JPH08235532A - Magneto-resistive magnetic head - Google Patents

Abstract

PURPOSE: To stabilize characteristics by enhancing the position accuracy of a reference to position a depth zero position and enhancing the position accuracy and depth accuracy for forming respective patterns. CONSTITUTION: At least the surface 7 side facing magnetic recording media of the groove part 10 formed on the surface of a lower shielding magnetic material 1 facing an MR element 5 is provided with a stepped part 30 to be a reference to position the depth zero position where the lower shielding magnetic material 1 is cut approximately perpendicularly. At this time, the stepped part 30 may be so formed that its one side edge 30a on the surface 7 side facing magnetic recording media aligns approximately to the zero position. The depth in the longitudinal direction of the magnetic gap of the stepped part 30 may be set at 10 to 100nm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect type magnetic head. More specifically, the present invention relates to a magnetoresistive effect magnetic head in which a stepped portion serving as a reference for positioning the depth zero position is formed in a shield magnetic body to stabilize characteristics.

[0002]

2. Description of the Related Art For example, a magnetoresistive effect magnetic head (hereinafter referred to as an MR head) used as a reproducing magnetic head in a magnetic recording / reproducing apparatus such as a hard disk drive is a medium as shown in FIG. Opposing surface 10
7, a pair of shield magnetic bodies 101, 10 having magnetic gaps G ₁ and G ₂ facing each other and facing each other.
A magnetoresistive effect element 105 (hereinafter referred to as an MR element 105) via two nonmagnetic insulating layers 111 and 112 between the two.
Is sandwiched between.

That is, in the MR head, an extra external magnetic field is shielded by the pair of shield magnetic bodies 101 and 102 so that only the desired external magnetic field enters the MR element 105. MR
Information is reproduced by utilizing the change in the resistance of the element 105.

At this time, in the MR element 105, electrodes 103 and 104 are laminated and formed on the front end and the rear end of a magnetoresistive film 113 (hereinafter referred to as MR film 113) serving as a magnetic sensing portion (hereinafter referred to as the front end). The electrode 103 at the part is referred to as the front end electrode 103, and the electrode 104 at the rear end is referred to as the rear end electrode 104.)
It has been done. Note that FIG. 19 shows an example in which the rear end electrode 104 is connected to the MR film 113 via the flux guide 109.

Therefore, information is reproduced by the tip electrode 10 described above.
3, a sense current is passed from the rear end electrode 104 to the MR film 113 to magnetize the MR film 113 in a predetermined direction, and the MR film 1 is generated because the magnetization direction is changed by an external magnetic field.
The change in the resistance value of 13 is detected as a voltage change.

The above-mentioned magnetic gaps G ₁ and G ₂ are
Each is composed of a gap film 108 and a tip electrode 103.

At this time, in the MR head, the bias conductor 106 for operating the MR element 105 in the characteristic region exhibiting excellent linearity and high sensitivity of the magnetoresistive effect characteristic is provided with the insulating layer 111. Through the above MR
It is provided so as to cross the element 105.

In the above MR head, the external magnetic field entering the MR element 105 leaks to the lower shield magnetic body 101 arranged on the side opposite to the side where the front and rear electrodes 103 and 104 are formed. In order to prevent the above, a groove portion 110 is formed in a portion of the lower shield magnetic body 101 facing the MR element 105 excluding the vicinity of the tip electrode 103, and the MR element 105 and the lower shield magnetic body 101 are formed in this portion. Are separated.

At this time, the bias conductor 10
6 may be embedded in the groove 110.

[0010]

By the way, the MR head as described above is manufactured as follows. That is, first, as shown in FIG. 20, a lower shield magnetic body 115 having a predetermined shape is formed on a substrate 113, and a flattening film 116 is formed so as to cover the lower shield magnetic body 115.

Next, as shown in FIG. 20, a groove 117 facing the upper surface 115a of the lower shield magnetic body 115 is formed by dry etching. At this time, in the groove portion 117, both side surfaces 117a and 117b are inclined surfaces,
It is formed as a so-called tapered groove portion. The opening side edge 117a ₁ of the groove 117 on the side facing the magnetic recording medium serves as a reference for positioning the depth zero position.

Next, as shown in FIG. 20, the groove 1 is formed.
An insulating film 118, which serves as a non-magnetic insulating layer, and a bias conductor 120 are sequentially stacked in the layer 17.

