JPH09198626A - Magnetoresistive head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the occurrence of an output change by ferromagnetic thin film in end region by forming a longitudinal bias field in adjacent joint parts and generating longitudinal bias in a magnetoresistive(MR) element. SOLUTION: The MR layer 13 exists only on the central active region and the longitudinal bias layers 15 consisting of a nonmagnetic material layer 17, a ferromagnetic thin film layer 16 and antiferromagnetic thin film layer 14 are formed in the end regions forming the adjacent joint parts. A nonmagnetic metallic layer 17 is formed on the ground surface of the ferromagnetic thin film layer 16, thereby, the stabilization of the magnetic characteristics of the ferromagnetic thin film layer 16 is made possible and the characteristics desirable as the magnetic head are obtd. The exchange bond bias between the ferromagnetic thin film layer 16 and the antiferromagnetic thin film layer 14 is thereby increased, and from this, the output change by the ferromagnetic thin film layer 14 in the end regions is lessened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect head, and more particularly to a magnetoresistive effect head used as a reproducing head of a magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art Conventionally, it has a high reproduction sensitivity and
Since the reproduction output does not depend on the relative speed between the magnetic recording medium and the magnetic head, a magnetoresistive effect (MR) head is known as a device advantageous for increasing the density and size of the magnetic recording apparatus. In such an MR head, an electrode is attached to the MR element to pass a current, and the change in resistance of the MR element is detected as an output. Many methods have been developed for attaching the MR head and the electrodes.

FIG. 6 is a sectional view showing the structure of an example of a conventional magnetoresistive head. As shown in the figure, in this conventional magnetoresistive (MR) head, a nonmagnetic spacer layer 12 and a magnetoresistive effect layer 13 are laminated on a soft magnetic thin film layer 11, and an antiferromagnetic thin film layer is further formed thereon. 14 and the conductor lead layer 21 are formed.

This MR head includes a magnetoresistive effect layer 13 which is an MR element extending over the entire MR head. The exchange bias layer extends only on the end region to generate a longitudinal bias, and the soft magnetic thin film layer 11 separated from the magnetoresistive effect layer 13 by the thin nonmagnetic spacer layer 12 generates a lateral bias. The read signal is determined by the distance between the conductor lead layers 21.

Another conventional magnetoresistive head is, for example, an MR head described in Japanese Patent Laid-Open No. 7-57223. In this MR head, an MR element exists only in the active region, and by forming a ferromagnetic thin film and an antiferromagnetic thin film in the end region, an exchange coupling bias is generated and a longitudinal bias is generated in the active region. Is.

[0006]

However, in the conventional MR head shown in FIG. 6, in addition to the output change in the active region, the MR device is present in the end region as well, but there is a slight change in the output. Occurs. This change in output causes deterioration of crosstalk when the device is used as an actual device. For this reason, the conventional MR head having the above-described structure has a limited possibility of higher density in the future.

In the conventional MR head described in the latter publication, the MR element exists only in the active region, but when the exchange coupling between the ferromagnetic layer and the antiferromagnetic layer is not sufficient, the ferromagnetic element in the end region is ferromagnetic. There is a problem in that the output changes due to the thin film.

[0008] The present invention has been made in view of the above points,
The MR element exists only on the central active region, and by forming a longitudinal bias field at the adjacent junction, a longitudinal bias is generated in the MR element and the output change due to the ferromagnetic thin film does not occur in the end region. An object is to provide a magnetoresistive effect head.

[0009]

In order to achieve the above-mentioned object, the present invention is directed to a layer including at least a magnetoresistive layer formed in a central active region on a substrate and a vertical direction in an adjacent junction of the active region. A longitudinal bias layer for generating a bias field, the longitudinal bias layer comprising a non-magnetic metal layer extending over an adjacent junction on the substrate, a ferromagnetic thin film layer formed on the non-magnetic metal layer, The structure has an antiferromagnetic thin film layer formed on a ferromagnetic thin film layer.

Here, it is desirable that the non-magnetic metal layer be tantalum or titanium, the ferromagnetic thin film layer be a nickel-iron alloy, and the antiferromagnetic thin film layer be an alloy containing manganese.

