JP2000348316A - Magnetoresistive magnetic head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the insulating property between a magnetoresistive element and an upper layer magnetic shield by forming an insulating film between a conductor film and a second nonmagnetic insulating film which forms an upper layer magnetic gap. SOLUTION: A lower layer magnetic shield 7 and an upper layer magnetic shield 8 are formed from a soft magnetic material. A nonmagnetic insulating film 11 is formed on both ends of the lower layer magnetic shield 7 formed on a substrate 2, while a protective film 12 consisting of a nonmagnetic insulating material is formed on the upper layer magnetic shield 8 formed on an upper layer magnetic gap. An insulating film 13 is formed between a conductor film 5 and the upper layer magnetic gap 10. The insulating film 13 is formed from an insulating material such as Al2O3. The film is preferably formed into larger film thickness than the film thickness of the nonmagnetic insulating film as the upper layer magnetic gap 10. Thus, the insulating property between the magnetoresistive element 6 and the upper layer magnetic shield 8 can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magneto-resistance effect type magnetic head for reading a signal recorded on a magnetic recording medium by utilizing a magneto-resistance effect and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, magnetoresistive elements (hereinafter referred to as M
It is called an R element. 2. Description of the Related Art A magneto-resistive magnetic head (hereinafter, referred to as an MR head) that reads a signal recorded on a magnetic recording medium by utilizing the magneto-resistive effect is widely used.

[0003] An MR element is a type of resistance element, and its electric resistance changes according to a change in an external magnetic field. The MR head is configured to read a magnetic signal recorded on a magnetic recording medium by utilizing a fact that a current value flowing through the MR element changes according to a signal magnetic field from the magnetic recording medium. Since the MR element has high sensitivity to the amount and direction of magnetic flux, the MR head can read a magnetic signal with a high linear density.

FIG. 24 shows an example of such an MR head. FIG. 24 is a front view of the MR head 100 as viewed from the side facing the recording medium. This MR head 100
A hard magnetic film 102 disposed on each end of the MR element 101;
And a magnetoresistive element 104 having a conductor film 103 disposed on the lower magnetic gap 107 by a pair of lower magnetic shields 105 and upper magnetic shields 106.
And an upper magnetic gap 108,
This is a so-called shield type MR head.

Here, the hard magnetic film 102 is
1 is for applying a bias magnetic field to the MR element 101 in order to stabilize the operation, and is made of a hard magnetic material having a high coercive force and is formed on the lower magnetic gap 107 via the base film 102a. Become. In such an MR head 100, as shown in FIG.
In order to make the magnetic coupling between the R element 101 and the hard magnetic film 102 good, the side surface of the MR element 101 has a gentle taper shape, and the hard magnetic film 102 It is formed so as to contact the MR element 101.

In manufacturing such an MR head 100, a so-called lift-off method is used.
The lift-off method generally means that a resist pattern is formed on a substrate in advance, and then a film-forming material is applied on the substrate on which the resist pattern is formed, and then the resist pattern is formed on the substrate. Together with the resist pattern to leave a film forming material other than the region where the resist pattern is formed. That is, in this method,
A film can be formed in a desired region without etching the region where the film is formed. The lift-off method may be performed in combination with an etching process for a substrate.

For example, as shown in FIG. 25, when the MR head 100 is manufactured, the lower magnetic gap 107 is formed.
Element 10 formed on non-magnetic insulating film 109 to be
An undercut resist pattern 111 is formed on the main surface of the magnetoresistive film 110 to be 1.
Next, by using the resist pattern 111 as a mask, the magnetoresistive film 110 is etched to form the above-described MR element 101 having a gentle taper shape.

Next, as shown in FIG. 26, a base film 112, a hard magnetic film 113, and a conductor film 114 are sequentially formed on the etched surface, thereby forming the above-described magnetoresistive element 104. Is formed.

Then, as shown in FIG. 27, the resist pattern 111 is removed, and the magnetoresistive effect element 104 is removed.
A non-magnetic insulating film serving as the upper magnetic gap 108 is formed thereon.

In such an MR head 100, when reproducing an information signal from a magnetic recording medium, the magnetic recording medium is run so as to face the MR element 101, and a signal magnetic field from the recording medium is detected by the MR element 101. I do. Here, the detection of the signal magnetic field by the MR element 101 is performed by supplying a sense current to the MR element 101 through the conductor film 103,
This is performed by detecting a voltage change of the sense current.

In the MR head 100, the portion sandwiched between the hard magnetic film 102 and the conductor film 103 has M
It becomes a magnetic sensing part of the R element 101, and the width of that part becomes the reproduction track width of the MR head 100.

[0012]

The above-mentioned M
The R head 100 is a shield type MR head. In order to cope with a high recording density, the lower magnetic shield 10 is required.
5 and the upper magnetic shield 106 need to be further narrowed.

