enlarged perspective view, and FIG.
The tip surface of the third magnetic layer 16 exposed at the same time is etched at the same time to retreat the tip surface from the air bearing surface, and the air bearing surface 1 of the overcoat layer 17 is removed.
A groove 32 is formed on the surface of the magnetic disk 8, which is continuous with the distal end surface of the third magnetic layer 16 which has been retracted as described above and reaches the end surface 33 of the slider 31 on the trailing side.

Conventionally, in order to improve the flying characteristics of a slider, a rail having a desired shape is formed on an air bearing surface of the slider. Argon ion beam milling has usually been used for etching to form such rails. However, it has been difficult to form the rail on the slider by such ion beam etching, and at the same time, to retreat the tip surface of the third magnetic layer and to form a groove continuous with the tip surface in the overcoat layer. .

Therefore, in this embodiment, reactive ion etching using CF ₄ and Cl ₂ based gas is adopted. According to such reactive ion etching, the etching rate for the insulating material such as Altic which forms the base 1 is 5 to 5 times lower than the etching rate for the magnetic material such as Permalloy which forms the third magnetic layer 16.
Since it is 7 times faster, the same etching process
4, the height of the third magnetic layer 16 from the air bearing surface 18 is 0.5 to 1.0.
μm. Further, in this case, the etching rate of the alumina constituting the overcoat layer 17 by reactive ion etching can be made substantially equal to the etching rate of the third magnetic layer 16 by appropriately selecting the etching conditions. ,
Therefore, the amount of retreat of the tip surface of the third magnetic layer can be made substantially the same as the depth of the groove 32.

As described above, the tip surface of the third magnetic layer 16 constituting the upper pole of the induction type thin film magnetic head is retracted from the air bearing surface 18 so that the tip surface of the third magnetic layer and the top surface of the third magnetic layer are magnetically displaced. The distance from the recording medium becomes longer accordingly, so that the leakage of magnetic flux from the tip surface of the fourth magnetic layer is effectively suppressed. Therefore, the width of the recording track does not increase and interferes with an adjacent track, so that a narrow recording track defined by the width of the pole tip made of the second magnetic layer 9 can be obtained, and the areal recording density can be reduced accordingly. Can be improved.

In this embodiment, the overcoat layer 1
The shape of the groove 32 formed on the surface constituting the air bearing surface 18 of the slider 7 seen from the direction perpendicular to the air bearing surface 18 is clearly shown in FIG. It is formed in a shape that expands toward. By forming the groove 32 having such a shape, contaminants invading between the end face of the MR element 19 or the end face of the write gap layer 8 appearing on the air bearing surface 18 of the slider 31 and the magnetic recording medium. Can be quickly eliminated along the groove, and the recording and reproducing characteristics of the thin film magnetic head can be improved. The width of the groove 32 may be larger than the width of the tip of the third magnetic layer 16. The air bearing surface 18 of the slider 31
The shape of the rail 34 formed is such that desired floating characteristics can be obtained, and is not limited to the shape shown in the drawings.

The present invention is not limited to the above-described embodiment, but can be variously modified and modified. For example, in the above-described embodiment, the composite type thin film magnetic head in which the inductive type thin film magnetic head for writing and the magnetoresistive effect type thin film magnetic head for reading are laminated on the substrate is used. The head does not have to be provided. Further, in the above-described embodiment, the trim structure is formed in the first magnetic layer 8 by performing etching using the pole tip constituted by the second magnetic layer 9 as a mask, but such a trim structure is not necessarily required. is not.

[0041]

As described above, according to the thin-film magnetic head according to the present invention, the tip end surface of the third magnetic layer 16 constituting the upper pole of the inductive type thin-film magnetic head appears on the air bearing surface 18 from the air bearing surface. , The distance between the leading end surface of the third magnetic layer and the magnetic recording medium can be increased, and therefore, the leakage of magnetic flux from the leading end surface of the third magnetic layer can be effectively suppressed. Therefore, the width of the recording track does not become wider than the width of the second magnetic layer 9 constituting the pole tip, and a high areal recording density can be realized. Further, since the utilization efficiency of the magnetic flux is improved, an efficient thin-film magnetic head can be obtained.

Further, as described above, the air bearing surface 18
A groove 32 is formed on the surface constituting the air bearing surface of the overcoat layer 17, the groove 32 being continuous with the distal end surface of the third magnetic layer 16 receded from the groove and extending to the trailing end surface 33 of the slider 31. In the example, the contaminant that has entered the gap between the slider and the recording medium can be removed more quickly through this groove, so that the contaminant does not deteriorate the recording characteristics.

Further, according to the manufacturing method of the present invention, in the same step as the etching step of forming the rail 34 on the air bearing surface 18 of the slider 31, the tip surface exposed on the air bearing surface of the third magnetic layer 16 is removed. Since the recess is formed by etching, the process is simplified, and the manufacturing cost is advantageous. Further, by adopting a material and an etching method that make an appropriate difference between an etching rate for retracting the front end face of the third magnetic layer 16 and an etching rate for forming the rail 34 on the air bearing surface 18. , Both the retraction amount and the rail height can be controlled simultaneously.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an initial step in a conventional standard thin film magnetic head manufacturing method.

FIG. 2 is a cross-sectional view showing the next step in the same manner.

FIG. 3 is a cross-sectional view showing the next step in the same manner.

FIG. 4 is a cross-sectional view showing the next step in the same manner.

