JP2000242910A - Mr head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in the recording performance even when the recording track width is decreased, by forming a part of an upper magnetic pole near the floating face by plating so that the film thickness of the plated magnetic film determines the recording track width, and by controlling the ratio of the height of the upper magnetic pole exposing on the floating face to the recording track width to a specified value or larger. SOLUTION: A plating base film 1a is formed on a recording gap 8, and a resist frame 11 is formed on the plating base film 1a. Then a nonmagnetic metal film 1b is formed by plating, and the resist frame 11 is removed. Further, the plating base film 1a is removed. Then while the nonmagnetic metal film 1b is partly covered with a resist 12, a plating magnetic metal film (top of an upper magnetic pole) 1 is formed on the side face of the nonmagnetic metal film 1b, and then the upper part of the plating magnetic metal film 1, the resist 12, the nonmagnetic metal film 1b and the plating base film 1a are removed. In this process, the height (h) of the upper magnetic pole to the recording track width Tw observed from the floating face are controlled to satisfy h/Tw>=6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an MR head having an inductive recording head and a magnetoresistive reproducing head, and more particularly to an MR head having a narrow track width.

[0002]

2. Description of the Related Art The recording density of hard disk drives has been increasing year by year, and the magnetic heads used have rapidly been replaced by inductive heads with separate recording / reproducing heads. The read / write separation type head is called an MR head because it uses a magnetoresistance effect (MR effect) for reproduction. FIG. 7 is a sectional view showing an example of a conventional MR head. FIG. 8 is a perspective view illustrating an example of a conventional MR head. In FIG. 8, an alumina insulating film and a lower shield 1 are formed on a non-magnetic substrate 106 made of alumina / titanium carbide or the like.
05, an insulating film, a magnetoresistive element 104, an insulating film, an intermediate shield 102 functioning as a lower magnetic pole, a recording gap, and an upper magnetic pole 101. Although the insulating film 110 that insulates the lower shield 105, the magnetoresistive element 104, and the intermediate shield 102 from each other is not shown, it is actually filled between the respective films. Intermediate shield 10
A recording gap 108 made of an insulating film is provided between the upper magnetic pole 2 and the upper magnetic pole 101, and functions as a magnetic gap of an inductive recording head. Further, a coil 107 is wound between the intermediate shield and the upper magnetic pole via an insulating film. A reproducing gap 109 made of an insulating film surrounding the magnetoresistive element 104 is provided between the intermediate shield and the lower shield, and functions as a magnetic gap of the magnetoresistive reproducing head. FIG. 7 is a partial sectional view of the conventional MR head as shown in FIG. 8 when viewed from the medium facing surface. The medium facing surface corresponds to a surface perpendicular to the arrow A in the figure.

The track density is increased in order to increase the recording density, but the recording track width must be correspondingly narrowed. Since the recording track width of the medium is substantially defined by the width of the upper magnetic pole tip, the width of the upper magnetic pole tip is hereinafter referred to as a recording track width Tw. Hereinafter, a description will be given of a conventional technique of forming an upper magnetic pole by a frame plating method, with reference to FIG. 9, illustrating a process from forming an intermediate shield to forming an upper magnetic pole. A recording gap 108 is formed on the intermediate shield 102. After forming the coil and the insulating film, a plating base film 101a is formed on the film of the recording gap 108 (FIG. 9A). This drawing shows only a portion corresponding to the tip of the upper magnetic pole. A resist is applied, exposed, and developed to form a plating frame pattern 111 (FIG. 9B).
A magnetic metal film 101 is formed as an upper magnetic pole by a plating method (FIG. 9C). The frame resist 111 is removed, and the plating base film 101a is removed by ion milling (FIG. 9).
(4)). Add pole trimming (Fig. 9
(5)).