However, when the distance between the lower magnetic shield 105 and the upper magnetic shield 106 is reduced, the lower magnetic shield 105 and the upper magnetic shield
In this case, there is a problem in securing insulation from the magnetoresistive element 4. In particular, the insulating property between the conductor film 103 and the upper magnetic shield 106 is poor, and it is very difficult to secure the insulating property at the interval G. For this reason, if the lower magnetic shield 105 and the upper magnetic shield 106 cannot be insulated from the magnetoresistive element 104, the output of the MR head decreases, resulting in a decrease in reliability and yield. May be greatly reduced.

Therefore, the present invention has been proposed in view of such a conventional situation, and a magnetoresistive effect type magnetic device capable of reliably ensuring insulation between a magnetic shield and a magnetoresistive effect element. It is an object to provide a head and a method of manufacturing the same.

[0015]

According to the present invention, there is provided a magnetoresistive head having a first soft magnetic film serving as a lower magnetic shield and a first soft magnetic film formed on the first soft magnetic film. A first non-magnetic insulating film serving as a lower magnetic gap; a magneto-resistive effect film serving as a magneto-resistive element formed on the first non-magnetic insulating film; A magnetoresistive element having a conductor film for supplying a sense current to the magnetoresistive element,
An insulating film formed on the conductor film, a second nonmagnetic insulating film serving as an upper magnetic gap formed on the magnetoresistive element having the insulating film, and a second nonmagnetic insulating film formed on the second nonmagnetic insulating film. And a second soft magnetic film serving as an upper magnetic shield formed.

As described above, in the magneto-resistance effect type magnetic head according to the present invention, since the insulating film is disposed between the conductor film and the second non-magnetic insulating film that forms the upper magnetic gap, The insulation between the resistance effect element body and the upper magnetic shield is improved. Further, the withstand voltage for each layer stacked on the magnetoresistive element is improved.

Further, in the method of manufacturing a magnetoresistive head according to the present invention for achieving this object, a first nonmagnetic insulating film serving as a lower magnetic gap is provided on a first soft magnetic film serving as a lower magnetic shield. Forming, forming a magnetoresistive effect film on the first non-magnetic insulating film, and supplying a sense current to the magnetoresistive effect devices formed at both ends of the magnetoresistive effect film. Forming a magnetoresistive element having a conductive film, a step of forming an insulating film on the conductive film, and forming a second non-magnetic insulating film on the magnetoresistive element having the insulating film And a step of forming a second soft magnetic film serving as an upper magnetic shield on the second non-magnetic insulating film.

As described above, in the method of manufacturing a magneto-resistance effect type magnetic head according to the present invention, the insulating film is formed between the conductor film and the second non-magnetic insulating film serving as the upper magnetic gap. In addition, it is possible to improve the insulation between the magnetoresistive element and the upper magnetic shield. In addition, it is possible to improve the breakdown voltage of each layer stacked on the magnetoresistive element.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, a magnetoresistive head according to the present invention will be described.

The magnetoresistive head shown in FIG. 1 (hereinafter, referred to as MR heads.) 1, a plurality of thin film layers constituting the head element, for example by Al ₂ 0 ₃ -TiC or various hard materials such as ceramics Substrate 2 formed in a substantially flat plate shape
It has a laminated structure on top and is used as a read-only magnetic head for reading magnetic signals recorded on a magnetic recording medium.

The MR head 1 is a so-called shield type MR head, and has a magnetoresistive effect element (hereinafter, referred to as a MR element).
It is called an MR element. ) 3 and a magnetoresistive element 6 having a hard magnetic film 4 disposed on both ends of the MR element 3 and a conductor film 5 disposed on the hard magnetic film 4, The magnetoresistive element 6 is sandwiched by a lower magnetic shield 7 and an upper magnetic shield 8 via a lower magnetic gap 9 and an upper magnetic gap 10.

The MR head 1 is a so-called horizontal type MR head in which the longitudinal direction of the MR element 3 is arranged substantially parallel to the surface facing the magnetic recording medium.

FIG. 1 is a sectional view taken on a plane parallel to the surface of the MR head 1 facing the magnetic recording medium.
Only the vicinity of a part to be a magnetic sensing part is shown in an enlarged manner.

In the magnetoresistive element 6, the MR element 3 detects a signal from a magnetic recording medium by a magnetoresistive effect. Specifically, a sense current is supplied to the MR element 3 via the conductor film 5 and a voltage change of the sense current is detected, so that a signal recorded on the magnetic recording medium is read.

Examples of the MR element 3 include a magnetoresistive element using an anisotropic magnetoresistive effect and a giant magnetoresistive element using a spin valve. Specifically, when the MR element 3 is a magnetoresistive element utilizing the anisotropic magnetoresistance effect, for example, Ta / NiFe
It is formed by forming a magnetoresistive film composed of Nb / Ta / NiFe / Ta on a soft magnetic film serving as the lower magnetic shield 7 in this order. On the other hand, when the MR element 3 is a giant magnetoresistive element using a spin valve, for example, Ta / NiFe / CoFe / Cu / CoF
The magnetoresistive film made of e / InMn / Ta is formed on the soft magnetic film to be the lower magnetic shield 7 in this order.

