JPH0896322A - Production of thin-film magnetic head - Google Patents

Abstract

PURPOSE: To maintain the specified thickness of a substrate by grinding this substrate by a grinding surface plate meeting the shape of the substrate deformed by forming of a oxide film of Al2 O3 , etc., by sputtering, etc. CONSTITUTION: A grinding device is mainly composed of a grinding surface plate 1 which functions mainly as a grinding machine and an oscillating mechanism 3 which laterally oscillates the substrate 2 placed on the grinding surface plate 1. The grinding surface plate 1 is a Cu-Kemet (R) surface plate formed into a disk shape by solidifying, for example, copper and metallic particles with a polymer material and is disposed rotatably in a direction A. The grinding surface of the grinding surface plate 1 is formed into a shape, such as convex shape or concave shape, meeting the shape of the substrate 2 deformed by the formation of the oxide film. The front surface of the grinding surface plate 1 is provided with grinding cloth 5 consisting of, for example, a polyester nonwoven fabric or foamed polyurethane (artificial leather) or elastic polisher of hard and soft double structures, etc. The substrate 2 formed into a disk shape is placed on the grinding surface plate 1 and the surface plate is provided with jig 6 covering the substrate 2 for the purpose of pressurization for guiding this substrate 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film magnetic head suitable for reading signal information recorded on a magnetic recording medium such as a hard disk.

[0002]

2. Description of the Related Art For example, as a read-only magnetic head mounted in a hard disk drive or the like, a magnetoresistive effect magnetic head (hereinafter referred to as MR
It is called a head. ) Is commonly used.

The MR head has a magnetoresistive effect element (hereinafter referred to as M
It is called an R element. ), A bias conductor that gives the MR element a magnetized state in a desired direction, and a pair of shield magnetic bodies that sandwich them from the film thickness direction.

Such an MR head is usually manufactured by sequentially laminating a lower shield magnetic body, a lower layer gap film, an MR element film, an upper layer gap film and an upper shield magnetic body on a substrate by vacuum thin film forming means such as sputtering. Has been done.

By the way, as a substrate for forming the element, a general ceramic substrate such as Al ₂ O ₃ --TiC (so-called Altic material) is used. This substrate has Al ₂ O ₃ for the purpose of insulation and protection of the head element.
An oxide film of, for example, 20 to 30 μm is formed by sputtering. Since the thin film head element is formed on the oxide film in the subsequent step, the oxide film is flattened by the polishing process in the next step.

[0006]

However, Al ₂ O ₃
When a film is formed by sputtering, the substrate is deformed into a convex shape or a concave shape due to thermal stress at the time of forming the film, internal stress of the film, or the like. When the substrate is deformed and is polished in the polishing process of the next step, the contact with the polishing platen made of copper kemet or the like having a flat polishing surface becomes uneven.
As a result, uneven wear and polishing unevenness occur, resulting in uneven thickness of the substrate after polishing.

For example, when the warp of the polishing surface before polishing is convexly curved, the center portion of the substrate is easily polished by polishing. Conversely, if the substrate is concavely curved,
When polishing is performed, the outer peripheral portion of the substrate is easily polished.
When such a difference in the polishing amount occurs, the thickness of the substrate varies, and it becomes difficult to secure the uniformity of the shield thickness in the subsequent flattening step of the lower shield magnetic body. When slider processing is performed, the slider length (substrate thickness) becomes non-uniform, and the flying height at disk startup after head assembly becomes unstable.

Therefore, the present invention has been proposed in view of the above problems of the prior art, and even if the shape of the substrate before polishing is warped such as convex or concave, it is uniform regardless of the deformation of the substrate. An object of the present invention is to provide a method for manufacturing a thin film magnetic head, which can perform polishing and can keep the thickness of a substrate after polishing constant.

[0009]

In order to manufacture a thin film magnetic head, first, an oxide film is formed on one main surface of a substrate. Next, the oxide film is polished by a polishing platen according to the shape of the substrate deformed by depositing the oxide film. Then, a thin film head element is formed on the polished oxide film.

A sputtering method is used to form an oxide film. The substrate, with Al ₂ O ₃ -TiC, the oxide film is preferably used an Al ₂ O ₃ film.

As the thin film head element formed here,
MR head, inductive head, or these MR
Any of a combination of a head and an inductive head may be used.

