JPH0836718A - Magnetoresistive magnetic head - Google Patents

Abstract

(57) [Abstract] [Purpose] A magnetoresistive effect element was used as a detection element,
The present invention relates to improvement of a magnetoresistive effect magnetic head exclusively for reproduction. [Structure] An undercoat film 12 formed on a soft magnetic layer 11 with a core width interval, the undercoat film 12 and the soft magnetic layer 1
1 is formed on the base film 12 and exhibits hard magnetic properties on the base film 12,
A magnetic film 13 exhibiting soft magnetism on the soft magnetic layer 11;
A non-magnetic intermediate layer 14 that is selectively formed in the gap between the base films 12, a magnetoresistive effect element formed on the intermediate layer 14 and the magnetic film 13, and the magnetoresistive elements on both sides of the intermediate layer 14. Extraction electrode 1 formed on the effect element
5, 16 and.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive effect magnetic head, and more particularly to improvement of a read-only magnetoresistive effect magnetic head using a magnetoresistive effect element as a magnetic sensing part. In recent years, with the increase in capacity of magnetic recording devices, which are external storage devices of computers, high performance magnetic heads have been required. In order to satisfy this requirement, an MR head that can be used for a small-diameter disk without depending on the speed of a recording medium and can obtain a high output has attracted attention.

[0002]

2. Description of the Related Art As shown in FIG. 3, a conventional magnetoresistive effect reproducing magnetic head (hereinafter referred to as an MR head) is a Ni magnetic head.
A nonmagnetic conductor layer 2 and a magnetoresistive effect (hereinafter referred to as MR) element 3 are sequentially formed on a soft magnetic layer 1 made of FeCr or the like,
Extraction electrodes 5 and 6 for detecting a detection voltage are formed at intervals on the MR element 3, and further, on the MR element 3 and on both sides of the extraction electrodes 5 and 6, the FeMn films 4 for controlling magnetic domains.
Is formed (for example, JP-A-63-
The structure is shown in 117310, etc.).

The operation of reading information from a recording medium using the above MR head will be described below. A recording medium such as a magnetic disk moves under the MR head in the film thickness direction of the head. Since a sense current from a constant current source (not shown) flows in the longitudinal direction of the MR element 3, when a signal magnetic field from a recording medium (not shown) enters the sense area 7 which is the central area of the MR element 3, the sense area is sensed. The electric resistance of the MR element 3 at 7 changes, and the voltage across the MR element 3 changes. This voltage change is detected as a detection voltage, and the extraction electrodes 5 and 6 are detected.
I took it out from and read out the information.

At this time, in order to linearize the reproduction output by the MR element 3 to obtain a linear response mode, the soft magnetic layer 1 is brought close to the MR element via the non-magnetic conductor layer 2, and the soft magnetic layer is generated by the magnetic field generated by the sense current. The magnetization of 1 is saturated perpendicular to the sense current. A magnetic field generated by this saturation magnetization applies a bias in the direction perpendicular to the sense current (hereinafter referred to as lateral bias) to the sense region of the MR element 3.

For the purpose of stable operation of the MR head,
An antiferromagnetic FeMn film 4 serving as a magnetic film for magnetic domain control is arranged at both ends of the MR element 3, and the exchange interaction between the FeMn film 4 and the MR element 3 causes a gap between the extraction electrodes 5 and 6 of the MR element 3. The magnetic domain of was controlled in one direction to suppress the above adverse effect.

[0006]

However, the FeMn film 4, which is the magnetic film for controlling the magnetic domain, is very likely to corrode,
There was a problem of lack of durability. The present invention has been made in view of the above problems, and is liable to corrode Fe
An object of the present invention is to provide a magnetoresistive effect magnetic head which can easily control magnetic domains at both ends of an MR element without using an Mn film and has high durability.

[0007]

Means for Solving the Problems The above-mentioned problems are solved by forming an underlayer film formed on a soft magnetic layer with a core width interval, and on the underlayer film and the soft magnetic layer. A hard magnetic layer, and a soft magnetic layer having a soft magnetic layer on the soft magnetic layer, and a non-magnetic intermediate layer selectively formed in the gap between the underlayer film, and formed on the intermediate layer and the magnetic film. This is solved by a magnetoresistive effect magnetic head having a magnetoresistive effect element and lead electrodes formed on the magnetoresistive effect element on both sides of the intermediate layer.