In the magnetoresistive element 6, the hard magnetic film 4 is used to stabilize the operation of the MR element 3.
This is for applying a bias magnetic field to the R element 3.
The hard magnetic film 4 is made of a hard magnetic material having a high coercive force such as CoCrPt, for example.
Are formed on the lower magnetic gap 9 through the gap. In the magnetoresistive element 6, as shown in FIG. 1, the side surface of the MR element 3 has a gently tapered shape in order to make the magnetic coupling between the MR element 3 and the hard magnetic film 4 good. As for the side surface having the tapered shape,
The hard magnetic film 4 is formed so as to contact the MR element 3. The magnetoresistive element 6 may have a structure in which the hard magnetic film 4 is not provided.

In the magnetoresistive element 6, the conductor film 5 serves as an electrode for supplying a sense current to the MR element 3, and is hardened at both ends of the MR element 3 using, for example, Ta. It is formed just above the magnetic film 4.

The lower magnetic shield 7 and the upper magnetic shield 8 are formed using a soft magnetic material such as Sendust. The lower magnetic shield 7 is formed on the substrate 2 with a width sufficient to magnetically shield the lower layer of the MR element 3, and a nonmagnetic insulating film 11 is provided at both ends. I have. On the other hand, the upper magnetic shield 8 is formed on the upper magnetic gap, on which a protective film 12 made of a nonmagnetic insulating material is formed.

The lower magnetic shield 7 and the upper magnetic shield 8 function to prevent a magnetic field other than a reproduction target from the signal magnetic field from the magnetic recording medium from being drawn into the MR element 3. That is, in the MR head 1, M
With respect to the R element 3, a signal magnetic field not to be reproduced is guided to the lower magnetic shield 7 and the upper magnetic shield 8, and only the signal magnetic field to be reproduced is guided to the MR element 3. Thereby, MR
In the head 1, the frequency characteristics of the MR element 3 and the reading resolution are improved. In the MR head 1, the M of the lower magnetic shield 7 and the upper magnetic shield 8
The distance from the R element 3 is the gap length.

The lower magnetic gap 9 and the upper magnetic gap 10 are formed from a nonmagnetic insulating film such as Al ₂ O ₃ or SiO ₂ .

In the MR head 1, an insulating film 13 is provided between the conductor film 5 and the upper magnetic gap 10. This insulating film 13 is formed using an insulating material such as Al ₂ O ₃ . The thickness of the insulating film 13 is preferably formed to be thicker than the thickness of the non-magnetic insulating film to be the upper magnetic gap 10, and is preferably, for example, 100 nm or more.

As a result, in the MR head 1, the insulation between the magnetoresistive element 6 and the upper magnetic shield 8 is improved. Further, the withstand voltage for each layer stacked on the magnetoresistive element 6 can be improved.
Therefore, the reliability can be improved, and an MR head compatible with high recording density can be obtained.

Next, a method for manufacturing a magnetoresistive head according to the present invention will be described in detail.

First, as shown in FIG. 2, a soft magnetic film 21 serving as a lower magnetic shield of a magnetoresistive head is provided on a substrate 20 whose surface is mirror-finished and sufficiently flattened.
Is formed by sputtering or the like. Here, the substrate 2
As the material of No. 0, from the viewpoint of processing characteristics and the like, for example, Al
₂ O ₃ —TiC is preferable, and as a material of the soft magnetic film 21, for example, Sendust is preferable from the viewpoint of soft magnetic characteristics and the like.

Next, as shown in FIG. 3, the soft magnetic film 21 is etched into a predetermined shape. Specifically, first, a resist layer is formed on the soft magnetic film 21, then the resist layer is patterned into a predetermined shape, and then the resist layer patterned into the predetermined shape is used as a mask. The magnetic film 21 is etched. Thereafter, by removing the resist layer, a soft magnetic film 21 having a predetermined shape is obtained as shown in FIG. The shape of the soft magnetic film 21 is set to be large enough to magnetically shield the lower layer of the magnetoresistive element formed in a later step.

Next, as shown in FIG. 4, a nonmagnetic insulating film 22 is formed by sputtering or the like so as to cover the soft magnetic film 21 having a predetermined shape. Here, as the material of the non-magnetic insulating film 22, for example, Al ₂ O ₃ or SiO ₂ is preferable from the viewpoint of insulating properties and abrasion resistance.

Next, as shown in FIG.
2 is polished until the surface of the soft magnetic film 21 is exposed.

