JPH07121836A - Magneto-resistance effect head - Google Patents

Abstract

PURPOSE:To obtain an excellent MR head with high accuracy in track width and having uniform megnetization by forming a pair of electrode layers in such a manner that all of parts formed on the MR element layer out of sides of electrodes opposite each other are made straight lines and that the distance between the layers of paired electrode layers is made equal at each position in the direction of the height of the MR element. CONSTITUTION:A NiFe film is formed on a substrate 8 over an insulating layer and etched in a specified shape to form a lower shield layer 9. Then a NiFe film is formed over a SiO2 film to produce an MR element layer 6 in a specified shape, and a Mo bias layer 10 is formed in a similar way. Then a Cu film is superposed on the MR element 6 and the insulating layer to form a pair of electrode layers 7. The distance between the electrodes is equal to the track width T of the MR element layer 6, while the rear end part 7a of the layer 7 is located behind the rear end 6a of the layer 6. Then a NiFe film is formed on a thin SiO2 film and etched in a specified shape to obtain an upper shield layer 11. Finally, the medium-facing surface of the element is machined to complete the process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetoresistive head having an MR element (magnetoresistive element).

[0002]

2. Description of the Related Art A magnetoresistive head (hereinafter referred to as an MR head) has a high reproducing sensitivity and a reproducing output is a medium.
Since it does not depend on the relative speed between the magnetic heads, it is advantageous for downsizing and high density of the magnetic recording device. For this reason, a recording / reproducing separated type composite thin film magnetic head in which recording is performed by the induction type magnetic head and reproduction is performed by the MR head is indispensable for future high density magnetic recording devices.

A thin film magnetic head is one in which a magnetic core layer, a conductor coil layer, an electrode layer and the like are formed on a substrate by applying a thin film deposition method and a photolithography technique, and an insulating layer is provided around the magnetic core. Compared with a conventional bulk type magnetic head in which a winding is wound around, it is easy to reduce the size and increase the density.

In recent years, in particular, in order to achieve high density recording in a magnetic disk device, it is necessary to realize a high precision narrow track. For that purpose, formation of the track width of the MR head is very important. Further, the MR head has a narrower gap length because the sensitivity is increased by reducing the gap depth length.

FIG. 7 is a perspective view showing a schematic structure of a shield type shunt bias type MR head. This MR
The head is made of Mo, Nb,
A bias conductor layer 2 made of Ti or the like is formed, and a pair of electrode layers 3 and 3 are further formed on the bias conductor layer 2 at intervals corresponding to the track width T. A pair of shield layers 4 and 5 are formed on both sides of the MR element layer 1, the bias conductor layer 2, and the electrode layers 3 and 3. And such a conventional M
In the R head, as shown in FIG. 8, a rear end 1a on the rear side (the side opposite to the medium facing surface) that defines the height of the MR element layer 1 (the length in the direction orthogonal to the medium facing surface). Electrode layer 3,
The rear end portions 3a, 3a on the rear side of 3 are formed on the same line.

The electrode layers 3 and 3 are formed by etching by ion beam etching or the like using a resist pattern formed by photolithography as a mask. Generally, the corners of the resist pattern in the photolithography process are rounded due to film slippage during development, and therefore the shapes of the electrode layers 3 and 3 formed by etching are also 3b and 3b in FIG.
The corners are rounded as shown in. Therefore, there is a problem that the track width T of the MR element layer 1 varies depending on the position of the MR element layer 1 in the height direction, and the track width cannot be defined with high accuracy. Further, since the distance between the electrode layers 3 and 3 differs depending on the position of the MR element layer 1 in the height direction,
There is also a problem that the amount of current differs depending on the position of the MR element layer 1, and the direction of the magnetization (magnetic moment) in the MR element layer 1 cannot be controlled uniformly depending on the position of the MR element.

