JPH0744824A - Magneto-resistance effect type magnetic head and production thereof - Google Patents

Abstract

PURPOSE:To suppress the reduction of reproduction output due to the branching of a sensing current and to suppress the deterioration of the magnetic characteristics of an MR element and an amorphous soft magnetic substance layer due to head treatment in a process for producing an MR head. CONSTITUTION:In an MR head with three-layered MR laminate 2 consisting of an MR element layer, a nonmagnetic material layer and an amorphous soft magnetic layer for applying a bias magnetic field between a pair of shielding layers 1, 4, a niobium oxide layer 22 is formed as the nonmagnetic material layer between the MR element 21 and the amorphous soft magnetic layer 23 by vacuum-depositing niobium in a low vacuum of <=8X10<-7>Torr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing device such as a magnetic disk device, and more particularly to a magnetoresistive head which is used in a magnetic recording device having a small size and a high signal density.

[0002]

2. Description of the Related Art A magnetic resistance effect type magnetic head (hereinafter referred to as MR
The head) has high reproduction sensitivity and the reproduction output does not depend on the relative speed between the recording medium and the head, and is suitable for downsizing of the magnetic recording apparatus and high signal density. In MR heads, in order to improve the resolution during reproduction,
A shield structure in which a magnetoresistive effect element (hereinafter, MR element) is sandwiched between a pair of shield layers is adopted.

Generally, the MR head is used as a read-only head having a linear characteristic by applying a magnetic bias to the MR element. For example, the MR head proposed in Japanese Examined Patent Publication No. 53-37205 has a substrate as shown in FIG.
The lower shield layer (6) and the upper shield layer (65) are arranged on the (7) along the moving direction of the recording medium (8), and the insulating layer (61) and the MR element layer ( 62), insulating layer (6
4) and a bias layer (63) are sequentially formed, and a magnetic bias is applied to the MR element layer (62) by the bias layer (63).

[0004]

By the way, the MR element layer
The insulating layer (64) interposed between the (62) and the bias layer (63) is required to have a sufficient resistance value in terms of its insulating characteristics. Therefore, in the MR head proposed in the above Japanese Patent Publication No. 53-37205, silicon dioxide having a thickness of 2000 angstrom is adopted as an insulating material. However, with such a large thickness, the bias magnetic field from the bias layer (63) does not sufficiently act on the MR element layer (62), which causes a problem in magnetic efficiency.

On the other hand, in Japanese Patent Publication No. 56-40406, a non-magnetic substance having a relatively high resistivity such as Ti is used in place of the insulating material. In the MR head, however, a non-magnetic substance layer is used. Since the sense current is shunted, there is a problem that the reproduction output of the MR element is reduced.

In the MR head, when an amorphous soft magnetic material is used as the conductive magnetic material of the bias layer,
In order to improve the magnetic characteristics of the amorphous soft magnetic material and to give the same easy axis direction as that of the MR element, 300 to 35
A heat treatment process at 0 ° C. is required. However, this heat treatment process causes non-magnetic substances such as Ti to diffuse into the MR element and the amorphous soft magnetic material, deteriorating their soft magnetic characteristics, and M
There is a problem that the reproduction output of the R head decreases.

An object of the present invention is to provide an MR head in which a non-magnetic material having a high resistance and which does not cause diffusion even after a heat treatment process is interposed between an MR element layer and a bias layer, and a simple manufacturing method thereof. It is to solve the above problems at once.

[0008]

The MR head according to the present invention employs niobium oxide, which has never been seen before, as a non-magnetic substance to be interposed between the MR element layer and the bias layer.

Also, in the method of manufacturing the MR head according to the present invention, the step of forming the niobium oxide layer between the MR element layer and the bias layer is performed in a low vacuum of 8 × 10 ⁻⁷ Torr or more, preferably 7 × 10 7. It is performed by vacuum-depositing niobium in a low vacuum of about ^-6 Torr.

[0010]

[Function] Niobium oxide is 5 × 10 ³ to 15 × 10 ³ μΩcm
It has been confirmed experimentally that it has a high specific resistance and that diffusion hardly occurs even after the heat treatment process. or,
According to the method of vacuum-depositing niobium in a low vacuum of 8 × 10 ⁻⁷ Torr or more, niobium is oxidized by the action of oxygen in the vapor deposition atmosphere to form a niobium oxide layer.