A base film formed on the soft magnetic layer with a space between core widths, a magnetic film selectively formed on the base film and exhibiting hard magnetism on the base film, and a soft magnetic layer on the soft magnetic layer. An intermediate layer selectively formed in the gap between the underlayer film and the magnetic film, a magnetoresistive effect element formed on the intermediate layer and the underlayer film, and on the magnetoresistive effect element on both sides of the intermediate layer. The problem is solved by a magnetoresistive effect type magnetic head having an extraction electrode formed.

[0009]

[Operation] According to the present invention, a base film made of, for example, a tungsten or chromium film is formed on the soft magnetic layer with a core width interval, and a CoCrTa film or the like is formed on the base film and the soft magnetic layer. A magnetic film exhibiting hard magnetism on the hard magnetic film and soft magnetism on the soft magnetic layer is formed, and an intermediate layer made of tantalum or titanium is selectively formed in the gap between the base films,
A magnetoresistive effect element (hereinafter referred to as an MR element) is formed on the intermediate layer and the magnetic film, and lead electrodes are formed on the magnetoresistive effect elements on both sides of the intermediate layer.

By the way, it is well known that when a CoCrTa film is formed on a base film made of a tungsten or chromium film, the CoCrTa film on the base film becomes a hard magnetic material because of its crystallinity. For this reason, on the underlying film formed in the regions at both ends of the MR element other than the core width region of the MR element.
The CoCrTa film becomes a hard magnetic film.
The exchange interaction between the Ta film and the magnetoresistive effect element formed thereon can control the magnetic domains at both ends of the MR element in one direction.

Thus, for the purpose of suppressing the adverse effect of Barkhausen noise, it is not necessary to use the FeMn film, which is an antiferromagnetic material, which is conventionally necessary for controlling the magnetic domains at both ends of the MR element, and the both ends of the MR element are not used. Since the magnetic domains can be controlled, it is possible to suppress the problem of deterioration in durability caused by using the easily corroded FeMn film as the magnetic film for controlling magnetic domains, which has been conventionally generated.

The CoCrTa film in the region other than the base film, that is, in the core width region, has a soft magnetic layer as the base film and exhibits soft magnetism in this region, so that it is the central region of the MR element. A lateral bias can also be applied to the sense region. In the present invention, on the soft magnetic layer,
An underlying film made of, for example, a tungsten or chromium film is formed with a core width interval, a CoCrTa film is selectively formed on the underlying film, and an intermediate film made of tantalum or titanium is formed in the gap between the underlying film on the soft magnetic layer and the CoCrTa film. A layer is selectively formed, a magnetoresistive effect element is formed on the intermediate layer and the CoCrTa film, and lead electrodes are formed on the magnetoresistive effect element on both sides of the intermediate layer.

In this case, since the CoCrTa film on the underlayer exhibits hard magnetism and the intermediate layer formed on the soft magnetic layer exhibits soft magnetism, the magnetoresistive effect magnetic head according to the present invention described above is used. Similarly, the magnetic domains at both ends of the MR element can be easily controlled without using a FeMn film that easily corrodes, and the durability of the magnetoresistive head is improved.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) First, tungsten (W) is formed on a substrate (not shown) such as a NiFeCr film having a film thickness of about 200 to 300Å and having a soft magnetic layer 11 having a core width of 3 μm or less. A base film 12 made of is formed to a thickness of about 100 Å by a sputtering method. Next, after cleaning the surfaces of the soft magnetic layer 11 and the base film 12 by ion milling,
The CoCrTa film 13 is formed to a thickness of about 200 to 300 Å by the sputtering method.

After that, the sense region 18 on the CoCrTa film 13 is formed.
The film thickness of 100 Å made of tantalum (Ta)
An intermediate layer 14 having a width of 3 μm or less is selectively formed by a lift-off method or the like, the surfaces of the CoCrTa film 13 and the intermediate layer 14 are cleaned by ion milling, and then a film thickness of 2 is obtained by a sputtering method.
An MR element 15 having a size of about 00 to 300 Å is formed, a predetermined patterning process is performed, and lead electrodes 16 and 17 are formed thereon so as to sandwich the sense width region. In the above manufacturing process, a uniform magnetic field is applied in the longitudinal direction of the head.

