JPH11296818A - Magnetoresistive head, magnetic head, and magnetic recording / reproducing device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] In a magnetic head having a narrow track width corresponding to a high recording density, an upper shield is formed between narrow electrodes.
Domain walls are likely to occur and noise during reproduction increases. A non-magnetic layer is provided on a part of an upper shield, and the non-magnetic layer is formed between a pair of electrodes on a medium facing surface and at a position equal to or lower than the height of the uppermost electrode. To prevent domain walls from forming in the upper shield.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head compatible with a high magnetic recording density, a manufacturing method, and a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art As a magnetic head of a current magnetic disk drive, a recording / reproducing separation type head is used in which recording is performed by a thin film magnetic head and reproduction is performed by a magnetoresistive head. Due to the recent improvement in areal recording density, a magnetoresistive head for reading which reads a signal recorded in a very narrow track width is required. In the current magnetoresistive head, as shown in FIG. 4, electrodes are formed on a magnetic domain control film, and the track width is defined by the distance between the electrodes.

A method for defining a narrow track width of a magnetoresistive head is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-45037.
As described in Japanese Patent Application Laid-Open No. 8-339512 or JP-A-8-339512, there is a method in which the distance between the electrodes is made smaller than the width of the magnetoresistive film by riding the electrodes up to the inside of the magnetoresistive film. In any case, as the recording density increases and the track width becomes narrower, an upper shield is formed on a narrow groove, and a magnetic domain wall is generated on the shield located above the track, which causes a problem during reproduction. Noise increases.

[0004]

As described above, as the recording density of a magnetic recording device increases, the electrode spacing for defining the track width is becoming narrower. When a shield is formed, a domain wall is generated in the shield located above the track, and noise during reproduction increases.

An object of the present invention is to provide a magnetoresistive head having the above-mentioned narrow track structure and low noise.

[0006]

SUMMARY OF THE INVENTION In a magnetoresistive head, a part of a shield located above a specified track is replaced with a nonmagnetic layer. This eliminates the domain wall of the upper shield, and makes it possible to manufacture a magnetoresistive head having less noise and a narrow track width.

[0007] By mounting the magnetoresistive head, a good magnetic recording / reproducing apparatus can be obtained.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.
This will be described more specifically with reference to the figures and tables.

(Embodiment 1) FIG. 1 shows a magnetoresistive head having a structure according to the present invention, in which a head end portion is viewed from a medium facing surface. A method for manufacturing this magnetoresistive head will be described with reference to FIGS. First, a CoZrNb film is formed as a lower shield 12 on a non-magnetic substrate 11 on which an insulating layer such as alumina is formed as a thin film and precision polished. Ni-Fe / Co / Cu / Co / Cr-Mn-Pt as a magnetoresistive film on alumina as the lower gap film 13
After forming the spin valve film 14 having a film structure (a),
Patterning was performed by ion milling (b).

Next, in order to suppress Barkhausen noise, a magnetic domain control layer 15 is formed on both sides of the magnetoresistive effect film.
An o-Cr-Pt permanent magnet film was provided (c). The electrode 16 is formed using a Cr / Au / Cr three-layer film so as to be joined to the magnetoresistive film (d). The electrode spacing at this time is 0.
It was 75 μm. After forming the electrodes, the upper gap film 1
7 was formed (e). Thereafter, the upper part of the electrode is covered with the interstitial forming film 18 and the resist 19,
A film 20 and a Ta nonmagnetic film 21 are formed (f), the interstitial forming film 18 and the resist 19 are removed by a lift-off method (g), a Ni—Fe film 22 is formed, and finally a protective film 23 is formed.
Was formed (h).

When the recorded magnetic disk is reproduced using the magnetoresistive head shown in FIG. 1, noise is reduced as compared with the conventional magnetoresistive head shown in FIG. , And the S / N ratio were greatly improved.
This is considered to be an effect that the domain wall generated in the shield is reduced by using the magnetoresistive head of this structure. Further, in this embodiment, the electrode interval is set to 0.
75 μm, but as the electrode spacing becomes narrower,
The effect is higher.

In this embodiment, the lower shield 12 and the upper shields 20 and 22 are made of Co-Zr-Nb or Ni-
Fe was used, but Sendust (Al-Si-Fe), C
Other soft magnetic materials having a low coercive force and a high magnetic permeability such as an o-based amorphous film can be used.

In this embodiment, the number of the non-magnetic layers is one. However, the effect is enhanced by forming a laminated structure of the shield film 20 and the non-magnetic film 21.

As the magnetoresistive effect film, a spin valve film having a structure of another magnetic layer / nonmagnetic layer / magnetic layer / antiferromagnetic layer or a giant magnetoresistance obtained by laminating [magnetic layer / nonmagnetic layer] a plurality of times. An effect film or an anisotropic magnetoresistive effect film such as a Ni—Fe film or a Ni—Co film provided with a means for applying a lateral bias magnetic field can be used. Further, although a Co—Cr—Pt permanent magnet film is used as the magnetic domain control layer 15, another permanent magnet film or a magnetic layer / antiferromagnetic layer laminated film may be used.

Embodiment 2 In this embodiment, another method of manufacturing a magnetoresistive head will be described with reference to FIGS. First,
An insulating layer of alumina or the like is formed as a thin film, and CoZrN
A b film is formed. Ni-Fe / Co / Cu / Ni / Fe / Co / Cu /
After forming a spin valve film 34 having a structure of a Co / Cr-Mn-Pt film (a), it was patterned by ion milling (b).

