JP2005346923A - Induction type thin film magnetic head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture an induction type thin film magnetic head having track width of 0.5 μm or less in good yield to cope with high recording density of a magnetic disk apparatus. <P>SOLUTION: In this induction type thin film magnetic head, film thickness of 3.0 μm or more of an upper part magnetic core can be formed and width of 0.5 μm or less of a lower part of the upper part magnetic core immediately after plating can be formed by forming the upper part magnetic core by a frame plating method using a frame formed by KrF or ArF excimer laser stepper. After that, the region in which a lower part magnetic core is not covered by the upper part magnetic core in the vicinity of a floating plane is eliminated (trimmed) by ion milling or the like with at least making a tip part of the upper part magnetic core as a mask. In this invention, since width of the tip part of the upper magnetic core immediately after plating can be formed in 0.5μm or less, a time and the number for triming from a horizontal direction for adjusting recording track width can be reduced, that is, variation of recording track width can be reduced. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inductive thin film magnetic head used for recording and a manufacturing method thereof.

  With the increase in recording density of magnetic disk devices, the magnetic recording medium has a higher coercive force, and the track width of the inductive thin film magnetic head used for recording has been reduced. As the magnetic recording medium has a higher holding power, the thickness of the induction type thin film magnetic head is increased in order to generate a sufficient magnetic flux for recording. That is, at present, the film thickness is thicker than the track width at the tip of the inductive thin film magnetic head, and its manufacture becomes increasingly difficult.

In order to solve this problem, a method for forming a narrow track width with high precision by dividing the upper magnetic core of the inductive thin film magnetic head into a front end portion and a rear portion and forming the upper magnetic core front end portion on a low step. Is described in JP-A-2-47809.

Japanese Patent Laid-Open No. 2-208812 (No. 2728487) discloses a method of reducing the recording blur at the magnetic pole end by making the width of the upper part of the lower magnetic core near the air bearing surface coincide with the width of the lower part of the upper magnetic core. No.).

JP-A-2-208812

  As described above, at the tip of the inductive thin film magnetic head, the film thickness is thicker than the track width, and its manufacture becomes increasingly difficult.

For example, as a method of forming an inductive thin film magnetic head having a recording track width of 0.3 μm by a conventional technique, after forming an upper magnetic core with a wide track width in advance, the wall surface of the inductive magnetic head is actively etched to be narrowed. A method for forming a track-width inductive thin film magnetic head is described in the 23rd Annual Meeting of the Japan Society of Applied Magnetics 6aB-3 (1999).

However, in the method of forming an inductive thin film magnetic head having a narrow track width by actively etching the wall surface of the inductive magnetic head in this way, the etching amount varies depending on parameters such as etching time and etching angle. In other words, it is difficult to manufacture an induction type thin film magnetic head having a desired track width with a high yield.

  In the inductive thin film magnetic head according to the present invention, the upper magnetic core is formed by frame plating using a frame formed by a KrF or ArF excimer laser stepper so that the upper magnetic core has a film thickness of 3.0 μm or more. In addition, the width of the lower portion of the upper magnetic core immediately after plating can be formed to 0.5 μm or less. Thereafter, using at least the tip of the upper magnetic core as a mask, the region of the lower magnetic core that is not covered by the upper magnetic core is removed (trimmed) by ion milling or the like in the vicinity of the air bearing surface. In the present invention, since the width of the tip of the upper magnetic core immediately after plating can be formed with 0.5 μm or less, the time and number of times of trimming from the lateral direction for adjusting the recording track width can be reduced, that is, the variation in the recording track width can be reduced. Can be reduced.

In addition, at least the shape of the upper magnetic core on the air bearing surface is wider at the top of the upper magnetic core than at the bottom of the upper magnetic core in contact with the magnetic gap film. Of the upper surface of the upper magnetic core that is in contact with the magnetic gap film and the side of the surface that is in contact with the magnetic gap film. The angle formed is greater than 0 and 20 degrees or less. Here, it is a side surface when the surface in contact with the magnetic gap film in the upper magnetic core is defined as the bottom surface. By forming the tip portion of the upper magnetic core in such a shape, even in an inductive thin film magnetic head having a track width of 0.5 μm or less, the recording information of adjacent tracks is broken while having a high recording magnetic field. The edge magnetic field can be reduced.

In addition, in order to facilitate trimming of the upper part of the lower magnetic core, at least the tip part of the upper magnetic core has a shape having substantially the same width as the lower part of the upper magnetic core at a height of 1.0 to 5.0 μm from the magnetic gap film, It is desirable that the expected angle from the lower magnetic core end to the upper magnetic core upper edge is 20 ° or less.