[0012]

[Action] Al ₂ O ₃ on a substrate made of -TiC Al ₂ O
_When an oxide film of ₃ or the like is formed by sputtering, the substrate is deformed in a convex shape or a concave shape due to thermal stress during sputtering and internal stress of the film. Therefore, the polishing surface of the polishing platen is shaped according to the shape of the deformed substrate, and the oxide film formed on the deformed substrate is polished. Then, since the polishing platen is used according to the deformation of the substrate, the oxide film is uniformly polished over the entire substrate, and finally the thickness of the substrate after polishing becomes constant.

[0013]

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.

First, the polishing apparatus used in the method of the present invention will be described. As shown in FIGS. 1 and 2, the polishing apparatus includes a polishing platen 1 that mainly functions as a polishing platen, and a swinging mechanism that horizontally swings a substrate 2 mounted on the polishing platen 1. 3 and 3.

The polishing platen 1 comprises a so-called copper Kemet platen, which is formed in a disk shape by, for example, solidifying copper and metal particles with a polymer material, and is provided at a substantially central portion of the apparatus body 4 having a substantially rectangular plane shape. 1 is rotatably provided in the direction of arrow A in FIG.

The polishing surface of the polishing platen 1 has a shape corresponding to the shape of the substrate 2 deformed by the formation of the oxide film, as will be described later. For example, if the surface of the substrate 2 to be polished is convex, the polishing surface of the polishing platen 1 is concave.
On the contrary, if the surface to be polished of the substrate 2 is concave, the polishing surface of the polishing platen 1 is convex.

On the surface of the polishing platen 1, there is provided a polishing cloth 5 made of, for example, polyester nonwoven fabric, foamed polyurethane (artificial leather), or an elastic polisher having a hard / soft double structure. Further, a disk-shaped substrate 2 is placed on the polishing platen 1. The substrate 2 is covered and cured for the purpose of guiding the substrate 2 or applying pressure to increase the polishing rate. A tool 6 is provided.

The jig 6 has a circular outer shape,
A circular concave portion 7 into which the substrate 2 is fitted is provided on the surface facing the polishing platen 1. The depth of the recess 7 is set so that the jig 6 is not polished by the polishing platen 1.
It is made shallower than the thickness of the substrate 2. Therefore, when the substrate 2 is fitted into the recess 7 and placed on the polishing platen 1, only the substrate 2 comes into contact with the polishing platen 1.

On the other hand, the swinging mechanism 3 has a carrier 8 for rotatably holding the pair of jigs 6, and a left-right direction of the carrier 8 along the center line of the polishing platen 1 as indicated by an arrow B in FIG. A drive motor 9 that functions as a drive source for swinging
A cam 10, a crankshaft 11, and a pair of sliders 1 for converting the rotary motion of the drive motor 9 into a swing motion.
2 and 13.

The carrier 8 is formed as a so-called spectacles-shaped support having a circular jig accommodating portion 14 and 15 for rotatably accommodating and holding the pair of jigs 6 and having a planar shape. The carrier 8 is provided with a center roller 16 and guide rollers 17 and 18 for rotatably storing and holding the jigs 6 stored in the jig storing portions 14 and 15.

The center roller 16 is rotatably provided as a disc between the pair of jig accommodating portions 14 and 15. The guide rollers 17 and 18 are rotatably provided as cylindrical rollers around the outer periphery of the jig housing portions 14 and 15 on the opposite side of the center roller 16.

On both sides of the carrier 8, sliders 1 for swinging the carrier 8 in the left-right direction are provided.
2 and 13 are provided. That is, the carrier 8
The slider 1 is slidable on the main body 4 of the apparatus via the cylindrical connecting members 19 and 20 at both ends thereof.
2 and 13 are provided. These sliders 12, 1
One of the sliders 3 is provided with a cam 10 and a crankshaft 11 for converting the rotary motion of the drive motor 9 into a swing motion.

Therefore, the rotational movement of the drive motor 9 is transmitted to the cam 10 and converted into swinging movement by the crankshaft 11 engaging with the cam 10.
As a result, the carrier 8 swings in the left-right direction. In addition,
The swing speed of the carrier 8 can be appropriately adjusted by the control device 21 provided on the device body 4.

