JPH087224A - Thin film forming method and thin film magnetic head manufacturing method - Google Patents

Abstract

(57) [Summary] [Purpose] Even if a laminated thin film is formed on irregularities, there is no unnecessary portion left when patterning, and good adhesion with the film on which the laminated thin film is formed. To get [Structure] A lower adhesion layer 2, a conductor layer 3, and an upper adhesion layer 4 are sequentially deposited on a substrate 1. The upper adhesion layer 4 is formed to have the same quality as that of the lower adhesion layer 2 and a thickness larger than that of the lower adhesion layer 2. Using the photoresist 12 having a predetermined shape formed on the upper adhesion layer 4 as a mask, the upper adhesion layer 4 and a part of the conductor layer 3 are ion-milled. After removing the photoresist 12, the conductor layer 3 and the lower adhesion layer 2 are chemically etched using the upper adhesion layer 4 as a mask. Conductor layer 3
The etching liquid of No. 1 does not affect the adhesion layers 2 and 4, and the etching liquid of the lower adhesion layer 2 does not affect the conductor layer 3. Although the upper adhesion layer 4 is etched together with the lower adhesion layer 2, the upper adhesion layer 4 remains after the etching of the lower adhesion layer 2 is completed because the upper adhesion layer 4 is thicker than the lower adhesion layer 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film forming method for patterning a laminated thin film into a desired shape and a method for manufacturing a thin film magnetic head used in a magnetic recording apparatus.

[0002]

2. Description of the Related Art In recent years, thin film magnetic heads have attracted attention in response to higher recording densities of magnetic recording / reproducing devices, higher data transfer speeds, higher number of channels, and the like. In particular, a magnetoresistive thin-film magnetic head whose reproduction output does not depend on the head traveling speed has attracted attention. FIG. 2 is a sectional view of a magnetoresistive effect thin film magnetic head manufactured according to an embodiment of the present invention. Since it has basically the same structure as the conventional one, its operation will be briefly described with reference to FIG. I'll do it. In FIG. 2, 1 is a substrate, 5 is a first insulating layer, 6 is a magnetoresistive element (hereinafter referred to as “MR element”), 8 is a second insulating layer, 9 is a yoke, and 10 is a third insulating layer. , 11 is a bias layer, 13 is a fourth insulating layer, 14 is an upper magnetic layer, 15 is a wear resistant film formed on the tape sliding surface, 16 is a magnetic gap layer,
18 is a protective layer.

A magnetic flux emitted from a medium such as a magnetic tape reaches the MR element 6 through the yoke 9. Further, the magnetic flux passes through the magnetic circuit that passes through the yoke 9 on the rear side, passes through the upper magnetic layer 14, and returns to the head surface. A bias magnetic field is applied to the MR element 6 that senses a signal so that the magnetization direction of the MR element 6 is oriented in an appropriate direction and efficient reproduction is possible. The bias layer 11 is for passing a current therethrough to generate the bias magnetic field.

A conventional method of manufacturing a thin film magnetic head will be described below. FIG. 6 is a process cross-sectional view showing a conventional method of manufacturing a thin film magnetic head (mainly a method of forming the bias layer 11), and FIG. 5 is a plan view after the formation of the bias layer 11. FIG. 7 is a sectional view taken along line CC ′ of FIG. 6 shows a cross section at a position corresponding to BB 'in FIG.

On the substrate 1, the first insulating layer 5, the MR element 6,
After the lead layer 7 (see FIG. 5), the second insulating layer 8, the yoke 9, and the third insulating layer 10 are sequentially formed, the bias layer 11 formed of a three-layer laminated thin film is formed (FIG. 6A). Next,
A photoresist 12 having a predetermined shape is formed on the bias layer 11.
And the bias layer 11 is processed into a predetermined shape by ion milling using the photoresist 12 as a mask.
A bias layer 11 is provided for applying an appropriate bias magnetic field to the R element 6 (FIGS. 6B and 6C).

