JPH06203337A - Magneto-resitance effect type magnetic head - Google Patents

Abstract

PURPOSE:To lessen the saturation of bias magnetic fields in a magneto-resistance effect element and the leakage of the bias magnetic fields and signal magnetic fields to a lower magnetic pole, to improve reproducing output and to stabilize reproducing characteristics. CONSTITUTION:A magneto-resistance effect element magneto-sensitive part consisting of the MR element 5, a front end electrode 7a, a rear end electrode 7b and a bias conductor 8 is disposed between the lower magnetic pole 2 and upper magnetic pole 3 laminated to face each other on a substrate 1. A groove part 10 is formed in the part facing the MR element 5 exclusive of the part of the lower magnetic pole 2 near the front end electrode 7a and a nonmagnetic metal 11 is embedded in this groove part 10. The hardness of the material constituting the lower magnetic pole and the hardness of the nonmagnetic metal may be made approximately the same at this time. The substrate may be formed as the lower magnetic pole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic resistance effect type magnetic head, and more particularly to the shape thereof.

[0002]

2. Description of the Related Art For example, a magnetoresistive effect magnetic head (hereinafter referred to as an MR head) is often used as a reproducing magnetic head of a hard disk drive. In the MR head, a lower magnetic pole and an upper magnetic pole are located in front of a substrate (slider) made of, for example, Al ₂ O ₃ —TiC, facing a contact surface with a hard disk, that is, an ABS (air bearing surface) surface. It is laminated with a predetermined gap between the ends. Then, a magnetoresistive effect magnetic sensing section (hereinafter referred to as MR) including at least a magnetoresistive effect element (hereinafter referred to as an MR element) via an insulating layer in the gap.
It is called a magnetic sensitive section. ) One end or its tip electrode is the above A
It is arranged so as to face the BS surface.

On the opposite side of the ABS surface, the M
The other electrode of the R magnetism sensing portion is provided substantially parallel to the one electrode. The MR element, which has been magnetized in a predetermined direction by energization, is operated in a characteristic region having excellent linearity and high sensitivity in a magnetoresistive effect characteristic in a substantially central portion of the MR magnetic sensitive section. A bias conductor is provided so as to cross the MR element via an insulating layer.

[0004]

However, in the above MR head, local saturation (especially at the tip of the MR element) of the bias magnetic field applied to the MR element by the bias conductor is likely to occur, and the MR The phenomenon that the linearity of the magnetoresistive effect characteristic of the element is impaired is occurring.

Further, the phenomenon that the bias magnetic field applied to the MR element by the bias conductor or the signal magnetic field entering the MR element leaks to the lower magnetic pole formed in the lower layer of the MR element through the insulating layer. Is also happening.

[0006] When the loss of the linearity of the magnetoresistive effect characteristic of the MR element due to the local saturation of the MR element of the bias magnetic field as described above and the leakage of the bias magnetic field or the signal magnetic field to the lower magnetic pole occur, the MR feeling is sensed. This leads to a reduction in the reproduction output of the magnetic part and instability of the reproduction characteristics.

Therefore, the present invention has been proposed in view of the conventional circumstances, and the local saturation of the bias magnetic field in the MR element, the leakage of the bias magnetic field and the signal magnetic field to the lower magnetic pole hardly occur, and the reproduction output is obtained. It is an object of the present invention to provide a magnetoresistive effect magnetic head having improved reproduction characteristics and stable reproduction characteristics.

[0008]

In order to achieve the above-mentioned object, the inventors of the present invention have made earnest studies, and as a result, provided a groove portion in a portion facing the MR element except the vicinity of the tip electrode of the lower magnetic pole,
By arranging a non-magnetic metal in the groove, a magnetic separation layer is formed between the MR element and the lower magnetic pole, and the bias magnetic field M
It has been found that it is possible to reduce local saturation, bias magnetic field, and signal magnetic field leakage to the lower magnetic pole in the R element.

That is, the present invention provides a magnetoresistive effect magnetic head comprising a lower magnetic pole and an upper magnetic pole, which are laminated on a substrate so as to face each other, and a magnetoresistive magnetic sensitive section is provided between the lower magnetic pole and the upper magnetic pole. It is characterized in that a groove portion is formed in a portion facing the magnetoresistive effect element except the vicinity thereof, and a nonmagnetic metal is embedded in the groove portion.