Subsequently, as shown in FIG. 21, an insulating film 121 to be a nonmagnetic insulating layer is laminated so as to cover the bias conductor 120.

Next, the insulating films 118 and 121 are formed as shown in FIG.
As shown in FIG. 2, surface polishing is performed until the lower shield magnetic body 115 is exposed. Then, at this time, the groove 117 exposed on the upper surface 115a of the lower shield magnetic body 115 exposed.
The opening side edge 117a ₁ is used as a reference for positioning the depth zero position.

After that, the MR element is formed via the gap film, and the upper shield magnetic body is formed via the non-magnetic insulating layer to obtain the MR head. And finally, the above M
The MR head is completed by polishing the R head from the surface facing the magnetic recording medium so that the magnetic gap has a predetermined depth.

However, when the MR head is manufactured in this way, the position accuracy of the depth zero position cannot be made very good.

When the insulating film is surface-polished to expose the lower shield magnetic body as described above, the polishing depth tends to vary, and the groove depth naturally varies. When variations occur in the depth of the groove portion in this way, since both side surfaces of the groove portion are inclined surfaces, the position of the opening side edge, that is, the reference for positioning the depth zero position also deviates.

Further, since the groove portion is formed by dry etching, the inclination angle of the side surface, which is the inclined surface, is likely to vary, and the variation in the inclination angle is caused in addition to the above polishing depth. The position of the opening side edge, that is, the reference for positioning the depth zero position is deviated.

When the reference for positioning the depth zero position is deviated as described above, the positional accuracy of a pattern such as an MR film or an electrode formed in alignment with the reference is not very good. . Therefore, the depth zero position determined by the rear end portion of the tip electrode, the length of the magnetic sensitive portion of the MR element, and the like vary, which causes variations in the characteristics of the manufactured MR head.

Furthermore, if the positional accuracy of the MR film is not very good as described above, the positional relationship between the MR element and the bias conductor varies, the bias efficiency of the manufactured MR head also varies, and the characteristics vary. Occurs.

Further, when the depth zero position varies as described above, when a plurality of MR heads are polished under the same conditions when the manufactured MR heads are polished to have a predetermined depth, the MR Since the depth zero position is different for each head, the depth variation also occurs and the manufactured M
The characteristics of the R head vary.

Therefore, the present invention has been proposed in view of the conventional circumstances, and improves the reference position accuracy for positioning the depth zero position, improves the formation position accuracy and depth accuracy of each pattern, and stabilizes the characteristics. An object is to provide an MR head.

[0023]

In order to achieve the above-mentioned object, the present invention provides an upper shield magnetic material and a lower shield magnetic material at a predetermined interval facing the magnetic recording medium facing surface, and these shield magnetic materials. In a magnetoresistive effect magnetic head in which a magnetoresistive effect element is arranged between the bodies so as to be orthogonal to a surface facing the magnetic recording medium, a groove portion is provided on a surface of the lower shield magnetic body facing the magnetoresistive effect element. At this portion, a step portion which is separated from the magnetoresistive effect element and serves as a reference for positioning the depth zero position where the lower shield magnetic body is substantially vertically cut is formed at least on the surface of the groove facing the magnetic recording medium. It is characterized by being provided.

In the magnetoresistive head of the present invention, it is preferable that one side edge of the step portion on the side facing the magnetic recording medium is substantially aligned with the depth zero position.

Further, in the magnetoresistive head of the present invention, a step may be provided on the side of the groove opposite to the surface facing the magnetic recording medium.

Furthermore, in the above-described magnetoresistive effect magnetic head of the present invention, the gap length of the magnetic gap thereof can be visually confirmed so as to visually confirm the stepped portion serving as a reference for positioning the depth zero position. Direction depth 10
It is preferable to set it to nm to 100 nm.

In the magnetoresistive head of the present invention, the bias conductor may be embedded in the groove or the bias conductor may be arranged on the upper shield magnetic body side.

[0028]

In the magnetoresistive head of the present invention, the lower shield magnetic body is substantially perpendicular to at least the magnetic recording medium facing surface side of the groove portion provided on the surface of the lower shield magnetic body facing the magnetoresistive effect element. Since the stepped portion that serves as a reference for positioning the depth zero position to be cut is provided, the reference for positioning the depth zero position is not the side surface that is the inclined surface of the groove but the stepped portion. Even if the polishing depth varies during the insulating layer polishing process during head manufacturing, and the opening side edge formation position of the groove varies, the reference position for positioning the depth zero position regardless of this variation in polishing depth. Accuracy is secured.