After that, after forming the fourth insulating layer 13, the magnetic gap layer 16, the upper magnetic layer 14 and the protective layer 18, the protective layer 18 is lapped so as to be flat (FIG. 6).
(D)), a protective substrate (not shown) is adhered, the tape sliding surface is processed into a predetermined shape, and further made into chips, and then CrN is used as a wear resistant film 15 (see FIG. 2) on the tape sliding surface. Is sputtered, and finally connected to an external circuit from the lead terminal extraction portion by a method such as wire bonding.

In the three-layer laminated thin film forming the bias layer 11, a vapor deposition film of Au having a small specific resistance and a vapor deposition film of Au are the third insulating layer 10 in order to operate efficiently at a low current.
Also, since the adhesion with the fourth insulating layer 13 is poor, it is composed of adhesion layers such as Ta and Cr formed on and under the vapor deposition film of Au.

[0008]

In the above conventional manufacturing method, the bias layer 11 is formed into a predetermined shape by ion milling, but the step portion (on the slope) of the yoke 9 is not uniformly milled. Au, Ta, etc. remain and become the bias remaining portion 17 (FIGS. 5 and 7), which is exposed on the sliding surface after the tape sliding surface processing. After chipping, a wear-resistant film 15 for protecting the sliding surface is formed as shown in the sectional view of the head of FIG. 2, but the bias remaining portion 17 remaining in the stepped portion of the yoke 9 is used. Abrasion resistant film 15 and bias layer 1
There was a problem that 1 was short-circuited. As a countermeasure against this, chemical etching in which the film deposited on the step portion is uniformly etched like the flat portion is conceivable. However, the adhesion layers formed as the upper and lower layers forming the bias layer 11 are simultaneously etched, and particularly the bias layer is formed. There was a problem that the adhesiveness with the fourth insulating layer 13 on 11 was poor and peeling occurred.

A first object of the present invention is that even if a laminated thin film is formed on an uneven surface, an unnecessary portion does not remain during patterning, and the laminated thin film is in close contact with a film or the like formed above and below it. It is an object of the present invention to provide a thin film forming method capable of maintaining good properties. A second object of the invention is a thin film in which an unnecessary portion of the bias layer does not remain in the step portion of the yoke and the bias layer can maintain good adhesion to the insulating film formed above and below the bias layer. A method of manufacturing a magnetic head is provided.

[0010]

A thin film forming method according to claim 1 is a thin film forming method for patterning a laminated thin film composed of first, second and third thin films into a desired shape.
A step of sequentially laminating a second thin film made of a material different from that of the first thin film, and a third thin film made of the same material as the first thin film and having a film thickness thicker than that of the first thin film on the first thin film. A step of forming a resist pattern on the third thin film and ion milling at least the third thin film using the resist pattern as a mask; a step of removing the resist pattern; and a step of chemically etching the second thin film. And a step of chemically etching the first thin film.

The thin film forming method according to claim 2 is the method according to claim 1.
In the thin film forming method described above, the second thin film is chemically etched using an etching solution that does not affect the first and third thin films, and the first thin film is formed using an etching solution that does not affect the second thin film. It is characterized in that the thin film is chemically etched. A method of manufacturing a thin film magnetic head according to claim 3, wherein a magnetoresistive effect element, a yoke for introducing a signal magnetic flux from a medium into the magnetoresistive effect element, and a laminated film of first, second and third conductor films are used. A method of manufacturing a thin film magnetic head comprising a bias layer for applying an appropriate bias magnetic field to a magnetoresistive effect element and an upper magnetic layer, the method comprising: A step of sequentially laminating a second conductor film made of a material different from that of the conductor film, and a third conductor film made of the same material as the first conductor film and having a film thickness larger than that of the first conductor film; A step of forming a resist pattern on the conductor film and ion milling at least the third conductor film using the resist pattern as a mask; a step of removing the resist pattern; and a step of chemically etching the second conductor film, The first conductor film Characterized in that it comprises a step of Mika Le etching.