By the way, when manufacturing the MR head as described above, the lower magnetic pole, the insulating layer, the MR magnetic sensing part,
The insulating layer and the upper magnetic pole are sequentially laminated to manufacture. Therefore,
In order to provide the lower magnetic pole with the groove portion in which the non-magnetic metal is arranged, the lower magnetic pole is laminated on the substrate and then the groove portion is provided, and the non-magnetic metal is embedded therein. At this time, the MR magnetic sensitive portion is further laminated on the groove portion in which the non-magnetic metal is embedded, so that the vicinity of the groove portion needs to be smooth. After the non-magnetic metal is embedded, the lower magnetic pole and the surface of the non-magnetic metal are polished. Will be applied. At this time, if the hardness of the non-magnetic metal and the material of the lower magnetic pole are significantly different, the polishing rate will be different,
It is difficult to process uniformly and it is difficult to obtain a smooth surface.

Therefore, according to the present invention, in the vicinity of the tip electrode of the lower magnetic pole of the magnetoresistive effect type magnetic head in which the magnetoresistive effect magnetic sensitive portion is arranged between the lower magnetic pole and the upper magnetic pole which are laminated on the substrate so as to face each other. In a magnetoresistive effect magnetic head in which a groove is formed in a portion opposite to the magnetoresistive effect element except that the nonmagnetic metal is embedded in the groove, the nonmagnetic metal has substantially the same hardness as the material forming the lower magnetic pole. It is characterized by being.

Further, in the magnetoresistive effect type magnetic head as described above, the substrate can be used as the lower magnetic pole. In the magnetoresistive effect type magnetic head as described above, the substrate is the lower magnetic pole. It is characterized by that.

[0013]

According to the present invention, in the magnetoresistive effect type magnetic head having the magnetoresistive effect magnetic sensitive portion between the lower magnetic pole and the upper magnetic pole, which are laminated on the substrate so as to face each other, in the vicinity of the tip electrode of the lower magnetic pole. Since a groove portion is formed in a portion facing the magnetoresistive effect element except for, and the nonmagnetic metal is embedded in the groove portion, saturation of the bias magnetic field in the magnetoresistive effect element,
The bias magnetic field or the information magnetic field is unlikely to leak to the lower magnetic pole.

Further, in the present invention, since the nonmagnetic metal in the magnetoresistive head as described above has substantially the same hardness as the material forming the lower magnetic pole, the lower magnetic pole and the nonmagnetic metal are uniformly processed. It is possible to

Further, according to the present invention, in the magnetoresistive effect type magnetic head as described above, since the substrate is the lower magnetic pole, the manufacturing process can be shortened.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described below with reference to the drawings. In the MR head of this embodiment, as shown in FIG. 1, a lower magnetic pole 1 and an upper magnetic pole 2 are laminated and formed on a substrate 3 called a slider so that their front ends face each other with a predetermined gap therebetween. It will be done.

The lower magnetic pole 1 is provided on the substrate 3, and one end of the lower magnetic pole 1 is made to face an ABS surface 4 which is a contact surface with a magnetic recording medium such as a hard disk.
It is provided so as to extend in a direction substantially orthogonal to the BS surface 4.

On the other hand, the upper magnetic pole 2 is provided so as to have one end thereof facing the ABS surface 4 and extends in a direction substantially orthogonal to the ABS surface 4, and the front end facing the ABS surface 4 is provided. It is bent and formed so that the space between the lower magnetic pole 1 and the lower magnetic pole 1 is narrowed. Further, the upper magnetic pole 2 magnetically contacts the lower magnetic pole 1 at the rear end to form a back gap and a closed magnetic path.

In the MR head of this embodiment,
An MR element 5, which is a magnetoresistive effect element, is provided rearward from the ABS surface 4 in the gap between the upper magnetic pole 2 and the lower magnetic pole 1. The MR element 5 is provided such that its longitudinal direction is orthogonal to the ABS surface 4, one edge thereof faces the ABS surface 4, and the trailing edge of the MR element 5 and the lower magnetic pole 1 face each other. The magnetic pole 2 is located almost in the middle. Further, the MR element 5 includes the substrate 3
In order to insulate the lower magnetic pole 1 provided above, the first
Is provided on the lower magnetic pole 1 through the insulating layer 6a. The MR element 5 has a structure in which a pair of magnetoresistive effect thin films that are magnetostatically coupled via a nonmagnetic insulating layer made of, for example, SiO ₂ are laminated in order to avoid the occurrence of Barkhausen noise. It is desirable to do.