Further, the polishing apparatus is provided with a polishing liquid supply tank 22 for supplying a polishing liquid such as diamond slurry to the polishing platen 1. A nozzle 23 is connected to the polishing liquid supply tank 22, and the polishing liquid is supplied from the tip of the nozzle 23 onto the polishing platen 1.

The operation of the polishing apparatus configured as described above is as follows. First, the substrate 2 on which the oxide film is sputtered is placed on the polishing platen 1. At this time, the surface on which the oxide film is formed is placed on the polishing platen 1 so that the surface becomes the polishing surface. That is, the oxide film formed on the substrate 2 is set on the polishing platen 1 so as to face downward.

Next, the jig 6 is dropped on the substrate 2. Then, the substrate 2 is fitted into the concave portion 7 provided in the jig 6, and the position of the substrate 2 is determined. At the same time, a load is applied to the substrate 2 by the jig 6.

Since the substrate 2 and the jig 6 are not bonded with wax or an adhesive, warpage or undulation of the substrate due to adhesive distortion does not occur. If necessary, a weight is placed on the jig 6 to increase the processing pressure,
The polishing rate may be increased.

Next, these jigs 6 are set in the jig accommodating portions 14 and 15 provided on the carrier 8. As a result,
The jig 6 includes a center roller 16 and guide rollers 17, 1.
It is held rotatably by 8 and.

Next, while rotating the polishing platen 1,
Turn on the drive motor 9. Then, the rotation of the drive motor 9 is transmitted to the cam 10, and is converted into swinging motion by the crankshaft 11 connected to the cam 10. Then, the one slider 12 and the other slider 13 connected to the crankshaft 11 swing the carrier 8 in the left-right direction.

As a result, the jig 6 and the substrate 2 rotatably held by the carrier 8 also swing together with them.

Then, the diamond slurry is supplied onto the polishing platen 1 from the tip of the nozzle 23 connected to the polishing liquid supply tank 22. Then, the substrate 2 is the polishing surface plate 1
Is rotated and the carrier 8 swings to polish the entire substrate.

When the substrate 2 is not rocked, uneven wear occurs at the central portion of the substrate due to the difference in peripheral speed between the inner and outer circumferences of the substrate 2.

Next, a method of manufacturing a thin film magnetic head using the above polishing apparatus will be described. In this embodiment, an example of a composite magnetic head in which a so-called inductive head, which is a recording head, is laminated on an MR head is shown.

In order to manufacture a composite type magnetic head, first,
A substrate made of general Al ₂ O ₃ —TiC is prepared as a slider material. Then, for the purpose of improving the insulating property and the surface property, for example, Al ₂ O ₃ is sputtered on one main surface of the substrate to form an oxide film. The thickness of the oxide film is about 10 in order to improve the insulation and surface properties.
It is about μm.

When Al ₂ O ₃ is sputtered, the substrate 25 on which the oxide film 24 is formed is subjected to the thermal stress during sputtering, the internal stress of the film, or the like, so that the substrate 25 shown in FIG.
As shown in (a), it tends to warp into a concave shape or a convex shape.

Next, in order to improve the surface property of the oxide film 24, the oxide film 24 is polished. At this time, if the warped substrate 25 is polished by using a polishing platen having a flat polishing surface, the central portion of the substrate or both end portions of the substrate is polished more than other portions, and uneven polishing causes the substrate after polishing to be uneven. The thickness varies. Therefore, in order to eliminate variations in polishing, polishing is performed by the polishing platen 1 according to the deformed shape of the substrate 25.

For example, when the substrate 25 is warped in a concave shape as shown in FIG. 3A, the oxide film 2 to be a polished surface is formed.
The polishing surface plate 1 shown in FIG. 3B having the polishing surface 1a having a convex shape opposite to the concave shape of 4 is used. This polishing surface plate 1 is
The inner peripheral side is made higher than the outer peripheral side to form a convex shape. On the other hand, when the substrate 25 is warped in a convex shape as shown in FIG. 4A, the polishing surface 1a has a concave shape opposite to the convex shape of the oxide film 24 which also serves as a polishing surface. The polishing surface plate 1 shown in FIG. Contrary to the previous one, this polishing platen 1 is made concave by making the outer peripheral side higher than the inner peripheral side.