The MR head as shown in FIG. 1 is completed by the above manufacturing method. By the way, W film and chrome (Cr)
In CoCrTa on the film, hexagonal CoCrTa crystals grow laterally in the film plane (hereinafter, this direction is referred to as in-plane direction) during the growth process. Therefore, it becomes hard magnetic in the in-plane direction of the film. Further, in CoCrTa on a film exhibiting soft magnetism such as a NiFe film, a hexagonal crystal of CoCrTa grows perpendicularly to the film surface in the growth process. Therefore, it is well known that the magnetic layer has a hard magnetic property in the direction perpendicular to the in-plane direction but has a soft magnetic property in the in-plane direction.

Due to this phenomenon, in the above MR head, the base film 1 made of W in the regions at both ends of the MR element 15 is formed.
CoCrTa film 13 on 2 is selectively hard magnetic films 13A and 13C
Has become. In addition, the soft magnetic layer 11 is also soft magnetic due to the crystallinity. Therefore, the hard magnetic films 13A and 13C on the base film 12 are replaced with the CoCrTa film 13
And the exchange interaction with the MR element 15 formed on it, the magnetic domain in the sense region of the MR element 15 can be controlled in one direction to suppress the adverse effect of Barkhausen noise and achieve stable operation. become.

Thus, the magnetic domains at both ends of the MR element can be controlled without using the FeMn film, which is an antiferromagnetic material, which was conventionally required to control the magnetic domains at both ends. It becomes possible to suppress the problem of deterioration of durability due to the use of the easily corroded FeMn film. Furthermore, since the CoCrTa film 13 on the soft magnetic layer 11 exhibits soft magnetism, it becomes possible to apply a lateral bias to the sense region 18 which is the central region of the MR element 15.

The operation of reading information from the recording medium using the above MR head will be briefly described below. A recording medium such as a magnetic disk moves under the head in the film thickness direction of the head. Since a sense current from a constant current source (not shown) flows in the longitudinal direction of the MR element 15,
When a signal magnetic field from a recording medium (not shown) enters the sense region 18, which is the central region of the MR device 15, the electric resistance of the MR device 15 in the sense region 18 changes, and the voltage across the MR device 15 changes. This voltage change is detected as a detection voltage and is taken out from the extraction electrodes 16 and 17 to read information. (Second Embodiment) The MR according to the second embodiment of the present invention will be described below.
The head will be described with reference to FIG. The description of the items common to the MR head of the first embodiment will be omitted to avoid duplication.

First, a film thickness 2 formed on a substrate (not shown)
A base film 22 made of W and having a core width interval of 3 μm or less is formed on the soft magnetic layer 21 such as a NiFeCr film having a thickness of about 100 to 300 Å to a thickness of about 100 Å by a sputtering method. Next, the soft magnetic layer 21 and the base film 2 are subjected to ion milling.
After cleaning 2 and, the CoCrTa film 23 is sputtered,
A thickness of about 200 to 300 Å is selectively formed on the base film 22.

After that, the base film 2 formed in the core width region
2 and a portion of the CoCrTa film 23, which is a gap, is made of Ta,
An intermediate layer 24 having a film thickness of about 100Å is selectively formed by a lift-off method or the like, the surfaces of the CoCrTa film 13 and the intermediate layer 24 are cleaned by ion milling, and then M is formed by a sputtering method.
After forming the R element 25 to a thickness of about 200 to 300 Å and performing a predetermined patterning process, the lead electrodes 26 and 27 on the MR element 25 so as to sandwich the sense region 28.
To form.

The MR head as shown in FIG. 2 is completed by the above manufacturing method. The operation at the time of reading is the same as that of the first embodiment, and therefore its explanation is omitted. This embodiment is different from the first embodiment in that the CoCrTa film is not formed on the entire surface but is selectively formed on the base film 22, and the base film 22 and the CoCrTa film 2 are formed.
That is, the intermediate layer 24 is selectively formed so as to be filled in the region of the gap 3.

That is, according to the above-mentioned MR head, the CoCrTa film 23 on the base film 22 formed outside the sense region 28 is selectively a hard magnetic film as in the first embodiment. Therefore, a hard magnetic film is formed on the base film 22.
The CoCrTa film 23 can control the magnetic domains at both ends of the MR element 25 in one direction by exchange interaction with the MR element 25 formed thereon.