Next, as shown in FIG. 6, the non-magnetic insulating film 23 serving as the lower magnetic gap of the magnetoresistive head.
Is formed by sputtering or the like. Here, as the material of the non-magnetic insulating film 23, for example, Al ₂ O ₃ or SiO ₂ is preferable from the viewpoint of insulating properties and abrasion resistance.

Next, as shown in FIG.
A magnetoresistive film 24 serving as an MR element is formed on the substrate 3. In the present invention, the type of the MR element is not particularly limited. For example, a magnetoresistance effect element using an anisotropic magnetoresistance effect may be used, or a giant magnetic element using a spin valve may be used. A resistance effect element may be used. When a magnetoresistive element utilizing the anisotropic magnetoresistive effect is used, the magnetoresistive film 24 is made of, for example, Ta /
NiFeNb / Ta / NiFe / Ta is formed by sequentially forming a film by sputtering or the like in this order. When a giant magnetoresistive element using a spin valve is used, the magnetoresistive film 24 is made of, for example, Ta / NiFe /
CoFe / Cu / CoFe / InMn / Ta are sequentially formed by sputtering in this order.

Next, as shown in FIG. 8, a resist layer 25 is formed on the magnetoresistive film 24. Here, when the resist layer 25 is formed, first, a first resist 25a made of a non-photosensitive resin soluble in a developing solution is thinly applied, and then a heat treatment is performed.
a is cured. Next, a second resist 25b made of a photosensitive resin is thickly applied on the first resist 25a, and thereafter, a pre-bake process is performed on the second resist 25b. Note that the first resist 25a has
A resist having a high dissolution rate when dissolved by a developer is used, and a resist having a low dissolution rate when dissolved by a developer is used as the second resist 25b.

Next, as shown in FIG. 9, the resist layer 25 is patterned into a predetermined shape by using a photolithography technique. Here, when patterning the resist layer 25 into a predetermined shape, first, the resist layer 25 is exposed so as to correspond to a desired pattern. Next, the exposed portions of the resist layer 25 are dissolved and removed with a developing solution, and then post-baking is performed. Thereby, the resist layer 25 at the exposed portion is removed, and as shown in FIG.
A resist layer 25 having a predetermined shape is obtained.

Here, the resist layer 25 is formed of a first resist 25 having a high dissolution rate when dissolved by a developer.
a and a second resist 25b having a slow dissolution rate when dissolved by a developer. Therefore, in the resist layer 25, the portion of the first resist 25a, which is the lower layer, is more etched by the developer than the second resist 25b, which is the upper layer,
As shown in FIG. 9, the lower layer has an undercut shape in which the lower layer is cut inward. As shown in FIG. 9, the second resist 25b, which is the upper layer of the resist layer 25,
Patterning is performed so that the cross-sectional shape becomes trapezoidal.

Note that, as shown in FIG.
In forming the resist, the size of the portion that is cut into the lower layer of the resist layer 25 is controlled by adjusting the heat treatment conditions for the first resist 25a, the development time of the resist layer 25, and the like. can do.

Next, as shown in FIG. 10, using the resist layer 25 patterned in a predetermined shape as a mask, the magnetoresistive film 24 is etched. At this time, since the cross-sectional shape of the second resist 25b, which is the upper layer portion of the resist layer 25, is trapezoidal, the resist layer 2
Magnetoresistive film 24 etched using mask 5 as a mask
Has a slightly tapered shape as shown in FIG.

Next, as shown in FIG.
While leaving 5, a hard magnetic film 26 and a conductor film 27 made of a magnetic material having a high coercive force are formed in this order by sputtering or the like. The hard magnetic film 26 is for applying a bias magnetic field to the magneto-resistance effect element in order to stabilize the operation of the magneto-resistance effect element.
A film of Cr is formed as a, and CoCrPt is sequentially formed thereon by sputtering or the like. On the other hand, the conductor film 27 serves as an electrode for supplying a sense current to the magnetoresistive element, and is formed, for example, by sequentially forming Ta in this order by sputtering or the like.

Thus, a magnetoresistive element is formed.

In this embodiment, the side surface of the magnetoresistive film 24 has a slight taper.
The contact area between the magnetoresistive film 24 and the hard magnetic film 26 is larger than in the case where the side surface of the magnetoresistive film 24 is vertically steep. As described above, the side surfaces of the magnetoresistive film 24 are tapered, and the area of the contact portion between the magnetoresistive film 24 and the hard magnetic film 26 is increased. The magnetic coupling state is good. As a result, the hard magnetic film 2
6, the effect of stabilizing the operation of the magnetoresistive element can be obtained higher, and the operation of the magnetoresistive element can be made more stable.

Further, an insulating film 28 made of an insulating material is formed on the hard magnetic film 26 and the conductor film 27 while leaving the resist layer 25. The insulating film 28 is for ensuring insulation between the conductor film 27 and a magnetic film serving as an upper magnetic shield, which will be described later. For example, Al ₂ O ₃ is formed by sputtering or the like.

