JPH10289424A - Manufacture of magnetic head slider - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a slider which has an accurate floating quantity and superior reliability for the manufacture of a magnetic head which needs to float low as represented by a negative pressure slider. SOLUTION: For this manufacturing method of the magnetic head slider, a mask in a specific shape is formed on the disk opposite surface of a magnetic head slider substrate and the part which is not converted with the mask is etched by dry etching, thereby obtaining a desired slider shape. In this case, negative type dry film resist(DFR) is laminated in two layers on the slider substrate and the DFR of the lower layer has higher sensitivity than the DFR of the upper layer. Those two layers of DFR are exposed and developed and the pattern in which the DFR of the upper layer stays back from the DFR of the lower layer, so the section of the two layers is tapered on the whole, this new shape makes it hard to deposit a resticking layer and a smooth worked surface having no blur can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head used for a magnetic disk drive, a magnetic tape, and the like, and more particularly to a method for manufacturing a thin film magnetic head slider.

[0002]

2. Description of the Related Art A flying magnetic head used in a magnetic disk drive has been required to minimize the flying height with an increase in recording density. As a technique responding to this, there is a so-called negative pressure slider. This is to precisely control the pressure generated on the air bearing surface by processing the slider's air bearing surface into a special calculated shape, there is little change in flying height due to changes in peripheral speed and skew angle, It is said that fluctuations in spacing loss between the magnetic head and the disk can be suppressed.

[0003] The shape of the air bearing of the negative pressure slider is as follows.
Unlike a conventional linear slider rail, it is configured by a combination of curves and a plurality of straight lines, so that machining using a grinding machine or the like was impossible. In view of this, processing by a so-called sputter etching method of engraving an air bearing shape on a magnetic head slider substrate by a sputtering effect of argon plasma has been proposed.
For example, Japanese Patent Publication Nos. 56-74862 and 60-2
No. 05879, etc., a processing method using ion beam etching or ion milling using a metal or a photoresist as a mask is disclosed. Further, Japanese Patent Application Laid-Open No. 61-120326 discloses an ion beam using a dry film resist as a mask. The processing method by beam etching is shown. Ion beam etching equipment and ion milling equipment used for these processing methods are:
Since the magnetic head slider substrate is etched by the ion bombardment of argon ions generated by plasma excitation of argon, it can be considered as a kind of sputter etching method.

However, in the processing using such an argon sputter etching method, some problems have been pointed out. The first problem is that particles sputtered from the substrate by ion bombardment adhere to the substrate again, as described in many documents, for example, Nikkan Kogyo Shimbun “Electron / Ion Beam Handbook Second Edition”, page 487. This is the "reattachment phenomenon".

A typical example of reattachment will be described with reference to FIG. With the progress of etching by argon ions 5,
Molecules and atoms sputtered from the magnetic head slider substrate 1 mainly deposit on the wall surface 7 of the mask 6 such as a resist and the wall surface 8 of the etched step, and the redeposition layer 9 is formed.
To form Since the argon ions 5 travel almost parallel to the redeposition layer 9, the redeposition layer 9 is hardly etched away during the etching step (FIG. 2).
(A)). As a result, after the etching is completed, even after the mask 6 is removed, a part of the re-adhesion layer 9 remains on the processing ridge line 10 as "burrs" (FIG. 2B). 0.1μ
In a recent negative pressure slider that requires a flying height of less than m, the presence of such burrs makes the pressure distribution on the disk-facing surface unstable, and makes it impossible to stably fly the head. Was causing the error. In the worst case, the surface of the disk is damaged, causing a catastrophic failure to lose the data itself.

[0006] In order to remove such burrs, after the etching is completed, an additional process such as performing mirror finishing on the slider surface again by a grinding machine may be performed. However,
In addition to the increase in cost due to the increase in the number of steps, it is necessary to reload the jig for etching from the jig for etching, so that sufficient accuracy could not be obtained and the yield was reduced.

It is known that so-called oblique processing, in which the substrate is rotated at an angle with respect to the direction of incidence of argon ions during etching, is effective in suppressing the occurrence of burrs. This is thought to be because the re-adhesion layer formed on the mask and the wall surface of the processing step can be removed by obliquely entering argon ions. However, it is necessary to rotate the magnetic head slider substrate in order to uniformly irradiate the argon ions on the wall faces in various directions, and as a result, the area near the processing ridgeline becomes a shadow of the mask and the processing step for a certain time Will be. Therefore, the processing speed of the shadowed portion is reduced, and the magnetic head slider substrate 1 exhibits a unique cross-sectional shape as illustrated in FIG. This results in an error with respect to the pressure design based on a generally performed rectangular cross section or inclined cross section, and there has been a problem that desired floating characteristics cannot be obtained.

[0008]

As described above, when a magnetic head slider is processed by dry etching typified by a sputter etching method using argon plasma, generation of burrs on a processed ridge line is inevitable. In addition, it has been pointed out that there is a danger that the reliability of the magnetic disk device is also reduced.

The present invention is a method of manufacturing a magnetic head slider which aims to solve the above problems and obtain a magnetic head slider having both stable flying characteristics and high reliability.