Further, in the magnetoresistive effect type magnetic head of the present invention, if the step portion is provided so that one side edge on the magnetic recording medium facing surface side substantially coincides with the depth zero position, the MR is produced at the time of manufacture. The alignment of each pattern such as a film and an electrode becomes easy.

Further, in the magnetoresistive head of the present invention, if a step portion is provided on the side of the groove opposite to the surface facing the magnetic recording medium, the width between the two step portions, that is, the opening of the groove portion. The width is regulated.

Furthermore, in the above-described magnetoresistive effect magnetic head of the present invention, if the depth of the magnetic gap of the stepped portion serving as a reference for positioning the depth zero position in the gap length direction is 10 nm to 100 nm, the stepped portion is formed. The section is visually confirmed.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments to which the present invention is applied will be described in detail below with reference to the drawings.

As shown in FIG. 1, the magnetoresistive effect magnetic head (hereinafter referred to as MR head) of the present embodiment has a gap facing the magnetic recording medium facing surface 7 on a substrate 31 called a slider. Between the pair of shield magnetic bodies 1 and 2 arranged to face each other with the magnetic gaps g ₁ and g ₂ being
A magnetoresistive effect element 5 (hereinafter referred to as MR element 5) in which electrodes 3 and 4 are laminated and formed on a front end portion and a rear end portion of a magnetoresistive effect film 32 (hereinafter referred to as MR film 32),
The MR element 5 is provided with a bias conductor 6 for applying a bias magnetic field. At this time, the magnetic gaps g ₁ and g ₂ are formed by the lower gap film 8 made of, for example, aluminum oxide (Al ₂ O ₃ ) and the electrode 3.

Hereinafter, the shield magnetic body 1 on the substrate 31 side will be referred to as the lower shield magnetic body 1, the other shield magnetic body 2 will be referred to as the upper shield magnetic body 2, and the electrode 3 on the tip side of the MR element 5 will be referred to as the tip electrode 3. And the electrode on the rear end side is referred to as the rear end electrode 4.

The lower shield magnetic body 1 and the upper shield magnetic body 2 function as shields so as not to be affected by a magnetic field from the magnetic recording medium separated from the MR element 5, that is, an extra external magnetic field. For example, it is made of permalloy or the like.

The lower shield magnetic body 1 is provided so as to extend in a direction orthogonal to the magnetic recording medium facing surface 7 with one side edge thereof facing. A groove portion 10 is formed in the lower shield magnetic body 1 at a portion facing the MR element 5 excluding the vicinity of the tip electrode 3. In this portion, the MR element 5 and the lower shield magnetic body 1 are separated from each other. are doing.

The groove 10 is a groove having a substantially U-shaped cross section with the side surfaces 10a and 10b being inclined surfaces. The groove 10 has a size capable of accommodating the bias conductor 6 therein, and has a magnetic gap g _{1 in the} lower shield magnetic body _1. , G ₂ are formed as groove portions formed in the track width direction.

On the other hand, similarly to the lower shield magnetic body 1, the upper shield magnetic body 2 is provided so as to extend in a direction orthogonal to the magnetic recording medium facing surface 7 with one side edge thereof facing. The upper shield magnetic body 2 is directly laminated on the front end electrode 3 on the magnetic recording medium facing surface 7 side, and is laminated on the rear end electrode 4 side via an insulating layer 12.

The MR element 5 is formed, for example, in a pattern having a substantially rectangular plane shape, and is provided so that its longitudinal direction is orthogonal to the magnetic recording medium facing surface 7, and one side edge thereof is magnetically recorded. It is provided so as to face the medium facing surface 7. Then, the MR constituting the MR element 5
The film 32 is composed of a thin film made of a ferromagnetic material such as permalloy, and is formed by a vacuum thin film forming technique such as vapor deposition or sputtering. Further, the MR film 3
2 may be a single-layer thin film made of a ferromagnetic material as described above, but a non-magnetic thin film such as aluminum oxide (Al ₂ O ₃ ) is used to avoid Barkhausen noise. It may be a stack of a pair of ferromagnetic material thin films that are magnetostatically coupled to each other.

