JPH06215323A - Production of thin film magnetic head - Google Patents

Abstract

PURPOSE:To flat the surface of the insulated film interposing between a lower magnetic core and a upper magnetic core in a composite type head and between the head elements in an inductive type head. CONSTITUTION:The insulated film 61 covering the lower head half body 8 or the under head element 41 is formed on a substrate 1. A resist layer 9 and 91 is formed so as to cover the insulated film. The resist layer is subjected to a reactive ion etching to expose the projecting part 62 of the insulated film 61, and also the remaining resist layer 9 surrounding the projecting part is adjusted to a prescribed thickness X. The insulated film 61 is made to flat by an ion beam etching. The prescribed thickness X is set at the value eliminating simultaneously the projecting part 62 of the insulated film 61 and the resist layer 9 by the ion beam etching.

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 magnetic head, particularly a thin film magnetic head, for use in various magnetic recording / reproducing devices such as hard disk devices and video tape recorders.

[0002]

2. Description of the Related Art In recent years, with the progress of downsizing in electronic equipment such as computers, there has been a demand for further reduction in size and capacity of hard disk devices used in the terminal devices. Therefore, as a magnetic head for signal recording / reproduction, a thin film magnetic head capable of recording at a higher density than a conventional bulk type head composed of a magnetic core and windings has been attracting attention.

Such a thin-film magnetic head is constructed by applying a thin-film deposition method or a photolithography technique on a substrate (1) as shown in FIG. 4 to form a lower magnetic core (2), a gap spacer ( 3), a conductor coil layer (4) and an upper magnetic core (5) are laminated, and the conductor coil layer (4) is an insulating layer.
Embedded in (6), the magnetic circuit is covered by a protective layer (7).

Further, development of a composite type thin film magnetic head having a laminated structure in which the inductive type head element as described above and the magnetoresistive effect type head element excellent in reproduction output characteristics are integrally provided is under way.

[0005]

Each of the inductive type or composite type thin film magnetic heads as described above has a laminated structure of thin films, and the thin films should be formed as the lamination progresses in the manufacturing process. The unevenness of the underlayer expands, which hinders the formation of the magnetic core and the upper head element formed on the surface of the underlayer.

For example, as shown in FIG. 5, the lower magnetic core (2)
When the upper magnetic core (5) is formed after forming the insulating layer (6) covering the upper coil conductor layer (4), the coil conductor layer (4) is interposed on the surface of the insulating layer (6). As a result, irregularities as shown in the figure occur. As a result, the shape accuracy of the upper magnetic core (5) is reduced, and the unevenness and peeling of the magnetic core are likely to occur especially in the step portion. There is also a problem that the desired characteristics cannot be obtained due to the unevenness.

In order to eliminate such unevenness, an insulating layer
An insulating layer having a flat surface by adopting polyimide resin or resist as the material of (6) and applying the material.
Although a method of forming (6) is known, in this case, since the heat resistance of the insulating layer (6) becomes low, a dry process mainly including sputtering or ion beam etching is used for the upper magnetic core (5). It cannot be used for formation. or,
An excellent soft magnetic material such as Fe-Al-Si alloy cannot be used as a material for the magnetic core because it requires high-temperature heat treatment.

An object of the present invention is to provide a lower magnetic core (2) and an upper magnetic core in an inductive thin film magnetic head.
A method of manufacturing a thin film magnetic head capable of flattening the surface of the insulating layer when forming an insulating layer (6) between (5) and between head elements in a composite type thin film magnetic head Is to provide.

[0009]

A method of manufacturing a thin film magnetic head according to the present invention comprises an insulating film (61) covering a lower head half (8) or a lower head element (81) on a substrate (1). Step of forming and resist layer having a flat surface covering the insulating film (61)
(9) A step of forming (91) and performing reactive ion etching on the resist layers (9) and (91) to expose the convex portion (62) formed on the surface of the insulating film (61). At the same time, a step of adjusting the remaining resist layer (9) surrounding the convex portion to a predetermined thickness X, and ion beam etching the convex portion (62) of the insulating film (61) using the resist layer (9) as a mask. And the step of flattening the surface of the insulating film (61) is performed, and the predetermined thickness X of the resist layer (9) is the same as the convex portion (62) of the insulating film (61) It is set to a value such that the layer (9) disappears at the same time.

[0010]

When the insulating film (61) is formed so as to cover the lower head half body (8) or the lower layer head element (81) on the substrate (1), the surface of the insulating film (61) has a lower head half body (8). 8) or rises according to the convex shape of the lower layer head element (81) to form the convex portion (62). The step of forming the resist layers (9) and (91) having a flat surface so as to cover the insulating film (61) is realized by a method such as spin coating a resist.

When the resist layers (9) and (91) are subjected to reactive ion etching, the resist layer is etched back to expose the protrusions (62) of the insulating film (61). Then, the resist layer (9) which surrounds the convex portion (62) and remains, is further etched back, and the thickness thereof is reduced. On the other hand, the insulating film (6
Since 1) is not affected by reactive ion etching, the convex portion (62) remains with the same thickness.