The thickness of the insulating film 28 is preferably formed to be larger than the thickness of a non-magnetic insulating film which will be an upper magnetic gap described later, and is preferably, for example, 100 nm or more.

As a result, the insulation between the magnetoresistive element and the soft magnetic film serving as the upper magnetic shield can be improved. Further, the withstand voltage for each layer laminated on the magnetoresistive element can be improved.

Next, as shown in FIGS. 12 and 13, the resist layer 25 is removed together with the hard magnetic film 26, the conductor film 27 and the insulating film 28 formed on the resist layer 25. FIG. 13 is a plan view of the state in which the resist layer 25 has been removed as viewed from above.

Next, as shown in FIGS. 14 and 15, a resist layer 29 having a predetermined shape is formed on the magnetoresistive film 24 and the insulating film 28. FIG. 15 is a sectional view taken along line A ₁ -A ₂ in FIG.

When forming the resist layer 29, first, the first resist 2 made of a non-photosensitive resin soluble in a developing solution is used.
9a is applied thinly and then subjected to a heat treatment.
Is hardened. Next, a second resist 29b made of a photosensitive resin is applied thickly on the first resist 29a, and thereafter, the second resist 29b is subjected to a pre-bake process. The first resist 29a used has a high dissolution rate when dissolved by a developer, and the second resist 29b has a high dissolution rate.
Use a material having a low dissolution rate when dissolved by a developer.

Next, using photolithography technology,
The resist layer 29 is patterned into a predetermined shape. Here, when patterning the resist layer 29 into a predetermined shape, first, the resist layer 29 is exposed so as to correspond to a desired pattern. Next, the exposed resist layer 2
9 is dissolved and removed with a developing solution, and then post-baking treatment is performed. Thereby, the resist layer 2 at the exposed location
9 is removed, and a resist layer 29 having a predetermined shape is obtained as shown in FIGS.

Here, the resist layer 29 is formed of a first resist 29 having a high dissolution rate when dissolved by a developer.
a and a second resist 29b having a slow dissolution rate when dissolved by a developer. Therefore, in the resist layer 29, the portion of the first resist 29a, which is the lower layer, is more etched by the developer than the second resist 29b, which is the upper layer,
As shown in FIG. 15, the lower layer has an undercut shape in which the lower layer bites inward.

Incidentally, as shown in FIG.
In forming the resist layer 9, the size of the portion of the resist layer 29 that intrudes into the lower layer can be adjusted by adjusting the heat treatment conditions for the first resist 29a, the development time of the resist layer 29, and the like. Can be controlled.

After the formation of the resist layer 29 as described above, as shown in FIG. 16, the magnetoresistive film 24 is etched using the resist layer 29 patterned into a predetermined shape as a mask. Here, not only is the magneto-resistance effect film 24 etched but also the hard magnetic film 2
6. A part of the conductor film 27 and the insulating film 28, that is, a part of the hard magnetic film 2 not covered by the resist layer 29.
6. The conductor film 27 and the insulating film 28 are also etched.

Next, as shown in FIGS. 17 and 18, the resist layer 29 is removed. As a result, the magnetoresistive element 24 formed by etching the magnetoresistive film 24 into a predetermined shape is formed on the nonmagnetic insulating film 23. FIG. 18 is a plan view of the state in which the resist layer 29 has been removed as viewed from above.

Next, as shown in FIGS. 19 and 20, a non-magnetic insulating film 30 to be an upper magnetic gap of the magneto-resistance effect type magnetic head is formed by sputtering or the like. FIG. 19 is a plan view of the state in which the nonmagnetic insulating film 30 is formed, as viewed from above, and shows a partly transparent state. Further, FIG. 20 is a sectional view of A ₃ -A ₄ in FIG.

The material of the non-magnetic insulating film 30 is as follows.
From the viewpoint of insulation characteristics and abrasion resistance, for example, Al ₂ O ₃ or S
iO ₂ is preferred.

Next, as shown in FIG. 21, a soft magnetic film 31 serving as an upper magnetic shield of the magneto-resistance effect type magnetic head is formed.
Is formed by sputtering or the like. Here, as a material of the soft magnetic film 31, for example, a Ni—Fe alloy is suitable from the viewpoint of soft magnetic characteristics and the like.

Next, as shown in FIG. 22, a protective film 32 made of a non-magnetic insulating material is formed by sputtering or the like. Here, as a material of the protective film 32, for example, Al ₂ O ₃ or SiO ₂ is preferable from the viewpoint of insulation characteristics, abrasion resistance, and the like.