The tip electrode 3 of the MR element 5 is MR
An electrode for supplying a sense current to the film 32, which is directly laminated on the MR film 32 with one side edge thereof facing the magnetic recording medium facing surface 7, and is electrically connected to the MR film 32. .

On the other hand, the rear end electrode 4 is laminated and formed on the rear end portion of the MR film 32 via the flux guide 9 formed for the purpose of improving the attraction of the signal magnetic field and uniforming the distribution of the bias magnetic field. . In order to enhance the effect of pulling in the signal entering the MR element 5, the flux guide 9
For example, a high magnetic permeability material such as permalloy or amorphous (CoZr type) material is used. In order to form such a flux guide 9, any vacuum thin film forming means such as sputtering, vapor deposition or plating can be used.

The rear end electrode 4 may be formed by directly laminating a part thereof on the rear end portion of the MR film 32. In this case, the flux guide 9 is used to form the rear end electrode 4 at the rear end portion. So that it is laminated on the part.

The bias conductor 6 is for applying a bias magnetic field to the MR element 5, and is located between the front electrode 3 and the rear electrode 4, and the front electrode 3 and the rear electrode 4 are formed. It is arranged in the groove portion 11 formed in the lower shield magnetic body 1 on the side opposite to the side where the magnetic field is formed. The bias conductor 6 is embedded in the insulating layer 11 so that the bias conductor 6 does not protrude from the groove 10.

Further, the bias conductor 6 is made of a metal material having a low resistance, for example, copper having excellent conductivity. Normally, the bias conductor 6 is composed of a thin single-layer film made of copper or the like. Considering the adhesiveness with the insulating layers 11 provided above and below the bias conductor 6, for example, as shown in FIG. It is preferable that the bias conductor 6 has a laminated film structure in which an intermediate layer 6a made of copper is sandwiched between laminated films 6b and 6c made of titanium in the film thickness direction.

The bias conductor 6 is formed in a direction substantially orthogonal to the longitudinal direction of the MR element 5, and a bias current from a DC power source (not shown) is applied to both ends of the bias conductor 6. There is. Therefore, the direct current flows in the track width direction which is the longitudinal direction of the wiring pattern, and the bias magnetic field is applied over the longitudinal direction of the MR element 5 which is the direction perpendicular to the magnetic recording medium facing surface 7. ing.

Further, the bias conductor 6 has a thickness t of about 50 nm to 400 nm and a conductor width W ₂ of about 1 μm to 8 μm in order to apply a bias magnetic field of a predetermined magnitude to the MR element 5. Preferably, the facing distance between the bias conductor 6 and the lower shield magnetic body 1 in the direction orthogonal to the magnetic recording medium facing surface 7, in other words, the facing distance L ₂ between the bias conductor 6 and the side surfaces 10a and 10b of the groove portion 10, It is preferable that L ₃ is about 0.1 μm to 2 μm in consideration of insulation properties, and the facing distance between the bias conductor 6 and the MR element 5 is about 0.1 μm to 2 μm in consideration of narrowing of the gap.

The insulating layer 11 in which the bias conductor 6 is embedded is, for example, Al ₂ O ₃ , SiO ₂ , SOG, S, which ensures the insulation with the bias conductor 6.
A film made of i ₃ N ₄ or the like is preferable. Further, the thickness of the insulating layer 11 arranged between the bias conductor 6 and the lower shield magnetic body 1 is about 0.1 μm to 1 μm in order to ensure the insulating property between the bias conductor 6 and the lower shield magnetic body 1. Preferably.

In the MR head of this embodiment, in particular, the groove portion 10 formed in the lower shield magnetic body 1.
The stepped portion 30 is formed on the surface facing the MR element 5. The step portion 30 is provided so as to cut out the opening side edge of the groove portion 10, and the side surface thereof is a surface perpendicular to the upper surface 1 a of the lower shield magnetic body 1.

Further, in this embodiment, the step portion 3
0 of the magnetic recording medium facing surface 7 on one side 30a corresponds to the end 3a of the front electrode 3 on the rear electrode 4 side.
0, in other words, the one side edge 30a is used as a reference for positioning the depth zero position.

Further, in this embodiment, the step portion 30
The depth of the magnetic gap in the gap length direction from 10 nm to 1
It is set to 00 nm.

