JP2833583B2 - Patterning method for magnetoresistive element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of patterning a magnetoresistive element, and more particularly to a method of forming a plurality of magnetoresistive elements on a wafer (substrate) when manufacturing a magnetoresistive head. The present invention relates to a method for patterning an effect element.

[0002]

2. Description of the Related Art With the miniaturization and large capacity of magnetic recording devices,
The density of magnetic recording technology is rapidly increasing. A reproducing head (hereinafter, referred to as an "MR head") utilizing a magnetoresistive effect (hereinafter, referred to as an "MR effect") can obtain a large reproducing output. The composite type head using the MR head as a reproducing unit is one of the main technologies for promoting higher density of magnetic recording.

In particular, a shield type MR head having a structure in which an MR element is arranged between two opposing magnetic shield films is effective as a magnetic head for a magnetic disk drive. FIG.
(Original Fig. 1) shows this shield type MR head and recording I
The structure example in the conventional example of the layer of the composite type head combined with the D head is shown.

In FIG. 10, a lower shield film 52 and a lower gap film 53 are sequentially laminated on a substrate 51 serving as a slider. On top of this, an MR comprising a magneto-sensitive portion 54A having a rectangular MR effect, and end regions 54B and 54C provided on both side ends of the magneto-sensitive portion 54A and having a function of dividing the magneto-sensitive portion 54A into a single magnetic domain. An element 54 is formed.

Further, an upper gap film 56, an upper shield film 57, a recording gap film 58, and an upper pole film 59 are sequentially formed thereon. A coil for recording current insulated by a photoresist is provided between the upper shield film 57 and the upper pole film 59.

The films forming these layers are patterned into a desired shape by a photolithographic method. In particular, the pattern of the MR element 54 has a film thickness of several tens [n].
m], the pattern width is as small as about 1 μm, and furthermore, 10 ⁷ [A / c
m ² ], it is necessary to suppress the occurrence of burrs due to the patterning of the MR element 54 so that the upper and lower gaps have a sufficient insulating function. Technology is required.

[0007]

In patterning the MR element 54, from the viewpoint of suppressing the occurrence of burrs, a photoresist pattern for determining its pattern shape is used.
It is desirable that the thickness of the component be as thin as possible.

However, it is difficult to apply a thin photoresist to the entire surface of the substrate 51 with a uniform thickness. It has been almost impossible to apply the resist thinly and uniformly.

FIGS. 6 to 8 show a conventional method.
An example of the step of forming a lower shield pattern (the entire lower shield film 52 disposed on the matrix) and then applying a photoresist for patterning the MR element 54 will be described. 6 to 8, the MR element 54 is formed after the step of applying a photoresist.

When the photoresist is applied to the entire surface of the substrate 51, the application is performed by rotating the substrate 51 at a high speed around the center of the substrate 51 as a rotation axis. In the figure, the arrow 61 indicates the direction in which the photoresist enters the lower shield pattern at each position. In particular, the lower shield pattern - in Fig. 6 the relationship between the traveling direction and the element shape of the photoresist in the emission element 52 _1n and 52 _n1, respectively a specific example 7 and 8. As is apparent from this conventional example, each of the lower shield pattern elements 52 ₁₁ to 52
52 _nn is asymmetric in the left-right and up-down directions as shown in FIGS. 7 and 8.

From this, the situation when the photoresist enters each of the lower shield pattern elements 52 _{11 to} 52 _nn greatly differs depending on the position on the substrate 51. As a result, the lower shield pattern - the thickness of the coating film of the photoresist down element 52 ₁₁ to 52 _nn portion varies greatly depending on the position on the substrate 51. This becomes more pronounced as the photoresist thickness decreases.

FIG. 9 shows each lower shield pattern element 5 when a photoresist having a thickness of 0.15 [μm] is applied.
The state in which the photoresist thickness on 2 _{11 to} 52 _nn changes depending on the position from the center of the substrate 51 is shown.

As is clear from the measurement results shown in FIG. 9, even if the substrate 51 has a thickness of about 0.15 μm near the center on the substrate 51, the thickness changes greatly as the distance from the center increases. The inconvenience has occurred.

[0014]

SUMMARY OF THE INVENTION The object of the present invention is to improve the disadvantages of the prior art and to make the coating thickness uniform when coating a relatively thin photoresist on a lower shield pattern via a lower gap film. Accordingly, it is an object of the present invention to provide a method of patterning a magnetoresistive element capable of further improving the uniformity of the quality of a plurality of magnetoresistive heads formed at one time by the same manufacturing process. .

[0015]

The photoresist enters the lower shield pattern when the photoresist is applied by rotating the substrate at a high speed because the thickness of the photoresist coating film in the substrate fluctuates. The inventors have found that there is a difference in the conditions for performing the same, and at the same time, a uniform photoresist coating thickness can be obtained by making the conditions for the photoresist to enter the lower shield pattern uniform within the wafer. Therefore, in the present invention, the following method has been found as a means for solving the above-mentioned problem.

