JP3344028B2 - Manufacturing method of magnetoresistive head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magnetoresistive head used in a magnetic recording / reproducing apparatus or the like.

[0002]

2. Description of the Related Art As the performance of conventional disk drives has been improved, various higher performances have also been required for thin-film magnetic heads used therein. As part of this, there is the use of a magnetoresistive head. Since the output of a magnetoresistive head does not depend on the peripheral speed, it has a great effect on increasing the capacity of a small-diameter disk device, but still has many technical problems in practical use. In particular, for a narrow track head in which the advantage of the magnetoresistive head is greatly exhibited, there is a major problem in the shape of a lead layer for extracting an electrode from the magnetoresistive element portion and a manufacturing method thereof.

A configuration of a thin-film magnetic head for a hard disk drive manufactured by using a conventional method of manufacturing a magnetoresistive head will be described below with reference to FIGS.
FIG. 4 is a perspective view showing a thin film magnetic head manufactured by using a conventional method for manufacturing a magnetoresistive head, and FIG.
It is a partial expanded sectional view of a part. The magnetoresistive head is a read-only head and is used in a form integrated with an inductive head for a normal recording operation. The thin-film magnetic head is formed by forming an element on a ceramic substrate using a thin-film forming technique, and is used in a state of a slider 1 for a magnetic disk device as shown in FIG. 4. When the thin-film magnetic head is mounted on the device, a floating rail is used. A gimbal is adhered in parallel to the back surface side of 2 and used as a magnetic head assembly state. The flying rail 2 takes various forms depending on the application, and is formed by two or three by mechanical processing or ion beam etching. FIG. 4 shows a case where three floating rails 2 are formed by machining. The thin film magnetic head is formed on the front side of the slider 1 in FIG. 4 and on the rear end face in the rotation direction of the medium during operation. In FIG. 4, 3 is an upper insulating layer, 4 is an upper magnetic layer, and 5 is a post-process. Is a pad portion for bonding wires.

[0006] Here, there are four pad portions 5 each because at least two terminals are required for the recording portion and the reproducing portion.

Next, a method for manufacturing a conventional magnetoresistive head will be described with reference to FIG. First, a lower shield layer 8 made of permalloy, sendust or an iron-based alloy material is formed on a ceramic substrate 6 coated with an insulator 7 such as alumina formed by sputtering by electroplating or sputtering. Then, a lower shield gap layer 9 made of an insulating material such as alumina is formed by a sputtering method, and a magnetoresistive effect element portion 10 is further laminated thereon. Although the magnetoresistive element section 10 is shown as a single layer in FIG. 5, the magnetoresistive element section 10 may have a two- to four-layer configuration depending on the bias method used to drive the magnetoresistive element section 10.

Next, a lead layer 11 is formed using a resistance material such as gold and an adhesion strengthening layer of chromium, titanium, tantalum or the like for strengthening the adhesion between gold and each of the upper and lower layers. The upper shield gap layer 12 is formed, and the upper shield layer 13 is sequentially laminated using permalloy or an iron-based alloy formed by an electroplating method or a sputtering method, thereby completing the creation of the reproducing head.

Next, for the recording head portion, first, a lower magnetic layer 14 of the recording portion is formed on the upper shield layer 13 by an electroplating method or the like. In order to prevent magnetic coupling between the upper shield layer 13 and the lower magnetic layer 14, a separation layer made of an insulating material such as alumina may be inserted between the two layers. Next, after laminating the gap layer 15 of the recording section, a lower insulating layer made of a resin such as a novolak or polyimide resin, a lower coil layer formed by electroplating or the like (not shown), and an upper insulating layer similar to the lower insulating image. The layers are sequentially laminated, the upper magnetic layer 16 is laminated by an electroplating method or the like, and finally the upper magnetic layer 16 is protected by a protective layer 17 of alumina or the like.