In the conventional method, since the upper magnetic pole is formed by the frame plating method as described above, it is necessary to thicken the frame resist in order to plate the magnetic film thickly. On the other hand, if the resist becomes thick, it becomes difficult to form a narrow frame pattern in the step (2). For example, the side surface of the frame is inclined so that it is not a vertical side surface, or the tip of the upper magnetic pole 101 cannot be accurately formed at Tw. That is, in the conventional method, if the recording track width is reduced while maintaining the dimensional accuracy, the height of the upper magnetic pole decreases. If the height of the upper magnetic pole decreases at the same time as the recording track width becomes narrower, the cross section of the upper magnetic pole becomes smaller, so that the total magnetic flux reaching the top end of the upper magnetic pole decreases, and the recording performance deteriorates. As described above, in the related art, when the recording track width is reduced, there is a problem that the recording performance is deteriorated.

[0005]

In the process of the conventional MR head, there has been a problem that the recording performance is deteriorated when the recording track width is reduced. Accordingly, an object of the present invention is to achieve both narrow track formation and recording performance.

[0006]

An MR head according to the present invention comprises:
The ratio of the height of the upper magnetic pole exposed on the air bearing surface to the recording track width is 5 or more. The MR head includes a magnetoresistive read head composed of a lower shield, an intermediate shield, and a magnetoresistive element in a read gap between the two shields, and an inductive write head having a coil provided between the intermediate shield and the upper magnetic pole. Is provided. The present invention has a great effect when the recording track width is 0.7 μm or less.
Further, the ratio h / of the recording track width Tw and the height h of the upper magnetic pole is calculated.
By setting Tw ≧ 6, the total amount of magnetic flux reaching the top end of the upper magnetic pole increases even in a narrow track of 0.7 μm or less, and high overwrite characteristics can be obtained.

The MR head according to the present invention is characterized in that a portion near the air bearing surface of the upper magnetic pole is formed by plating, and the thickness of the plated magnetic film defines the recording track width.

The present invention also provides a method of manufacturing an MR head in which a portion near the air bearing surface of an upper magnetic pole is formed by plating, and the thickness of a plated magnetic film defines a recording track width. Using the produced nonmagnetic metal film as a plating electrode, a portion near the air bearing surface of the upper magnetic pole is formed on at least a side surface of the plating electrode by a plating method.

The present invention also relates to a method of manufacturing an MR head in which a portion near the air bearing surface of an upper magnetic pole is formed by plating, and the thickness of a plated magnetic film defines a recording track width. After forming the part near the air bearing surface,
The method is characterized in that the nonmagnetic metal film formed by the frame plating method is removed by selective etching of a material in a portion near the air bearing surface of the upper magnetic pole.

The present invention also relates to a method of manufacturing an MR head in which a portion near an air bearing surface of an upper magnetic pole is formed by plating and the thickness of a plated magnetic film defines a recording track width. After the film is formed, a frame resist is formed, and thereafter, the metal film is subjected to ion milling to re-attach the metal film to the side surface of the frame resist, thereby forming a base film for upper pole plating.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An MR head according to the present invention will be described below with reference to the drawings. 1 and 2 are cross-sectional views for explaining a manufacturing process of the MR head of the present invention. FIG. 2 is a continuation of the manufacturing process of FIG. FIGS. 3 and 4 are cross-sectional views illustrating the steps of manufacturing the MR head of the present invention. FIG. 4 is a continuation of the manufacturing process of FIG. FIG. 5 is a cross-sectional view for explaining a manufacturing process of the MR head of FIG. FIG. 6 is a cross-sectional view of an MR head according to the present invention, and corresponds to an MR head manufactured in a manufacturing process including any of the manufacturing processes of FIGS. 1 and 2 or the manufacturing processes of FIGS. (11) in FIG. 2 or (11) in FIG. 4 corresponds to the main part of the BB section of the MR head in FIG. FIG. 6 corresponds to, for example, a cross-sectional view seen from the direction of arrow B in FIG.

As a first embodiment, a process for forming an MR head according to the present invention will be described with reference to FIGS. 1, 2, 5 and 6. FIG.
First, steps required until a structure shown in FIG. 5 is formed will be described. An alumina nonmagnetic insulating film 42 was formed on an alumina / titanium carbide substrate 41. A lower shield 43 of 80Ni20Fe was formed on the nonmagnetic insulating film 42 by plating. After laminating a nonmagnetic insulating film 44 of alumina as a nonmagnetic insulating film constituting a reproducing gap thereon, a magnetoresistive element 45 and an electrode film for supplying current thereto were formed. The electrode film includes a permanent magnet film for applying a bias to the magnetoresistive element. Further, a nonmagnetic insulating film 46 constituting a reproducing gap was laminated.

Next, an 80Ni20Fe film is formed on the nonmagnetic insulating film by sputtering as a conductive film 47 serving as a base for plating. Here, the 80Ni20Fe film is a magnetic film having a composition of 80% nickel and 20% iron. A photoresist film is applied on the conductive film 47 and baked at a predetermined temperature. A photomask is positioned and exposed on this resist film, followed by development and washing. This process forms a resist pattern along the outer shape of the intermediate shield 2. Next, an 80Ni20Fe film was plated using a plating solution containing nickel sulfide or iron sulfide to form an intermediate shield 2 having a thickness of 4 μm. After the plating, washing and drying were performed to remove components and moisture of the plating solution.

Next, after forming an insulating film of 6 μm, polishing is performed so that the thickness of the intermediate shield 2 becomes 2.5 μm (CM
P), the intermediate shield 2 was exposed (not shown in FIG. 5).
CMP (Chemical Mechanical Polishing) is a polishing method for obtaining a precise and flat polished surface by adding an etchant to a polishing material. A resist is applied, exposed and developed to form a frame for plating, and a 45Ni55Fe film is formed on a connection portion (back contact 31) with the upper magnetic pole by 5 μm.
m. Next, after an alumina film having a thickness of 0.2 μm was formed as an insulating film for the recording gap 8, an insulating film 22 was formed, and the first turn of the first layer of the helical thin-film coil 24 was formed thereon by plating using a frame. .

Next, the manufacturing process of the main part of FIG. 5 will be described with reference to FIGS. Thereafter, a non-magnetic conductive film was formed as a plating base film 1a by a sputtering method (FIG. 1, (1)). A resist was applied, exposed, and developed on the plating base film 1a to form a plating frame 11 (FIG. 1, (2)). The thickness of the frame was 7 μm, and the frame interval was 3 μm. Then C
Non-magnetic metal film 1b such as u or Ni is plated at a thickness of 6 μm.
(FIG. 1, (3)). After removing the resist on the frame with an organic solvent
(FIG. 1, (4)), plating underlayer 1a by ion milling
Was removed. Although not shown in FIG. 1, by covering a part of the substrate 41 with a resist and leaving a part of the plating base film 1 a,
Conduction during plating in a later step is facilitated.

Next, a resist 12 is applied, exposed and developed.
A part of the nonmagnetic metal film 1b plated in the steps (FIGS. 1, (6)) and (3) was covered (FIGS. 1, (6)). In this state, a 45Ni55Fe film as a plating magnetic metal film was plated on the side surface of the nonmagnetic metal film 1b to a thickness of 0.6 μm (FIG. 2, (7)) to form the top pole tip 1. 45Ni55Fe plated on a part of the upper surface of the nonmagnetic metal film 1b by ion milling
The film was removed (FIG. 2, (8)).

The resist 12 is removed with an organic solvent (FIG. 2,
(9)), the nonmagnetic metal film 1b and the plating base film 1a were removed by selective etching (FIG. 2, (10)). After protecting the thin film coil (corresponding to 24 in FIG. 5) with a resist, pole trimming by ion milling was performed using the tip of the upper magnetic pole as a mask (FIG. 2, (11)). FIG. 2 (11) shows the recording track width Tw and the height h of the upper magnetic pole as viewed from the air bearing surface. Here, the pole trimming refers to processing at least a part of the upper magnetic pole or the intermediate shield to have a track width.

Next, the description returns to FIG. Next, after forming the insulating film 23 covering the upper magnetic pole tip 1 and the intermediate shield 2, the upper magnetic pole tip 1 and the back contact 31 were exposed by polishing (CMP) (FIG. 5). A second layer 25 of a thin-film coil having four turns is formed thereon, and an insulating layer 26 covering the thin-film coil is further formed. Then, a 3.0 μm-thick 45Ni55Fe film is formed as an upper magnetic pole rear portion 40 by plating. . Finally, an insulating film such as alumina was laminated as a protective film 27 by sputtering. FIG. 6 shows the cross-sectional shape of the MR head thus obtained.

In Example 1, an MR head having a recording track width of 0.5 μm at the top of the top pole and a top pole height of 3.5 μm was obtained. The recording / reproducing characteristics of the MR head having the above configuration were evaluated under the following conditions. A medium (disk) having a coercive force of 3500 Oe was rotated at 5400 rpm, and recording and reproduction were performed with an MR head. That is, the MR head is made to face the medium by floating the slider with the MR head at a constant flying height with respect to the medium, and recording and reproduction are performed at the initial recording frequency, and then reproduction is performed after recording at the overwriting frequency. Then, the overwrite characteristics were evaluated. In the evaluation of overwriting, first, a signal of a long wavelength is recorded on a magnetic disk, then the signal Vh is read out, then a signal of a short wavelength is overwritten, and then the remaining Vl of the previously recorded long wavelength signal is read. The overwrite characteristic (O / W) is a logarithmic value of a ratio between a signal before overwriting and a signal remaining after overwriting, that is, the following expression is expressed in dB. O / W = 20 × log (V1 / Vh) Hereinafter, the value of O / W is referred to as overwriting.

If the overwrite is low, the previously recorded signal remains and the reproduced output signal is apt to generate noise. Therefore, it is desirable that the overwrite be about -30 dB or less. In this embodiment, the magnetic levitation amount is 35 nm, and the current density of the reproducing element is 8 nm.
0 MA / cm ² , recording current 35 mA, initial recording 70
kFCI and 420 kFCI for overwriting. As a result, a high recording performance of -36 dB was obtained for the overwriting of the MR head.

The MR prepared by the manufacturing method of the prior art (FIG. 9)
In the head, the recording track width at the tip of the upper magnetic pole was 0.5 μm as in Example 1, but the height of the upper magnetic pole was 2.0 μm from the limit of photolithography. Others were manufactured under the same conditions as in Example 1. When measured under the same conditions as in Example 1, the overwrite was -23 dB, and the recording characteristics could not be obtained with the conventional narrow track head.

As a second embodiment, FIGS. 3 and 4 show a process of forming an upper magnetic pole by reattaching a plating base film to the side surface of a resist by ion milling. The steps up to providing the first-layer thin-film coil on the substrate are described in Example 1.
Is the same as First, 80Ni is formed on a substrate via an insulating film.
A lower shield made of a 20Fe film is formed, and a non-magnetic insulating film such as alumina for a reproducing gap is laminated thereon.
A magnetoresistive element was formed, and a nonmagnetic insulating film for a reproducing gap was further laminated. The configuration of the magnetoresistive element is the same as that of the first embodiment. On these, an intermediate shield was formed. The intermediate shield is a 4 μm thick 80Ni20Fe film.

Next, after forming an insulating film of 6 μm, polishing is performed so that the thickness of the intermediate shield becomes 2.5 μm (CM
P), the intermediate shield was exposed. A resist was applied, exposed and developed to form a plating frame, and a 45Ni55Fe film was plated to a thickness of 5 μm on a connection portion (back contact) with the upper magnetic pole. Next, 0.2 μm of alumina was formed as an insulating film for the recording gap 8, and then an insulating film was formed. On the insulating film, five turns of a first layer of a spiral thin film coil were formed by frame plating.

Next, main steps of the second embodiment will be described with reference to FIGS. A non-magnetic conductive film was formed by a sputtering method for the plating base 1a (FIG. 3, (1)). The resist is applied, exposed, developed, and the plating frames 11a, 11
b was formed (FIG. 3, (2)). The thickness of the frame is 7 μm,
The frame interval was 3 μm. Ion milling was performed under conditions where the angle of incidence of argon ions was almost vertical (Fig. 3,
(3)), by scattering the plating base film 1a between the frames,
Re-attached to the sides of the resist frames 11a and 11b
(FIG. 3, (4)). By reducing the incident angle and adding an ion milling process mainly in one direction (FIG. 3, (5)), the redeposition film 1d on one side was removed (FIG. 3, (6)). Then 4
A 5Ni55Fe film was formed in a thickness of 0.6 μm by a plating method (FIG. 4, (7)) to form an upper magnetic pole tip (plated magnetic metal film 1). By ion milling (FIG. 4, (8)), the 45Ni55Fe film plated on a part of the upper surface of the resist was shaved, and the cross section of the plated magnetic metal film was adjusted to a rectangular shape (FIG. 4, (8)).
(9)).

The resist 11b was removed with an organic solvent, and the plating base film 1a and its redeposition film 1c were removed by selective etching (FIG. 4, (10).
Selective etching is possible by using a solution obtained by dissolving 360 g of ceric ammonium nitrate in 2040 g of pure etching solution. After protecting the thin film coil with resist
(Not shown in FIG. 4), the upper magnetic pole tip 1 was used as a mask to perform trimming by ion milling (FIG. 4, (1)
1)).

Thereafter, the process was carried out under the same conditions as in Example 1 to produce an MR head. The recording gap length is 0.
The 2 μm thin-film coil has 9 turns in two layers. Finally, the recording track width at the tip of the upper magnetic pole was 0.5 μm and the height of the upper magnetic pole was 3.5 μm. When evaluated under the same conditions as in Example 1, the overwrite of the MR head of Example 2 was −35 d.
B and high recording performance, and achieved both narrow recording track width and high recording characteristics.

A third embodiment will be described as a modification of the first embodiment. The MR head according to the third embodiment is manufactured during the manufacturing process according to the first embodiment.
1 (1) to 2 (9) and FIGS. 5 to 6
2 (10) and (11) were deleted. The advantage of this configuration is that, since the nonmagnetic metal film 1b is provided on the side surface of the upper magnetic pole tip 1, even if the stress when sputtering alumina is increased in the step of covering the insulating film 23 in FIG. Top pole tip 1
Is not distorted.

In the third embodiment, since the intermediate shield was not trimmed, the recording magnetic field leaked slightly from the side surface of the tip of the upper magnetic pole to the intermediate shield. Since the width of the top end of the upper pole (recording track width) itself is smaller than that of the conventional technology, the width of the leaked recording magnetic field is smaller than that of the conventional MR head, and it can be said that the recording performance is improved. However, the width of the data bit recorded on the magnetic medium was slightly increased as compared with the first or second embodiment in which the leakage magnetic field was sufficiently suppressed.
A fourth embodiment will be described as a configuration that improves this point and is similar to the first or second embodiment.

In the MR head according to the fourth embodiment, the upper surface of the intermediate shield (the side on which the recording gap 8 is laminated) is formed before the steps (1) and (1) of FIG. Trimmed. That is, after forming the intermediate shield, a resist member having a width equal to the recording track width was formed at a position where the tip of the upper magnetic pole should abut. Subsequently, the intermediate shield was etched by ion milling. The part covered with the resist remains because it is not etched,
A convex shape corresponding to the recording track width was formed on the upper surface of the intermediate shield. Subsequently, a non-magnetic film such as alumina was laminated by sputtering, and was filled in a portion etched by ion milling. Further, the non-magnetic film raised around the convex shape was etched by ion milling to form a plane corresponding to the upper surface of the convex shape. An alumina film was formed on this plane to form a recording gap 8. Subsequent steps were the same as in Example 3.