Since the deformation of the substrate 25 depends on the sputtering conditions and the like, the degree of deformation differs for each sputtering. For this reason, the polishing surface 1a of the polishing platen 1 must be machined in accordance with the warp of the substrate 25 in each case. Therefore, in order to eliminate such troublesomeness, the relationship between the flatness of the substrate and the height difference of the polishing surface 1a of the polishing surface plate 1 is investigated in advance, and the polishing surface 1a of the polishing surface plate 1 is processed based on the relationship. For example, the polishing surface plate 1
Can be easily processed and can be moved to the next step quickly.

The relationship between the flatness of the substrate and the height difference of the polishing surface of the polishing platen is shown in FIG. Such FIG. 5 is obtained by preparing several polishing plates of which the inner and outer circumferences have height differences on the polishing surface in advance, and polishing the substrate with several types of surface plates having different height differences. The height difference between the inner and outer circumferences of the surface plate on the horizontal axis in Fig. 5 is shown in Fig. 6.
As shown in FIG. 5, a distance R ₃ = 97.5 mm from the surface plate center of the polishing surface plate 1 having a radius R ₁ of 190 mm, and a distance R ₂ = 18 from the surface plate center in the radial direction.
It is represented as a height difference H at a position of 0.0 mm.
The height difference of the surface plate is based on 0 μm on the outer circumference.

On the other hand, the substrate flatness on the vertical axis in FIG. 5 represents the flatness on the oxide film side of the substrate after polishing. As shown in FIG. 7, the substrate flatness is based on both end edges A and B of the substrate (this is 0
μm. ), The maximum value C of the curve is taken, and it is defined as the vertical distance D or E of the line perpendicular to the straight line connecting the maximum value C and A, B.

When the substrate is flat, C is placed on the line connecting A and B, and the substrate flatness is 0 μm.
A plus number represents a case where the substrate is deformed into a convex shape as shown in FIG. 7A, and a minus number represents a case where the substrate is deformed into a concave shape as shown in FIG. 7B. The substrate flatness is directly measured by using a contact type shape measuring device.

Note that the flatness on the side opposite to the polishing surface has almost no change in value and is warped to the side opposite to the polishing surface. For example, if the polishing surface is convex, the surface opposite to the polishing surface is concave.

As shown in FIG. 5, when the outer circumference of the polishing platen is set higher than the inner circumference, the peripheral speed of the substrate is larger on the outer circumference, and the outer peripheral side of the substrate is more easily polished. Therefore, the polished surface of the substrate after polishing is flat. The degree becomes convex. On the contrary, when the inner circumference of the polishing platen is set higher than the outer circumference, the inner circumference of the substrate is easily polished, so that the flatness of the polished surface of the substrate is formed to be concave. On the other hand, when it is desired to finish the both surfaces of the substrate to be flat after polishing, that is, in order to set the substrate flatness to 0 μm, the inner surface of the platen is lower than the outer surface by about 7 μm as compared with FIG. 5 (indicated by a negative value in the figure). It suffices to carry out polishing using a surface plate.

The height difference between the inner and outer circumferences of the surface plate is 0 μm.
In other words, the flatness of both surfaces of the substrate after polishing does not become 0 μm even when polishing is performed in the case of a flat platen shape because the polishing rate difference and the swing range due to the peripheral speed difference between the inner and outer surfaces of the platen. Conceivable.

From this FIG. 5, the height difference between the inner and outer circumferences of the polishing platen is determined according to the flatness of the substrate before polishing, and the desired height difference is corrected on the platen before and after polishing, and the polishing is performed. For example, the polishing amount becomes uniform and a predetermined substrate thickness can be obtained. As shown in FIG. 3A, when the substrate 25 before polishing is concave,
The inner circumference of the polishing surface 1a of the polishing platen 1 is corrected higher than the outer circumference. On the contrary, as shown in FIG. 4A, the substrate 2 before polishing
When 5 is convex, the inner circumference of the polishing surface 1a of the polishing platen 1 is corrected to be lower than the outer circumference.