With the above steps, the thin film process for manufacturing the MR head is completed. Then, as shown in FIG.
The side surface on which the MR element is formed is polished until the end of the MR element is exposed, or the MR head is machined by cutting the MR head from the substrate 1 into a predetermined shape. Is completed. Note that FIG.
FIG. 4 is a plan view of a state in which the side surface on which the element is formed is polished until an end of the MR element is exposed, as viewed from above, and a part of the side is shown as being transparent;

In this MR head, as shown in FIG. 23, the surface on the side where the end of the MR element is exposed is the recording medium facing surface S
Becomes That is, when an information signal is reproduced from a recording medium using this MR head, the recording medium is caused to travel so that the end of the MR element faces the exposed surface, and the signal magnetic field from the recording medium is generated. It is detected by the MR element whose end is exposed on the recording medium facing surface S. The detection of the signal magnetic field by the MR element is performed by supplying a sense current to the MR element via the conductive film 27 and detecting a voltage change of the sense current.

Further, in this MR head, as shown in FIG. 23, the interval Tp between the MR elements in the portion sandwiched between the hard magnetic film 26 and the conductor film 27 becomes the reproduction track width. In other words, the reproducing track width of this MR head is defined by etching the magnetoresistive film 24 using the resist layer 25 as a mask in the steps shown in FIGS.

In this MR head, as shown in FIG. 23, the length Dp from the end of the MR element on the side facing the recording medium to the other end is a so-called depth length (the recording medium of the magneto-sensitive portion). (Depth from the facing surface S). In other words, in the steps shown in FIGS.
The depth of the MR head is defined by etching the magnetoresistive film 24 with the mask as a mask. However, the depth length also depends on the amount of polishing when the side surface on which the MR element is formed is polished. When the amount of polishing is large, the depth length of the magnetoresistive head is determined by the resist layer 29. Is greater than the length from the end of the magnetoresistive element 24 on the side facing the recording medium to the other end when the magnetoresistive film 24 is etched using the mask as a mask.
Slightly smaller.

In the MR head manufactured as described above, the insulating film 28 is formed between the conductor film 27 and the non-magnetic insulating film 30 serving as the upper magnetic gap. The insulation between the magnetoresistive element and the upper magnetic shield is improved. Further, the withstand voltage for each layer laminated on the magnetoresistive element can be improved.

Thus, in this MR head, even if the distance between the soft magnetic film 21 serving as the lower magnetic shield and the soft magnetic film 29 serving as the upper magnetic shield is reduced, the distance between the soft magnetic film 21 and the magnetoresistive element is reduced. Can be sufficiently secured. In other words, in this MR head, the distance between the upper magnetic shield and the lower magnetic shield can be further reduced while ensuring insulation between the magnetoresistive element and the magnetic shield, thereby further increasing the recording density. Can be handled.

Therefore, a magnetoresistive head having improved reliability can be manufactured, and productivity can be greatly improved.

In the thin film process for manufacturing the MR head, the undercut resist layers 25 and 29 are used.
When forming a resist, a so-called two-layer resist method is used in which two resists having different dissolution rates in a developing solution are stacked and used, but the undercut resist layer 25,
29 can also be formed with a single resist layer.

In the case where the single-layer resist layer has an undercut shape, first, a photosensitive resist is applied to form a single-layer resist layer, and then the resist layer is subjected to a pre-bake treatment. Apply. Next, the resist layer is exposed so as to correspond to a desired pattern, and thereafter, the resist layer is subjected to a baking process. The baking process here is a process for accelerating the dissolution rate of the lower layer of the resist layer in the developing solution. Next, the exposed portion of the resist layer is dissolved and removed with a developing solution, and then post-baking is performed. As a result, the exposed portion of the resist layer is removed, and the resist layer has a predetermined shape.

When the resist layer is formed as described above,
After exposure of the resist layer, the resist layer is baked to increase the dissolution rate of the lower layer, so that when the resist layer is developed with a developer, the lower layer of the resist layer is more developed than the upper layer. More etching by liquid. Therefore, the resist layer 25 shown in FIG.
As in the case of the resist layer 29 shown in FIG. 5, an undercut-shaped resist layer in which the lower layer portion is cut inward is obtained.

In the MR head, the conductive film 5
Is not used as it is as an external connection terminal. A second conductor film having a lower electric resistance is connected to the side of the conductor film 5 that is not connected to the MR element 3. May be used as external connection terminals. Here, the second conductor film is preferably formed of a material having low electric resistance such as Cu as thick as possible by plating or the like. As described above, the MR element 3 is connected via the second conductor film having a low electric resistance.
By supplying the sense current to the MR element 3, the resistance value of the sense current path from the external connection terminal to the MR element 3 can be further reduced, and the reproduction characteristics of the MR head can be further improved.

Further, in the above description, only the manufacturing process of the MR head which is a read-only magnetic head has been described.
On the head, an inductive magnetic head may be laminated as a recording magnetic head.