According to the present invention, when an MR head that produces a longitudinal bias field from an end region to an active region by exchange coupling between a ferromagnetic thin film and an antiferromagnetic thin film, a non-magnetic underlayer of the ferromagnetic thin film is formed. It was confirmed by experiments by the present inventor that a metal layer is formed, and thereby the magnetic characteristics of the ferromagnetic thin film can be stabilized to the characteristics desirable for the magnetic head. As a result, in the present invention, the exchange coupling bias can be increased.

[0012]

Next, an embodiment of the present invention will be described. FIG. 1 is a structural sectional view of an embodiment of an MR head according to the present invention. As shown in the figure, this MR
The head has a soft magnetic thin film layer 11, a non-magnetic spacer layer 12 and a magnetoresistive effect (M
R) layer 13 constitutes an active region in which layers are laminated, and a nonmagnetic metal layer 17, a ferromagnetic thin film layer 16 and an antiferromagnetic thin film layer 14 are sequentially laminated adjacent to the active region, and further, an antiferromagnetic thin film layer. 14 is a structure in which the conductor lead layer 21 is formed on the surface 14.

That is, this MR head has the MR layer 13
Exists only on the central active region, and a longitudinal bias field composed of the non-magnetic metal layer 17, the ferromagnetic thin film layer 16 and the antiferromagnetic thin film layer 14 is formed in the end region adjacent to the central active region. Is formed in the vertical direction bias layer 15.

Next, a method of manufacturing the MR head according to this embodiment will be described with reference to FIGS. First, FIG.
As shown in FIG. 5, a soft magnetic thin film layer 11 is formed on a ceramic substrate 1 such as AlTiC, and a nonmagnetic spacer layer 12 is further formed thereon to form a lateral bias structure.

Next, as shown in FIG. 2, an MR layer 13 is formed on the non-magnetic spacer layer 12, a photoresist or the like is applied thereon, and a photoresist is patterned to form a stencil 31. Turn into. Here, the stencil 31 is composed of a single layer resist using the image reversal method.

One exposure and one development step defines the edge contour of the resist. The undercut is generated by dissolving the resist in an appropriate exposure amount and an appropriate developing solution, and the undercut distance is determined by the developing time. The height of the undercut is determined by the exposure time.

Next, as shown in FIG. 3, the soft magnetic thin film layer 1
1. The non-magnetic spacer layer 12 and the MR layer 13 are processed and patterned by ion milling, sputter etching or chemical etching using the stencil 31 as a mask. The soft magnetic thin film layer 11, the non-magnetic spacer layer 12 and the MR layer 13 become narrower in the upward direction, and their inclined edges are defined by the stencil 31.

Next, the non-magnetic metal layer 1 is added to the above device.
7, a longitudinal bias layer 15 is formed by sequentially stacking the ferromagnetic thin film layer 16 and the antiferromagnetic thin film layer 14 as shown in FIG. At this time, the stencil 31 is used to define the edge of the vertical bias layer 15. In addition,
The vertical bias layer 15 also adheres to the upper surface of the stencil 31.

The same stencil 31 is then used to deposit a conductor lead layer 21 on the longitudinal bias layer 15 to create sensor conductor leads, as shown in FIG. At this time, the conductor lead layer 2 is also formed on the upper surface of the stencil 31.
1 is attached.

Thereafter, the stencil 31 and the magnetic material deposited on the upper surface of the stencil 31 in a considerable amount at the time of forming the longitudinal bias layer 15 and the conductor lead material at the time of forming the conductor lead layer 21 are removed together by a lift-off process. As shown in FIG. 5, the MR head having the vertical bias layer 15 in the end region is formed. This longitudinal bias layer 15
Is a MR3 layer structure extending only to the active region (that is, the soft magnetic thin film layer 11, the non-magnetic spacer layer 12 and the MR layer 13).
And a magnetically continuous adjacent junction.