For example, the polished surface of the substrate before polishing (oxide film 2
If the flatness of the surface on which 4 is formed) is concavely warped by 1 μm, the inner circumference of the polishing surface 1a of the polishing platen 1 is corrected to be higher than the outer circumference by about 10 μm from FIG. On the contrary, if the warp is 1 μm in a convex shape, the inner circumference of the polishing surface 1a of the polishing platen 1 is corrected to be lower than the outer circumference by about 25 μm from FIG. Then, as shown in FIGS. 3 (c) and 4 (c),
The plate thickness F at the center of the substrate and the plate thickness G at the edge of the substrate are almost the same, and the plate thickness of the entire substrate is uniform.

As shown in FIG. 8, when the flatness of the polished surface of the substrate before polishing is a concave warp, when the inner circumference of the polishing surface 1a of the polishing platen 1 is lowered and polishing is performed, The thickness of the substrate 25 after polishing becomes non-uniform (F ≠ G). Similarly, FIG.
As shown in, when the flatness of the polishing surface of the substrate before polishing is a convex warp, when polishing is performed by increasing the inner circumference of the polishing surface 1a of the polishing surface plate 1, polishing of the substrate 25 after polishing is performed. The thickness is non-uniform (F ≠ G).

Based on the above description, the flatness of the substrate 25 deformed by sputtering is obtained, and from this value, the height difference between the inner and outer circumferences formed on the polishing surface 1a of the polishing platen 1 is obtained from FIG. Then, the polishing surface 1a of the polishing platen 1 is polished so that the obtained height difference is obtained. In order to provide the polishing platen 1 with a height difference, a Dunyamond electrodeposition ring on the surface of which diamond is electrodeposited is used.

If the diamond electrodeposition ring is fixed to one point on the surface plate before the polishing of the substrate 25 is started and the diamond electrodeposition ring is rotated on the surface plate, a copper Kemet surface plate softer than diamond can be easily formed. Can be scraped. If it is desired to increase the outer peripheral side of the polishing surface plate 1, if the diamond electrodeposition ring is installed on the inner peripheral side of the polishing surface plate 1 and polishing is performed, the polishing rate on the inner peripheral side increases, The peripheral side is further polished, and the outer peripheral side can be made higher. On the contrary, when the inner peripheral side of the polishing platen 1 is raised, if a diamond electrodeposition ring is installed on the outer peripheral side of the polishing platen 1 and polishing is performed,
The polishing rate on the outer peripheral side is increased, the outer peripheral side is further polished, and the inner peripheral side can be increased. In this way, by using a material harder than the polishing platen 1,
The height difference of the polishing platen 1 can be easily corrected.

After the processing of the polishing surface 1a of the polishing platen 1 is completed, the oxide film 24 formed on the substrate 25 is polished using the above-described polishing apparatus. First, the diamond slurry is supplied to perform rough cutting. After that, the polishing liquid is replaced with a polishing liquid in which, for example, silica-based ultrafine particles are suspended in an alkaline solution having a pH of about 10, and mechanochemical polishing is performed to smooth the unevenness of the polishing surface.

Mechanochemical polishing is simply described by using a polishing liquid prepared by dispersing colloidal silica (SiO ₂ ) ultrafine particles in a weak alkaline solution, and a foamed polyurethane type suede type artificial leather made of polymer resin or the like. This is a method of polishing a substrate that is an object to be polished by combining a polishing cloth. According to such mechanochemical polishing, S in the polishing liquid is
By complex polishing that combines mechanical polishing with io ₂ abrasive grains and chemical etching with a weak alkaline solution,
Due to the interaction between the two, it is possible to perform mirror polishing with a surface roughness of about 1 nm or less in terms of the centerline average roughness Ra.

As a result, despite the deformed substrate 25, uniform polishing makes the thickness of the entire substrate substantially constant.

Next, as shown in FIG. 10, a lower shield magnetic body 26 is formed on the flattened oxide film 24. To form the lower shield magnetic body 26, a magnetic material such as sendust (Fe-Al-Si) is sputtered to a film thickness of 1.5 μm to 3.0 μm, and then processed into a predetermined shape. .

Next, as shown in FIG. 11, a lead electrode 27 having a predetermined wiring pattern for supplying a current to an MR element and a bias conductor which will be described later is connected to the lower shield magnetic body 26 on the oxide film 24. Form in non-overlapping areas.

The lead electrode 27 has a film thickness of 1.5 μm.
˜3.0 μm Cu pattern plating.