When an inductive magnetic head is laminated on the MR head, an inductive magnetic head may be newly formed on the protective film 12 by a thin film process, or a magnetoresistive effect may be obtained. Magnetic film 8 serving as an upper magnetic shield of a magnetic head
May be used as a lower magnetic core of an inductive magnetic head, and a magnetic gap film, a thin-film coil, an upper magnetic core and the like constituting the inductive magnetic head may be formed on the soft magnetic film 8.

The MR head manufactured by applying the present invention is not limited to a hard disk drive but can be widely used in the field of magnetic recording.
For example, the present invention can be used in a magnetic recording / reproducing apparatus using a flexible disk as a recording medium, a magnetic recording / reproducing apparatus using a magnetic tape as a recording medium, and the like.

[0078]

As described above in detail, according to the present invention, an insulating film is formed between a conductor film and a second non-magnetic insulating film serving as an upper magnetic gap. The insulation between the resistance effect element body and the upper magnetic shield is improved. Further, the withstand voltage for each layer stacked on the magnetoresistive element can be improved. This allows
Even if the space between the soft magnetic film serving as the lower magnetic shield and the soft magnetic film serving as the upper magnetic shield is narrowed, sufficient insulation between them and the magnetoresistive element can be ensured. In other words, the distance between the upper magnetic shield and the lower magnetic shield can be further reduced while ensuring insulation between the magnetoresistive element and the magnetic shield, and it is possible to cope with higher recording density. it can.

Therefore, according to the present invention, it is possible to manufacture a magneto-resistance effect type magnetic head with improved reliability, and it is possible to greatly improve productivity.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration example of a magnetoresistive magnetic head to which the present invention is applied, and is a cross-sectional view of a surface parallel to a surface facing a magnetic recording medium in the magnetoresistive magnetic head.

FIG. 2 is a cross-sectional view showing a state in which a soft magnetic film serving as a lower magnetic shield is formed on a substrate, sequentially showing a manufacturing process of the magneto-resistance effect type magnetic head.

FIG. 3 is a cross-sectional view showing a state in which a soft magnetic film serving as a lower magnetic shield is etched into a predetermined shape, sequentially showing a manufacturing process of the magneto-resistance effect type magnetic head.

FIG. 4 is a cross-sectional view showing a state in which a non-magnetic insulating film is formed on a soft magnetic film serving as a lower magnetic shield, in order, sequentially illustrating manufacturing steps of the magneto-resistance effect type magnetic head.

FIG. 5 is a cross-sectional view showing a manufacturing process of the magneto-resistance effect type magnetic head in order, and showing a state where the non-magnetic insulating film is polished until the surface of the soft magnetic film is exposed.

FIG. 6 is a cross-sectional view showing a state in which a non-magnetic insulating film serving as a lower magnetic gap is formed, sequentially showing manufacturing steps of the magneto-resistance effect type magnetic head.

FIG. 7 is a cross-sectional view showing a state in which a magneto-resistance effect film serving as a magneto-resistance effect element is formed, sequentially illustrating a manufacturing process of the magneto-resistance effect type magnetic head.

FIG. 8 is a cross-sectional view showing a state in which a resist layer is formed on the magnetoresistive effect film, sequentially illustrating the steps of manufacturing the magnetoresistive effect type magnetic head.

FIG. 9 is a cross-sectional view showing the steps of manufacturing the magneto-resistance effect type magnetic head sequentially, showing a state in which a resist layer formed on the magneto-resistance effect film is patterned into a predetermined shape.

FIG. 10 is a cross-sectional view showing a state in which the magneto-resistance effect film is etched using the resist layer as a mask, sequentially illustrating the manufacturing steps of the magneto-resistance effect type magnetic head.

FIG. 11 is a cross-sectional view showing a state in which a hard magnetic film and a conductor film are formed while a resist layer is left, while sequentially showing the manufacturing process of the magnetoresistive head.

FIG. 12 is a sectional view sequentially showing the manufacturing steps of the magnetoresistive effect type magnetic head, in which the resist layer is removed together with the hard magnetic film and the conductor film formed on the resist layer; is there.

FIG. 13 is a plan view showing a state in which the resist layer is removed together with the hard magnetic film and the conductor film formed on the resist layer, sequentially showing the manufacturing steps of the magnetoresistive head. is there.

FIG. 14 is a view sequentially showing a manufacturing process of the magneto-resistance effect type magnetic head, in which a magneto-resistance effect film and a conductor film are
FIG. 4 is a plan view showing a state where a resist layer having a predetermined shape is formed.

FIG. 15 is a view sequentially showing a manufacturing process of the magneto-resistance effect type magnetic head.
FIG. 4 is a cross-sectional view showing a state where a resist layer having a predetermined shape is formed.

FIG. 16 is a cross-sectional view showing the steps of manufacturing the magneto-resistance effect type magnetic head in sequence, showing a state where the magneto-resistance effect film is etched using the resist layer as a mask.

FIG. 17 is a sectional view sequentially showing the manufacturing process of the magneto-resistance effect type magnetic head, showing a state where a resist layer used as a mask when etching the magneto-resistance effect film is removed.