A pair of electrodes 7a and 7b (hereinafter, referred to as an electrode 7a provided on the ABS surface 4 side) for passing a sense current from a constant current source (not shown) is provided at the front end and the rear end of the MR element 5. Is referred to as the front end electrode 7a, and the electrode 7b provided at the rear end portion is referred to as the rear end electrode 7b) are electrically connected to the MR element 5 and are stacked.

The tip electrode 7a is formed as a wiring pattern having a substantially L shape in a plan view, and one end thereof is laminated on the tip of the MR element 5. Then, one side edge portion of the pattern of the tip electrode 7a on the side laminated on the MR element 5 is exposed to the ABS surface 4. The end portion of the wiring pattern drawn out to the back side is a grounding terminal portion.

On the other hand, the rear end electrode 7b is the front end electrode 7a.
Similar to the above, the wiring pattern is formed in a substantially L-shaped plane, and is provided on the opposite side of the tip electrode 7a with the MR element 5 interposed therebetween. And, one end of the rear end electrode 7b is
The MR element 5 is laminated on the rear end portion thereof. The end of the wiring pattern pulled out to the back side serves as a current source terminal.

The front electrode 7a and the rear electrode 7b are
A bias conductor 8 is provided between the MR element 5 and the MR element 5, which is given a magnetized state in a predetermined direction by energization, to operate in a characteristic region exhibiting excellent linearity and high sensitivity of the magnetoresistive effect characteristic. There is. The bias conductor 8 is provided across the MR element 5 between the electrodes 7a and 7b, and both ends of the bias conductor 8 are drawn out to the back side. The end portion pulled out to the back side serves as a terminal portion for passing a current through the bias conductor 8. The bias conductor 8 includes the MR element 5, both electrodes 7a,
It is formed on the second insulating layer 6b to insulate it from 7b. The upper magnetic pole 2 is formed on the bias conductor 8 via the third insulating layer 6c, and the protective film layer 9 is provided on the upper magnetic pole 2 so as to protect the MR head from inadvertent external force or the like. It has become.

In particular, in the MR head of this embodiment, the groove portion 10 is provided at a position facing the MR element 5 except the vicinity of the tip electrode 7a of the lower magnetic pole 1, and the nonmagnetic metal 11 is provided in the groove portion 10. It is embedded. The groove 10 in which the non-magnetic metal 11 is embedded locally saturates the bias magnetic field generated by the bias conductor 8 in the MR element 5,
It is provided in order to prevent the bias magnetic field or the information magnetic field from leaking from the MR element 5 to the lower magnetic pole 1, and the depth thereof is preferably on the order of 100 nm. Further, as the non-magnetic metal 11, the non-magnetic metal 11 may be used because of the manufacturing process described later.
A material having a hardness equivalent to that of the material forming the lower magnetic pole 1 is preferable, and metals such as Ti, Ta, Cu and Ni are preferable. A non-magnetic oxide material or the like may be used instead of the non-magnetic metal 11, but it is not preferable because the hardness is different from that of the lower magnetic pole 1.

By the way, the above-mentioned MR head is manufactured through the following manufacturing steps. First, the lower magnetic pole 1 is formed on the substrate 3. That is, as shown in FIG.
A NiFe film for forming the lower magnetic pole 1 is formed on the substrate 3 by electroplating, and the NiFe film is processed into the lower magnetic pole 1 having a predetermined shape by lithography.

Next, as shown in FIG. 3, a groove 10 having a depth of several hundred nm is formed at a predetermined position of the lower magnetic pole 1 by photolithography or ion etching. Then
As shown in FIG. 4, a non-magnetic metal 11 is formed on the lower magnetic pole 1 having a groove 10 by sputtering or electroplating.
Is formed thicker than the depth of the groove portion 10. By the way, in the subsequent step, since the MR magnetic sensing portion and the like are laminated on the lower magnetic pole 1, the surface of the lower magnetic pole 1 needs to be smooth. Therefore, the lower magnetic pole 1 on which the non-magnetic metal 11 is formed is first mechanically polished by using a metal surface plate (for example, a tin surface plate, a copper Kemet surface plate, etc.) and diamond abrasive grains, and thereafter. A wrap sheet having flexibility to improve surface smoothness (for example, a cloth polishing sheet) and Si
Polishing is performed using O ₂ abrasive grains to obtain the lower magnetic pole 1 having the groove portion 10 in which the non-magnetic metal 11 having high surface smoothness is embedded as shown in FIG.

