JPH10222832A - Magnetic head slider and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the rail width accuracy of a floating surface of a magnetic head slider by lowering the discharge rate of a processing chamber and making the speed at which the material to be etched or reaction product adheres to side walls the same or higher as or than the etching speed of the side walls. SOLUTION: A protective film 15 is deposited on the floating surface by sputtering or CVD and a resist 16 is formed. A mask for processing the rails is formed by lithography. The etching is executed by using the resist 15 as a mask the and the rail patterns of the resist 16 are transferred to alumina titanium carbide 13. Deposits 19 adhere to the alumina titanium carbide 13 and the entire part of the side walls of the resist 16. The deposits 19 consist of the chloride of the aluminum and the chloride of the titanium formed by the reaction of the aluminum and titanium which are the materials to be etched with the etching gas. If a sufficient discharge rate is obtainable at the time of etching, the greater part of the chloride of the aluminum and titanium is gasified and discharged. The chloride adheres to the side walls if the discharge rate is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thin film magnetic head slider and a method for manufacturing the same.

[0002]

2. Description of the Related Art The recording density of a magnetic disk drive has been dramatically improved year by year. For this purpose, it is essential to reduce the flying height of a magnetic head slider and its variation. FIG. 3 is an explanatory view of the flying state of the magnetic head slider. The magnetic head slider 1 has a flying surface 2 which is a surface facing a magnetic disk 11, a tapered portion 4, a magnetic element 5,
It has an air inlet end 7 and an air outlet end 8 and is supported by a leaf spring 10. The rail 3 shown in FIG. 2 is formed on the floating surface 2. When magnetic disk rotation is stopped, magnetic head 1
And the magnetic disk 11 are in contact with each other, but when the number of rotations reaches a certain value, an air bearing is formed by an air flow flowing in from the air inflow end 7 and flowing out from the air outflow end 8 along the rail 3 in FIG. A floating force is generated, and the leaf spring 10 shown in FIG.
The floating amount 12 is determined by the pressing force and the floating force. It is an important task to reduce the flying height 12 and to reduce the variation in the flying height caused by a manufacturing error of the rail 3.

In recent years, as a most effective means for reducing the flying height, a method using a non-linear rail has been actively used as disclosed in Japanese Patent Application Laid-Open No. 4-27667.

A process for forming a magnetic head slider having a non-linear rail will be described with reference to FIG. After the magnetic element 5 is formed on alumina titanium carbide 13 which is a substrate material, the substrate is cut into blocks 14 each including a plurality of magnetic head sliders and polished to a predetermined size to form the floating surface 2 (a ), A protective film 15 is formed on the air bearing surface by sputtering, CVD or the like (b), a resist 16 which is a mask material for forming a rail is formed, and a resist pattern is formed by lithography (c). (D) and (e), and cut into individual magnetic heads (f) to obtain a magnetic head slider 1 'in FIG. Step (d) of forming a rail on the air bearing surface includes:
Since the rail shape is non-linear and cannot be formed by machining using a conventional grindstone, etching processes such as reactive ion etching, plasma etching, sputter etching and ion milling are usually used.

The flying height of a magnetic head slider having a non-linear rail is determined by many parameters such as the flatness of the flying surface, the shape and depth of the rail, the rigidity of the support spring, the mounting position on the support spring, and the load. Is done. The variation in the flying height changes under the influence of the manufacturing error of each parameter, but is particularly affected by the deviation of the rail shape and the depth from the design values. Therefore, it is important to improve the accuracy of the process shown in FIG. 5D in order to stably manufacture a magnetic head slider having a small flying height variation.

FIG. 4 shows a sectional shape of the rail. In the step (d), it is necessary to improve the shape and depth of the rail, but the present invention relates to the accuracy of the shape of the rail. Although a detailed description of the technology for improving the accuracy of the depth of the rail is omitted, a technology for monitoring the amount of processing is generally used. The shape of the rail is usually evaluated by the width of the rail indicated by B in FIG. The width B of the rail is smaller than the initial width because the resist is processed in the lateral direction during the etching process as compared with the initial width A of the resist.
Usually, B <A. Here, AB is defined as a dimension shift. The accuracy of the rail width depends on the exposure of the resist,
It is determined by the accuracy of the width A of the resist and the amount of dimensional shift determined by the development conditions. That is, the exposure and development conditions of the resist are optimized, the width accuracy A of the resist is high, and the smaller the amount of dimensional shift, the higher the rail width accuracy. Under general conditions of resist formation and etching, the rail width accuracy can be sufficiently achieved up to about ± 5%.