As a result, as shown in FIG. 12, a lower shield magnetic body 26 having a predetermined shape on the oxide film 24,
A lead electrode 27 having a predetermined wiring pattern is formed around the lower shield magnetic body 26.

Next, in order to flatten the lower shield magnetic body 26 and the lead electrode 27, as shown in FIG. 13, a flattening film 28 made of Al ₂ O ₃ is formed on the lower shield magnetic body 26 and the lead electrode 27 so as to have a thickness of 3 μm to 6 μm. To be formed by sputtering.

Thereafter, the flattening film 28 is flat-polished by a mechanical polishing method using diamond abrasive grains. The surface polishing is performed by the MR element or the like laminated on the lower shield magnetic body 26 and the lower shield magnetic body 26 in the next step.
This is for eliminating a short circuit or a disconnection defect due to a step or the like on the surface of the lower shield magnetic body 26.

As shown in FIG. 14, planar polishing is performed until the lower shield magnetic body 26 and the lead electrode 27 are exposed, and finally the thickness of the lower shield magnetic body 26 and the lead electrode 27 is 1 μm to 2.5 μm. Until it becomes.

Next, as shown in FIG. 15, a lower gap film 29 is formed on the lower shield magnetic body 26. The lower gap film 29 has both a function as a gap film and a function for ensuring insulation between the lower shield magnetic body 26 and the MR element and the electrodes connected thereto, and therefore, for example, an Al ₂ O ₃ film is used. Is preferred.

Since the lower gap film 29 is mechanochemically polished in the next step, it is formed thicker than a predetermined lower magnetic gap length. In this embodiment, 200
nm to 400 nm.

Next, as shown in FIG. 16, the lower gap film 29 is planarly polished by mechanochemical polishing until it has a predetermined thickness (100 nm or less). As a result, the polished surface 29a of the lower gap film 29 becomes the MR element formation surface. Since this MR element forming surface is polished by mechanochemical polishing, the surface roughness is extremely smooth with the center line average roughness Ra of 1 nm or less.
The film thickness is directly measured by an optical measuring device.

Next, the lead electrode 2 is formed on the lower gap film 29.
A contact hole (not shown) for making electrical connection 7 is formed. By this step, a structure having a predetermined gap length and having a facing distance between the MR element and the lower shield magnetic body 26 after the depth of zero is sufficient to reduce magnetic interaction is formed.

Then, as shown in FIG. 17, an MR element 30 is formed on the flattened lower gap film 29. To form the MR element 30, permalloy (Fe-
After forming a film of Ni) by sputtering or vapor deposition, it is processed into a predetermined shape. In this embodiment, the film thickness of the MR element 30 is 100 nm or less.

Next, as shown in FIG. 18, the MR element 30
In order to electrically insulate the bias conductor formed in the next step, an insulating film 31 such as SiO ₂ is formed on the MR element 30 by sputtering.

Next, as shown in FIG. 19, the MR element 3
A contact hole 32 for removing electrical contact by removing a part of the insulating film 31 at the rear end portion 30a of 0 and the end portion of the lead electrode 27 (the contact hole for the lead electrode is not shown). To form.

Then, as shown in FIG. 20, a bias conductor 33 for generating a bias magnetic field and the MR element 30.
A conductor 34 (hereinafter, referred to as a rear end electrode 34) for flowing a sense current is formed on the substrate.

The bias conductor 32 is provided on the insulating film 31 at a position facing the MR element 30, and is formed as a strip-shaped pattern perpendicular to the longitudinal direction of the MR element 30. On the other hand, the rear end electrode 34 is partially provided on the rear end edge side of the MR element 30 on the insulating film 31, and is electrically connected to the MR element 30 in the contact hole 32.

The bias conductor 33 and the rear end electrode 34
Considering the adhesion between the insulating film 31 and the insulating layer formed in the next step, it is desirable to have a laminated film structure in which, for example, Ti / Cu / Ti is sputtered in this order. Of course, only Cu may be used if there is no problem of adhesion.

Next, as shown in FIG. 21, for insulation between the upper shielding magnetic body formed in the step described later and the bias conductor 33 and rear electrode 34, by sputtering an insulating layer 35 such as SiO ₂ These bias conductors 33
And the rear end electrode 34 are laminated so as to completely cover them.