A method of manufacturing a thin-film magnetic head according to a fourth aspect is the method of manufacturing a thin-film magnetic head according to the third aspect, wherein a second etching method is used which does not affect the first and third conductor films. Chemically etch the conductor film,
It is characterized in that the first conductor film is chemically etched by using an etching solution that does not affect the second conductor film.

[0013]

According to the thin film forming method of the present invention, the first and second
In order to pattern the laminated thin film composed of the third thin film into a desired shape, at least the third thin film is ion-milled using the resist pattern as a mask, and then the second thin film is chemically etched. Since the second thin film and the third thin film are made of different materials, the second thin film is etched using an etchant that does not affect the third thin film, and the first thin film is chemically etched. At this time, since the first thin film and the second thin film are made of different materials, by etching the first thin film with an etching solution that does not affect the second thin film, there is no progress of side etching or the like, which is favorable. The pattern is obtained.
Note that when the first thin film is chemically etched, the third thin film made of the same material is also etched. However, since the third thin film is formed to be thicker than the first thin film,
The third thin film remains at the end of the etching of the third thin film. Therefore, if the first, second, and third thin films forming the laminated thin film are, for example, conductor films and insulating films are formed on and under the conductive films, the first and third thin films have good adhesion to the insulating film. By using a good thin film, good adhesion can be maintained between the laminated thin film and the insulating films above and below it. In addition, since chemical etching is used for etching the first and second thin films, even when this laminated thin film is formed on an uneven surface, it is uniformly etched in the same manner as the flat portion, so that a step portion of the unevenness is formed. Unwanted parts do not remain without being etched.

According to the method of manufacturing a thin film magnetic head of the present invention, in order to pattern the bias layer formed of the first, second and third conductor films into a desired shape, at least the resist pattern is used as a mask. After ion-milling the third conductor film, the second conductor film is chemically etched. At this time, since the second conductor film and the third conductor film are made of different materials, the third conductor film is affected. Etching the second conductor film using a non-etching solution,
The first conductor film is chemically etched, but since the first conductor film and the second conductor film are made of different materials at this time, the first conductor film is removed by using an etching solution that does not affect the second conductor film. By etching, the side etching amount is small, and a highly accurate and good pattern can be obtained. Note that when the first conductor film is chemically etched, the third conductor film made of the same material is also etched, but the third conductor film is thicker than the first conductor film. , First
The third conductor film remains at the end of the etching of the conductor film. Therefore, by using a conductor film having good adhesiveness with the insulating film for the first and third conductor films, the adhesiveness between the bias layer and the insulating films formed above and below the bias layer can be kept good. Further, since the chemical etching is used for the etching of the first and second conductor films, an unnecessary portion of the bias layer does not remain in the step portion of the yoke and, for example, a wear resistant film formed on the tape sliding surface is formed. It is possible to prevent short circuit with the bias layer.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1A to 1C are process sectional views showing a thin film forming method according to the present invention. A lower adhesion layer (first thin film) 2, a conductor layer (second thin film) 3, and an upper adhesion layer (third thin film) 4 are sequentially deposited on the substrate 1 (FIG. 1A). Here, the upper adhesion layer 4 is formed to be of the same quality as the lower adhesion layer 2 and thicker than the lower adhesion layer 2.

Next, a photoresist 12 having a predetermined shape is formed on the upper adhesion layer 4 (FIG. 1 (b)), and the photoresist 12 is used as a mask to form the upper adhesion layer 4 and the conductor layer 3.
Ion milling a part of it (Fig. 1 (c)). afterwards,
The photoresist 12 is removed with a stripper (see FIG. 1).
(D)). Next, the conductor layer 3 and the lower adhesion layer 2 are chemically etched using the upper adhesion layer 4 as a mask. Here, the etching solution for the conductor layer 3 does not affect the adhesion layers 2 and 4, and the etching solution for the lower adhesion layer 2 does not affect the conductor layer 3. Lower adhesion layer 2
Upper adhesion layer 4 formed of the same film during the etching of
Is evenly etched. However, since the upper adhesive layer 4 is thicker than the lower adhesive layer 2, the upper adhesive layer 4 remains even after the etching of the lower adhesive layer 2 is completed (see FIG. 1).
(E)).

