JPH05189720A - Thin-film magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To obtain the thin-film magnetic head having good recording and reproducing characteristics by forming a magnetic shielding layer of a soft magnetic layers which is formed by partially deteriorating the magnetic characteristics of the specific part in the surface layer part on a recording head side by addition of an impurity. CONSTITUTION:This thin-film magnetic head 1 has a reproducing head part RH consisting of a magneto-resistance effect element 14 and a pair of the magnetic shielding layers 12 and 17 holding this element and a recording head part WH having the one magnetic shielding layer 17 as a part of a magnetic core MC. The magnetic shielding layer 17 is formed as the soft magnetic layer formed by partially deteriorating the magnetic characteristics of the specific part 172 in the surface layer part on the recording head WH side. The magnetic shielding layer 17 is commonly used for reproducing and recording and is deteriorated in the magnetic characteristics of the specific part 172 in the surface layer part of the recording head part WH side by adding the impurity partially thereto, by which the saturation magnetic flux density is decreased. Then, there is no need for flattening the surface as a pretreatment for the next film formation after disposing the magnetic shielding layer 17.

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 section composed of a magnetoresistive effect element and an inductive recording head section are integrated, and a method for manufacturing the same.

In a magnetic disk device, the diameter of a magnetic disk, which is a recording medium, is being reduced. Along with this, a thin film magnetic head incorporating a magnetoresistive effect element capable of obtaining a large reproduction output even when the relative movement speed with respect to the magnetic disk is small is drawing attention.

[0003]

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

Conventionally, a magnetoresistive effect element and a reproducing head portion composed of a pair of magnetic shield layers (soft magnetic layers) sandwiching the magnetoresistive effect element, a coil and a pair of magnetic poles (soft magnetic layer constituting a magnetic core). A thin film magnetic head in which an inductive recording head section is integrated is known.

Usually, in this type of composite type thin film magnetic head, in order to facilitate head position control relating to recording and reproduction, the above-mentioned head portions are arranged as close to each other as possible.
To have a simple head structure that is advantageous in terms of manufacturing cost,
One of the magnetic shield layers is configured to also serve as a magnetic pole. That is, one magnetic layer is provided as a component common to both the reproducing head section and the recording head section.

By the way, the dimension of the magnetoresistive effect element in the track width direction becomes longer than the track width by at least the provision of electrodes. It is advantageous that the dimension of the magnetic shield layer in the track width direction is longer than that of the magnetoresistive effect element in terms of noise reduction during reproduction. Therefore, if a magnetic shield layer longer than the track width is used as a magnetic pole during recording, the magnetic flux leaks to the outside of the track to cause so-called recording blur.

Therefore, in the conventional composite type thin film magnetic head, as disclosed in Japanese Patent Laid-Open No. 2-208812,
As a magnetic layer which is also used as a magnetic shield layer and a magnetic pole (hereinafter referred to as "combined magnetic layer"), magnetic layers having different film thicknesses are provided depending on the portion in the track width direction.

FIG. 6 is a cross-sectional view of an essential part schematically showing the structure of a conventional thin film magnetic head 1j. This figure shows a sectional structure as seen from the recording medium side. The thin-film magnetic head 1j is a composite type head having a reproducing head portion RH and a recording head portion WH, and is composed of a support 11 and the following portions laminated in that order on the support 11.

First, a lower magnetic shield layer 12 having a predetermined shape is provided on the support 11, and the nonmagnetic layer 1 is formed thereon.
A magnetoresistive effect element layer (hereinafter, referred to as “MR layer”) 14 and an electrode layer 15 are provided via the element 3. MR layer 14
An upper magnetic shield layer and a dual-purpose magnetic layer 17j serving as a lower magnetic pole are provided on the above via a non-magnetic layer 16, and an upper magnetic pole 20 is provided thereon via a gap layer 19. Then, the protective film 23 is provided as the 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, at the time of recording, it is possible to suppress the recording bleeding by concentrating the magnetic flux within the range of the track width w. Further, during reproduction, the magnetic shield range for the MR layer 14 can be sufficiently widened, and the SN ratio of the reproduced signal can be increased.

[0012]

Generally, a film forming technique such as a sputtering method or vacuum evaporation is used for forming a thin film. 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 poor step coverage.

When patterning a thin film by the photolithography method, it is desirable that the thin film to be patterned is planar in view of preventing patterning failure due to resist peeling and facilitating mask alignment.

Therefore, in the conventional thin-film magnetic head 1j, after the dual-purpose magnetic layer 17j having a step is formed by etching or the like as described above, the gap layer 19 and the top pole 20 relating to the performance of the head are provided. In order to flatten the film formation surface, it is necessary to provide the non-magnetic layer 18 (see FIG. 6) that fills the step 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 is accompanied by film formation of the non-magnetic layer and flattening treatment such as etchback. There is a problem in that it requires a lot of man-hours and is disadvantageous in terms of productivity.