In this MR head, the longitudinal bias layer 1
The non-magnetic metal layer 1 is provided as an underlayer of the ferromagnetic thin film layer 16 constituting
It has been confirmed by experiments by the present inventor that the magnetic characteristics of the ferromagnetic thin film layer 16 can be stabilized and desirable characteristics as a magnetic head can be obtained. Therefore, the ferromagnetic thin film layer 16 and the antiferromagnetic thin film layer 1
It is possible to increase the exchange-coupling bias with respect to No. 4 and thereby reduce the output change due to the ferromagnetic thin film layer 14 in the end region.

The bottom nonmagnetic metal layer 17 of the longitudinal bias layer 15 in this embodiment is tantalum (Ta).
Materials such as titanium and titanium (Ti) are desirable. Further, nickel-iron (NiFe) is suitable for the ferromagnetic thin film layer 16 which is an intermediate layer of the vertical bias layer 15. Further, manganese-iron (MnFe) or manganese-nickel (MnNi) is desirable for the uppermost antiferromagnetic thin film layer 14 of the longitudinal bias layer 15. The conductor lead layer 21 includes gold (Au), copper (C
u) and tungsten (W) are preferably non-magnetic metals having a low specific resistance.

The soft magnetic thin film layer 11 of the MR3 layer in the active region is made of cobalt-zirconium-molybdenum (Co).
ZrMo) or nickel-iron-rhodium (NiFe
Rh) is desirable, non-magnetic spacer layer 12 is preferably non-magnetic metal tantalum (Ta) or titanium (Ti), and MR layer 13 is desirably nickel-iron (NiFe).

The present invention is not limited to the above embodiment, and a two-layer resist may be used in the step of forming the stencil 31, for example. When using this two-layer resist stencil, the stencil is formed by a relatively thin underlayer and a thick imaging layer. With one exposure and one development process, the edge contour of the resist is defined similarly to the image reversal method,
The undercut is produced by dissolution of the lower layer in a suitable developing solution, and the undercut distance is determined by the developing time. The height of the undercut is determined by the thickness of the underlying resist.

[0025]

As described above, according to the present invention,
The MR layer exists only in the active region, and the longitudinal bias layer is M.
In the MR head provided in each end region forming the adjacent junction with the R layer, the non-magnetic metal layer is formed under the ferromagnetic thin film so that the exchange coupling bias can be increased. By increasing the exchange coupling bias in the partial region, it is possible to reduce the output change due to the ferromagnetic thin film in the end region.

Further, according to the present invention, MR which is easy to manufacture
MR with layers present only in the active region and longitudinal bias layers at each end region forming an adjacent junction with the MR layer.
The head can be realized.

[Brief description of drawings]

FIG. 1 is a structural cross-sectional view of an embodiment of the present invention.

FIG. 2 is a structural cross-sectional view (No. 1) in the manufacturing process of the embodiment of the present invention.

FIG. 3 is a structural cross-sectional view (No. 2) in the manufacturing process of the embodiment of the present invention.

FIG. 4 is a structural cross-sectional view (3) in the manufacturing process of the embodiment of the present invention.

FIG. 5 is a structural cross-sectional view (No. 4) in the manufacturing process of the embodiment of the present invention.

FIG. 6 is a structural cross-sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramics substrate 11 Soft magnetic thin film layer 12 Nonmagnetic spacer layer 13 Magnetoresistance effect (MR) layer 14 Antiferromagnetic thin film layer 15 Longitudinal bias layer 16 Ferromagnetic thin film layer 17 Nonmagnetic thin film layer 21 Conductor lead layer 31 Stencil

Claims (4)

[Claims] 1. A layer comprising at least a magnetoresistive layer formed in a central active region of a substrate, and a longitudinal bias layer for generating a longitudinal bias field at an adjacent junction of the active region. The longitudinal bias layer includes a nonmagnetic metal layer extending on the adjacent junction on the substrate, and a ferromagnetic thin film layer formed on the nonmagnetic metal layer.
A magnetoresistive head comprising an antiferromagnetic thin film layer formed on the ferromagnetic thin film layer. 2. The magnetoresistive head according to claim 1, wherein the non-magnetic metal layer is made of tantalum or titanium. 3. The magnetoresistive head according to claim 1, wherein the ferromagnetic thin film layer is made of a nickel-iron alloy. 4. The magnetoresistive head according to claim 1, wherein the antiferromagnetic thin film layer is made of an alloy containing manganese.