FIG. 5 is a cross-sectional view showing the next step in the same manner.

FIG. 6 is a cross-sectional view showing the next step in the same manner.

FIG. 7 is a cross-sectional view showing the next step in the same manner.

FIG. 8 is a cross-sectional view showing the next step in the same manner.

FIG. 9 is a cross-sectional view showing the next step in the same manner.

FIG. 10 is a sectional view of a completed conventional thin film magnetic head.

FIG. 11 is a sectional view of a magnetic pole portion of a completed conventional thin-film magnetic head.

FIG. 12 is a plan view of a completed conventional thin film magnetic head.

FIG. 13 is a perspective view showing a slider cut out from a wafer in the method of manufacturing a thin-film magnetic head according to the present invention.

FIG. 14 is a perspective view showing the slider in the next step in the same manner.

FIG. 15 is an enlarged perspective view showing a magnetic pole portion of the same.

FIG. 16 is also a front view of the magnetic pole part.

[Explanation of symbols]

Reference Signs List 1 base, 2 alumina insulating layer, 3 lower shield layer, 4 first shield gap layer, 5 magnetoresistive layer, 6 second shield gap layer, 7 first magnetic layer, 8 write gap layer, 9 second Magnetic layer,
10, 11, 13, 15 insulating layer, 12, 14
Thin film coil, 16 third magnetic layer, 17 overcoat layer, 18 air bearing surface, 19 MR reproducing element, 31 slider, 32 groove, 33 slider trailing side end face, 34 rail

Claims (7)

[Claims] A first magnetic layer having a magnetic pole portion exposed on an air bearing surface of a slider; and a magnetic pole portion facing a magnetic recording medium and forming a pole tip having a width defining a recording track width. An end face of the magnetic pole portion forms an air bearing surface together with an end face of the magnetic pole portion of the first magnetic layer; and the second magnetic layer is A third magnetic layer in contact with the opposite side and magnetically coupled to the first magnetic layer at a rear position away from the air bearing surface; and a magnetic pole portion of the first magnetic layer and a second magnetic layer at least at the magnetic pole portion. A gap layer made of a nonmagnetic material interposed between the magnetic layer and the first magnetic layer and the second magnetic layer so as to generate a magnetic flux for writing to a magnetic recording medium on the air bearing surface. And third magnetism A thin-film coil having a portion provided with an insulating layer interposed therebetween; and an overcoat layer provided so as to cover the first, second, and third magnetic layers, the gap layer, and the insulating layer. A thin-film magnetic head comprising: the first, second, and third magnetic layers, a gap layer, an insulating layer, a thin-film coil, and a base supporting the overcoat layer; and a tip of the third magnetic layer. A thin-film magnetic head characterized in that the surface is retreated from the air bearing surface, and the retreated tip surface is exposed to the air bearing surface through an opening formed in the overcoat layer. 2. A groove which is continuous with a front end surface of the third magnetic layer and extends to a trailing end surface of the slider is provided on a surface constituting an air bearing surface of the overcoat layer. 2. The thin-film magnetic head according to claim 1, wherein: 3. The shape of the groove formed on the surface of the overcoat layer as viewed from a direction perpendicular to the air bearing surface,
3. The thin-film magnetic head according to claim 2, wherein the thin-film magnetic head expands from a front end surface of the second magnetic layer toward an end surface on a trailing side of the slider. 4. The slider according to claim 1, wherein the amount of retreat of the tip surface of the third magnetic layer from the air bearing surface is smaller than the height of a rail formed on the air bearing surface of the slider. The thin-film magnetic head according to any one of the above. 5. A first magnetic layer having a magnetic pole portion exposed on an air bearing surface of a slider, and a magnetic pole portion facing a magnetic recording medium and forming a pole tip having a width defining a recording track width. An end face of the magnetic pole portion forms an air bearing surface together with an end face of the magnetic pole portion of the first magnetic layer; and the second magnetic layer is A third magnetic layer in contact with the opposite side and magnetically coupled to the first magnetic layer at a rear position away from the air bearing surface; and a magnetic pole portion of the first magnetic layer and a second magnetic layer at least at the magnetic pole portion. A gap layer made of a nonmagnetic material interposed between the magnetic layer and the first magnetic layer and the second magnetic layer so as to generate a magnetic flux for writing to a magnetic recording medium on the air bearing surface. And third magnetism A thin-film coil having a portion provided with an insulating layer interposed therebetween; and an overcoat layer provided so as to cover the first, second, and third magnetic layers, the gap layer, and the insulating layer. A method for manufacturing a thin-film magnetic head comprising: the first, second, and third magnetic layers, a gap layer, an insulating layer, a thin-film coil, and a substrate that supports an overcoat layer; A method for manufacturing a thin-film magnetic head, comprising: selectively etching a front end surface of a magnetic layer that appears on an air bearing surface to retreat a front end surface of a second magnetic layer from an air bearing surface of a slider. 6. A groove which is continuous with the front end surface of the third magnetic layer and reaches the end surface on the trailing side of the slider at the same time as the front end surface of the third magnetic layer is retracted from the air bearing surface. The method according to claim 5, wherein the thin film magnetic head is formed on a surface of the overcoat layer. 7. A rail having a predetermined shape is simultaneously formed on an air bearing surface of a slider by an etching process for recessing a front end surface of the second magnetic layer and forming a groove on a surface of the overcoat layer. 7. The method for manufacturing a thin-film magnetic head according to claim 5, wherein: