JP2966620B2 - Thin film magnetic head and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin-film magnetic head in which a reproducing head comprising a magnetoresistive element and an inductive recording head are integrated, and a method of manufacturing the same.

2. Description of the Related Art In a magnetic disk drive, the diameter of a magnetic disk as a recording medium has been reduced. Accordingly, a thin film magnetic head incorporating a magnetoresistive element capable of obtaining a large reproduction output even when the relative moving speed with respect to the magnetic disk is low has been attracting attention.

[0003]

2. Description of the Related Art A magnetoresistive element can be used only for reading (reproducing) information from a magnetic recording medium. Therefore, for writing (recording) information, it is necessary to use other electromagnetic conversion means.

[0004] Conventionally, a reproducing head portion comprising a magnetoresistive effect element and a pair of magnetic shield layers (soft magnetic layers) sandwiching the magnetoresistive effect element, and a coil and a pair of magnetic poles (soft magnetic layer constituting a magnetic core). 2. Description of the Related Art A thin-film magnetic head in which an inductive recording head is integrated is known.

In general, this type of composite type thin-film magnetic head has the above-described heads arranged as close as possible to facilitate head position control for recording and reproduction.
In order to have a simple head structure that is advantageous in terms of manufacturing cost,
One magnetic shield layer is configured to also serve as a magnetic pole. That is, one magnetic layer is provided as a component common to both the read head unit and the write head unit.

Incidentally, the dimension of the magnetoresistive element in the track width direction is longer than the track width by at least the provision of the electrodes. It is advantageous that the dimension of the magnetic shield layer in the track width direction is longer than that of the magnetoresistive element in order to reduce noise during reproduction. Therefore, if a magnetic shield layer longer than the track width is used as a magnetic pole at the time of recording, the magnetic flux leaks to the outside of the track and so-called recording bleeding occurs.

Therefore, in a conventional composite type thin film magnetic head, as disclosed in Japanese Patent Application Laid-Open No. 2-208812,
As a magnetic shield layer and a magnetic layer that also serves as a magnetic pole (hereinafter, also referred to as a “multipurpose magnetic layer”), a magnetic layer having a different thickness depending on a portion in the track width direction is provided.

FIG. 6 is a cross-sectional view of a main part schematically showing the structure of a conventional thin-film magnetic head 1j. FIG. 1 shows a cross-sectional structure as viewed from the recording medium side. The thin-film magnetic head 1j is a composite-type head having a reproducing head RH and a recording head WH, and includes a support 11 and the following components sequentially laminated thereon.

First, a lower magnetic shield layer 12 having a predetermined shape is provided on a support 11, and a nonmagnetic layer 1 is formed thereon.
3, a magnetoresistive element layer (hereinafter, referred to as “MR layer”) 14 and an electrode layer 15 are provided. MR layer 14
On top of this, an upper magnetic shield layer and a dual-purpose magnetic layer 17j serving as a lower magnetic pole are provided via a nonmagnetic layer 16, and an upper magnetic pole 20 is further provided thereon via a gap layer 19. Then, a protective film 23 is provided as an uppermost layer.

In the thin-film magnetic head 1j, the dual-purpose magnetic layer 17j is processed so that the central portion of the drawing corresponding to the track width w is thicker than other portions. That is,
The dual-purpose magnetic layer 17j is a layer having a step in which a lower layer portion having the same planar shape as the lower magnetic shield layer 12 and an upper layer portion having the same planar shape as the upper magnetic pole 20 are integrated. ing.

As a result, when recording, the magnetic flux is concentrated within the range of the track width w, thereby suppressing the recording bleeding. Further, at the time of reproduction, the magnetic shield range for the MR layer 14 can be sufficiently widened, and the SN ratio of a reproduction signal can be increased.

[0012]

Generally, a thin film is formed by a film forming technique such as sputtering or vacuum evaporation. At this time, it is desirable that the film formation surface be as flat as possible in order to make the film thickness and film quality uniform. That is, if there is a step on the film formation surface, a desired thin film may not be obtained due to a poor step coverage.

When patterning a thin film by photolithography, it is desirable that the thin film to be patterned be planar in order to prevent patterning failure due to resist peeling and facilitate mask alignment.

Therefore, in the conventional thin-film magnetic head 1j, upon manufacturing, after providing the dual-purpose magnetic layer 17j having a step by etching as described above, the gap layer 19 and the upper magnetic pole 20 related to the performance of the head are formed. In order to flatten the surface on which the film is to be formed, it is necessary to provide a nonmagnetic layer 18 (see FIG. 6) that fills the steps of the dual-purpose magnetic layer 17j.

That is, the head structure of the conventional thin-film magnetic head 1j is manufactured because the formation of the dual-purpose magnetic layer 17j exhibiting a desired magnetic action involves the formation of a nonmagnetic layer and flattening processing such as etch-back. There was a problem that it was disadvantageous in terms of productivity because of many man-hours.

The present invention has been made in view of such a problem, and
It is an object of the present invention to provide a composite type thin film magnetic head having good read characteristics and a head structure advantageous in productivity, and a manufacturing method suitable for manufacturing the same.

[0017]

According to a first aspect of the present invention, there is provided a head for solving the above-mentioned problems, as shown in FIG. 1, a magnetoresistive effect element and a pair of magnetic shield layers sandwiching the element. 17. The thin-film magnetic head 1 according to claim 1, further comprising a read head RH including a read head 17 and a write head WH including the one magnetic shield layer 17 as a part of a magnetic core MC. It is made of a soft magnetic layer in which the magnetic properties of the specific portion 172 of the surface layer on the side of the head WH are partially deteriorated by adding impurities.

In the head according to the second aspect of the present invention, the specific portion 172 corresponds to a portion excluding a portion facing the magnetic pole 20 constituting the magnetic core MC together with the magnetic shield layer 17.

In the head according to the third aspect of the present invention, the specific portion 172 has a smaller saturation magnetic flux density or magnetic permeability than other portions 171 in the magnetic shield layer 17. The manufacturing method according to claim 4, wherein the magnetic pole 20 having a predetermined shape is provided on the soft magnetic layer 17A corresponding to the magnetic shield layer 17, and then the soft magnetic layer 20 is formed by ion implantation or thermal diffusion. Impurities are introduced into the layer 17A from its upper surface.

According to a fifth aspect of the present invention, the magnetic pole 20 itself is used as a mask for introducing impurities.

[0021]

The magnetic shield layer 17, which is used for both reproduction and recording,
Rather than having a stepped structure as in the related art, impurities are partially introduced (added) to deteriorate the magnetic characteristics of the specific portion 172 of the surface layer portion on the recording head portion WH side, that is, the saturation magnetic flux density or the permeability. By reducing the magnetic susceptibility, the magnetic recording medium is provided so as to exhibit the same magnetic action suitable for both reproduction and recording as in the related art. Therefore, after the magnetic shield layer 17 is provided, it is not necessary to planarize the surface as a pretreatment for the next film formation.

The impurity is introduced after the magnetic pole 20 constituting the magnetic core MC of the write head unit WH is provided together with the magnetic shield layer 17 by ion implantation or thermal diffusion. As a result, the specific portion 1 that degrades the magnetic characteristics
Self-alignment between the magnetic pole 72 and the magnetic pole 20 becomes possible.

When the impurities are introduced, if the magnetic pole 20 itself is used as a mask, the impurities are also introduced into the surface portion of the magnetic pole 20, and the magnetic properties of the magnetic pole 20 gradually deteriorate as it approaches the upper surface. I do. Therefore, irrespective of special processing, disturbance of residual magnetization (medium magnetization after recording) due to an edge effect at the upper end of the magnetic pole 20 can be suppressed.

[0024]

2A and 2B are diagrams showing the structure of a thin-film magnetic head 1 according to the present invention. FIG. 2A is a sectional view of a main part, and FIG. 2B is a plan view showing shapes and arrangements of main components. FIG. 2A is a view similar to FIG.
Corresponds to a section taken along the line AA of FIG. Also, in FIG. 2, components having the same functions as those in FIG.

The thin-film magnetic head 1 is a composite head having a reproducing head RH based on a magnetoresistance effect and a recording head WH based on electromagnetic induction.
A lower magnetic shield layer 12 made of a soft magnetic material (a high magnetic permeability material) such as permalloy, an MR layer 14 sandwiched between nonmagnetic layers 13 and 16, and an upper magnetic shield layer (hereinafter also referred to as a lower magnetic pole). "Combined magnetic layer") 17,
It comprises a gap layer 19 made of silicon dioxide or the like, an interlayer insulator 21 made of a thermosetting resin or the like, a spiral coil 22, an upper magnetic pole 20, and a protective film 23.

The dual-purpose magnetic layer 17 and the upper magnetic pole 20 are integrated by a contact portion 30 so as to form a magnetic core MC. The inner end and the outer end of the coil 22 are respectively connected to external connection terminals (not shown). In FIG. 2, the illustration of the electrode layer 15 (see FIG. 1) that overlaps the MR layer 14 is omitted.

As shown in FIG. 2B, the planar shape of the upper magnetic pole 20 is such that the width of the gap (left end in the figure) defining the track width w is narrower than the other. . On the other hand, when configuring the magnetic core MC, the magnetic poles 20
The planar shape of the dual-purpose magnetic layer 17 that is paired with the track width w
Since it is necessary to completely cover the longer dimension MR layer 14, the width of the gap portion is set to the same shape as the other portions.
That is, the dual-purpose magnetic layer 17 has a region E17b that does not face the magnetic pole 20 as shown by hatching in the figure, and the width of the dual-purpose magnetic layer 17 on the surface facing the recording medium is larger than the width of the magnetic pole 20. .

For this reason, if the magnetic properties of the dual-purpose magnetic layer 17 in the track width direction are uniform, the magnetic flux expands at the time of recording, and recording bleeding occurs. Therefore, in the thin-film magnetic head 1, as described below, the dual-purpose magnetic layer 17 in which the magnetic characteristics are partially deteriorated in the region E17b is provided.

FIG. 1 is a cross-sectional view schematically showing a configuration of a main part of a thin-film magnetic head 1 according to the present invention. This figure corresponds to the cross section taken along the line II of FIG. 2B and shows a cross-sectional structure viewed from the recording medium side.

As shown in FIG. 1, the dual-purpose magnetic layer 1
Reference numeral 7 denotes a flat plate-like layer having a uniform thickness (about 2 to 4 μm) on the whole shape. However, the film quality related to the magnetic characteristics is not uniform, and after the film formation by a sputtering method or the like, a quality alteration process (impurity introduction process) for partially deteriorating the magnetic characteristics is performed.

That is, an area of the surface layer portion having a predetermined thickness (for example, half the thickness of the dual-purpose magnetic layer 17) from the surface of the dual-purpose magnetic layer 17 on the side of the recording head portion WH (the magnetic pole 20 side) and not facing the magnetic pole 20 The portion 172 of (the above-described region E17b)
The saturation magnetic flux density or the magnetic permeability is smaller than the other portions 171 and the magnetic characteristics of the magnetic core MC are inferior. That is, the dual-purpose magnetic layer 17 is a layer having a step structure in which the center in the track width direction is substantially thick and both ends are thin in terms of magnetic characteristics.

Therefore, during recording, the magnetic flux is concentrated within the range of the track width w, so that the recording bleeding is suppressed. Further, at the time of reproduction, the magnetic shield is performed in the same range as the lower magnetic shield layer 12 by the portion 171 in which the magnetic characteristics are not degraded, so that noise can be reduced.

Hereinafter, a method of manufacturing the thin-film magnetic head 1 of this embodiment will be described. FIG. 3 shows a first example of the manufacturing method of the present invention.
It is sectional drawing which shows the state of each manufacturing stage which concerns on an Example.

Here, it is assumed that the coating of the MR layer 14 and the electrode layer 15 with the nonmagnetic layer 16 has already been completed [FIG.
(A)]. The total thickness of the MR layer 14 and the electrode layer 15 is about 0.2 μm, which is 1/10 or less of the non-magnetic layer 16 and the dual-purpose magnetic layer 17 thereon. After the magnetic layer 16 is provided, it is not particularly necessary to planarize the surface.

On the non-magnetic layer 16, first, a soft magnetic layer 17A corresponding to the dual-purpose magnetic layer 17 having the above-described shape is provided by sequentially performing film formation by sputtering and patterning by photolithography. The soft magnetic layer 17A at this stage is a layer having a uniform film quality. Next, the non-magnetic layer 1
A silicon dioxide film 19A serving as the gap layer 19 is provided by a sputtering method so as to cover the entire surface of the soft magnetic layer 17A including the surface of No. 6, and a coil 22 and the like (not shown) are provided here. Upper magnetic pole 2 on top
A soft magnetic layer 20A having a value of 0 is provided [FIG. 3 (b)].

Subsequently, a resist layer 60 having a shape corresponding to the magnetic pole 20 is provided, and using the resist layer 60 as an etching mask, the soft magnetic layer 20A and the silicon dioxide film 1 are formed.
9A is collectively patterned [FIG. 3 (c)]. At this time, since the magnetic pole 20 is required to have high patterning accuracy in defining the track width w, ion milling is used as an etching technique.

At the stage after the magnetic poles 20 are provided, in order to form the dual-purpose magnetic layer 17 having the above-described magnetic characteristics, impurities are introduced into the soft magnetic layer 17A to partially reduce the magnetic characteristics. Deteriorates.

For example, as shown in FIG.
In the state where the resist layer 60 is left even after the patterning of 0,
Chromium (Cr), niobium (N
b), metal ions such as zirconium (Zr) are introduced as impurities. At this time, conditions such as the amount of impurities to be introduced are appropriately selected, and the composition of the soft magnetic layer 17A may be changed to lower the saturation magnetic flux density, or the crystallinity of the soft magnetic layer 17A may be changed to lower the magnetic permeability. May be.

FIG. 4 is a sectional view showing a state of one manufacturing stage according to a second embodiment of the manufacturing method of the present invention. In FIG. 4, impurities are partially introduced into the soft magnetic layer 17A from the upper surface by ion implantation using the magnetic pole 20 itself as a mask. In this case, impurities are also introduced into the magnetic pole 20 and the magnetic characteristics of the surface layer portion 202 of the magnetic pole 20 deteriorate. However, since the portion 201 where the magnetic characteristics have not deteriorated remains on the gap layer 14 side, the recording characteristics are not impaired as a whole. On the contrary, since the degree of deterioration gradually decreases downward, This is advantageous in suppressing disturbance of the residual magnetization due to the edge effect at the edge of the surface layer 20.

As shown in FIGS. 3 and 4, when ion implantation is used to introduce impurities, the silicon dioxide film 19A does not necessarily need to be patterned into the same shape as the magnetic pole 20. Silicon dioxide film 1 left as it is
Impurities can be implanted into the soft magnetic layer 17A through 9A.

FIG. 5 is a sectional view showing a state in a manufacturing stage according to a third embodiment of the manufacturing method of the present invention. In FIG. 5, an impurity is partially introduced into the soft magnetic layer 17A by a thermal diffusion method instead of the ion implantation method, thereby deteriorating the magnetic characteristics of the surface portion 172.