FIG. 6 is a partially enlarged plan view schematically showing the magnetoresistive element portion of FIG. 5, and FIG. 7 is a sectional view of the magnetoresistive element portion taken along line BB of FIG. Since the magnetoresistive element 10 is a magnetic flux responsive reproducing head, a reproduction output independent of the speed of the medium can be obtained. However, the output is smaller as the height H of the magnetoresistive element 10 is smaller. It becomes bigger. Normally, the width L and the thin thickness T of the lead layer 11 are larger than the height (width) H and the thin thickness t of the magnetoresistive element portion 10,
L is several tens of μm, T is 1000 to 2000 °, H is 1 to 3 μm, and t is 500 to 1000 including the bias layer.
Å. In the magnetoresistive head, the region where the electric resistance is the highest in structure is the magnetoresistive element section 10.

Next, the junction between the magnetoresistive element 10 and the lead layer 11 as viewed from the medium facing surface will be described with reference to FIG. The shape of the end face of the lead layer 11 is ideally preferably perpendicular to the magnetoresistive element section 10, but it is not desired to damage the magnetoresistive element section 10 located in the lower layer in the forming process. The lead layer 11 is usually formed using a lift-off method for reasons such as reducing the distance between the magnetoresistive element portion 10 and the upper shield layer 13. In the lift-off method, after forming a pattern with a photoresist or the like, a film is attached by sputtering or vapor deposition, and the film attached on the pattern of the photoresist or the like is removed simultaneously with the photoresist or the like to obtain a pattern of a necessary material. The method has the following properties. That is, as shown in FIG. 8, when a film is to be formed near a certain upright pattern 18 by sputtering or vapor deposition,
Since the probability of particles adhering to the vicinity of the pattern 18 decreases, the film thickness gradually decreases as approaching the pattern 18. This tendency becomes more pronounced as the pattern height U increases,
The width S until the film thickness becomes constant also increases. For the above reason, as shown in FIG. 7, the cross-sectional shape of the end face of the lead layer 11 is an acute angle with respect to the magnetoresistive element section 10, and is constant from the junction C with the magnetoresistive element section 10. The film thickness gradually changes during the width S up to the position where the film becomes thick. Here, the reproduction track width of the magnetoresistive element section 10 is determined by the distance T.sub.D between the lead layer 11 and the junction C of the magnetoresistive element section 10. W. In the end surface of the lead layer 11 having such a shape, even if the lead layer 11 and the magnetoresistive element section 10 are bonded, the magnetoresistive element section 1
A region where the resistance of the lead layer 11 is not so small as compared to the resistance of 0 exists between the widths S. In the magnetoresistive effect element portion 10 in such a region, the resistance change due to the external magnetic field is changed to the change in the voltage between the terminals of the lead layer 11, so that the read track width is effectively widened. At this time, since the change in magnetoresistance at the junction between the lead layer 11 and the magnetoresistive element section 10 is gradually reduced in the direction in which the thickness of the lead layer 11 increases, the change in resistance that contributes to the change in voltage between the lead terminals decreases. There is a problem that the end point of the track width is blurred, and the off-track characteristic at the time of driving the magnetoresistive head is deteriorated. In addition, the resistance naturally increases in the region (width S) where the thickness of the lead layer 11 gradually decreases. Although the electric resistance of the magnetoresistive effect element section 10 is originally high,
If the height H of the magnetoresistive element section 10 is reduced or the film thickness t is reduced in order to improve the reproduction output, the electric resistance of the magnetoresistive element section 10 increases more and more. Become. When the magnetoresistive head is driven, a constant DC current is applied to the magnetoresistive element 10, but when the electric resistance of the magnetoresistive element 10 increases, the temperature of the magnetoresistive element 10 becomes a resistance value. Increases in proportion to the product of the square of the current value and the current value, so that the temperature of the magnetoresistive effect element section 10 sharply rises as the element resistance increases. Therefore, as the temperature of the magnetoresistive effect element 10 rises, the effect of thermal noise on the reproduction signal becomes remarkable, and when an exchange bias is used, the antiferromagnetic film is thermally unstable. This causes a problem of instability of bias and generation of Barkhausen noise. The above problem becomes more serious as the width S becomes wider and the track width becomes narrower. Therefore, in order to obtain a desired effective reproduction track width and a stable low-resistance magnetoresistive element section 10, the width S needs to be reduced as much as possible.