In view of such a problem, the present invention provides recording / recording.
An object of the present invention is to provide a composite type thin film magnetic head having a head structure having good reproducing characteristics and being advantageous in terms of productivity, and a manufacturing method suitable for manufacturing the same.

[0017]

In order to solve the above-mentioned problems, the head according to the invention of claim 1 has a magnetoresistive effect element 14 and a pair of magnetic shield layers 12 sandwiching the magnetoresistive effect element 14, as shown in FIG. A thin-film magnetic head 1 having a reproducing head section RH composed of 17 and a recording head section WH having the one magnetic shield layer 17 as a part of a magnetic core MC, wherein the magnetic shield layer 17 is the recording layer. It is composed of a soft magnetic layer in which the magnetic characteristics of the specific portion 172 of the surface layer portion on the head WH side are partially deteriorated by the addition of 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 which constitutes the magnetic core MC together with the magnetic shield layer 17.

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

In the manufacturing method according to the fifth aspect of the present invention, the magnetic pole 20 itself is used as an impurity introduction mask.

[0021]

The magnetic shield layer 17 which is used for both reproduction and recording,
Rather than forming a step structure as in the conventional case, 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 permeability. By making the magnetic susceptibility small, it is provided so as to exhibit a magnetic effect suitable for both reproduction and recording as a whole as a whole. Therefore, it is not necessary to flatten the surface as a pretreatment for the next film formation after providing the magnetic shield layer 17.

The introduction of impurities is performed after the magnetic pole 20 forming the magnetic core MC of the recording head portion WH is provided together with the magnetic shield layer 17 by using the ion implantation method or the thermal diffusion method. Thereby, the specific portion 1 that deteriorates the magnetic characteristics
Self-alignment between 72 and the magnetic pole 20 is possible.

Further, when the magnetic pole 20 itself is used as a mask when introducing the impurities, the impurities are also introduced into the surface layer of the magnetic pole 20, and the film quality of the magnetic pole 20 gradually deteriorates as it approaches the upper surface. To do. For this reason, it is possible to suppress the disturbance of the residual magnetization (medium magnetization after recording) due to the edge effect at the upper end portion of the magnetic pole 20 without any special processing.

[0024]

2A and 2B are views showing the structure of a thin film magnetic head 1 according to the present invention. FIG. 2A is a cross-sectional view of the main part, and FIG. 2B is a plan view showing the shape and arrangement of the main constituent elements. 2 (a) is shown in FIG. 2 (b).
Corresponds to a cross section taken along the line A-A of FIG. In addition, in FIG. 2, components having the same functions as those in FIG. 6 are denoted by the same reference numerals regardless of the difference in material and structure.

The thin film magnetic head 1 is a composite type head having a reproducing head portion RH due to a magnetoresistive effect and a recording head portion WH due to electromagnetic induction, and a non-magnetic support 11,
A lower magnetic shield layer 12 made of a soft magnetic material (high magnetic permeability material) such as permalloy, an MR layer 14 sandwiched between nonmagnetic layers 13 and 16, an upper magnetic shield layer also used as a lower magnetic pole (hereinafter "A dual-purpose magnetic layer") 17,
It is composed of a gap layer 19 made of silicon dioxide or the like, an interlayer insulator 21 such as a thermosetting resin, 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 the contact portion 30 so as to form the magnetic core MC. The inner end and the outer end of the coil 22 are connected to external connection terminals (not shown). In FIG. 2, the illustration of the electrode layer 15 (see FIG. 1) overlying 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 portion (left end portion in the figure) that defines the track width w is narrower than the other. .. On the other hand, in forming the magnetic core MC, the magnetic pole 20
The planar shape of the dual-purpose magnetic layer 17 paired with the track width w is
Since it is necessary to completely cover the MR layer 14 having a longer dimension, the width of the gap portion has the same shape as the others.
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 characteristics of the dual-purpose magnetic layer 17 are uniform in the track width direction, the magnetic flux spreads during recording, causing recording bleeding. Therefore, the thin-film magnetic head 1 is provided with the dual-purpose magnetic layer 17 in which the magnetic characteristics are partially deteriorated in the region E17b, as described below.

FIG. 1 is a sectional view schematically showing the structure of a main part of a thin film magnetic head 1 according to the present invention. It should be noted that the drawing corresponds to a cross section taken along the line I-I 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
7 is a flat plate-like layer having a uniform film thickness (about 2 to 4 μm) on the whole shape. However, the film quality related to the magnetic properties is not uniform, and after the film formation by the sputtering method or the like, a modification treatment (impurity introduction process) for partially deteriorating the magnetic properties is performed.