That is, according to the present invention, a lower shield film and a lower gap film are sequentially laminated on a substrate serving as a slider, and a magnetoresistive effect element (MR element) having a rectangular magnetic sensing portion is provided thereon. An upper gap film, an upper shield film, a recording gap film, and an upper pole film are sequentially formed thereon, and a recording current coil portion insulated by a photoresist is interposed between the upper shield film and the upper pole film. In a laminated magnetoresistive head, after forming a lower shield pattern composed of a plurality of lower shield pattern elements as a lower shield film described above on a substrate, a lower gap film is interposed on the lower shield pattern element. A step of applying a photoresist for patterning the provided magnetoresistive element (MR element). When the respective magnetoresistive elements are patterned, each lower shield pattern element is set in advance to a circular shape or a similar shape.

In this case, each of the above-mentioned magnetoresistive effect elements (MR elements) is formed uniformly at the center of each lower shield pattern element formed in a circular or similar shape. Become

After that, the magnetoresistive effect element (MR element) is uniformly arranged so as to be located at the center of each of the plurality of shield pattern elements and patterned. Also,
When the above-described magnetoresistive elements (MR elements) are patterned, the lower shield pattern element is set in advance to a circular shape or a shape similar thereto.

In this case, each of the lower shield patterns formed in a circular shape or a shape similar thereto has a magnetoresistive effect element.
It is convenient to maintain uniform quality in mass production if it is arranged uniformly in the center of the element.

Further, it is practically preferable to set the average thickness of the photoresist applied at the time of patterning each of the above-described magnetoresistance effect elements to 200 [nm].

For this reason, in the present invention, since each lower shield pattern element is set to a circular shape or a shape similar thereto, the lower shield pattern element is formed on the pattern of each lower shield pattern element via a lower gap film. When applying a photoresist for patterning the MR element by rotating the substrate at a high speed around the center of the substrate as a rotation axis, the condition for the photoresist to enter the pattern of the lower shield is determined by an arbitrary condition of the substrate. It can be almost identical in position.

For this reason, for example, when a photoresist having a thickness of 0.15 [μm] is applied, the thickness of the photoresist on the lower shield pattern element is approximately 0. It could be confirmed that the film was uniformly applied with a thickness of 15 [μm].

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. First, in FIG.
Reference numeral 11 denotes a substrate serving as a slider. This substrate 11
Is in the present embodiment, Al ₂ O ₃ -Ti C substrate is used. A lower shield film 12 and a lower gap film 13 are sequentially laminated on the substrate 11 serving as the slider as in the case of the above-described conventional example, and a rectangular magnetic sensing portion 14A is formed thereon.
Is formed (same as 14 _{11 to} 14 _nn in FIG. 1), and further thereon,
An upper gap film 16, an upper shield film 17, a recording gap film 18, and an upper pole film 19 are sequentially formed. A recording current coil (not shown) insulated by a photoresist is laminated between the upper shield film 17 and the upper pole film 18.

Here, the magnetoresistive effect element (MR element) 1
4 (same as 14 _{11 to} 14 _nn in FIG. 1) will be described in detail.

First, a shield pattern composed of a plurality of lower shield pattern elements 12 _{11 to} 12 _nn (see FIG. 1) as the lower shield film 12 is formed on the substrate 11 and then the shield pattern elements 12 _{11 to} 12 _nn. Thin film 10 on top
0 to form an alumina film [nm] as the lower gap film 13, on which is coated with a photoresist, then uniformly magnetically corresponding to the central portion of each of the plurality of shield pattern elements 12 ₁₁ to 12 _nn Resistance effect element (MR element) 14 ₁₁ -1
The MR element is patterned so that 4 _nn is located.

The above-mentioned lower shield pattern elements 12 _{11 to} 12 _nn are formed in a circular shape having a thickness of 2 [μm] and made of a FeSiAl alloy.

[0027] Each magneto-resistive element (MR element) 14 ₁₁ -
When the 14 _nn pattern is formed, as described above, the lower shield pattern elements 12 _{11 to} 12 _nn are set in advance to a circular shape or a shape similar thereto. In this case, each MR element 1
4 _{11 to} 14 _nn are determined such that the intersection of the diagonal lines of the rectangular magnetic sensing part and the center point of each lower shield pattern element 12 _{11 to} 12 _nn match.

On the other hand, the average thickness of the photoresist on each of the lower shield pattern elements 12 _{11 to} 12 _nn formed in a circular or similar shape is set to 200 nm or less. When forming the MR elements 14 _{11 to} 14 _nn, a 100 nm thin alumina film is formed as a lower gap film 13 on this pattern, and then the magnetosensitive portion 1 is formed.
A soft magnetic film, a magnetic spacer film, and an MR film for forming 4A are formed.

As a soft magnetic film, a 30 nm thick Co
The ZrMo film has a thickness of 10 [n] as a magnetic spacer film.
m] of the Ta film and an MR film of 20 nm thick N
An iFe film was used.

Then, after patterning for defining the width of the magneto-sensitive portion is performed, the end regions 14B, 14B are lifted off using the photoresist mask used for the patterning.
A Co Pt Cr film for forming C was formed with a thickness of 30 [nm].