[0010]

It has been pointed out that one of the causes of the deposition of the re-adhesion layer is that a negative resist is usually used for processing a slider. This is because, when the slider substrate is to be etched by dry etching, the consumption of the resist is severe, so that the slider substrate cannot be used unless it has a thickness of several tens of microns like a dry film resist (hereinafter referred to as DFR). DFR
Is generally a negative type, so a negative type resist is necessarily used. However, since the negative type resist can be cross-linked by exposure to ultraviolet light and serve as a mask, the cross-linking tends to progress toward the resist surface. Therefore, the cross-sectional shape of the resist patterned by exposure and development processing has an inverse taper. For this reason, sputtered particles emitted from the substrate during the etching are easily deposited, and as a result, a re-adhesion layer is formed. It is the present invention that captures these phenomena and devises the cross-sectional area of the resist used as a mask to change from an inverse taper to a taper.
In the present invention, two DFRs are stacked on a substrate. At this time, a lower layer DFR having higher sensitivity than the upper layer DFR is used. When such a two-layer DFR is exposed and developed, the upper layer DFR
Since the FR is a pattern recessed from the lower DFR,
The cross section of the entire two layers becomes substantially tapered. With such a cross-sectional shape, a re-adhesion layer is not easily deposited, and a magnetic head slider having a smooth processed surface without burrs can be manufactured.

The operation of the present invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing the steps of the present invention. First, FIG.
As shown in (a), the first DFR 2 is coated on the air bearing surface of the magnetic head slider substrate 1. Since the DFR is usually provided with a protective film, after the protective film is peeled off, the second DFR 3 is laminated to form the form shown in FIG. Here, the first DFR 2 has higher sensitivity to ultraviolet light than the second DFR 3. This is exposed to ultraviolet rays through a reticle mask 4 on which a desired shape is projected as shown in FIG. 1C, and further developed to form a pattern having a cross-sectional shape as shown in FIG. 1D. I do. At this time, the shape of the step becomes closer to a taper type. This is because the first DFR2 is more sensitive than the second DFR3, and the cross-linking region is widened. When dry etching is performed using the resist formed as described above as a mask (FIG. 1 (e)) and the DFR is peeled off, as shown in FIG. An air bearing shape having a step shape can be formed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first step of applying a first negative photoresist to a thin substrate, and a second step of applying a second negative photoresist on the first negative photoresist. A second step, a third step of exposing the first and second negative photoresists through a mask projected to form a desired shape, and a third step obtained in the third step. A fourth step of patterning the first and second negative photoresists by a development process, and a method of manufacturing a magnetic head slider for forming an air bearing surface having a desired shape by a dry etching method on the patterned substrate, A method of manufacturing a magnetic head slider, wherein the exposure sensitivity of the first negative photoresist is higher than that of the second negative photoresist.

[0013]

【Example】

(Embodiment 1) An embodiment of a method of manufacturing a magnetic head slider according to the present invention will be described with reference to FIG. First, FIG.
The first DFR 2 is coated on the air bearing surface of the magnetic head slider substrate 1 as described above. Here, α-530 type DFR manufactured by Tokyo Ohka Kogyo Co., Ltd. was laminated by a roll heated to 100 ° C. After cooling, the protective film was peeled off, and the second DFR3 was laminated to form the form shown in FIG. Here, the second DFR has α made by Tokyo Ohka Kogyo Co., Ltd.
A -430 type DFR was used, which is less sensitive to ultraviolet light than the? -530 used as the first DFR.

The substrate on which the first and second DFRs are laminated is exposed to ultraviolet rays through a reticle mask 4 on which a desired shape is projected as shown in FIG. A pattern having a cross-sectional shape as shown in FIG. At this time, the shape of the step becomes closer to a taper type. This is because α-530 is converted to α-430
This is because the sensitivity is higher.

Using the resist formed as described above as a mask, dry etching is performed to a depth of 6 μm using an argon ion beam etching apparatus (ion milling apparatus) as shown in FIG.
As shown in FIG. 1 (e), an air bearing shape having a stepped shape close to a taper without burrs due to the redeposition layer was formed. The magnetic head provided with the slider manufactured in this manner provided remarkably excellent results in flying accuracy and reliability.

[0016]

As described above, according to the present invention, it is possible to obtain a slider with excellent reliability and stable flying characteristics, which can greatly contribute to a higher recording density of an external storage device.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a process of the present invention.

FIG. 2 is a conceptual diagram illustrating etching by a conventional method.

FIG. 3 is a cross-sectional view of a main part of a cross section of a magnetic head slider processed by a conventional method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 air bearing surface 2 first dry film resist 3 second dry film resist 4 reticle mask 5 argon ion 6 resist mask 7 resist side wall 8 step side wall 9 redeposition layer 10 processing ridge

Claims (1)

[Claims] 1. A first step of applying a first negative photoresist to a thin plate-like substrate, and a second step of applying a second negative photoresist on the first negative photoresist. And a third step of exposing the first and second negative-type photoresists through a mask projected to form a desired shape, and the first and second steps obtained in the third step. A fourth step of patterning the second negative photoresist by a development process, and a method of manufacturing a magnetic head slider for forming an air bearing surface having a desired shape by dry etching the patterned substrate; A method of manufacturing a magnetic head slider, wherein the exposure sensitivity of one negative photoresist is higher than that of the second negative photoresist.