FIG. 18 is a plan view sequentially showing the steps of manufacturing the magneto-resistance effect type magnetic head, showing a state in which a resist layer used as a mask when etching the magneto-resistance effect film is removed.

FIG. 19 is a plan view sequentially showing the steps of manufacturing the magneto-resistance effect type magnetic head, showing a state in which a non-magnetic insulating film serving as an upper magnetic gap is formed.

FIG. 20 is a cross-sectional view showing a state in which a non-magnetic insulating film serving as an upper magnetic gap is formed, sequentially illustrating the steps of manufacturing the magneto-resistance effect type magnetic head.

FIG. 21 is a cross-sectional view showing a state in which a soft magnetic film serving as an upper magnetic shield is formed, sequentially illustrating the manufacturing steps of the magneto-resistance effect type magnetic head.

FIG. 22 is a sectional view sequentially showing the manufacturing steps of the magnetoresistive effect type magnetic head, showing a state in which a protective film is formed.

FIG. 23 is a plan view showing the steps of manufacturing the magnetoresistive effect type magnetic head sequentially, and showing a state where the side surface on the side where the magnetoresistive effect element is formed is polished;

FIG. 24 is a plan view of a main part of a conventional shield type magnetoresistive magnetic head, as viewed from a recording medium facing surface side.

FIG. 25 is a cross-sectional view showing a state in which the magnetoresistive effect film is etched using the resist pattern as a mask, sequentially showing the steps of manufacturing the magnetoresistive effect type magnetic head.

FIG. 26 is a sectional view sequentially showing the manufacturing steps of the same magnetoresistive effect type magnetic head, showing a state in which a hard magnetic film and a conductor film are formed with a resist pattern left.

FIG. 27 is a sectional view sequentially showing the manufacturing process of the magneto-resistance effect type magnetic head, in which a resist pattern is removed and a non-magnetic insulating film serving as an upper magnetic gap is formed;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 magneto-resistance effect type magnetic head (MR head), 3 magneto-resistance effect element (MR element), 4 hard magnetic film, 5 conductor film, 6 magneto-resistance effect element, 7 lower magnetic shield, 8 upper magnetic shield, 9 Lower magnetic gap, 1
0 upper magnetic gap, 13 insulating film, 21 soft magnetic film (lower magnetic shield), 23 non-magnetic insulating film (lower magnetic gap), 24 magnetoresistive effect film (MR element), 25
Resist layer, 26 hard magnetic film, 27 conductor film, 28
Insulating film, 29 resist layer, 30 non-magnetic insulating film (upper magnetic gap), 31 soft magnetic film (upper magnetic shield)

Claims (8)

[Claims] A first soft magnetic film serving as a lower magnetic shield; a first nonmagnetic insulating film serving as a lower magnetic gap formed on the first soft magnetic film; A magnetoresistive film to be a magnetoresistive element formed on the insulating film; and a conductor film for supplying a sense current to the magnetoresistive elements formed at both ends of the magnetoresistive film. A magnetoresistive element, an insulating film formed on the conductor film, a second nonmagnetic insulating film serving as an upper magnetic gap formed on the magnetoresistive element having the insulating film, And a second soft magnetic film serving as an upper magnetic shield formed on the second non-magnetic insulating film. 2. A hard magnetic layer for applying a bias magnetic field to a magnetoresistive element, which is located between the first nonmagnetic insulating film and the conductor film at both ends of the magnetoresistive effect film. 2. The film according to claim 1, wherein each of the films is formed.
The magnetoresistive effect type magnetic head according to the above. 3. The magnetoresistive head according to claim 1, wherein the thickness of the insulating film is greater than the thickness of the second non-magnetic insulating film. 4. A magnetoresistive head according to claim 3, wherein said insulating film has a thickness of 100 nm or more. 5. A step of forming a first non-magnetic insulating film to be a lower magnetic gap on a first soft magnetic film to be a lower magnetic shield; and a magnetoresistive element on the first non-magnetic insulating film. Forming a magnetoresistive element having a magnetoresistive film to be provided, and a conductor film for supplying a sense current to the magnetoresistive elements formed at both ends of the magnetoresistive film, Forming an insulating film on the conductor film, forming a second non-magnetic insulating film on the magnetoresistive element having the insulating film, and forming an upper layer on the second non-magnetic insulating film, Forming a second soft magnetic film serving as a magnetic shield. 6. A hard magnetic material for applying a bias magnetic field to a magnetoresistive element, located between both ends of the magnetoresistive film and between the first nonmagnetic insulating film and the conductor film. 6. The method according to claim 5, wherein a film is formed. 7. The method according to claim 5, wherein the thickness of the insulating film is larger than the thickness of the second non-magnetic insulating film. 8. The method according to claim 7, wherein said insulating film has a thickness of 100 nm or more.