Then, as shown in FIGS. 22 and 23,
Insulating film 31 laminated on the tip portion 30b of the MR element 30
And the insulating layer 35 are removed, and the tip portion 30 of the MR element 30 is removed.
A contact hole 36 exposing b is formed.

Next, as shown in FIG. 24, an upper gap film 37 is formed on the insulating layer 35 including the tip portion 30b of the MR element 30 facing the contact hole 36.

The upper gap film 37 functions as a gap film and also functions as a tip electrode for passing a sense current to the MR element 30, and is therefore a metal film such as Ti.

Subsequently, the upper shield magnetic body 38 is formed on the upper gap film 37. Upper shield magnetic body 38
Like the lower shield magnetic body 26, is formed by sputtering a metallic magnetic material. The formation method is
It is the same as the lower shield magnetic body 26.

As a result, as shown in FIG. 25, the MR element 30 is replaced with the lower shield magnetic body 26 and the upper shield magnetic body 3.
A shield type MR head, which is a reproducing head sandwiched between 8 and 8, is completed.

Next, an inductive head for recording is formed on the MR head. The inductive head formed here is a so-called 3-pole structure composite magnetic head in which the upper shield magnetic body 38 of the MR head is used as one recording magnetic core.

To form an inductive head, first, as shown in FIG.
The recording gap film 39 is formed by sputtering l ₂ O ₃ . Then, a contact hole 40 for removing a part of the recording gap film 39 and magnetically coupling a recording thin-film magnetic core and an upper shield magnetic body 38 described later.
To form.

Next, in order to insulate the upper shield magnetic body 38 from the recording coil described later and to obtain a flat coil forming surface, a first flattening layer 41 made of an organic material is formed on the recording gap film 39. Form on top. Subsequently, the recording coil 42 is spirally formed on the first flattening layer 41 by patterning Cu.

Next, in order to insulate the recording coil 42 from the recording thin-film magnetic core described later on the recording coil 42 and to obtain a flat magnetic core formation surface, a second organic material is used. The flattening layer 43 is formed on the first flattening layer 41 and the recording coil 42.

Next, the other recording thin-film magnetic core 44 is plated or sputtered with a magnetic material such as permalloy on the second flattening layer 43, and then processed into a predetermined shape to form an inductive head. Complete.

On the recording thin film magnetic core 44, a protective film 4 made of Al ₂ O ₃ or the like is provided for protecting the element.
5 is formed.

Next, a connection terminal with an external circuit (not shown) is formed, and a composite magnetic head having a 3-pole structure is completed through slider processing and an assembling process.

In the composite magnetic head completed through the above steps, the lower shield magnetic body 26 and the MR element 30 are provided.
A lower reproducing magnetic gap g ₁ is formed between the upper shield magnetic body 38 and the MR element 30, and an upper reproducing magnetic gap g ₂ is formed between the upper shield magnetic body 38 and the MR element 30. Then, a recording magnetic gap g ₃ is formed between the upper shield magnetic body 38 and the recording thin film magnetic core 44.

In the present invention, Al ₂ O ₃ —TiC is generally used for the substrate.
The amount of change in the size and the warp of the substrate flatness is due to the wafer process and the process capability of the process,
It is not particularly limited. Further, in the present embodiment, an example of a composite type magnetic head in which an MR head and an inductive head are laminated on the same substrate has been described, but the method of the present invention has the same operational effect even if the MR head alone or the inductive head alone is provided on the substrate. There is.

[0085]

As is apparent from the above description, in the method of the present invention, the polishing rate according to the shape of the substrate deformed by depositing an oxide film such as Al ₂ O ₃ by sputtering or the like. Since the oxide film is polished by the disk, the oxide film can be uniformly polished over the entire substrate, and finally the thickness of the substrate after polishing can be made constant. Therefore, in the subsequent step of flattening the shield magnetic body, the uniformity of the shield thickness and the uniformity of the slider length (substrate thickness) when slider processing is performed can be ensured, and the flying height at disk startup after head assembly Can be stable.

[Brief description of drawings]

FIG. 1 is a plan view of a polishing apparatus used in a method of the present invention.

FIG. 2 is a front view of a polishing apparatus used in the method of the present invention.