That is, referring to FIG. 3, after patterning of magnetic pole 20 is completed, for example, chromium film 70 is provided so as to cover the exposed surface of soft magnetic layer 17A including the surface of magnetic pole 20. Then, the chromium is heated to a temperature of about 300 ° C. to diffuse chromium from the chromium film 70 into the soft magnetic layer 17A.

Also in this case, in the magnetic pole 20, a portion 202 having deteriorated magnetic properties and a portion 201 remaining without deterioration are formed as in the combined magnetic layer 17, as described above. This leads to an improvement in the magnetic characteristics of the thin-film magnetic head 1.

According to the above-described embodiment, the portion 172 having deteriorated magnetic characteristics is provided in the dual-purpose magnetic layer 17 by the ion implantation method or the thermal diffusion method. The magnetic characteristics gradually deteriorate with the portion 171. Therefore, as before,
The dual-purpose magnetic layer 17 is more advantageous than the case where the dual-purpose magnetic layer 17j having the step structure is brought into contact with the nonmagnetic layer 18 in suppressing disturbance of residual magnetization due to the edge effect.

[0045]

According to the present invention, it is possible to provide a composite type thin film magnetic head having a head structure having good recording / reproducing characteristics and excellent productivity.

According to the fourth aspect of the present invention, high performance can be achieved by self-alignment. According to the fifth aspect of the invention, the disturbance of the residual magnetization can be suppressed without adding a special step.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a configuration of a main part of a thin-film magnetic head according to the present invention.

FIG. 2 is a diagram showing a structure of a thin-film magnetic head according to the present invention.

FIG. 3 is a cross-sectional view showing a state of each manufacturing stage according to the first embodiment of the manufacturing method of the present invention.

FIG. 4 is a cross-sectional view showing a state in a manufacturing stage according to a second embodiment of the manufacturing method of the present invention.

FIG. 5 is a sectional view showing a state in a manufacturing stage according to a third embodiment of the manufacturing method of the present invention.

FIG. 6 is a cross-sectional view of a main part schematically showing the structure of a conventional thin-film magnetic head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 thin-film magnetic head 14 MR layer (magnetoresistive element) 12 magnetic shield layer 17 dual-purpose magnetic layer (magnetic shield layer) RH reproducing head unit WH recording head unit MC magnetic core 172 part of dual-purpose magnetic layer (specific part) 171 dual-purpose magnetism Except for a specific portion of the layer 20 Upper magnetic pole (magnetic pole) 17A Soft magnetic layer

Claims (5)

(57) [Claims] 1. A read head (RH) comprising a magnetoresistive element (14) and a pair of magnetic shield layers (12) and (17) sandwiching the element, and the one magnetic shield layer (17).
Head part (WH) that makes a part of magnetic core (MC)
Wherein the magnetic shield layer (17) comprises the recording head (W).
A thin-film magnetic head comprising a soft magnetic layer in which magnetic properties of a specific portion (172) of a surface layer portion on the H) side are partially deteriorated by adding an impurity. 2. The method according to claim 1, wherein the specific portion (172) corresponds to a portion excluding a portion facing the magnetic pole (20) constituting the magnetic core (MC) together with the magnetic shield layer (17). The thin-film magnetic head according to claim 1. 3. The magnetic head according to claim 1, wherein a saturation magnetic flux density or a magnetic permeability of the specific portion (172) is smaller than that of another portion (171) in the magnetic shield layer (17). Thin film magnetic head. 4. The method for manufacturing a thin-film magnetic head (1) according to claim 1, wherein the soft magnetic layer (1) corresponding to the magnetic shield layer (17) is provided.
7A), after the magnetic pole (20) having a predetermined shape is provided, impurities are introduced into the soft magnetic layer (17A) from the upper surface thereof by ion implantation or thermal diffusion. Head manufacturing method. 5. The method according to claim 4, wherein the magnetic pole (20) itself is used as a mask for introducing impurities.