[0010]

In order to reduce the width S, it is conceivable to reduce the thickness of the lift-off material shown in FIG. 8. However, this means has the following problems.

First, after forming the lower shield layer 8, the lower shield gap layer 9, and the magnetoresistive element portion 10,
As shown in FIG. 9A, a photoresist pattern 19 for lifting off the lead layer 11 is formed. Here, by adjusting the viscosity of the photoresist and the number of rotations of the substrate at the time of application, a photoresist film thickness V required for a region where a lead pattern is formed can be obtained. Due to the step formed by the lower shield layer 8, a region W in which the photoresist cannot be sufficiently applied occurs in the vicinity thereof. This is a problem that is determined by the thickness relationship and the properties of the viscous fluid in the vicinity of the step. Is extremely likely to occur. Using the photoresist pattern 19 thus formed, FIG.
9 (b), a film 20 is formed by vapor deposition or sputtering.
If lift-off is performed in (c), a film residue 21 will be formed near the step formed in the lower shield layer 8 where the photoresist pattern 19 has not been applied. Since this film residue 21 is generated over the entire periphery of the pattern end of the lower shield layer 8, the film residue 21 is
Short-circuit between the two terminals, or short-circuit or insulation failure between the upper shield layer 13 and the lead layer 11 thereover. Invite. Further, if the remaining film 21 is remarkable, the lift-off cannot be performed, and the function as the magnetoresistive effect element portion 10 cannot be achieved.

The present invention has been made in view of the above-described problems, and has the following characteristics,
An object of the present invention is to provide a method of manufacturing a magnetoresistive head having excellent reliability.

[0013]

According to the present invention, the magnetoresistive element portion and the lead layer are formed after the periphery of the lower shield layer is made substantially flat.

[0014]

According to the above means, the periphery of the lower shield layer is flattened to eliminate the remaining film and to obtain a magnetoresistive head having a stable effective reproduction track width and a low resistance. A thin photoresist pattern for formation can be formed.

[0015]

SUMMARY OF THE INVENTION The present invention provides a method for processing a substrate.
Form the lower shield layer before and above the lower shield layer before processing
The gap layer before processing is formed on the gap layer before processing.
A magnetoresistive element is formed, and on the magnetoresistive element is formed.
Both sides of the magnetoresistive element on the gap layer before processing
Forming a first mask at an interval toward the first mask;
Remove the first mask by laminating a conductive film through
And lead on the magnetoresistive element and the gap layer before processing.
In the step after forming the lead layer and forming the lead layer,
Make the gap layer before processing and the lower shield layer before processing
Forming a second mask to be processed into a shape,
By etching through the mask, the gap before processing
Process the lower layer and the lower shield layer before processing into
And a lower shield layer.

(Embodiment 1) FIGS. 1 (a) to 1 (e) are manufacturing process diagrams when a lead layer is formed in a method of manufacturing a magnetoresistive head according to a first embodiment of the present invention. The vicinity of the resistance effect element section 10 is shown as an enlarged cross section as viewed from the medium facing surface.

First, referring to FIG. 1A, a substrate 6 made of ceramic coated with an insulator 7 such as alumina formed by a sputtering method is formed by electroplating or a sputtering method so that the entire substrate 6 or a desired shape is formed. The lower shield layer 8 is formed largely of permalloy, sendust or an iron-based alloy material. Here, when the magnetoresistive head is machined into a magnetic head slider shape, the marker used for machining usually uses the magnetoresistive element section 10,
The lower shield layer 8 is not left in the region where the processing marker is formed so that the lower shield layer 8 is not damaged when the lower shield layer 8 is processed into a desired shape later. Similarly, for a photomask overlay marker used when forming another layer, it is necessary to prevent the lower shield layer 8 from being left in the formation region for the same reason.