[0011]

According to the MR head of the present invention, the MR
Since the niobium oxide layer between the element layer and the bias layer has a high resistance, the sense current is not shunted to the niobium oxide layer, and a high reproduction output can be obtained. Further, when the magnetic characteristics of the bias layer are improved by the heat treatment, the niobium oxide layer does not cause diffusion due to the heat treatment, so that the magnetic characteristics are not likely to deteriorate.

Further, according to the method of manufacturing the MR head of the present invention, a high resistance niobium oxide layer can be formed by only lowering the degree of vacuum when vacuum depositing niobium. It's simple.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In the MR head according to the present invention, an MR composite layer (2) described later is formed on a lower shield layer (1) via a lower insulating layer (not shown) as shown in FIG. )
A pair of electrode layers (3) and (3) are formed on the surface of, and an upper shield layer (4) is arranged via an upper insulating layer (not shown).

As shown in FIG. 2, the MR composite layer (2) has a three-layer structure consisting of an MR element layer (21), a niobium oxide layer (22) and an amorphous soft magnetic layer (23). The MR element layer (21) is made of permalloy, and the amorphous soft magnetic layer (23) is made of Co type amorphous. The niobium oxide layer (22) is formed by vacuum-depositing niobium in a low vacuum of about 7 × 10 ^-6 Torr.

FIG. 3 is a graph obtained by experimentally investigating the relationship between the vacuum degree during vapor deposition and the specific resistance of the niobium oxide layer when the niobium oxide layer is formed by vacuum vapor deposition of niobium. Here, crystallized glass was used for the substrate on which the niobium oxide layer was to be formed, and the substrate temperature was 200 ° C. A metal niobium having a purity of 99.9% was used as a vapor deposition source. Oxygen gas is not introduced during vapor deposition. The vapor deposition rate at this time was 3 to 5 Å / sec, and the film thickness was 300 Å. As shown in the figure, at a low vacuum of 1 × 10 ^-6 Torr or higher, a high resistivity exceeding 5 × 10 ³ μΩcm is obtained.

Further, in order to investigate the diffusivity of the niobium oxide layer due to the heat treatment, a permalloy layer (81 wt% Ni-19 wt% F) having a film thickness of 400 Å serving as an MR element layer is obtained.
e) and a niobium oxide layer having a film thickness of 300 Å are continuously formed by a vacuum vapor deposition method, and the laminated film thus obtained is subjected to a heat treatment in a vacuum (vacuum degree of 2 × 10 ⁻⁶ Torr) (350
(° C., 2 hours). Then, the laminated film after the heat treatment was subjected to component analysis in the depth direction using Auger electron spectroscopy. The result is shown in FIG.

In FIG. 4, the sputtering time on the horizontal axis represents the depth of analysis, and the concentration on the vertical axis represents the relative component ratio. As shown in the figure, Nb and O are exchanged with Ni and Fe in a narrow region after the sputtering time of 7 to 8 minutes, so that niobium oxide does not diffuse even after the heat treatment process of the amorphous soft magnetic material. It has been found.

5 and 6 show a method of manufacturing an MR head according to the present invention. First, in FIG. 5 (a), the on Al ₂ O ₃ -TiC substrate thickness of about 2.6mm (5), Al ₂
Insulating layer with a thickness of 10 ~ 15μm by sputtering O ₃
(Not shown) is formed. Then, permalloy (80 wt% Ni-20 wt% Fe) was deposited on the insulating layer by bias sputtering to a thickness of 1 μm, and the lower shield layer was formed.
Form (1). Here, the bias is applied in order to obtain good soft magnetic characteristics, and sputtering is performed while applying −100 V to the substrate.

At this time, a uniaxial anisotropy is imparted to the permalloy film by applying a magnetic field in the in-plane direction of the substrate. As a method of applying a magnetic field, a permanent magnet or an electromagnet is installed in the vacuum chamber. In this embodiment, a permanent magnet is installed on the substrate holder and a magnetic field of 100 Oe is applied.

Then, the permalloy film is shaped into a predetermined shape by using a well-known photolithography technique such as an ion milling method. At this time, etching is performed in consideration of the direction of the easy axis of magnetization. After that, Al ₂ O ₃ is sputtered to a thickness of 1000 Å so as to cover the surface of the lower shield layer (1), and a lower insulating layer (not shown) is formed.