Therefore, by controlling the etching time by the reactive ion etching, the resist layer (9)
It is possible to obtain a predetermined thickness X by which the projections (62) of the insulating film (61) and the resist layer (9) disappear at the same time by adjusting the thickness of the resist film (9) by ion beam etching which is a post-process.

When the convex portion (62) of the insulating film (61) is subjected to ion beam etching using the resist layer (9) whose thickness is adjusted as a mask, the convex portion of the resist layer (9) and the insulating film (61) is formed. (62) is simultaneously etched back at a rate according to each etching rate. At this time, since the resist layer (9) is adjusted to the above-mentioned predetermined thickness X, when the resist layer (9) disappears, the convex portions (62) of the insulating film (61) also disappear, and the surface becomes A flat insulating layer (6) will be formed.

[0014]

According to the method of manufacturing a thin film magnetic head according to the present invention, an ordinary edge material such as an oxide film is used as an insulating film material without using a conventional organic resin having poor heat resistance. Further, by combining reactive ion etching and ion beam etching, the surface of the insulating film having irregularities can be easily flattened.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. The thin-film magnetic head for carrying out the present invention is not only an inductive thin-film magnetic head, but also a composite thin-film magnetic head in which an inductive head element and a magnetoresistive head element are integrated, The target is any type of magnetic head having a laminated structure of thin films, such as a composite type thin film magnetic head in which a plurality of inductive head elements are laminated.

FIGS. 1 and 2 show steps in a section taken along the line AA of FIG. 4, in which a lower magnetic core (2) in an inductive type thin film magnetic head, It is assumed that the lower head half body (8) including the gap spacer (3) and the coil conductor layer (4) and the lower head element (81) in the composite type thin film magnetic head are formed in advance.

As shown in FIG. 1A, on the substrate (1), the lower head half body (8) or the lower head element (81) is covered to form SiO ₂
By sputtering, an insulating film of approximately uniform thickness
(61) is formed. Here, the insulating film (61) is raised according to the convex shape of the lower head half body (8) or the lower layer head element (81) and has a convex portion (62) of height H. The insulating layer is not limited to SiO ₂ , but various insulating materials such as SiN and Al ₂ O ₃ can be used.

Next, as shown in FIG. 1B, a first resist layer 9 is formed by spin-coating a negative type resist such as OMR-85. Here, the resist is applied in a shape that conforms to the surface shape of the insulating film (61) and rises according to the protrusions (62).

Then, the convex portions of the first resist layer (9) are exposed.
After removing by a developing process to expose the surface of the convex portion (62) as shown in FIG. 1C, the second resist layer (9) as shown in FIG.
1) is formed into a substantially uniform thickness by spin coating. As a result, the irregularities on the surface of the resist layer are sufficiently relaxed.

For example, when the first resist layer 9 is formed in the step of FIG. 1B, the spinner rotation speed is 1000 rp.
m, the rotation speed of the spinner at the time of forming the second resist layer (91) in the step of FIG. 2D is 2500 rpm, and the thickness of the second resist layer (91) is 5.7 μm, the resist layer surface The unevenness of 4 is relaxed from the initial 2.4 μm to 0.2 μm.

Further, a positive type resist is generally used in the formation of the lower head half body (8) or the lower layer head element (81), whereas a negative type resist is adopted as the first resist layer (9). Therefore, the mask used for exposing the resist in the step of forming the lower head half body (8) or the lower layer head element (81) and the projection of the first resist layer (9) as shown in FIG. 1 (c). The mask used for exposure for removing a portion has the same pattern, and both can be used in common.

Thereafter, as shown in FIG. 2 (a), a resist layer (9
Reactive ion etching equipment (RIE) for 1) and 9)
By using ashing with oxygen radicals to reduce the resist thickness and finally expose the surface of the convex portion (62) of the insulating film (61) as shown in FIG.
The thickness of the first resist layer (9) surrounding the convex portion (62) is adjusted to a predetermined value X calculated by the following mathematical formula 1.

[0023]

[Equation 1] X = H (E _re / E _SiO2 ).

Here, H is the height of the convex portion (62), and E _re is the first
The etching rate of the resist layer (9), E _SiO2 is the insulating film (6
It is the etching rate of 1).

In the ashing process by RIE, when the input power of 100 W and the oxygen gas pressure of 0.1 Torr are set as the ashing conditions, the surface roughness R after flattening is set.
a was 350 angstroms, while input power was 5
When 0 W and an oxygen gas pressure of 0.2 Torr were set, the surface roughness Ra after flattening was improved to 100 angstrom. This is considered to be because under the latter condition, the plasma atmosphere contains less ionic components and more radical components, so that surface roughness due to ion bombardment is suppressed.

Therefore, in implementing the present invention, RIE
As the ashing conditions, it is desirable to set an input power of 50 W and an oxygen gas pressure of 0.2 Torr.