The above-described magnetic sensing portion 14A and end regions 14B, 1
In order to finally define the shape of the MR element 14 composed of 4C, by high-speed rotation around the center of the substrate,
A photoresist equivalent to 0.15 [μm] was applied. FIG. 4 shows measurement results of the film thickness distribution of the photoresist applied to the upper region corresponding to the lower shield pattern elements 12 _{11 to} 12 _nn at this time. As a result, it was confirmed that the photoresist was applied almost uniformly.

Thereafter, as described above, the MR element 14
(14 ₁₁ -14 _nn ), a current-carrying electrode was formed, an alumina film having a thickness of 100 [nm] was formed as the upper gap film 16, and a NiFe film having a thickness of 3 [μm] was further shielded with an upper shield. It was formed as a film 17. On top of this, the recording gap film 18
After forming an alumina film having a thickness of 300 [nm] and forming a Cu coil insulated by photoresist, a 4 [μm] thick NiFe film as the upper pole film 19 is formed.
A pattern was formed.

Finally, the substrate 11 was made into a slider to form an MR / ID composite head.

Next, under the same conditions, the MR / I
I made a D composite head and compared it with this. In this case, in the MR / ID composite head shown in the conventional example (FIG. 10), many short-circuits with the upper shield 56 of the MR element 54 and variations in output characteristics were observed. This is because the MR element 54 was not formed uniformly due to a large variation in the photoresist thickness when the MR element was patterned.

On the other hand, the MR /
In the ID composite head (shown in FIG. 5), the short circuit and the variation in the above-described conventional example were greatly reduced, and therefore, a significant improvement in the yield could be confirmed.

[0036]

As described above, according to the present invention, it is possible to achieve a uniform coating thickness when a relatively thin photoresist is coated on a lower shield pattern via a lower gap film. For this reason, it is possible to greatly reduce the variation in the MR element in the substrate. Therefore, when this is used, the uniformity of the quality of the magnetoresistive head can be further improved, and the manufacturing yield can be reduced. It is possible to provide an unprecedented and excellent method of patterning a magnetoresistive element which can achieve a great improvement.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.
FIG. 4 is an explanatory diagram showing a photoresist coating process for setting an MR element on each lower shield pattern element on a substrate via a lower gap film.

FIG. 2 is a detailed explanatory view showing a part of a photoresist coating process for patterning an MR element through a lower gap film on a lower shield pattern element in FIG. 1;

FIG. 3 is a detailed explanatory view showing a part of a photoresist coating process for patterning an MR element on a lower shield pattern element via a lower gap film in FIG. 1;

FIG. 4 is a diagram showing an example of measuring the thickness of a photoresist applied by the method disclosed in FIG. 1;

FIG. 5 is an explanatory diagram showing an example of a head formed by the method disclosed in FIG. 1;

FIG. 6 is a diagram showing one embodiment of a conventional example.
FIG. 4 is an explanatory diagram showing a photoresist coating process for setting an MR element on each lower shield pattern element on a substrate via a lower gap film.

FIG. 7 is a detailed explanatory view showing a part of a photoresist coating process for patterning the MR element through the lower gap film on the lower shield pattern element in FIG. 6 (conventional example).

FIG. 8 is a detailed explanatory view showing a part of a photoresist coating process for patterning the MR element on the lower shield pattern element via a lower gap film in FIG. 6 (conventional example).

FIG. 9 is a diagram showing an example of measuring the thickness of a photoresist applied by the method disclosed in FIG. 6 (conventional example).

FIG. 10 is an explanatory diagram showing an example of a composite magnetic head formed by the method disclosed in FIG. 6 (conventional example).

[Explanation of symbols]

11 substrate 12 lower shield film 12 ₁₁ to 12 _nn under shielding pattern - emission element 13 lower gap film 14, 14 ₁₁ to 14 _nn magnetoresistive element (MR element) 16 upper gap film 17 upper shield film 18 recording gap film 19 above Pole membrane

Claims (3)

(57) [Claims] 1. A lower shield film and a lower gap film are sequentially laminated on a substrate serving as a slider, and a magnetoresistive effect element having a rectangular magneto-sensitive portion is provided thereon, and an upper gap film is further provided thereon. , An upper shield film, a write gap film, and an upper pole film are sequentially formed, and a recording current coil portion insulated by a photoresist is laminated between the upper shield film and the upper pole film. In the head, after forming a lower shield pattern including a plurality of lower shield pattern elements as the lower shield film on the substrate, the magnetoresistance effect element formed on the lower shield pattern element via a lower gap film Applying a photoresist for patterning the lower shield pattern element before patterning each of the magnetoresistive elements. Patterning method of the magnetoresistive element, characterized in that the set into a circular or a shape equivalent thereto. 2. The lower shield pattern, wherein the magnetoresistive effect element is formed in a circular or similar shape.
2. The method according to claim 1, wherein the pattern is formed uniformly at the center of the element. 3. An average thickness of a photoresist applied when patterning each of said magnetoresistive elements is 200.
2. The patterning method for a magnetoresistive element according to claim 1, wherein the value is set to [nm] or less.