A so-called stitched structure in which the upper magnetic core is composed of a first upper magnetic core formed on the magnetic gap film and the thin insulating film and a second upper magnetic core formed on the insulating film covering the coil. -The same effect can be obtained with a pole head. When the present invention is applied to a stitched pole head, the width at the top of the first upper magnetic core is wider than the width at the bottom, so that the contact between the first upper magnetic core and the second upper magnetic core The area is increased, and magnetic flux leakage at the contact portion can be reduced.

Even in an inductive thin film magnetic head having a magnetic pole end layer composed of a magnetic film / magnetic gap film / magnetic film formed between the lower magnetic core and the upper magnetic core in the vicinity of the air bearing surface, the width is lower than the width below the magnetic pole end layer. Since the upper portion is wide and the contact area between the pole end layer and the upper magnetic core can be increased, leakage of magnetic flux at the contact portion can be reduced, and an induction type thin film magnetic head having a high recording magnetic field can be provided.

  By implementing the present invention, an inductive thin film magnetic head having a high recording magnetic field with a track width of 0.5 μm or less can be provided with a high yield.

  An embodiment of a thin film magnetic head according to the present invention is shown in FIG. FIG. 1A is a view of a thin film magnetic head according to the present invention as viewed from the air bearing surface, and FIG. 1B is a cross-sectional view of the main part of the tip of the induction type thin film magnetic head according to the present invention. The thin film magnetic head according to the present invention is roughly divided into a reproducing head and a recording head (inductive thin film magnetic head). In this embodiment, the recording head is a stitched pole type head.

The reproducing head includes a lower magnetic shield 2 and an upper magnetic shield 4 formed on the substrate 1, a reproducing element formed between the upper and lower shields, and an insulating film that insulates the reproducing element. It comprises a resistance effect (GMR) element 8 and an electrode 3. The electrode 3 is composed of a laminated film of a permanent magnet film that applies a longitudinal bias to the GMR element and a metal film having a lower resistivity.

The recording head includes a lower magnetic core 5, an upper magnetic core, a magnetic gap film 7, and a coil 11. In the present invention, an insulating film is provided between the upper magnetic shield 4 and the lower magnetic core 5 in order to reduce the influence of the recording magnetic field on the reproducing head.

The manufacturing process of the induction type thin film magnetic head according to the present invention is as follows. A magnetic gap film 7 and an insulating film 10 for determining the magnetic gap position are sequentially formed at least near the air bearing surface on the lower magnetic core 5. The magnetic gap length is defined by the distance between the tip position of the insulating film 10 and the air bearing surface, thereby changing the recording magnetic field strength and the recording magnetic field distribution.

Subsequently, a mask material such as a photoresist is applied, and a frame is formed so that the first upper magnetic core 6 extends over the magnetic gap film 7 and the insulating film 10 that determines the magnetic gap position, and this frame is used. Then, the first upper magnetic core 6 is formed by frame plating. By forming the frame with a KrF or ArF excimer laser stepper, the width of the tip of the first upper magnetic core 6 immediately after plating can be easily reduced to 0.5 μm or less. After removing the frame, the first upper magnetic core 6 is used as a mask, and at least the magnetic gap film 7 in the region not covered by the first upper magnetic core 6 near the air bearing surface and the upper part of the lower magnetic core 5 are ionized. Trimming is performed by milling or reactive ion etching. At this time, the shape seen from the air bearing surface of the first upper magnetic core 6 is important. That is, when the estimated angle 12 from the lower end of the upper magnetic core to the upper end of the upper magnetic core increases, the contact area between the first upper magnetic core 6 and the second upper magnetic core 9 increases, and the magnetic flux Since the leakage of the magnetic field is reduced, the decrease in the recording magnetic field can be suppressed even with a track width of 0.5 μm or less. On the other hand, the upper magnetic core is larger than the lower part of the upper magnetic core. The upper part of the lower magnetic core is larger than the lower part. At this time, the isomagnetic field curve becomes wider on the lower magnetic core side than on the upper magnetic core side, that is, the effective track width becomes wider. Further, the isomagnetic field curve spreads along the shape of the air bearing surface of the upper magnetic core. In order to solve this problem, at least the tip of the upper magnetic core has a shape that is substantially the same as the width of the lower part of the upper magnetic core at a height of 1.0 to 5.0 μm from the magnetic gap film, and the end of the lower part of the upper magnetic core is formed. It is desirable that the expected angle from the upper part to the upper end of the upper magnetic core is 20 ° or less.

Next, an insulating film such as alumina is deposited, and the upper portion of the first upper magnetic core 6 is exposed by a planarization technique such as chemical mechanical etching (CMP). Subsequently, after forming the coil 11 and the insulating film covering the coil, the second upper magnetic core 9 is formed.
The second upper magnetic core is connected to the first upper magnetic core at the tip and the lower magnetic core 5 at the rear. In addition, it is desirable that the tip of the second upper magnetic core is receded by 0.5 to 3.0 μm from the air bearing surface.

In this embodiment, the coil is formed above the first upper magnetic core, but it may be embedded in an insulating film disposed around the first upper magnetic core by a damascene method or the like.

FIG. 2 is a view obtained by observing the shape of the air bearing surface of the inductive thin film magnetic head by SEM. Fig. 2 (a) shows the shape of the air bearing surface of an induction thin film magnetic head when the frame for forming the first upper magnetic core is formed using I-line. Fig. 2 (b) shows the KrF excimer laser stepper. FIG. 6 is a view of the shape of the air bearing surface of the induction type magnetic head when a frame is formed by SEM, observed by SEM. Like the stitched pole type head shown in FIG. 1, when the upper magnetic core is divided into the tip and the rear, and flattening by CMP or the like is required, the required film of the first upper magnetic core It is necessary to make the film thickness thicker by 0.5 to 2.0 μm than the thickness. Therefore, in this embodiment, the target film thickness of the first upper magnetic core is set to 3.0 μm or more. When the frame was formed using the I line as shown in FIG. 2 (a), when the track width was 0.6 μm, the film thickness of the portion having substantially the same width as the track width was approximately 2.0 μm. When the track width was 0.6 μm or less, the frame could not be resolved satisfactorily and did not lead to plating. On the other hand, when a KrF excimer laser stepper is used to form the frame, when the track width is 0.32 μm, the film thickness of the portion having the same width as the track width is approximately 3.0 μm, which is greater than when using the I line. In addition, it is possible to increase the film thickness of a portion having a narrow track width and the same width as the track width.

The cross-sectional shape of the frame can be controlled by the resist film thickness, exposure conditions, development conditions, and the like. In order to increase the recording magnetic field, it is desirable to increase the width on the upper side of the upper magnetic core. However, in order to reduce the spread of the recording magnetic field at the track end and obtain a uniform recording magnetic field within the recording track width, it is necessary to trim the upper part of the lower magnetic core using the upper magnetic core as a mask. If the core width is too different between the lower side and the upper side of the core, there is a problem that trimming does not work well. In order to increase the recording magnetic field and perform trimming well, the cross-sectional shape of the frame is controlled. Specifically, the expected angle 12 from the lower end of the upper magnetic core to the upper end of the upper magnetic core is set to 0 to 0. 20 ° is desirable. Even if the expected angle 12 from the end of the upper magnetic core to the end of the upper magnetic core is 20 ° or more, it is possible to obtain a good trimming shape by laying down the angle of ion milling at the time of trimming horizontally However, this is not preferable because the yield in the wafer plane or between lots may be lowered.

FIG. 3 is a sectional view of the tip of another embodiment of the induction type thin film magnetic head according to the present invention. A feature of the present invention is that a notch structure 51 having a length of 0.5 to 3.0 μm and a film thickness of 0.5 to 3.0 μm is formed in the vicinity of the air bearing surface on the lower magnetic core 5 and a nonmagnetic film covering the notch structure 51 is formed. After the formation, the first upper magnetic core 6 longer than the notch structure is formed after flattening by the CMP method or the like. Needless to say, the region not covered by the upper magnetic core in the vicinity of the air bearing surface above the notch structure 51 needs to be removed by trimming.
For the same reason as described above, at least the tip of the upper magnetic core has a shape having a width substantially equal to the width of the lower part of the upper magnetic core at a height of 1.0 to 5.0 μm from the magnetic gap film, It is desirable that the expected angle from the end portion to the upper end portion of the upper magnetic core is 20 ° or less. In this embodiment, the coil is embedded between the lower magnetic core and the upper surface of the first upper magnetic core. However, there is no problem even if the coil is formed above the first upper magnetic core.

FIG. 4 is a sectional view of the tip of another embodiment of the induction type thin film magnetic head according to the present invention. A feature of the present invention is that after a frame is formed on the lower magnetic core 5 by a KrF or ArF excimer laser stepper, a notch structure 51 of a magnetic film, a magnetic gap film 7 of a nonmagnetic film, and a first upper part of the magnetic film The magnetic core 6 is formed continuously by a plating method. In the present embodiment, for the same reason as described above, at least the tip of the upper magnetic core is shaped to have a width substantially the same as the width of the lower portion of the upper magnetic core at a height of 1.0 to 5.0 μm from the magnetic gap film. It is desirable that the expected angle from the lower end of the core to the upper end of the upper magnetic core is 20 ° or less. The coil is also disposed above the first upper magnetic core in this embodiment, but is embedded in the insulating film around the notch structure 51, the magnetic gap film 7 and the first upper magnetic core 6. There is no problem.

The thinner the film thickness of the first upper magnetic core 6 is, the better the track width processing accuracy is. However, if the film thickness is too thin, saturation of the magnetic flux occurs in the magnetic pole end layer 11 and the magnetic field strength of the inductive thin film magnetic head decreases. However, the thickness of the first upper magnetic core 6 can be reduced by using a material with high saturation magnetic flux density such as (40-60) Ni- (60-40) Fe or Co-Ni-Fe. However, the magnetic flux saturation in the pole tip layer is less likely to occur.

With the increase in recording density of magnetic disk devices, not only the track width is narrowed but also the linear recording density is improved, and therefore the recording frequency of the inductive thin film magnetic head is improved. As the recording frequency increases, the magnetic field strength of the head decreases due to eddy current loss. Eddy current loss depends on the cross-sectional area and specific resistance of the magnetic core of the inductive thin film magnetic head. Since the first upper magnetic core 6 is small, it may be considered that there is almost no eddy current loss. In order to reduce the eddy current loss of the second upper magnetic core 9 and the lower magnetic core 5, use a magnetic film having a large specific resistance (preferably 100 μΩ · cm or more) or make it difficult for the eddy current to flow. It is desirable to use a magnetic multilayer film composed of a laminated film of a magnetic film and an insulating film as the magnetic core material.

  FIG. 5 is a diagram showing a magnetic disk apparatus of an embodiment using an induction type thin film magnetic head according to the present invention. 1 shows an outline of applying an inductive thin film magnetic head according to the present invention to a magnetic disk device as a magnetic recording device. However, it is possible to mount the inductive thin film magnetic head of the present invention also on a magnetic recording apparatus such as a magnetic tape apparatus.

  The illustrated magnetic disk device comprises a magnetic disk 1110 as a magnetic recording medium formed on a disk for recording data in a recording area called a concentric track, and a magnetic transducer, and reads and writes the data. The magnetic head 1118 according to the present invention, actuator means for moving the magnetic head 1118 to a predetermined position on the magnetic disk 1110, transmission / reception of data read and written by the magnetic head 1118, movement of the actuator means, etc. And a control means for controlling.

  Furthermore, a disk array device having a large storage capacity can be formed by connecting a plurality of magnetic disk devices.

It is a figure which shows the principal part of the front-end | tip part of the thin film magnetic head by this invention. It is the figure which observed the air bearing surface shape of the induction type thin film magnetic head by SEM. It is a figure which shows the cross section of the front-end | tip part of another Example of the thin film magnetic head by this invention. It is a figure which shows the cross section of the front-end | tip part of another Example of the thin film magnetic head by this invention. 1 is a diagram showing a magnetic disk device using an induction type thin film magnetic head according to the present invention. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Lower magnetic shield, 3 ... Electrode, 4 ... Upper magnetic shield, 5 ... Lower magnetic core, 6 ... First upper magnetic core, 7 ... Magnetic gap film, 8 ... GMR element, 9 ... Second Upper magnetic core, 10 ... insulating film for determining magnetic gap position, 11 ... coil, 12 ... expected angle from the lower magnetic core end to the upper magnetic core upper edge, 51 ... notch structure.

Claims (4)

  The lower magnetic core formed on the substrate, the magnetic gap film formed on at least the tip of the lower magnetic core, and the magnetic gap film and the tip are coupled to each other, and the lower magnetic core and the rear end are coupled to each other. An upper magnetic core; a coil formed between the upper magnetic core and the lower magnetic core; and an insulating layer formed between the coil, the upper magnetic core, and the coil and the lower magnetic core. The upper magnetic core has an air bearing surface having a width on a side opposite to the magnetic gap film larger than a width of a surface in contact with the magnetic gap film, and an end of the surface in contact with the magnetic gap film and the surface The angle formed between the line connecting the end of the side surface opposite to the magnetic gap film and the side surface of the surface in contact with the magnetic gap film is greater than 0 and 20 ° or less, and the width of the surface in contact with the magnetic gap film is Be less than 0.5μm Inductive thin film magnetic head according to symptoms.   2. The induction according to claim 1, wherein the upper magnetic core has a width substantially equal to a width of a surface in contact with the magnetic gap film at a height of 1.0 to 5.0 μm from the magnetic gap film on the air bearing surface. Type thin film magnetic head.   A pole tip layer in which a first magnetic film, a magnetic gap film, and a second magnetic film are stacked in this order is formed between the lower magnetic core and the upper magnetic core at the tip. Item 3. The induction type thin film magnetic head according to Item 1 or 2. At least the upper magnetic core, the first upper magnetic core, or the magnetic pole end layer is formed by a frame plating method, and a KrF or ArF excimer laser stepper is used for patterning an almost frame. Item 4. The induction type thin film magnetic head according to Item 1.

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