In the MR head according to the present invention, the magnetoresistive element 45 includes a magnetoresistive film, a spacer, and a SAL.
A SAL bias type MR element having a film, a spin valve type MR element having a soft magnetic film joined with an antiferromagnetic film, a non-magnetic metal film and a soft magnetic film, a GMR element having a configuration in which a plurality of soft magnetic films are stacked, A tunnel junction type MR element having a configuration in which an insulating film is interposed between two soft magnetic films could be used. It is preferable that the reproducing track width of these elements is smaller than the width (recording track width) of the tip of the upper magnetic pole of the MR head.

[0031]

As described above, by using the structure of the present invention, it is possible to achieve both a narrow recording track width and high recording characteristics.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a manufacturing process of an MR head according to the present invention.

FIG. 2 is a cross-sectional view illustrating a manufacturing process of the MR head of the present invention.

FIG. 3 is a sectional view for explaining a manufacturing process of the MR head of the present invention.

FIG. 4 is a sectional view for explaining a manufacturing process of the MR head of the present invention.

FIG. 5 is a sectional view for explaining a manufacturing process of the MR head of the present invention.

FIG. 6 is a sectional view of an MR head according to the present invention.

FIG. 7 is a sectional view of a conventional MR head.

FIG. 8 is a perspective view of a conventional MR head.

FIG. 9 is a cross-sectional view illustrating a manufacturing process of a conventional MR head.

[Explanation of symbols]

1 top magnetic pole tip (plated magnetic metal film), 1a plating base film, 1b non-magnetic metal film, 1c redeposition film, 1d
Redeposition film, 2 intermediate shield, 8 recording gap, 1
1 frame, 11a frame, 11b frame,
12 resist, 22 insulating layer, 23 insulating layer, 24
Thin film coil, 25 thin film coil, 26 insulating layer, 27
Protective film, 31 Back contact, 40 Upper magnetic pole, 4
1 Alumina-titanium carbide substrate, 42 non-magnetic insulating film, 43 lower shield, 44 non-magnetic insulating film, 45
Magneto-resistive element, 46 non-magnetic insulating film, 47 conductive film,
101 upper magnetic pole (plated magnetic metal film), 102 intermediate shield, 103 electrode film, 104 magnetoresistive element, 1
05 lower shield, 106 non-magnetic substrate, 107 coil, 108 recording gap, 109 reproduction gap,
110 non-magnetic insulating film, 101a plating base film, 11
One frame.

Claims (5)

[Claims] 1. A magnetoresistive read head comprising a lower shield, an intermediate shield, and a magnetoresistive element in a read gap between the two shields, and an inductive recording apparatus provided with a coil between the intermediate shield and an upper magnetic pole. M with head
The MR head according to claim 1, wherein the ratio of the height of the upper magnetic pole exposed on the air bearing surface to the recording track width is 6 or more. 2. An MR head having a magnetoresistive reproducing head and an inductive recording head, a portion near an air bearing surface of an upper magnetic pole is formed by a plating method, and a thickness of a plated magnetic film determines a recording track width. An MR head characterized in that it is specified. 3. The method for manufacturing an MR head according to claim 2, wherein a nonmagnetic metal film formed by a frame plating method is used as a plating electrode, and an air bearing surface of an upper magnetic pole is provided on at least a side surface of the plating electrode. A method for manufacturing an MR head, comprising: manufacturing a portion in the vicinity by a plating method. 4. The method of manufacturing an MR head according to claim 3, wherein a non-magnetic metal film formed by frame plating is formed near the air bearing surface of the upper magnetic pole after forming a portion near the air bearing surface of the upper magnetic pole. A method for manufacturing an MR head, wherein the material is partially removed by selective etching. 5. The method of manufacturing an MR head according to claim 2, wherein a frame resist is formed after forming a metal film, and then ion milling is performed on the metal film to form a side surface of the frame resist. Re-attach the metal film,
A method for manufacturing an MR head, comprising a base film for upper pole plating.