As described above, according to this embodiment, a part of the upper adhesion layer 4 and the conductor layer 3 is formed by ion milling, and the chemical etching of the conductor layer 3 and the lower adhesion layer 2 does not affect each other. Since the etching liquid is used, the side etching amount is small and a good pattern can be obtained. Further, the upper adhesion layer 4 is etched together with the lower adhesion layer 2, but since the upper adhesion layer 4 is formed thicker than the lower adhesion layer 2 at first, the lower adhesion layer 2 is formed.
The upper adhesion layer 4 remains even after the end of the etching, and good adhesion with a thin film (not shown) formed thereon is maintained. Of course, in this case, the adhesion with the substrate 1 under the lower adhesion layer 2 is also good. Further, since chemical etching is used for etching the conductor layer 3 and the lower adhesion layer 2, even when this laminated thin film is formed on an uneven surface,
Similar to the flat portion, it is uniformly etched, and an unnecessary portion is not left in the stepped portion of the unevenness without being etched.

In this embodiment, part of the upper adhesion layer 4 and the conductor layer 3 is ion-milled, but even if only the upper adhesion layer 4 is ion-milled, the upper adhesion layer 4 and the conductor layer 3 are also ion-milled. The same effect can be obtained by performing ion milling of the entire layer 3. Next, a method of manufacturing a thin film magnetic head using the thin film forming method of the present invention will be described. Figure 2
FIG. 4 is a sectional view of a magnetoresistive effect thin film magnetic head manufactured according to an embodiment of the present invention, and FIG. 4 is a process sectional view showing a method of manufacturing the thin film magnetic head of this embodiment (mainly a method of forming the bias layer 11). Yes, FIG. 3 is a plan view after the bias layer 11 is formed. Note that FIG. 4 shows a cross section at a position corresponding to AA ′ in FIG.

On the substrate 1, the first insulating layer 5, the MR element 6,
After the lead layer 7 (FIG. 3), the second insulating layer 8, the yoke 9, and the third insulating layer 10 are sequentially formed, the bias layer 11 is formed. The bias layer 11 is a lower adhesion layer 2 shown in FIG.
Similar to the laminated thin film composed of the conductor layer 3 and the upper adhesion layer 4,
It is formed as a laminated thin film of three layers. First, the bias layer 11
Is used as a lower adhesion layer (first conductor film) that constitutes
Au is used as an intermediate conductor layer (second conductor film) of 0 nm.
00 nm, Ta as an upper adhesion layer (third conductor film) 6
0 nm is laminated (FIG. 4A).

Next, a photoresist 12 is formed in a predetermined shape on the bias layer 11 by lithography, and the photoresist 12 is used as a mask to ion-mill the upper adhesion layer of the bias layer 11 and a part of the conductor layer. (FIG.4 (b)). Then, the photoresist 12 is removed with a stripping solution, and the conductor layer of the bias layer 11 remaining in the flat portion and the step portion on the yoke 9 is chemically etched with an iodine / potassium iodide mixed aqueous solution (FIG. 4C). ). At this time, the iodine / potassium iodide mixed aqueous solution has no influence on Ta, which is the upper and lower adhesion layers of the bias layer 11.

Next, after washing with water, the lower adhesion layer of the bias layer 11 is chemically etched with an aqueous sodium hydroxide solution heated to 60 ° C. to form the bias layer 11 having a desired shape.
Is obtained (FIG. 4 (d)). Here, an aqueous solution of sodium hydroxide is used as an etching solution for Ta that is the adhesion layer. Since this etching solution dissolves the photoresist, the photoresist 12 is removed before the etching of the lower adhesion layer to prevent resist flow. I have to keep it. Since the photoresist 12 is removed, when the lower adhesion layer is etched, the upper adhesion layer is also etched at the same time. However, since the upper adhesion layer is thicker than the lower adhesion layer, at the end of etching the lower adhesion layer However, the upper adhesion layer will remain. Further, since the aqueous solution of sodium hydroxide has no effect on the intermediate conductor layer Au, side etching or the like does not proceed.