Next, a lower shield gap layer 9 made of an insulating material such as alumina formed by a sputtering method is formed, and a magnetoresistive effect element portion 10 is sequentially laminated thereon. Although the magnetoresistive element section 10 is shown as a single layer in the drawing, it has a two- to four-layer configuration depending on the bias method when driving the magnetoresistive element section 10 as described above.

Next, referring to FIG. 1B, a thin photoresist pattern 19 for lift-off for forming the lead layer 11 is formed. This photoresist pattern 19 is formed in a range of 1 μm or less and thicker than the thickness of the lead layer. In order to easily perform the lift-off, it is desirable that the photoresist pattern 19 has an inverse tapered shape, and it is necessary to perform pattern control with high precision. Therefore, this resist is usually an image reversal resist made of a novolak resin. Is used. For the same purpose, a positive resist made of normal novolak resin is treated with an amine solvent to invert the pattern, or the surface is treated with a solvent such as monochlorobenzene to reduce the development speed of the surface layer and form an overhang. May be created. Further, from the viewpoint of forming an inverted tapered shape, a negative type resist such as a cyclized rubber can be used. Furthermore, on the premise that the later formation of the lead layer 11 is performed by vapor deposition, a normal positive resist can be used as it is, as long as a pattern cross section nearly perpendicular can be obtained. Since the lower shield layer 8 exists over almost the entire surface of the substrate 6 as described above, the thin photoresist pattern 1 is affected by the step of the lower shield layer 8 as in the related art.
There is no region where 9 is extremely thin or no resist is attached near the region where the required pattern is formed.
The conventional problem that occurs when the lead layer 11 is formed later can be avoided.

Next, in FIG. 1C, lead layers 11 and 20 formed using a low-resistance material such as gold are adhered to the entire substrate 6 by sputtering or vapor deposition. A material such as titanium, chromium, tantalum, or tungsten is simultaneously formed on the upper and lower sides of the gold in order to improve the adhesion of the gold, and lift-off is performed in FIG. 1 (d). At the same time, it is removed, and the formation of the lead layer 11 is completed. Since unnecessary lead material is completely removed at the time of this lift-off, a short circuit between both terminals of the lead layer 11, the lead layer 11 and the upper shield layer 13 to be formed later will be described.
No short circuit or insulation failure occurs.

Next, as shown in FIG. 1E, in order to process the lower shield layer 8 into a required shape, an etching process such as ion milling is performed after a photoresist pattern is formed. Even if a film residue occurs at a position far away from the region where the magnetoresistive head is formed, it is possible to completely remove the film residue during the etching process. After processing the lower shield layer 8 into a desired shape as described above, although not shown, the upper shield gap layer 12 formed of an insulating material such as alumina, a permalloy or iron formed by an electroplating method or a sputtering method. The upper shield layer 13 formed by using the base alloy is sequentially laminated to complete the creation of the reproducing head. When an exchange bias or a hard bias is used, the magnetic head is directly contacted with the magnetoresistive element 10 or on the magnetoresistive element 10 or the lead layer 11.
Is formed using an alloy of iron and manganese or a cobalt-based alloy at the lowermost portion. Next, a recording unit is created. However, this is the same as the conventional example, and the description is omitted.

In the magnetoresistive head formed as described above, the width at which the lead layer 11 is gradually thinned at the junction between the lead layer 11 and the magnetoresistive element section 10 is reduced.
In addition, since the remaining film can be eliminated, a stable effective reproduction track width and a low element resistance are obtained, and the reliability is improved by a simple manufacturing method.