The roundness of the corners of the electrode layers 3 and 3 occurs on both sides of the corner on the medium facing surface side and the corner on the side opposite to the medium facing surface during etching formation, but on the medium facing surface side. The roundness that occurs in the corners of the is removed by the subsequent medium facing surface processing, and is not a problem.

In addition to the above-mentioned conventional MR head structure, the above-mentioned problem is caused by a structure in which a pair of electrode layers are formed on the MR element layer and a bias conductor layer is further formed thereon, and Co This also occurs in the structure of a soft bias type MR head in which an MR element layer is formed on a bias layer made of a system-based amorphous material, as well as the structures of exchange bias type and self-bias type MR heads.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the drawbacks of the above-mentioned conventional example, and by eliminating the fact that the track width of the MR element layer differs depending on the position in the height direction, the MR element layer is formed. It is an object of the present invention to provide an MR head in which the track width of the MR element can be defined with high accuracy, and the direction of magnetization in the MR element layer 1 can be uniformly controlled.

[0010]

The MR head of the present invention comprises:
In an MR head including an MR element layer and a pair of electrode layers for passing a current through the MR element layer between a pair of shield layers, a rear end portion of the pair of electrode layers is a rear end portion of the MR element layer. And a roundness formed at a rear-side corner inside the pair of electrode layers is completely rearward of a rear end of the MR element layer.

[0011]

According to the above structure, all of the sides of the pair of electrode layers facing each other formed on the MR element layer are straight portions, and the distance between the pair of electrode layers on the MR element layer. Are equal at any position in the height direction of the MR element layer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a plan view showing the positional relationship between the MR element layer and the electrode layer in the shield type shunt bias type MR head of this embodiment.

In the figure, reference numeral 6 is an MR element layer, and a pair of electrode layers 7, 7 are formed on the MR element layer 6 at intervals corresponding to a track width T. The front end of the MR element layer 6 on the front side (medium facing surface side) and the front end of the electrode layers 7, 7 on the front side are on the same line. Also, the MR
Rear end portion 6 on the rear side (opposite the medium facing side) of the element layer 6
a and rear end portions 7a, 7a on the rear side (opposite to the medium facing side) of the electrode layers 7, 7 are the rear end portions 7a of the electrode layers 7, 7,
7a is located rearward of the rear end portion 6a of the MR element layer 6 from the medium facing surface. That is, as shown in FIG. 2, the width b of the electrode layers 7, 7 is 1 μm or more larger than the width (length in the height direction) a of the MR element layer 6, and the rear side of the electrode layers 7, 7 is The corner roundings 7b and 7b are located completely rearward of the MR element layer 6.

Next, a method of manufacturing the MR head of this embodiment will be described with reference to FIGS. Note that FIGS. 3, 4A, 5A, and 6 are cross-sectional views, and FIGS. 4B and 5B are plan views.

First, as shown in FIG. 3, 0.5 to 5 made of NiFe or the like is formed on the substrate 8 with an insulating layer (not shown) interposed therebetween.
A soft magnetic film having a thickness of 2.0 μm is formed by sputtering or the like, and the lower shield layer 9 is formed by etching into a predetermined shape.

Next, as shown in FIGS. 4A and 4B, an insulating layer (not shown) made of SiO ₂ , Al ₂ O ₃ or the like is formed on the lower shield layer 9 by 0.1 to 0. After forming a film having a thickness of 5 μm, a magnetoresistive material such as NiFe is formed by sputtering or the like, and then etched into a predetermined shape to form an MR.
The element layer 6 is formed. At this time, the bias layer 10 made of Mo, Nb, Ti or the like is similarly formed on the MR element layer 6.

Next, as shown in FIGS. 5A and 5B, a conductive film of Cu or the like is formed on the MR element layer 6 and the insulating layer on which the bias layer 10 is formed, and etching is performed. Thus, a pair of electrode layers 7 and 7 are formed. As described above, the distance between the pair of electrode layers 7, 7 is equal to the track width T of the MR element layer 6, and the rear end portion 7a is located rearward of the rear end portion 6a of the MR element layer 6.