In this embodiment, the length L ₁ of the magnetic sensing portion, which is the distance from the end 3a of the tip electrode 3 of the MR element 5 to the end surface 9a of the flux guide 9 on the tip electrode 3 side, is 6 μm.
m from one side edge 30a of the stepped portion 30 to the other side edge 3
The groove width W ₁ which is the distance to 0b and which is the width of the opening of the groove 10 is set to 8 μm.

Therefore, in the magnetoresistive effect magnetic head of this embodiment, M of the groove portion 10 of the lower shield magnetic body 1 is M.
Since the one side edge 30a of the step portion 30 provided on the side facing the R element 5 serves as a reference for positioning the depth zero position, the polishing depth varies in the polishing step of the insulating layer 11 during its manufacture, Even if the opening side edge formation position of the groove 10 varies, the reference for positioning the depth zero position is reliably determined regardless of the variation of the polishing depth, and the position accuracy is ensured.

From this fact, the positional accuracy of the pattern of the MR film, the electrode, etc. formed by aligning with the reference for positioning the depth zero position is also secured, and the depth zero position and the MR
The length of the magnetic sensitive portion of the element and the positional relationship between the MR element and the bias conductor are ensured with accuracy, and the characteristics are stabilized.

Further, since the position accuracy of the depth zero position is ensured, the dispersion of the depth is unlikely to occur during the polishing process so that the predetermined depth length is obtained during the manufacturing, and the characteristics are stabilized.

Further, in the MR head of the present embodiment, one side edge 30a of the step portion 30 to the other side edge 30b of the stepped portion 30 is used.
The width of the opening of the groove 10 is restricted by.

Furthermore, in the MR head of this embodiment, the depth of the magnetic gap of the step portion 30 in the gap length direction is 10 nm to 100 nm.
Is visually confirmed.

Next, a method of manufacturing the MR head of this embodiment will be described in the order of steps. In order to manufacture the MR head of this embodiment, first, as shown in FIG. 3, a substrate 13 made of, for example, calcium aluminate titanate (Al ₂ O ₃ —TiC) material or the like.
Then, an Al ₂ O ₃ film (not shown) is formed on the substrate 13 in order to improve the insulating property and surface property of the substrate 13. Then, a magnetic film 14 made of, for example, permalloy or sendust is formed on the Al ₂ O ₃ film (not shown) by a method such as plating or sputtering.

Next, the magnetic film 14 is dry-etched to form a predetermined shape of the lower shield magnetic body 1 as shown in FIG.
5 is formed. Subsequently, as shown in FIG. 5, a flattening film 16 made of Al ₂ O ₃ or the like is formed on the lower shield magnetic body 15 so as to cover it. Next, as shown in FIG. 6, the flattening film 16 is polished to expose the lower shield magnetic body 15 and make the lower shield magnetic body 15 have a predetermined thickness.

Next, a resist having an opening having a predetermined shape is arranged on the lower shield magnetic body 15, and then dry etching is performed, so that the lower shield magnetic body 15 has a substantially U-shaped cross section as shown in FIG. Thus, the groove portion 17 is formed in which both side surfaces 17a and 17b are inclined surfaces.

Next, as shown in FIG. 8, Al _{2 is formed} on the lower shield magnetic body 15 and the flattening film 16 including the inside of the groove portion 17.
The first insulating film 18 made of O ₃ or the like is formed by sputtering or the like.

Next, as shown in FIG. 9, a metal film 19 made of copper for forming a bias conductor is formed on the first insulating film 18 by sputtering. At this time,
The metal film 19 may be a laminated film in which a film made of copper is sandwiched between films made of titanium from the film thickness direction as described above.

Next, the metal film 19 is left only in the groove portion 17, patterned so as not to protrude from the groove portion 17 and dry-etched, so that the bias conductor 20 having a substantially trapezoidal cross section as shown in FIG. To form.
As a result, the bias conductor 20 is completely embedded in the groove 17 and does not protrude from the groove 17.

Next, the first insulating film 18 is etched except for the portion formed in the groove 17, so that the lower shield magnetic body 15 is exposed and the groove 17 is formed, as shown in FIG.
The first insulating film 18 is left only inside.

Then, as shown in FIG. 12, the groove 1 is formed.
A second insulating film 21 made of Al ₂ O ₃ or the like is formed on the lower shield magnetic body 15 including the inside by sputtering or the like. The second insulating film 21 also functions as a flattening film.