In this embodiment, the lower shield layer 8 is formed into a desired shape after the lead layer 11 is formed.
According to the gist of the present invention, the processing of the lower shield layer 8 may be performed at any time after the formation of the lead layer 11 and if there is no problem in manufacturing. For example, upper shield gap layer 1
It is also possible to process after forming 2.

(Embodiment 2) FIGS. 2 (a) to 2 (d) are manufacturing process diagrams when a lead layer is formed in a method of manufacturing a magnetoresistive head according to a second embodiment of the present invention.

First, as shown in FIG. 2A, a permalloy, sendust or iron is formed on a ceramic substrate 6 coated with an insulator 7 such as alumina formed by a sputtering method, by electroplating or sputtering. The lower shield layer 8 is formed from a system alloy material, and is processed into a desired shape by ion beam etching or the like.

Next, as shown in FIG. 2B, the lower shield layer 8 is formed.
The other region is covered with an insulator 22 such as alumina to form the same plane as the lower shield layer 8 and the lower shield layer 8 is embedded. This form is a method in which an insulator such as alumina is attached to the entire surface of the substrate 6 by a sputtering method at least as much as the lower shield layer 8 and then flattened by mechanical polishing. Various methods can be adopted, such as a method of removing by etching, a method of forming a photoresist pattern equivalent to that of the lower shield layer 8 before attaching alumina, and removing alumina by a lift-off method after alumina sputtering.
By embedding the lower shield layer 8 flat with the insulator 22 as described above, the step of the lower shield layer 8 can be almost eliminated, and therefore, the lower shield gap layer 9 and the magnetoresistive element are not devised in the subsequent steps. Effect element part 1
0, the lead layer 11 can be sequentially laminated. Since there is no step in the lower shield layer 8, the photoresist pattern of the lead layer 11 can be easily thinned as shown in FIG. 2C, and a lift-off with no remaining film can be realized (FIG. 2D). )). Except for the method of forming the lower shield layer 8, the method is the same as that of Example 1 including the method of forming the lead layer 11. Although the effect is the same, in this embodiment, since a step of the lower shield layer 8 hardly occurs, it is possible to obtain a stable manufacturing method in which no film residue particularly occurs. Further, according to the present embodiment, it is possible to easily change the dimensions in design such that the shape of the lower shield layer 8 is smaller than that of the lead layer 11.

(Embodiment 3) FIGS. 3 (a) to 3 (c) are manufacturing process charts when a lead layer is formed in a method of manufacturing a magnetoresistive head according to a third embodiment of the present invention.

First, in FIG. 3A, an insulator 7 such as alumina is formed on a substrate 6 by a sputtering method. The film thickness is a film thickness obtained by adding the film thickness of the lower shield layer 8 to the normal film thickness or a film thickness slightly larger than that. Next, in FIG. 3B, a concave portion 23 having the same shape as the desired lower shield layer 8 is formed in the insulator 7 such as alumina by ion beam etching or the like. Next, as shown in FIG. 3C, the lower shield layer 8 is formed of substantially permalloy, sendust or an iron-based alloy material on the entire substrate 6 by electroplating or sputtering, and then the entire surface of the substrate 6 is mechanically polished or the like. Flatten. As in the following (Example 2), similar effects can be obtained by forming each layer as shown in FIGS. 2 (c) to 2 (d).

[0029]

As described above, according to the present invention, before processing on a substrate,
Form the lower shield layer and place it on the lower shield layer before processing
Form a gap layer before processing, and place a magnetic layer on the gap layer before processing.
The magnetoresistive element is formed, and the magnetoresistive element is
On both sides of the magnetoresistive element on the gap layer before construction
The first mask is formed at intervals in
Removing the first mask by laminating a conductive film through
Lead on the magnetoresistive element and gap layer before processing
In the process after forming the layer and forming the lead layer,
Pre-process gap layer and pre-process lower shield layer in specified shape
Forming a second mask to be processed so that
By etching through the mask, the gap layer before processing
And the lower shield layer before processing into a predetermined shape
Since the layer and the lower shield layer are formed , the width at which the lead layer is gradually thinned at the junction between the lead layer and the magnetoresistive element can be reduced, and the remaining film can be eliminated, so that stable effective reproduction can be achieved. A highly reliable magnetoresistive head having a track width and a low element resistance can be obtained by a simple manufacturing method.