That is, in the surface layer portion having a predetermined thickness (for example, half the film thickness of the dual-purpose magnetic layer 17) from the surface of the dual-purpose magnetic layer 17 on the recording head portion WH side (the magnetic pole 20 side), a region not facing the magnetic pole 20. The portion 172 of the above-mentioned area E17b is
The saturation magnetic flux density or magnetic permeability is smaller than that of the other portion 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 central portion in the track width direction is thick and both end portions are thin in terms of magnetic characteristics.

Therefore, at the time of recording, since the magnetic flux concentrates within the range of the track width w, the recording blur is suppressed. Further, during 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 deteriorated, whereby noise can be reduced.

The method of manufacturing the thin film magnetic head 1 of this embodiment will be described below. FIG. 3 shows a first 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 MR layer 14 and the electrode layer 15 have already been covered with the nonmagnetic layer 16 [FIG.
(A)]. The total thickness of the MR layer 14 and the electrode layer 15 is about 0.2 μm, which is one-tenth or less that of each of the non-magnetic layer 16 and the dual-purpose magnetic layer 17 thereon. After providing the magnetic layer 16, it is not necessary to flatten the surface.

On the non-magnetic layer 16, first, film formation by a sputtering method and patterning by a photolithography method are sequentially performed to provide a soft magnetic layer 17A corresponding to the dual-purpose magnetic layer 17 having the above-described shape. The soft magnetic layer 17A at this stage has a uniform film quality. Next, the non-magnetic layer 1
The silicon dioxide film 19A to be the gap layer 19 is provided by the sputtering method so as to cover the entire surface of the soft magnetic layer 17A including the surface of the silicon oxide film 6, and the coil 22 and the like not shown here are provided. Magnetic pole 2 on top
A soft magnetic layer 20A having a thickness of 0 is provided [FIG. 3 (b)].

Then, a resist layer 60 having a shape corresponding to the magnetic pole 20 is provided, and the soft magnetic layer 20A and the silicon dioxide film 1 are used by using the resist layer 60 as an etching mask.
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 method.

Then, in order to form the dual-purpose magnetic layer 17 having the above-mentioned magnetic characteristics at the stage after the magnetic pole 20 is thus provided, impurities are introduced into the soft magnetic layer 17A to partially change the magnetic characteristics. Deteriorate.

For example, as shown in FIG. 3D, the magnetic pole 2
With the resist layer 60 left after patterning 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 introduced may be appropriately selected to change the composition of the soft magnetic layer 17A to reduce the saturation magnetic flux density, or the crystallinity of the soft magnetic layer 17A may be changed to reduce the magnetic permeability. You may let me.

FIG. 4 is a sectional view showing a state of one manufacturing stage according to the second embodiment of the manufacturing method of the present invention. In FIG. 4, using the magnetic pole 20 itself as a mask, impurities are partially introduced into the soft magnetic layer 17A from the upper surface by ion implantation. 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 in which the magnetic characteristics are not deteriorated remains on the side of the gap layer 14, the recording characteristics are not impaired as a whole, and conversely, the degree of deterioration is gradually reduced downward. This is advantageous in suppressing the 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 the ion implantation method is used for introducing impurities, the silicon dioxide film 19A does not necessarily have to be patterned into the same shape as the magnetic pole 20, and the film formation state Silicon dioxide film left as it is 1
Impurities can be injected into the soft magnetic layer 17A via 9A.

FIG. 5 is a sectional view showing the state of one manufacturing stage according to the 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 to deteriorate the magnetic characteristics of the surface layer portion 172.

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

In this case as well, in the magnetic pole 20, a portion 202 having deteriorated magnetic characteristics and a portion 201 remaining without deterioration are formed similarly to the dual-purpose magnetic layer 17, but as described above, This leads to improvement of the magnetic characteristics of the thin film magnetic head 1.

According to the above-described embodiment, since the portion 172 having the deteriorated magnetic characteristics is provided in the dual-purpose magnetic layer 17 by the ion implantation method or the thermal diffusion method, in reality, the portion 172 having the deteriorated magnetic characteristics and other portions are formed. The magnetic characteristics gradually deteriorate between the part 171 and the part 171. Therefore, as in the past,
Compared with the case where the dual-purpose magnetic layer 17j having the step structure and the non-magnetic layer 18 are brought into contact with each other, the dual-purpose magnetic layer 17 is advantageous in suppressing the disturbance of the 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 which has good recording / reproducing characteristics and excellent productivity.

According to the invention of claim 4, it is possible to improve the performance by self-alignment. According to the invention of claim 5, the disturbance of the residual magnetization can be suppressed without adding a special step.

[Brief description of 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 step according to the first embodiment of the manufacturing method of the present invention.

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 thin film magnetic head 14 MR layer (magnetoresistive element) 12 magnetic shield layer 17 combined magnetic layer (magnetic shield layer) RH reproducing head part WH recording head part MC magnetic core 172 part of combined magnetic layer (specific part) 171 combined magnetism Part other than a specific part of the layer 20 Top magnetic pole (magnetic pole) 17A Soft magnetic layer

Claims (5)

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