Next, as shown in FIG. 2C, the first resist layer
Etchback is performed on the insulating film (61) and the insulating film (61) by an ion beam etching apparatus (IBE). As a result, when the first resist layer (9) disappears as shown in FIG. 2 (d), the convex portions (62) of the insulating film (61) also disappear, and the insulating layer (6) having a flat surface is formed. Will be done.

Here, in order to optimize the etching conditions of IBE, the relationship between the ion beam incident angle and the etching rate was examined, and as shown in FIG. 3, the etching rates of the resist and the SiO _{2 as} the insulating film are Also becomes maximum at an incident angle of about 60 degrees, and the ratio E _re /
It has been confirmed that E _SiO2 also has a maximum at an incident angle of about 60 degrees.

Therefore, in the present embodiment, the ion beam incident angle in the etching step of FIG. 2C is set to 60 degrees in order to increase the throughput. In this case, the resist etching rate E _re is 393 Å / min, S
The etching rate E _SiO2 of iO ₂ is 448 Å / min, and the ratio E _re / E _SiO2 of both etching rates is 0.1.
It becomes 877.

Further, in this case, the first resist layer of FIG.
The predetermined thickness X of (9) becomes X = 1.75 μm from Equation 1 when the initial height H of the convex portion (62) is 2 μm.

After the flat insulating layer (6) is formed as described above, the upper magnetic core (5) and the protective layer (7) are formed on the insulating layer (6).
Alternatively, the process of forming the upper layer head element is the same as the conventional process, and finally the inductive type thin film magnetic head as shown in FIG. 4 or the composite type thin film magnetic head described above is completed.

According to the above-mentioned manufacturing method, the resist thickness before etching back can be adjusted by introducing the resist ashing step by RIE, so that the resist etching rate by IBE and the etching rate of the insulating layer can be set to any values. Even if there is, it is possible to flatten the insulating layer by etching back.

Also, while the etching rate of the resist by IBE is about 400 angstrom / min,
Since the etching rate by RIE is as high as about 1000 angstrom / min, the process time can be shortened and high throughput can be realized as compared with the resist etching by IBE alone.

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 limiting 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 process drawing showing the first half of a method of manufacturing a thin film magnetic head according to the present invention.

FIG. 2 is a process drawing showing the latter half of the above manufacturing method.

FIG. 3 is a graph showing a relationship between an ion beam incident angle and an etching rate in ion beam etching.

FIG. 4 is a sectional view showing a main part of a thin film magnetic head.

FIG. 5 is a cross-sectional view illustrating a defect of the conventional manufacturing method.

[Explanation of symbols]

 (1) Substrate (6) Insulating layer (61) Insulating film (8) Lower head half body (9) First resist layer (91) Second resist layer

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 1, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

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 limiting the scope. Further, the configuration of each part of the present invention is not limited to the above embodiment, but various modifications can be made within the technical scope described in the claims. example
For example, in the above-described embodiment, the planarization using the negative resist is performed.
Although the method was shown, the lower head half (8) or the lower layer head
Used to expose the resist during the element (81) formation process
The first resist layer with the black and white mask reversed
If used for exposure to remove the convex portion of (9), a positive type laser
It is also possible to flatten using a gist, such as OFPR.
Needless to say.

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

Claims (2)

[Claims] 1. A lower magnetic core (2), a conductor coil layer (4) and an upper magnetic core, which constitute a magnetic circuit, on a substrate (1).
In a method of manufacturing a thin film magnetic head in which (5) is laminated via an insulating layer, an insulating film (61) is covered with a lower head half body (8) so as to cover the lower head half body (8) including a lower magnetic core (2). ) And a resist layer (9) (91) with a flat surface covering the insulating film (61).
And the resist layer (9) (91) is subjected to reactive ion etching to expose the convex portion (62) formed on the surface of the insulating film (61) and to form the convex portion. Surrounding resist layer
The step of adjusting (9) to a predetermined thickness X, and the convex portion (62) of the insulating film (61) is subjected to ion beam etching using the resist layer (9) as a mask to flatten the surface of the insulating film (61). And a predetermined thickness X of the resist layer (9).
Is set to such a value that the projections (62) of the insulating film (61) and the resist layer (9) disappear at the same time by the ion beam etching. 2. A method of manufacturing a thin film magnetic head comprising a plurality of head elements laminated on a substrate (1) via an insulating layer, wherein an insulating film (61) covers the lower head element (81). A step of forming the head element (81) thicker, and a resist layer (9) (91) covering the insulating film (61) and having a flat surface
And the resist layer (9) (91) is subjected to reactive ion etching to expose the convex portion (62) formed on the surface of the insulating film (61) and to form the convex portion. Surrounding resist layer
A step of adjusting (9) to a predetermined thickness X, and a step of flattening the surface of the insulating film (61) by ion beam etching the convex portions of the insulating film (61) using the resist layer (9) as a mask. And the predetermined thickness X of the resist layer (9) is
The convex portion of the insulating film (61) formed by the ion beam etching
A method of manufacturing a thin film magnetic head, wherein the value is set such that (62) and the resist layer (9) disappear at the same time.