Next, as shown in FIG. 13, the second insulating film 21 is surface-polished to expose the lower shield magnetic body 15. At this time, the above-mentioned surface polishing is carried out by a combination of mechanical polishing with a diamond abrasive having a diameter of 2 μm and a copper Kemet surface plate, and buff polishing with a SiO ₂ abrasive and a fibrous cloth.

As a result, the polished surface of the lower shield magnetic body 1 is flattened, and its surface roughness is about 1 nm, which is a very smooth surface. However, since the warp of the substrate cannot be corrected in the mechanical polishing, the polishing depth varies due to the influence of the substrate warping before the mechanical polishing, and the thickness of the lower shield magnetic body 1 and the depth of the groove portion 17 affect the substrate. Internal variation occurs.

Next, when planarization is performed by the above-mentioned buffing, the amount of polishing in the buffing is small, so the substrate 13
Polishing is performed without depending on the warp of the. In addition, the bias conductor 20 which is a metal film and the second insulating film 2 made of Al ₂ O ₃
When polishing is performed by mechanical polishing using a grindstone or the like due to the difference in polishing rate of 1, the insulating film 21 is polished faster than the metal film. However, buffing causes a difference in polishing rate. The generated step can be eliminated. However, it is impossible to eliminate the variation in the depth of the groove portion 17 generated during the mechanical polishing by the buffing, and the variation in the depth of the groove portion 17 remains.

In this way, the groove portion 1 is subjected to mechanical polishing.
When the depth variation of 7 occurs, the side surface 1 of the groove 17 is
Since 7a and 17b are tapered, the position of the opening side edge of the groove 17 is displaced. In other words, the reference for positioning the depth zero position is deviated.
Since the groove portion 17 is formed by dry etching, the inclination angles of the side surfaces 17a and 17b, which are inclined surfaces, also vary, which also causes a shift in the position of the opening side edge of the groove portion 17, A deviation occurs in the reference for positioning the depth zero position.

Therefore, in this embodiment, as shown in FIG. 14, a step portion 29 is formed by dry etching on the opening side of the groove portion 17, that is, on the side facing the MR element formed in a later step. The step portion 29 is a step portion provided by notching the opening side edges of the side surfaces 17 a and 17 b of the groove portion 17, and the side surface thereof is the lower shield magnetic body 15.
Is a surface perpendicular to the upper surface 15a of the.

It should be noted that the step portion 29 has a width of 0.01 .mu.m to .0 .mu.m from the opening side edge of the side surface 17a of the groove 17 before the step portion 29 is formed to the side facing the magnetic recording medium.
One side edge 29a of the step portion 29 formed at a position of 3 μm
From the other side edge 29b to the groove width of 8 μm
And the width of the opening of the groove 17 is always constant. Further, in the step portion 29, the depth of the magnetic gap in the gap length direction is set to 10 nm to 100 nm,
I am able to confirm visually.

In the present embodiment, the one side edge 29a of the step portion 29 is used as a reference for positioning the depth zero position. Therefore, in this embodiment, even if the position of the opening side edge of the groove portion, which was conventionally used as a reference for positioning the depth zero position, is displaced due to the variation in the polishing depth,
As described above, since the stepped portion is newly formed and the reference for positioning the depth zero position is re-formed, the reference for positioning the depth zero position is reliably determined regardless of the variation in the polishing depth.

Next, as shown in FIGS. 15 and 16, the lower shield magnet including the inside of the groove portion 17 in which the step portion 29 is formed (however, the step portion 29 is not shown in FIG. 15). A lower gap film 22 forming the magnetic gap g ₁ is formed on the body 15. The lower gap film 22 may be formed by sputtering Al ₂ O ₃ .

Then, in order to prevent Barkhausen noise from being generated in the MR element formed in the subsequent step, the lower gap film 22 is buffed by the same method as the method described in the second insulating film 21 plane polishing step. To flatten. As a result, the surface of the lower gap film 22 has a surface roughness of 1
It has a very smooth surface of about nm. However, at this time,
In order to secure the gap length accuracy of the magnetic gap g ₁ ,
The buffing amount of the gap film is 200 nm or less.

In this embodiment, the depth of the magnetic gap of the step portion 29 in the gap length direction is 10 nm to 100 nm.
However, this step portion can be visually confirmed in the above process, and does not impair the gap length accuracy. Also,
A step portion is formed in a portion corresponding to the step portion 29 of the lower gap film 22, but this step portion is eliminated by the buffing.