[0007]

However, in recent years, with the extremely low flying height of the magnetic head, the accuracy required for the rail width has become more severe, and the accuracy of ± 1% to 2% has been required. Was. It is very difficult to achieve such accuracy with conventional techniques.

[0008]

In order to solve the above-mentioned problems, in the present invention, when etching a non-linear rail on the air bearing surface, the etching rate of the side wall is suppressed, that is, the dimensional shift is reduced as much as possible. Make it smaller. Since the rail width variation is caused by the variation in the dimension shift amount, the smaller the dimension shift, the smaller the variation. Therefore, the dimension shift is most preferably 0. If the dimensional shift is 0, the variation is also 0. Therefore, the accuracy of the rail width is affected only by the width accuracy of the resist. As for the precision of the resist, a sufficient target precision can be obtained if the film thickness is made uniform and optimum exposure and development conditions are found.

In order to suppress the etching rate of the side wall, it is necessary to select processing conditions such that the rate at which an object to be etched or a reaction product adheres to the side wall during the etching process is equal to or faster than the speed at which the side wall is etched. Good. Such processing conditions include, for example, lowering the exhaust capacity of the processing chamber so that substances generated during etching are not positively exhausted, to attach a large amount to the side wall, or by selecting an appropriate gas, This can be realized by forming a reaction product that is not easily gasified and attaching it to the side wall, using a sufficiently thick resist, or the like.

[0010] Further, in the state where the deposits remain on the side walls,
There is a concern that the protrusion-like deposits may damage the magnetic disk and cause a failure, and that the detachment of the deposits may cause a failure in the magnetic disk drive. It is desirable to remove part or all.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) A first embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a schematic view of the magnetic head slider 1 formed according to the present invention. The magnetic head slider 1 of the present invention has a floating surface 2, a non-linear rail 3, a tapered portion 4, a magnetic element 5, an element forming portion 6, and a non-linear rail 3 formed on the floating surface.
It has an air inlet end 7 and an air outlet end 8.

The process of manufacturing the magnetic head slider of the present invention will be described with reference to FIGS. 6, 7, 8, 9, and 10. As shown in FIG. 7, the alumina titanium carbide 13
After the magnetic element 5 is formed, a plurality of head blocks 14 are formed by cutting the head element 14 into predetermined dimensions, and the head block is fixed to a head block polishing jig 20 and polished.
To form The head block 14 is arranged on the head block fixing jig 18. FIG. 6A shows a side view of this block as viewed from the magnetic element side. Protective film 1 on air bearing surface 1
5 was formed by sputtering or CVD (b),
A resist 16 is formed, and a mask for rail processing is formed by lithography (c). The resist 16 is etched using the resist 16 as a mask material, and the rail pattern of the resist is transferred to alumina titanium carbide (d). FIG.
Is a known capacitively coupled RIE device. In FIG. 8, 1
3 is alumina titanium carbide, 40 is a main valve,
29 is a vacuum pump, 35 is a gas inlet, and 36 is plasma. An etching gas is supplied from the gas inlet 35,
When a bias voltage is applied, the plasma 36 is excited, and ions are incident on the substrate to perform processing. R
The IE uses a mixed gas of BCl3, Cl2 and argon, the flow rates are 10 sccm, 4 sccm, and 15 sccm, respectively, the degree of vacuum is 3 Pa, the opening ratio of the main valve is 50%, the bias voltage is 500 V, and the processing time is 400 minutes. The groove depth of the rail 3 thus processed is about 10 μm (e). FIG. 10B shows a cross-sectional shape of the rail at this time. The deposit 41 is attached to the entire surface of the side wall of the alumina titanium carbide and the resist. The deposit consists of aluminum chloride and titanium chloride produced by reacting aluminum and titanium to be etched with an etching gas. Since the boiling point of aluminum chloride is 183 degrees and the boiling point of titanium chloride is 136 degrees, if a sufficient pumping speed can be obtained during etching, most of aluminum and titanium chlorides are gasified, and a vacuum pump is used. Here, since the opening ratio of the main valve was reduced and the exhaust speed was reduced, the exhaust gas adhered to the side wall without being exhausted. Therefore, the etching of the side wall was suppressed, and the width A of the resist before etching was 104 μm, while the width B of the alumina titanium carbide after etching, that is, the rail width was 1 μm.
The variation in the rail width of all the rails processed at the same time was 0.9 μm in 3σ.

