JPH09282617A - Production of magnetoresistance effect head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetoresistance effect head coping with narrow track width by forming an electrode layer of the magnetoreslstance effect layer in a lift-off process which uses a photoresist pattern having a bridge-like shape in the track part. SOLUTION: A magnetoresistance effect layer (MR element) 5 is formed on the film of a magnetoresistance effect head where a lower magnetic layer 3 and an insulating layer 4 are formed. The photoresist 2 is formed like a stencil so that the resist 2 on the element 5 has a bridge-like cross section having no axis. The resist 2 on the element 5 is shown as if it is suspended in air, however, the this part is held by the surrounding resist 2. Thereby, the production process of the magnetoresistance effect head can be simplified. By forming a resist pattern having a bridge-like cross section in the track part, the obtd. structure a magnetoresistance effect head copes with narrow track width.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetoresistive head by forming a thin film.

[0002]

2. Description of the Related Art In recent years, as magnetic disk drives have become smaller and larger in capacity, higher performance and higher density recording of thin film magnetic heads have been required. On the other hand, detecting magnetically written information using the magnetoresistance effect has been known for many years.

In a conventional thin-film magnetic head, writing and reading of information are performed by a single head element. However, the optimum conditions for writing and reading are not always the same, and such conditions are not necessarily the same. In such a case, for example, there is a problem that the read performance decreases when the write performance is improved. However, a composite magnetic head in which an inductive type magnetic head is a write-only head and a magnetic head utilizing the magnetoresistance effect is a read-only head (hereinafter, referred to as a magnetoresistance effect head) is a write head and a read head. It is possible to design each head optimally.

Here, in order to achieve high-density recording in a magnetoresistive effect head, an active area (hereinafter, referred to as a track width) for sensing a magnetoresistance change is reduced, and an insulating layer sandwiching the magnetoresistance change layer is formed. It is required to be thinner.

In the case where the insulating layer is thinned, the quality of the insulating layer and the shape of the portion covered with the insulating layer are important points in manufacturing.
For example, when there is a step having a height of 0.15 μm, it is difficult to cover this step with an insulating layer having a thickness of 0.1 μm.
Therefore, as one method of eliminating the step, the workability of the insulating coating can be improved by giving a slope (taper) to the step.

Conventionally, when a pattern is formed in a magnetoresistive head, a processing method such as an ion milling method or a sputter etching method is used. For example, in the case of using an ion milling method, a step portion is provided with a gentle slope. It is difficult to do. Further, when the ion milling process is performed, it is not easy to determine the end time of the processing, and there is a disadvantage that a layer other than the layer to be removed is also removed.

[0007]

When a pattern of the above-described magnetoresistive head is formed, a method of forming the pattern without using a technique such as an ion milling method is as follows.
The lift-off method is generally known. As a method of forming the lift-off pattern, a method using two or three layers of photoresist (hereinafter, referred to as a multilayer resist) is used.
Is generally known. However, the formation of a lift-off pattern using a multilayer resist has a drawback that the number of processing steps increases because there is a step of applying a photoresist repeatedly.

The track width of the magnetic head, which is further narrowed by high-density recording, is smaller than that of a conventional photoresist lift-off pattern that leaves an axial portion in the track portion.
It is expected that work will be more difficult.

[0009]

In order to solve the above-mentioned problems, a method of manufacturing a magnetoresistive head according to the present invention comprises:
An electrode layer provided on the magnetoresistive layer is formed by a lift-off process using a photoresist pattern in which a track portion has a bridge shape. Further, the photoresist pattern is made of a single layer photoresist. This makes it possible to reduce man-hours and to cope with a narrow track width.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, as one embodiment of the present invention, a method of forming electrodes and bias layers in a magnetoresistive head using the present invention will be described.

FIG. 1 is a cross-sectional view of a single-layer resist in manufacturing a magnetoresistive head according to an embodiment of the present invention.

Referring to FIG. 1, in the present invention, a photoresist 2 is formed on a substrate 1 by using an image inversion type single-layer resist and setting an appropriate exposure amount, overall exposure amount and development time. A stencil shape is obtained. In this case, the amount of overhang and the height of the shaft portion (columnar photoresist remaining at the center) are defined by the exposure amount and the development time.

FIG. 2 is a plan view showing an example of a typical pattern shape of electrodes and bias layers of a magnetoresistive head to which the present invention is applied. FIG. 3 is a cross-sectional view of FIG.
FIG. 4 is a sectional view taken along the line A ', and FIG. 4 is a sectional view taken along the line BB' of FIG.

Referring to FIGS. 2 to 4, a magnetoresistive layer (hereinafter referred to as an MR element) 5 is formed on a film in which a lower magnetic film 3 and an insulating film 4 are laminated on a magnetoresistive head. Since the photoresist 2 has the stencil shape shown in FIG. 1, the photoresist 2 on the MR element 5 has a bridge-type cross-section without the shaft portion. In the sectional view shown in FIG.
Although the upper photoresist 2 is drawn as if it were floating in the air, it is actually supported by the peripheral photoresist 2 as can be seen from FIGS.

Here, when the track width becomes narrower as a magnetoresistive head compatible with a high track density, it is difficult to obtain a sufficient overhang amount with a stencil structure having a shaft portion. For example, it is theoretically difficult to obtain an overhang amount of 1 μm for a track width of 2 μm. Therefore, FIG.
The above-mentioned problem can be solved by using a resist pattern having a bridge-type (bridge-type) cross-sectional shape without a shaft portion in a track portion as shown in FIG.

FIG. 5 is a sectional view showing a state after a sputtered film such as an electrode layer is formed on the resist pattern shown in FIG. 2 and viewed from the track width direction. In FIG. 5, after the sputtering film (electrode layer) 6 is formed for a predetermined time, the photoresist 2 is subjected to a lift-off process.
An inclined surface is formed by the sputtered film (electrode layer) 6 at the stepped portion. This facilitates the subsequent formation of an insulating film (not shown).

FIG. 6 is an enlarged view showing an example of a film formation state of the sputtered film after the lift-off step.
As shown in FIG. 6, when the film thickness is 200 nm, for example, the taper angle becomes 10 ° or less, and the step is eliminated.

[0018]

As described above, the method of manufacturing a magnetoresistive head according to the present invention can simplify the manufacturing process of the magnetoresistive head by using a lift-off pattern of a single-layer photoresist. . Further, by using a resist pattern having a bridge-type (bridge-type) cross-sectional structure in the track portion, it is possible to cope with a magnetoresistive head having a narrow track width.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a single-layer resist in manufacturing a magnetoresistive head according to an embodiment of the present invention.

FIG. 2 is a plan view showing an example of a typical pattern shape of an electrode and a bias layer of a magnetoresistive head to which the present invention is applied.

FIG. 3 is a sectional view taken along line AA ′ of FIG. 2;

FIG. 4 is a sectional view taken along line BB ′ of FIG. 2;

FIG. 5 is a cross-sectional view showing a state after a sputter film is formed in FIG.

FIG. 6 is an enlarged view showing an example of a film formation state of a sputtered film after lift-off.

[Explanation of symbols]

 1 substrate 2 photoresist 3 lower magnetic film 4 insulating film 5 MR element (magnetoresistive layer) 6 sputter film (electrode layer)

Claims (2)

[Claims] 1. A method for manufacturing a magnetoresistive head, wherein an electrode layer provided on a magnetoresistive layer is formed by a lift-off process using a photoresist pattern whose track portion has a bridge shape. 2. The method according to claim 1, wherein the photoresist pattern comprises a single layer of photoresist.