Next, as shown in FIG. 17, the MR film 23 is formed on the lower gap film 22. The MR film 23 is formed by forming permalloy by sputtering or vapor deposition, and then forming it into a planar rectangular pattern whose longitudinal direction is perpendicular to the surface facing the magnetic recording medium.

At this time, the second insulating film 21 in the groove 17 is formed.
Is flattened, the bias conductor 20 and the MR are
The distance between the surfaces facing the film 23 is set to a distance sufficient for insulation by the gap film 22. Therefore, even when the gap film 22 is thinned by narrowing the gap, the MR
It is possible to reliably avoid a short circuit between the element and the bias conductor 20.

Further, in the present embodiment, the one side edge 29a of the step portion 29 is used as a reference for positioning the depth zero position, and since the reference positional accuracy is secured,
The formation position accuracy of the MR film 23 formed in accordance with this is also ensured. Therefore, the accuracy of the positional relationship between the bias conductor 20 and the MR film 23 is ensured, variation in bias efficiency among MR heads is suppressed, and variation in characteristics of the MR head is suppressed.

Next, a tip electrode is formed on the MR film 23. Then, after forming a flux guide, a rear end electrode is formed and an MR element is formed. At this time, in this embodiment, since the reference positional accuracy for positioning the depth zero position is ensured as described above, the positional accuracy of the tip electrode, the flux guide, and the rear electrode formed in accordance with this is accurate. Is also secured, and the depth zero position determined by the rear end of the tip electrode, the length of the magnetic sensitive portion of the MR film 23, and the like are regulated with good accuracy.

At this time, bias lead conductors connected to both ends of the bias conductor 20 embedded in the groove 17 in the same layer as the rear end electrode are also formed. The bias lead conductor may be formed in a separate process from the rear end electrode, but since the electrode material and film thickness can be the same as those of the rear end electrode, they are formed here at the same time as the rear end electrode. .

Next, an upper shield magnetic body is formed with an insulating layer interposed. The upper shield magnetic body is connected to the tip electrode and is a part of the lead conductor of the MR film 23.

Further, each terminal portion is formed, and polishing is performed from the surface facing the magnetic recording medium to a predetermined depth length,
The MR head of this embodiment as shown in FIG. 1 is completed.

At this time, in this embodiment, the depth zero position is regulated with good accuracy, and even if a plurality of MR heads are polished under the same condition, the depth does not vary and the characteristics are stabilized. To do.

In this embodiment, an example in which the bias conductor is embedded in the groove portion formed on the side opposite to the side where the electrodes of the MR element are formed has been described. MR placed on the shield magnetic body side
It goes without saying that it is also applicable to the head.

[0084]

As is apparent from the above description, in the magnetoresistive head of the present invention, at least the magnetic recording medium of the groove portion provided on the surface of the lower shield magnetic body facing the magnetoresistive element. Since the stepped portion that serves as a reference for positioning the depth zero position for cutting the lower shield magnetic body substantially vertically is provided on the facing surface side, on the side surface where the inclined surface of the groove portion is the reference for positioning the depth zero position. However, even if the polishing depth varies in the insulating layer polishing step during the manufacturing of the magnetoresistive magnetic head, and the opening side edge formation position of the groove varies,
The reference positional accuracy for positioning the depth zero position is ensured regardless of the variation in the polishing depth.

Therefore, the forming position accuracy of the MR film and the electrodes forming the MR element formed in accordance with the reference for positioning the depth zero position becomes good, and the depth zero position and M
The accuracy of the magnetic sensing portion length of the R element and the positional relationship between the MR element and the bias conductor are improved, and the characteristics of the magnetoresistive effect magnetic head are stabilized. Furthermore, since the accuracy of the depth zero position is good as described above, the depth length of the magnetoresistive magnetic head is also regulated with good accuracy and the characteristics are stabilized.

Further, in the magnetoresistive effect magnetic head of the present invention, if the step portion is provided so that one side edge of the magnetic recording medium facing surface side substantially coincides with the depth zero position, the MR is produced at the time of manufacture. The alignment of each pattern such as a film and an electrode becomes easy.

Further, in the magnetoresistive head of the present invention described above, if a step is provided on the side of the groove opposite to the surface facing the magnetic recording medium, the width between the two steps, that is, the opening of the groove. The width is regulated.