Thus, in the same manner as the first embodiment, M
Since the magnetic domain can be controlled without using the FeMn film that is an antiferromagnetic material that was conventionally required to control the magnetic domains at both ends of the R element, the FeMn film, which has been a problem in the past, is apt to be corroded. By using it, it becomes possible to solve the problem of lack of durability. Further, since the CoCrTa film 23 is not formed in the region other than the base film, that is, the core width region, and only the intermediate layer is formed therein, the intermediate layer 24 is soft magnetic in this region. This makes it possible to apply a lateral bias to the sense region 28 which is the central region of the MR element 26.

(Other Embodiments) In the above-mentioned first and second embodiments, W was used as the material of the base film, but the present invention is not limited to this, and the same effect can be obtained with chromium (Cr), for example. Play. Similarly, although Ta was used as the material of the intermediate layer, the present invention is not limited to this, and titanium (Ti), for example, also exhibits the same effect.

[0026]

As described above, according to the present invention, a base film made of, for example, a tungsten or chromium film is formed on the soft magnetic layer with a core width interval, and the base film and the soft magnetic layer are formed, for example. An intermediate layer made of CoCrTa film or the like, which exhibits hard magnetism on the hard magnetic film and soft magnetism on the soft magnetic layer, and an intermediate layer made of tantalum or titanium is selectively formed in the gap between the underlying films. And the MR element is formed on the magnetic film, and the extraction electrodes are formed on the magnetoresistive effect elements on both sides of the intermediate layer.

Thus, for the purpose of suppressing the adverse effect of Barkhausen noise, it is not necessary to use the FeMn film, which is an antiferromagnetic material, which is conventionally necessary for controlling the magnetic domains at both ends of the MR element, and the both ends of the MR element are not used. Since the magnetic domains can be controlled, it is possible to suppress the problem of deterioration in durability caused by using the easily corroded FeMn film as the magnetic film for controlling magnetic domains, which has been conventionally generated.

Further, the CoCrTa film in the region other than the base film, that is, in the core width region, has the soft magnetic layer as the base film and exhibits soft magnetism in this region, so that it is the central region of the MR element. It is also possible to apply a lateral bias to the sense region.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a structure of an MR head according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating a structure of an MR head according to a second embodiment of the present invention.

FIG. 3 is a perspective view illustrating a structure of an MR head according to a conventional example.

[Explanation of symbols]

 1 Soft Magnetic Layer 2 Non-Magnetic Conductor Layer 3 MR Element 4 FeMn Film 5 Extraction Electrode 6 Extraction Electrode 7 Sense Area 11 Soft Magnetic Layer 12 Base Film 13 CoCrTa Film 14 Intermediate Layer 15 MR Element 16 Extraction Electrode 17 Extraction Electrode 18 Sense Area 21 Soft magnetic layer 22 Underlayer film 23 CoCrTa film 24 Intermediate layer 25 MR element 26 Extraction electrode 27 Extraction electrode

Claims (3)

[Claims] 1. A base film formed on a soft magnetic layer with a core width interval, and a base film formed on the base film and the soft magnetic layer, exhibiting hard magnetism on the base film, A magnetic film exhibiting soft magnetism on the layer, an intermediate layer selectively formed in the gap between the underlayer film and exhibiting non-magnetism, a magnetoresistive effect element formed on the intermediate layer and the magnetic film, and the intermediate layer And a lead-out electrode formed on the magnetoresistive effect element on both sides of the magnetoresistive effect element. 2. A base film formed on the soft magnetic layer with a core width interval, a magnetic film selectively formed on the base film and exhibiting hard magnetic properties on the base film, and the soft magnetic layer. An intermediate layer selectively formed in the gap between the underlying film and the magnetic film, a magnetoresistive effect element formed on the intermediate layer and the underlying film, and the magnetoresistive effect elements on both sides of the intermediate layer. A magnetoresistive effect magnetic head having an extraction electrode formed on the magnetic head. 3. The underlayer film is made of a tungsten or chromium film, and the intermediate layer is made of tantalum or titanium.
The magnetoresistive head according to claim 1 or 2, wherein the magnetic film is a CoCrTa film.