Next, the fourth insulating layer 13, the magnetic gap layer 16 and the upper magnetic layer 14 are formed (FIG. 4E). Then, as shown in FIG. 2, a protective layer 18 is formed, wrapping is performed so that the surface is flat, a protective substrate (not shown) is bonded, and the tape sliding surface is processed into a predetermined shape. After chipping, CrN is sputtered on the sliding surface of the tape as the abrasion resistant film 15, and finally the lead terminal is connected to an external circuit by a method such as wire bonding.

As described above, according to the method of manufacturing the thin film magnetic head of this embodiment, the lower adhesion layer and the conductor layer are chemically etched in forming the bias layer 11 including the lower adhesion layer, the conductor layer and the upper adhesion layer. Therefore, the conductor film does not remain even on the step portion of the yoke 9, so that the conductor film of the bias layer 11 is not exposed on the tape sliding surface, and the abrasion resistant film 15 and the bias layer 11 are not short-circuited. Also,
The upper adhesion layer is of the same quality as the lower adhesion layer, but since it is formed to have a large film thickness at the beginning, it does not disappear even after the chemical etching of the lower adhesion layer is completed, and the adhesion with the upper fourth insulating layer 13 is also maintained. Can be maintained well. It goes without saying that the adhesion with the lower third insulating layer 10 is also good. In addition, since the part of the conductor layer is removed by ion milling together with the upper adhesion layer, side etching of the conductor layer due to chemical etching is reduced, and a highly accurate pattern is maintained.

Although the upper adhesion layer and a part of the conductor layer are ion-milled in forming the bias layer 11 in this embodiment, even if only the upper adhesion layer is ion-milled, the upper adhesion layer and the conductor layer may be ion-milled again. The same effect can be obtained by performing ion milling of all layers and conductor layers. Further, in this embodiment, the method of forming the bias layer of the thin film magnetic head has been described. However, a thin film magnetic head having a more complicated surface unevenness can be easily formed into a thin film and a good pattern can be obtained. In addition, Ta / A of this embodiment
In addition to u / Ta patterning, a highly accurate pattern can be obtained even in a laminated film made of the same material on the upper and lower sides.

[0025]

According to the thin film forming method of the present invention, the first and second methods are provided.
In order to pattern the laminated thin film composed of the third thin film into a desired shape, at least the third thin film is ion-milled using the resist pattern as a mask, and then the second thin film is chemically etched. Since the second thin film and the third thin film are made of different materials, the second thin film is etched using an etchant that does not affect the third thin film, and the first thin film is chemically etched. At this time, since the first thin film and the second thin film are made of different materials, by etching the first thin film with an etching solution that does not affect the second thin film, there is no progress of side etching or the like, which is favorable. The pattern is obtained.
Note that when the first thin film is chemically etched, the third thin film made of the same material is also etched. However, since the third thin film is formed to be thicker than the first thin film,
The third thin film remains at the end of the etching of the third thin film. Therefore, if the first, second, and third thin films forming the laminated thin film are, for example, conductor films and insulating films are formed on and under the conductive films, the first and third thin films have good adhesion to the insulating film. By using a good thin film, good adhesion can be maintained between the laminated thin film and the insulating films above and below it. In addition, since chemical etching is used for etching the first and second thin films, even when this laminated thin film is formed on an uneven surface, it is uniformly etched in the same manner as the flat portion, so that a step portion of the unevenness is formed. Unwanted parts do not remain without being etched.