Furthermore, in the above-described magnetoresistive head of the present invention, if the depth of the magnetic gap of the stepped portion serving as a reference for positioning the depth zero position in the gap length direction is 10 nm to 100 nm, the above stepped portion is formed. The parts are visually confirmed, which makes it easier to confirm the reference.

[Brief description of drawings]

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

FIG. 2 is an enlarged sectional view of an essential part showing an example of a bias conductor of a magnetoresistive effect magnetic head to which the present invention is applied.

FIG. 3 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in order of steps, showing steps of forming a magnetic film on a substrate.

FIG. 4 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in order of steps, and showing steps of forming a lower shield magnetic body.

FIG. 5 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing steps of forming a planarizing film.

FIG. 6 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing a step of polishing a flattening film.

FIG. 7 is a sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing a step of forming a groove in a lower shield magnetic body.

FIG. 8 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing a step of forming a first insulating film.

FIG. 9 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing steps of forming a metal film.

FIG. 10 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing steps of forming a bias conductor.

FIG. 11 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in order of steps, showing a state in which a first insulating film is etched.

FIG. 12 is a sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing a step of forming a second insulating film.

FIG. 13 is a cross-sectional view showing the method of manufacturing the magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing a step of planarly polishing the second insulating film.

FIG. 14 is a cross-sectional view showing a method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in order of steps, showing steps for forming a step portion.

FIG. 15 is a cross-sectional view showing the method of manufacturing the magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing the step of forming a lower gap film.

FIG. 16 is a cross-sectional view showing the method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied in the order of steps, in which the step of forming the lower gap film is enlarged.

FIG. 17 is a cross-sectional view showing the method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied, in the order of steps, and showing a step of forming an MR element.

FIG. 18 is a sectional view showing the method of manufacturing a magnetoresistive effect magnetic head to which the present invention is applied in the order of steps, and is an enlarged view showing a step of forming an MR element.

FIG. 19 is a schematic cross-sectional view of essential parts showing a conventional magnetoresistive effect magnetic head.

FIG. 20 is a sectional view showing the method of manufacturing the conventional magnetoresistive effect magnetic head in the order of steps, and showing the step of forming an insulating film and a bias conductor on the lower shield magnetic body.

FIG. 21 is a sectional view showing the method of manufacturing the conventional magnetoresistive effect magnetic head in the order of steps, and showing the step of forming an insulating film.

FIG. 22 is a cross-sectional view showing the method of manufacturing the conventional magnetoresistive effect magnetic head in the order of steps, and showing the step of planarly polishing the insulating film.

[Explanation of symbols]

1 ... Lower shield magnetic body 2 ... Upper shield magnetic body 5 ... MR element 6 ... Bias conductor 7 ... Magnetic recording medium facing surface 10 ... Groove portion 30 ... Step portion 30a, 30b ··· one side edge g _1, g ₂ ··· magnetic gap

Claims (6)

[Claims] 1. An upper shield magnetic body and a lower shield magnetic body are arranged at predetermined intervals facing a magnetic recording medium facing surface, and a magnetoresistive effect element is orthogonal to the magnetic recording medium facing surface between the shield magnetic bodies. In the magnetoresistive effect magnetic head arranged as described above, a groove is provided on the surface of the lower shield magnetic body facing the magnetoresistive effect element, and at this portion, the groove is separated from the magnetoresistive effect element. A magnetoresistive effect magnetic head characterized in that a step portion which serves as a reference for positioning a depth zero position for substantially vertically cutting a lower shield magnetic body is provided on at least the magnetic recording medium facing surface side of the groove portion. 2. The magnetoresistive effect magnetic head according to claim 1, wherein one side edge of the step portion on the surface facing the magnetic recording medium is substantially aligned with the depth zero position. 3. The magnetoresistive effect magnetic head according to claim 1, wherein a step is provided on the side of the groove opposite to the surface facing the magnetic recording medium. 4. The magnetoresistive effect magnetic head according to claim 1, wherein the depth of the magnetic gap of the step portion in the gap length direction is 10 nm to 100 nm. 5. The magnetoresistive effect magnetic head according to claim 1, wherein the bias conductor is embedded in the groove. 6. The magnetoresistive effect magnetic head according to claim 1, wherein the bias conductor is arranged on the side of the upper shield magnetic body.