Next, as shown in FIGS. 6A and 6B, SiO ₂ and Al ₂ are formed on the MR element layer 6, the electrode layer 7 and the insulating layer.
An insulating layer (not shown) made of O ₃ or the like is added in an amount of 0.1 to 0.5 μm.
After being formed to a thickness of 0.5 m, a soft magnetic film such as NiFe is formed for 0.5 to 2.
The upper shield layer 11 is formed by forming a film by sputtering with a thickness of 0 μm and etching the film into a predetermined shape.

The MR head of this embodiment is completed by subjecting the surface of the laminated body formed by the above steps to the medium facing surface to machining such as cutting. By this machining, a part of the MR element layer 6 and the electrode layers 7, 7 on the medium facing surface side is also removed, and the roundness formed at the front corners of the electrode layers 7, 7 is scraped off.

In the MR head of this embodiment as described above,
In the process of FIG. 5, when etching is performed, the electrode layer 7,
Rounded portions 7b, 7b are formed at the rear corners of the MR element 7. However, the rear end portions 7a, 7a of the electrode layers 7, 7 are located at the rear side by 1 μm or more than the rear end portion 6a of the MR element layer 6. Therefore, the rounded portions 7b and 7b are formed on the rear end portion 6b of the MR element layer 6.
It is located completely rearward of the MR element layer 6 and is not located on the MR element layer 6 at all. Therefore, of the portions inside the pair of electrode layers 7, 7 (sides facing each other), the portions located above the MR element layer 6 are all linear portions 7c, 7c, and the pair of electrode layers 7 are formed. , 7, the track width T
Has the same length at any position in the height direction of the MR element layer 6. Therefore, in the MR head of this embodiment, the track is defined with high accuracy. Further, since the distance between the pair of electrode layers 7 on the MR element layer 6 is equal at any position in the height direction, the amount of current flowing in the MR element layer 6 is substantially equal at all positions. , MR
The magnetization direction in the element layer 6 becomes uniform.

The present invention is not limited to the shield type shunt bias type MR head as in the above embodiment, but is also a soft bias type MR head and an exchange bias type M head.
Similar effects can be obtained also in the R head and the self-bias type MR head.

[0023]

According to the present invention, the track width of the MR element layer can be regulated with high accuracy, and moreover, the direction of magnetization in the MR element can be uniformly controlled, and the reproducing characteristic is excellent. An MR head can be provided.

[Brief description of drawings]

FIG. 1 is a plan view showing a positional relationship between an MR element layer and an electrode layer in an MR head of the present invention.

FIG. 2 is a diagram showing a dimensional relationship between an MR element layer and an electrode layer of the MR head of the present invention.

FIG. 3 is a diagram showing a method for manufacturing the MR head of the present invention.

FIG. 4 is a diagram showing a method for manufacturing the MR head of the present invention.

FIG. 5 is a diagram showing a method for manufacturing the MR head of the present invention.

FIG. 6 is a diagram showing a method for manufacturing the MR head of the present invention.

FIG. 7 is a perspective view showing a schematic configuration of an MR head.

FIG. 8 is a plan view showing a positional relationship between an MR element layer and an electrode layer in a conventional MR head.

FIG. 9 is a diagram showing a defect of a conventional MR head.

[Explanation of sign]

 6 MR element layer 6a Rear end 7 Electrode layer 7a Rear end 7b Roundness 9 Lower shield layer 11 Upper shield layer

Claims (1)

[Claims] 1. A magnetoresistive head including a magnetoresistive effect element layer and a pair of electrode layers for passing a current through the magnetoresistive effect element layer between a pair of shield layers. A rear end portion of the magnetoresistive effect element layer is located rearward of the rear end portion of the magnetoresistive effect element layer, and a roundness formed at a rear side corner inside the pair of electrode layers has a rear end portion of the magnetoresistive effect element layer. The magnetoresistive head is characterized in that it is located completely on the rear side.