Next, in the step of FIG. 5B, first, a 400 Å thick permalloy film (81 wt% Ni-19 wt% Fe) to be the MR element layer (21) is deposited in a magnetic field. Form. In this embodiment, in order to align the easy axis of magnetization of the MR element layer, vapor deposition is performed at a substrate temperature of 200 ° C. while applying a magnetic field of 70 Oe. After that, the main valve of the vapor deposition apparatus is narrowed to increase the exhaust conductance to lower the degree of vacuum, and niobium is vapor-deposited in this atmosphere to form a niobium oxide layer (22) having a thickness of 300 Å. In this embodiment, the degree of vacuum is 7 × 10 ^-6 Torr.

Further, a thickness 50 to form the amorphous soft magnetic layer (23).
A 0 Å CoZrMo film is formed by sputtering. Then, the laminated film composed of the above three layers is
Simultaneous patterning is performed using a well-known photolithography technique such as an ion milling method. At this time, patterning is performed so that the longitudinal direction of the MR element layer becomes the easy axis of magnetization. In this embodiment, the rectangular shape is 100 μm in the longitudinal direction and 5 μm in the direction orthogonal thereto.

Next, in order to improve the soft magnetic properties of the amorphous soft magnetic layer (23) and impart uniaxial anisotropy, a magnetic field of 450 Oe is applied in the longitudinal direction of the MR element layer (21). Then, heat treatment is performed in vacuum at 330 ° C. for 2 hours to complete the composite layer (2).

In FIG. 6A, Ti and C are formed to form an electrode layer for supplying a sense current to the MR element layer.
A laminated film (31) of u is formed. Here, the film thicknesses of Ti and Cu are set to 200 angstroms and 1200 angstroms, respectively.

Further, in FIG. 6B, the laminated film 31 is formed into a pair of electrode layers by using a well-known photolithography technique.
(3) Shape to (3). Here, a pair of electrode layers (3) (3)
The interval is set to 5 μm to define the track width.

After that, a 1800 Å thick SiO ₂ film to be an upper insulating layer is formed by a sputtering method. Further, a 1 μm thick permalloy film (80 wt% Ni-20 wt% Fe) to be the upper shield layer is formed in the same manner as the lower shield layer, and a predetermined shape is formed by using a well-known photolithography technique such as ion milling. The upper shield layer (4) is etched and shaped.

Thereafter, the upper insulating layer is subjected to through hole processing of the terminal portion by using a well-known photolithography technique, and C which is a constituent material of the terminal portion is formed.
The thickness of the laminated film of u and Au is 2μ by the sputtering method.
It is formed into m and is etched and shaped into a predetermined shape. Finally, a 3 μm-thick Al ₂ O ₃ film serving as a protective layer is formed by using the lift-off method to simultaneously perform through hole processing of the terminal portion. This completes the MR head of the present invention.

As described above, according to the present invention, by forming the non-magnetic conductor layer using niobium oxide having a low diffusivity and a high resistance, it is possible to suppress the reduction of the reproduction output due to the shunting of the sense current. Of course, it is possible to suppress the deterioration of the magnetic characteristics of the MR element and the amorphous soft magnetic material layer due to the heat treatment process in the MR head manufacturing process, and as a result, it is possible to obtain the MR head having a high reproducing capability.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing a laminated structure of an MR composite layer.

FIG. 3 is a graph showing the relationship between the degree of vacuum and the specific resistance of niobium oxide in the niobium vacuum vapor deposition process.

FIG. 4 is a graph showing the results of component analysis by Auger electron spectroscopy.

FIG. 5 is a process drawing showing the first half of the method of manufacturing the MR head according to the present invention.

FIG. 6 is a process drawing showing the latter half of the above.

FIG. 7 is a sectional view showing the structure of a conventional MR head.

[Explanation of symbols]

 (1) Lower shield layer (2) MR composite layer (21) MR element layer (22) Niobium oxide layer (23) Amorphous soft magnetic layer (4) Upper shield layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Takeda 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Isao Yasuda 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Within the corporation

Claims (2)

[Claims] 1. A magnetoresistive effect type magnetic head, wherein a magnetoresistive effect element layer and a bias layer for applying a bias magnetic field to the magnetoresistive effect element layer are formed between a pair of shield layers. A magnetoresistive effect magnetic head characterized in that a niobium oxide layer is interposed between the layer and the bias layer. 2. A method of manufacturing a magnetoresistive effect magnetic head, wherein a magnetoresistive effect element layer and a bias layer for applying a bias magnetic field to the magnetoresistive effect element layer are formed between a pair of shield layers, A niobium oxide layer is formed between the magnetoresistive element layer and the bias layer, and the niobium oxide layer is formed by vacuum-depositing niobium in a low vacuum of 8 × 10 ⁻⁷ Torr or more. Type magnetic head manufacturing method.