After the etching, the polishing process (f) is performed using the polishing cloth 17 to remove the deposits generated during the etching process. The polishing at this time will be described in detail below.
FIG. 9 is a conceptual diagram of the polishing process of the head block 14. In FIG. 9, 14 is a head block fixed on a head block fixing jig 18, 21 is a rotatable chuck,
17 is a polishing cloth stuck on a rotatable surface plate 22, 23
Is a polishing liquid. The head block 14 fixed on the head block fixing jig 18 is attached to the chuck 21,
While the polishing liquid 23 is supplied to the surface of the rotating polishing pad 17, the head block 14 fixed on the head block fixing jig 18 is swung in the radial direction of the platen 22 while being pressed and slid on the polishing pad 17. . An example of the polishing conditions is as follows. The diameter of the platen 22 and the polishing cloth 17 is 300 mm,
The rotation speed of the chuck 21 and the platen 22 is 20 r / mi in the same direction.
n, the swing width of the chuck 20 is 10 mm, the swing speed is 5 mm / sec,
Polishing pressure: 10 kPa, average polishing rate: 80 mm / sec, polyester nonwoven fabric as the polishing cloth 17, and diamond slurry having an average particle size of 0.25μ as the polishing liquid 23, 10ml / m2.
The amount of in was added dropwise. The polishing time is 3 minutes. Under the above conditions, the polyester nonwoven fabric is sufficiently deformed, and the resist and the side wall of the rail are polished in contact with the polyester nonwoven fabric as shown in FIG. FIG. 10 (c) shows the cross-sectional shape of the rail after this adhering matter removal polishing process.
As compared with the state before polishing in FIG. 10B, the attached matter is not completely removed, and the resist is receded from the position before polishing. However, since the rail width C and the rail groove depth after polishing shown in FIG. 10D do not change from those before polishing, the accuracy of the rail width is 100 μm ± 0.9 μm.

After the adhering matter removal polishing, the resist is removed, the block is peeled off from the head block fixing jig, and cut into individual magnetic head sliders 1 shown in FIG.
The magnetic head slider shown in FIG. 2 is obtained.

By the above process, the rail width variation is 100 μm ± 0.9 μm at 3σ, that is, a slider rail having a rail width accuracy of 1% or less is obtained. A magnetic head slider capable of low flying can be produced at a high yield.

(Comparative Example 1) A first comparative example of the present invention will be described with reference to FIGS.

The process up to FIG. 7 and FIG.
This is the same as the first embodiment. In the process of FIG. 5D, etching is performed under the following conditions using the well-known capacitively coupled RIE apparatus shown in FIG. BCl3 and C
Using a mixed gas of 12 and argon, the flow rate is 20
sccm, 8 sccm, 30 sccm, the degree of vacuum is 3 Pa, the opening ratio of the main valve is 100%, the bias voltage is 500 V, and the processing time is 400 minutes. The groove depth of the rail 3 thus processed is about 10 μm (e). The cross-sectional shape of the rail at this time is shown in FIG. The deposits on the side walls seen in Example 1 are not seen in this case. Here, since the opening ratio of the main valve was 100%, a sufficient pumping speed was obtained, and most of the chlorides of aluminum and titanium were evacuated to the vacuum pump. Therefore, the side wall was etched and receded greatly, and the width A of the resist before etching was 104 μm, whereas the width B of the alumina titanium carbide after etching, that is, the rail width was 80 μm.
μm, and the variation in rail width was ± 6 μm at 3σ. After the etching process, the resist is removed, the block is peeled off from the head block fixing jig, and cut into individual magnetic head sliders 1 shown in FIG. 5F to obtain the magnetic head slider shown in FIG.

In the above-described process, the rail width accuracy is 80 μm ± 6 μm evaluated at 3σ, and the rail width accuracy is ± 3 μm.
7.5%, which does not achieve the target value.