When the material to be embedded in the groove 10 is the non-magnetic metal 11 as described above, there is no great difference in hardness between the lower magnetic pole 1 and the non-magnetic metal 11, so that the non-magnetic metal 11 is uniformly polished to form the non-magnetic metal 11 film. Even if polishing is performed after the formation, there is no step between the lower magnetic pole 1 and the nonmagnetic metal 11, and a smooth surface can be obtained. However, as described above, the groove 1
When a nonmagnetic oxide material or the like is used as the material to be embedded in 0, the lower magnetic pole 1 and the groove portion 10 as shown in FIG.
Since there is a difference in hardness between the non-magnetic oxide materials 12 embedded in, the polishing will cause a step as shown in the figure. For example, when a NiFe film is used as the lower magnetic pole 1 and Al ₂ O ₃ is used as the non-magnetic material, a surface pressure of 60 g / cm ^{2 is applied} by a metal surface plate (copper Kemet surface plate) and diamond abrasive grains (particle diameter 2 μm). When polishing was performed at a rotation speed of 60 rpm, a step of about 0.1 μm was formed at the boundary between the lower magnetic pole 1 and the nonmagnetic oxide material 12. Thereafter, it was polished using a cross abrasive sheet and SiO ₂ abrasive grains in order to improve the surface smoothness of a non-magnetic oxide material 12 by SiO ₂ Al
₂ O ₃ was chemically polished, and the surface of the nonmagnetic oxide material 12 was dented. As described above, the lower magnetic pole 1
Since the MR magnetic sensitive portion and the like are laminated on the upper surface, the surface of the lower magnetic pole 1 needs to be a smooth surface, and the above-described step difference is not preferable. Therefore, as the non-magnetic material to be embedded in the groove 10 formed in the lower magnetic pole 1, a non-magnetic metal, particularly a non-magnetic metal having substantially the same hardness as the lower magnetic pole 1, is preferable.

Then, the first insulating layers 6a, M are formed on the lower magnetic pole 1 having the groove portion 10 in which the nonmagnetic metal 11 is embedded.
As shown in FIG. 1, the R element 5, the front electrode 7a and the rear electrode 7b, the second insulating layer 6b, the bias conductor 8, the third insulating layer 6c, the upper magnetic pole 2, and the protective film layer 9 are sequentially laminated. Obtain an MR head.

In the MR head of this embodiment described above, the substrate can be used as the lower magnetic pole. For example, as shown in FIG. 7, the first insulating layer 26 is formed on the substrate 23.
a, MR element 25, front electrode 27a and rear electrode 27
b, the second insulating layer 26b, the bias conductor 28, the third insulating layer 26c, the upper magnetic pole 22, and the protective film layer 29 may be sequentially laminated. In the above MR head,
The substrate 23 also serves as the lower magnetic pole. Also in this MR head, the first insulating layer 26a, the MR element 25, the front electrode 27a and the rear electrode 27b, the second insulating layer 26b, the bias conductor 28, the third insulating layer 26c, the upper magnetic pole 22,
The shape, arrangement position, and role of the protective film layer 29 are as described above. A groove portion 30 is provided in the substrate 23 serving as a lower magnetic pole, and a nonmagnetic metal 31 is embedded in the groove portion 30.

Such an MR head is also manufactured through the manufacturing process described above. However, since the substrate is the lower magnetic pole, first, the groove portion 30 having a depth of several hundred nm is formed at a predetermined position of the substrate by photolithography and ion etching as described above. Then, a non-magnetic metal 31 is formed on this by sputtering or electroplating.
Is formed to be thicker than the depth of the groove portion 30, and the surface thereof is polished. Then, the first insulating layer 26a, the MR element 25, and the tip electrode 2 are formed.
7a and the rear end electrode 27b, the second insulating layer 26b, the bias conductor 28, the third insulating layer 26c, the upper magnetic pole 22, and the protective film layer 29 are sequentially laminated to obtain an MR head as shown in FIG.

In this embodiment, a so-called shield type MR head has been described, but it goes without saying that the present invention is also applicable to a so-called yoke type MR head.

In the MR head of this embodiment, since the groove portion is formed in the portion facing the MR element except the lower magnetic pole or the vicinity of the tip electrode of the substrate, and the nonmagnetic metal is buried in the groove portion, the bias conductor is used. The bias magnetic field applied to the MR element is unlikely to be locally saturated (especially at the tip of the MR element) in the MR element, and the bias magnetic field is evenly distributed over the entire magnetic sensing portion between the front electrode and the rear electrode of the MR element. When applied, the magnetoresistive effect characteristics of the MR element are made uniform, and the entire magnetic sensing portion of the MR element can operate in a linear operation region, so that the linearity of the magnetoresistive effect characteristics of the MR element is improved.