Next, in order to suppress Barkhausen noise, a magnetic domain control layer 35 is formed on both sides of the magnetoresistive effect film.
An o-Cr-Pt permanent magnet film was provided (c). The electrode 36 is formed using a Cr / Au / Cr three-layer film so as to be joined to the magnetoresistive film (d). After the formation of the electrodes, a thin carbon film 38 was formed as the upper gap film 37 for detection of alumina and a CMP method (chemical mechanical polishing method) (e).

On top of this, a Ni-Fe shield film 39, T
a The non-magnetic film 40 and the Ni-Fe shield film are formed in this order (f), and polished by the CMP method until the carbon film 38 is detected (g, enlarged view). Thereafter, a shield film 41 and a protective film 42 having desired thicknesses are formed (h),
A magnetoresistive head having a structure similar to that of FIG. 1 is manufactured. When a magnetic disk was reproduced using this head, the same results as in Example 1 were obtained.

(Embodiment 3) A recording / reproducing separation type head combining the magnetoresistive head of Example 1 and a thin film magnetic head for recording was manufactured. The thin-film magnetic head uses the upper shield of the magnetoresistive head as the lower core, covers the coil made by plating on the upper shield, forms an upper core made of Ni-Fe, and patterns it into a predetermined shape. Later, it was covered with a protective film.

Using the recording / reproducing separation type head of the present invention, a magnetic disk drive was manufactured. FIG. 5 shows a schematic view of the structure of the magnetic disk drive.

For the magnetic recording medium 51, a Co-Cr-Pt material was used. The recording track width was 1.0 μm, and the reproduction track width was 0.75 μm. The magnetoresistive film of the magnetoresistive head uses a spin-valve film with high reproduction output, and a non-magnetic layer is formed on a part of the shield to reduce the number of magnetic walls in the shield and reduce noise. Become. As a result, a magnetic recording / reproducing apparatus having a high recording density and a high S / N ratio and capable of excellent reproduction even with a narrow track width can be manufactured. The magnetic head of the present invention is particularly suitable for 4G
This is effective for a magnetic recording / reproducing apparatus having a recording density of b / in ² or more. It is considered essential for a magnetic recording / reproducing apparatus having a recording density of 10 Gb / in ² or more.

[0021]

As described above, as the recording density of the magnetic recording apparatus increases, the electrode spacing for defining the track width is becoming narrower, and an upper shield is formed thereon via an electrical insulating film. In this case, a domain wall is generated in the shield located at the top of the track and noise is reduced,
The S / N ratio at the time of reproduction decreases.

In the magnetoresistive head, a part of the shield located above the specified track is replaced with a nonmagnetic layer. Thus, a magnetoresistive head having a high S / N ratio and a narrow track width can be manufactured. Further, by mounting the magnetoresistive head, a magnetic recording / reproducing apparatus can be obtained. Further, a high-performance magnetic recording / reproducing apparatus can be obtained by using a recording / reproducing separation type head in which the magnetoresistance effect type head and a recording thin film magnetic head are combined.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a magnetoresistive head according to the present invention.

FIGS. 2A to 2H are cross-sectional views illustrating a method of manufacturing a magnetoresistive head according to the present invention.

FIGS. 3A to 3H are cross-sectional views showing another method of manufacturing a magnetoresistive head according to the present invention.

FIG. 4 is a sectional view showing a conventional magnetoresistive head.

FIGS. 5A and 5B are a plan view of the magnetic disk drive of the present invention and a sectional view taken along line AA 'of FIG. 5A.

[Explanation of symbols]

11, 31 ... substrate, 12, 32 ... lower shield, 13,
33: lower gap, 14, 34: magnetoresistive film, 1
5, 35: magnetic domain control film, 16, 36: electrode, 17, 37
... upper gap, 18 ... interstitial film, 19 ... resist,
20, 22, 39, 41 ... upper shield, 21, 40 ...
Non-magnetic intermediate layer, 23, 42: protective film, 51: magnetic recording medium, 52: magnetic recording medium drive, 53: magnetic head, 5
4 magnetic head drive unit 55 recording / reproducing signal processing system

Claims (4)

[Claims] A magnetoresistive film for converting a magnetic signal into an electric signal; a pair of magnetic domain control films for applying a longitudinal bias magnetic field for suppressing Barkhausen noise of the magnetoresistive film; In a magnetoresistive head provided between an upper shield and a lower shield with an insulating layer interposed therebetween, a magnetoresistive element having a pair of electrodes for flowing a signal detection current through the resistive effect film has one of the upper shields. One or more nonmagnetic layers are formed in the portion, the nonmagnetic layer is provided between the pair of electrodes on the medium facing surface, and the position of the nonmagnetic layer is equal to or less than the height of the uppermost electrode. A magnetoresistive head provided in the head. 2. The magnetoresistance effect film includes a plurality of magnetic layers and an antiferromagnetic layer separated by a nonmagnetic layer, and at least one of the plurality of magnetic layers is exchange-coupled with the antiferromagnetic layer. 2. The magnetoresistive head according to claim 1, wherein the magnetoresistive head is a multilayer film in which a magnetoresistive effect occurs depending on the direction of magnetization of the magnetic layer separated by the nonmagnetic layer. 3. A magnetic head comprising a combination of the magnetoresistive head according to claim 1 and a thin film magnetic head. 4. A magnetic recording / reproducing apparatus equipped with the magnetic head according to claim 1.