[Brief description of the drawings]

FIG. 1A is a view showing a manufacturing process when a lead layer is formed in a method of manufacturing a magnetoresistive head according to a first embodiment of the present invention. FIG. 1B is a diagram showing a magnetoresistive effect according to the first embodiment of the present invention. (C) is a manufacturing process diagram when forming a lead layer in the method for manufacturing a magnetoresistive head according to the first embodiment of the present invention. FIG. 7E is a view showing a manufacturing process when a lead layer is formed in the method of manufacturing the magnetoresistive head according to the first embodiment. FIG. Manufacturing process diagram

FIG. 2A is a view showing a manufacturing process when a lead layer is formed in a method of manufacturing a magnetoresistive head according to a second embodiment of the present invention; FIG. 2B is a diagram showing a magnetoresistive effect according to the second embodiment of the present invention; FIG. 4C is a manufacturing process diagram when forming a lead layer in the method for manufacturing a die head. FIG. 6D is a manufacturing process diagram when forming a lead layer in the method for manufacturing a magnetoresistive head according to the second embodiment of the present invention. Manufacturing process chart at the time of forming the lead layer in the method of manufacturing the magnetoresistive head according to the second embodiment of the present invention.

FIG. 3A is a view showing a manufacturing process when a lead layer is formed in a method of manufacturing a magnetoresistive head according to a third embodiment of the present invention; FIG. 3B is a diagram showing a magnetoresistive effect according to the third embodiment of the present invention; FIG. 7C is a manufacturing process diagram of the method of manufacturing the die head when the lead layer is formed, and FIG.

FIG. 4 is a perspective view showing a thin-film magnetic head manufactured using a conventional method of manufacturing a magnetoresistive head.

FIG. 5 is a partially enlarged sectional view of a portion A in FIG. 4;

FIG. 6 is a partially enlarged plan view schematically showing the magnetoresistive element of FIG. 5;

FIG. 7 is a cross-sectional view of the magnetoresistive element of FIG. 6 taken along line BB.

FIG. 8 is a manufacturing process diagram when a lead layer is formed in a conventional method for manufacturing a magnetoresistive head.

9A is a manufacturing process diagram of a conventional method of manufacturing a magnetoresistive head when a lead layer is formed. FIG. 9B is a manufacturing process diagram of a conventional method of manufacturing a magnetoresistive head when forming a lead layer. (C) is a manufacturing process diagram of a conventional method of manufacturing a magnetoresistive head when a lead layer is formed.

[Explanation of symbols]

 Reference Signs List 8 lower shield layer 10 magnetoresistive element section 11 lead layer 13 upper shield layer 15 gap layer

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideki Yoshinaka 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-5-143940 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) G11B 5/39 G11B 5/31

Claims (1)

(57) [Claims] 1. A lower shield layer before processing is formed on a substrate,
Form a gap layer before processing on the lower shield layer before processing.
Forming a magnetoresistive element on the gap layer before processing.
Formed on the magnetoresistive effect element portion and the gear before processing.
On the top layer and on both sides of the magnetoresistive element.
Forming a first mask with a gap between the first mask and the first mask;
The first mask is removed by stacking conductive films through
The magnetoresistive effect element portion and the gap before processing
Forming a lead layer on the layer, after forming the lead layer
In the process, the pre-processing gap layer and the pre-processing lower layer
The second process is to process the outer shield layer into a predetermined shape.
Forming a mask and etching through the second mask
By doing so, the gap layer before processing and the lower shell before processing are formed.
The shield layer is machined into the specified shape, and the gap layer and lower
A method for manufacturing a magnetoresistive head, comprising forming a shield layer .