Also, the bias magnetic field applied to the MR element by the bias conductor and the signal magnetic field entering the MR element are less likely to leak to the lower magnetic pole formed in the lower layer of the MR element, so that a strong signal is applied to the MR element. A magnetic field comes in.

As a result, in the MR head of this embodiment, the reproduction output is improved and the reproduction output is stabilized.

Further, in the MR head of this embodiment,
Since the hardness of the non-magnetic metal embedded in the groove is substantially the same as the hardness of the lower magnetic pole or the substrate, the surface of the lower magnetic pole or the substrate and the non-magnetic metal can be uniformly processed, and a smooth surface can be obtained. Therefore, the characteristics of the MR element formed on the lower magnetic pole or the substrate can be stabilized.

Further, in the MR head of this embodiment,
The substrate may be the lower magnetic pole, and the manufacturing process can be shortened without impairing its characteristics.

[0037]

As is apparent from the above description, in the present invention, the magnetoresistive effect magnetic sensitive portion is disposed between the lower magnetic pole and the upper magnetic pole which are laminated on the substrate so as to face each other. In the effect type magnetic head, a groove is formed in a portion facing the magnetoresistive effect element excluding the vicinity of the tip electrode of the lower magnetic pole, and a nonmagnetic metal is embedded in the groove, so that saturation of the bias magnetic field in the magnetoresistive effect element occurs. The leakage of the bias magnetic field or the information magnetic field to the lower magnetic pole is unlikely to occur, and the improvement and stabilization of the reproduction output of the magnetoresistive head can be achieved.

Further, in the present invention, since the nonmagnetic metal in the above-described magnetoresistive magnetic head has substantially the same hardness as the material forming the lower magnetic pole, the lower magnetic pole and the nonmagnetic metal are uniformly processed. Since it is possible to stabilize the characteristics of the magnetoresistive effect element formed on the lower magnetic pole, the reproduction output of the magnetoresistive effect type magnetic head is improved and stabilized.

Further, according to the present invention, in the above-mentioned magnetoresistive effect type magnetic head, since the substrate is the lower magnetic pole, the manufacturing process can be shortened,
Its industrial value is very high.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of essential parts showing an embodiment of a magnetoresistive effect magnetic head to which the present invention is applied.

FIG. 2 is a cross-sectional view showing a manufacturing process of an embodiment of a magnetoresistive effect magnetic head to which the present invention is applied and showing a process of forming a lower magnetic pole on a substrate.

FIG. 3 is a cross-sectional view showing a step of forming a groove on the lower magnetic pole.

FIG. 4 is a cross-sectional view showing a step of forming a nonmagnetic metal film in a groove.

FIG. 5 is a cross-sectional view showing a state where the lower magnetic pole is polished.

FIG. 6 is a cross-sectional view showing a state in which a nonmagnetic oxide material is embedded in a groove and polishing is performed.

FIG. 7 is a schematic cross-sectional view of a main part showing another embodiment of the magnetoresistive effect magnetic head to which the present invention is applied.

[Explanation of symbols]

 1 --- Lower magnetic pole 2,22-Upper magnetic pole 3,23-Substrate 4 --- ABS surface 5,25-MR Element 6a, 26a ... First insulating layer 6b, 26b ... Second insulating layer 6c, 26c ... Third insulating layer 7a, 27a ... Tip electrode 7b, 27b ... Rear end Electrodes 8, 28 ... Bias conductors 9, 29 ... Protective film layer 10, 30 ... Grooves 11, 31 ... Non-magnetic metal

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Mamoru Sasaki 6-735 Kitashinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (3)

[Claims] 1. A magnetoresistive effect type magnetic head comprising a magnetoresistive effect magnetic sensitive portion between a lower magnetic pole and an upper magnetic pole, which are laminated facing each other on a substrate, except for the vicinity of the tip electrode of the lower magnetic pole. A magnetoresistive effect type magnetic head, characterized in that a groove is formed in a portion facing the magnetoresistive effect element, and a nonmagnetic metal is embedded in the groove. 2. The magnetoresistive effect magnetic head according to claim 1, wherein the nonmagnetic metal has substantially the same hardness as the material forming the lower magnetic pole. 3. A magnetoresistive effect magnetic head according to claim 1, wherein the substrate has a lower magnetic pole.