The method of manufacturing the thin film magnetic head of the present invention is
In order to pattern the bias layer composed of the first, second and third conductor films into a desired shape, at least the third conductor film is ion-milled using the resist pattern as a mask, and then the second conductor film is removed. Although chemical etching is performed, at this time, since the second conductor film and the third conductor film are made of different materials, the second conductor film is etched using an etching solution that does not affect the third conductor film, , The first conductor film is chemically etched. At this time, since the first conductor film and the second conductor film are made of different materials, the first conductor film is etched using an etching solution that does not affect the second conductor film. By etching the conductor film, the side etching amount is small, and a good pattern can be obtained with high accuracy. Note that when the first conductor film is chemically etched, the third conductor film made of the same material is also etched, but the third conductor film is the first conductor film.
Since the thickness of the third conductor film is larger than that of the third conductor film, the third conductor film remains at the end of the etching of the first conductor film.
Therefore, by using a conductor film having good adhesiveness with the insulating film for the first and third conductor films, the adhesiveness between the bias layer and the insulating films formed above and below the bias layer can be kept good. Further, since the chemical etching is used for the etching of the first and second conductor films, an unnecessary portion of the bias layer does not remain in the step portion of the yoke and, for example, a wear resistant film formed on the tape sliding surface is formed. It is possible to prevent short circuit with the bias layer.

[Brief description of drawings]

FIG. 1 is a process sectional view showing a thin film forming method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a thin film magnetic head manufactured according to an example of the present invention.

FIG. 3 is a plan view of a thin film magnetic head according to an embodiment of the present invention after forming a bias layer.

FIG. 4 is a process sectional view showing the method of manufacturing the thin-film magnetic head of the embodiment of the invention.

FIG. 5 is a plan view of a conventional thin film magnetic head after forming a bias layer.

FIG. 6 is a process sectional view showing a method of manufacturing a conventional thin film magnetic head.

FIG. 7 is a cross-sectional view of a conventional thin film magnetic head after forming a bias layer.

[Explanation of symbols]

 1 substrate 2 lower adhesion layer (first thin film) 3 conductor layer (second thin film) 4 upper adhesion layer (third thin film) 5 first insulating layer 6 MR element 7 lead 8 second insulating layer 9 yoke 10th 3 Insulating Layer 11 Bias Layer 12 Photoresist 13 Fourth Insulating Layer 14 Upper Magnetic Layer 15 Abrasion Resistant Film 16 Magnetic Gap Layer 18 Protective Layer

Claims (4)

[Claims] 1. A thin film forming method for patterning a laminated thin film composed of first, second and third thin films into a desired shape, which is different from the first thin film on the first thin film. A step of sequentially laminating the second thin film made of the same material, and the third thin film made of the same material as the first thin film and having a film thickness larger than that of the first thin film; and on the third thin film. A step of forming a resist pattern and ion milling at least the third thin film using the resist pattern as a mask; a step of removing the resist pattern; a step of chemically etching the second thin film; And a step of chemically etching the thin film. 2. The second thin film is chemically etched using an etching solution that does not affect the first and third thin films, and the first thin film is etched using an etching solution that does not affect the second thin film. The thin film forming method according to claim 1, wherein the thin film is chemically etched. 3. A magnetoresistive effect element, a yoke for introducing a signal magnetic flux from a medium into the magnetoresistive effect element,
A bias layer formed of a laminated film of second and third conductor films, which gives an appropriate bias magnetic field to the magnetoresistive effect element;
A method of manufacturing a thin-film magnetic head including an upper magnetic layer, comprising: the first conductor film on the yoke via an insulating film; and the second conductor film made of a material different from that of the first conductor film. A step of sequentially laminating the third conductor film having the same material as that of the first conductor film and having a film thickness thicker than that of the first conductor film; and forming a resist pattern on the third conductor film. Forming and using this resist pattern as a mask, ion milling at least the third conductor film; removing the resist pattern; chemically etching the second conductor film; and the first conductor. And a step of chemically etching the film. 4. The second conductor film is chemically etched using an etching solution that does not affect the first and third conductor films, and the second etching method is performed using an etching solution that does not affect the second conductor film. 4. The method of manufacturing a thin film magnetic head according to claim 3, wherein the first conductor film is chemically etched.