FIG. 3 is a diagram showing a process of polishing the substrate by a polishing platen according to the shape of the substrate warped in a concave shape to make the polishing amount uniform.

FIG. 4 is a diagram showing a step of polishing the substrate by a polishing platen according to the shape of the substrate warped in a convex shape to make the polishing amount uniform.

FIG. 5 is a characteristic diagram showing a height difference of a polishing platen and a substrate flatness of a polished surface after polishing.

FIG. 6A is a sectional view of a polishing platen having a concave shape,
(B) is sectional drawing of the polishing surface plate made convex.

FIG. 7 is a diagram showing definitions of substrate flatness,
(A) is a case where the substrate is warped in a convex shape, (b) is a case where the substrate is warped in a concave shape, and (c) is a case where the substrate is flat.

FIG. 8 is a diagram showing a step of polishing the substrate by using a polishing platen having a shape opposite to the substrate curved in a concave shape.

FIG. 9 is a diagram showing a step of polishing the substrate by using a polishing platen having a shape opposite to that of the substrate curved in a convex shape.

FIG. 10 is a cross-sectional view showing a step of forming a lower shield magnetic body, which sequentially shows the steps of manufacturing the composite magnetic head.

FIG. 11 is a cross-sectional view showing a step of forming a lead electrode, showing the steps of manufacturing the composite magnetic head in order.

FIG. 12 is a plan view showing a step of forming the lead electrode, showing the manufacturing steps of the composite magnetic head in order.

FIG. 13 is a cross-sectional view showing a step of forming a flattening film, showing the steps of manufacturing the composite magnetic head in order.

FIG. 14 is a cross-sectional view showing a flattening step, showing the manufacturing steps of the composite magnetic head in order.

FIG. 15 is a fragmentary enlarged cross-sectional view showing a step of forming a lower layer gap film, showing the steps of manufacturing the composite magnetic head in order.

FIG. 16 is a fragmentary enlarged cross-sectional view showing a step of polishing the lower gap film by mechanochemical polishing, showing the manufacturing steps of the composite magnetic head in order.

FIG. 17 is a fragmentary enlarged cross-sectional view showing the MR element forming step, showing the manufacturing steps of the composite magnetic head in order.

FIG. 18 is a cross-sectional view showing a step of manufacturing the composite magnetic head in order and showing an insulating film forming step.

FIG. 19 is a cross-sectional view showing a step of forming a contact hole, showing the steps of manufacturing the composite magnetic head in order.

FIG. 20 is a cross-sectional view showing a step of forming a bias conductor, which sequentially shows the steps of manufacturing the composite magnetic head.

FIG. 21 is a cross-sectional view showing an insulating layer forming step, showing the manufacturing steps of the composite magnetic head in order.

FIG. 22 is a cross-sectional view showing a step of forming a contact hole, showing the step of manufacturing the composite magnetic head in order.

FIG. 23 is a plan view showing a step of forming a contact hole, showing the manufacturing steps of the composite magnetic head in order.

FIG. 24 is a cross-sectional view showing the manufacturing process of the composite magnetic head in order and showing the upper shield magnetic body forming process.

FIG. 25 is a plan view showing the manufacturing process of the composite magnetic head in order and showing the upper shield magnetic body forming process.

FIG. 26 is an enlarged cross-sectional view of a main part of a composite magnetic head in which an inductive head is laminated on an MR head.

[Explanation of symbols]

 1 Polishing Surface Plate 24 Oxide Film 25 Substrate 26 Lower Shield Magnetic Material 27 Lead Electrode 29 Lower Gap Film 30 MR Element 33 Bias Conductor 34 Rear End Electrode 38 Upper Shield Magnetic Material 44 Thin Film Magnetic Core for Recording

Claims (4)

[Claims] 1. A step of forming an oxide film on a main surface of a substrate, and a step of polishing the surface of the oxide film according to the shape of the substrate deformed by forming the oxide film. And a step of forming a thin film head element on the polished oxide film. 2. The method of manufacturing a thin film magnetic head according to claim 1, wherein the substrate is made of Al ₂ O ₃ —TiC. 3. The method of manufacturing a thin film magnetic head according to claim 1, wherein the oxide film is made of Al ₂ O ₃ . 4. The method of manufacturing a thin film magnetic head according to claim 1, wherein the oxide film is formed by sputtering.