(Embodiment 2) In the second embodiment of the present invention, the first step up to the step of forming a mask pattern of the resist 16 is the first step.
The etching process is performed under the following conditions. In the process of FIG. 5D, etching is performed under the following conditions using a known capacitively coupled RIE apparatus shown in FIG. A mixed gas of CF4 and argon was used, the flow rate was 20 sccm, the degree of vacuum was 3 Pa, the opening ratio of the main valve was 85%, the bias voltage was 500 V, and the processing time was 320 minutes. The groove depth of the rail 3 thus processed is about 1
0μ (e). The cross-sectional shape of the rail at this time is shown in FIG.
This is shown in FIG. The deposit 41 is attached to the entire surface of the side wall of the alumina titanium carbide and the resist. Most of the deposit is aluminum fluoride, and slightly contains titanium fluoride. Since the boiling point of aluminum fluoride is 1000 degrees or more and the boiling point of titanium fluoride is about 280 degrees, most of titanium fluoride is gasified and exhausted to a vacuum pump. It adheres to the side wall without changing. Therefore, the etching of the side wall was suppressed, and the width A of the resist before etching was 104 μm, whereas the width B of the alumina titanium carbide after etching, that is, the rail width was 101 μm,
The variation of the rail width of all the rails processed at the same time was 0.8 μm in 3σ. Since this deposit is made of aluminum fluoride dissolved in water, it is washed and removed using pure water after etching. Since alumina titanium carbide does not dissolve in pure water, the rail width C shown in FIG.
Does not change.

After cleaning, the resist is removed, the block is peeled off from the head block fixing jig, and cut into individual magnetic head sliders 1 shown in FIG. 5F to obtain the magnetic head slider shown in FIG.

In the above-described process, the rail width accuracy is 101 μm ± 0.8 μm evaluated at 3σ, that is, ±±.
0.8%.

(Embodiment 3) In a third embodiment of the present invention, the steps up to the step of forming a mask pattern of the resist 16 are the first steps.
This is the same as the embodiment. However, here as resist
A dry film resist having a thickness of about 75 μm is used.
After the formation of the resist mask pattern, etching is performed under the following conditions. In the process of FIG. 6D, etching is performed under the following conditions using an ion milling apparatus having a known electron cyclotron resonance type ion source shown in FIG. A mixed gas of C ₂ H ₂ F ₄ and argon was used, the flow rates were both 10 sccm, the degree of vacuum was 0.05 Pa,
The acceleration voltage is 800 V, the ion current density is 1 mA / cm ² , the ion beam incident angle is 45 degrees, and the processing time is 300 minutes.
The groove depth of the rail 3 thus processed is about 10 μm.
(E). The cross-sectional shape of the rail at this time is shown in FIG.
(B). The deposit 41 is attached to the entire surface of the side wall of the alumina titanium carbide and the resist. The majority of this deposit is aluminum fluoride and resist and C ₂
It is an organic substance produced from H ₂ F ₄ , and slightly contains titanium fluoride. Since the side walls were protected by the deposits, the etching of the side walls was suppressed, and the width A of the resist before etching was 104 μm, whereas the width B of the alumina titanium carbide after etching, that is, the rail width was 99 μm. The variation in the rail width of all the rails processed at the same time was 1.0 μm in 3σ.

Usually, when processing rails by ion milling, a dry film resist having a thickness of about 30 μm to 40 μm is used, and processing proceeds as shown in FIG. During processing, a small surface called a facet shown at 42 in FIG. 15B is formed, and when the processing is completed, the facet reaches the surface of alumina titanium carbide as shown in FIG. 15C. The angle of the side wall of the resist was 85 degrees at the time of pattern formation shown in FIG. 15A, but became 60 degrees due to the growth of the facet, and it was more exposed to the ion beam, so that it was difficult for deposits to adhere. . Therefore, when a dry film resist having a thickness of 30 μm to 40 μm is used, no deposit remains at the end of ion milling. However, if the resist is thick, the processing will be as shown in FIG.
Although the facet is generated as shown in the figure, the facet does not reach the surface of the alumina titanium carbide at the end of ion milling due to the thick resist, and the angle between the resist and the substrate surface is still 85 degrees because the resist is thick. , Thick deposits are deposited on the side walls.

After the ion milling, the polishing process (f) is performed using the polishing cloth 17 as in the first embodiment, and the deposits generated during the ion milling are removed. The polishing conditions are as follows. The diameter of the platen 22 and the polishing pad 17 is 300 mm, the rotation speed of the chuck 21 and the platen 22 is 20 r / min in the same direction,
The swing width of the chuck 20 is 10 mm, the swing speed is 5 mm / sec, the polishing pressure is 10 kPa, the average polishing speed is 80 mm / sec, and the polishing cloth 17 is used.
Was used, and a diamond slurry having an average particle size of 0.25 μm was used as the polishing liquid 23, and a drop amount of 10 ml / min was dropped. The polishing time is 5 minutes. As shown in FIG. 6F, polishing is performed in a state where the resist and the side wall of the rail are in contact with the polyester nonwoven fabric. FIG. 14C shows a cross-sectional shape of the rail after the adhering matter removal polishing process. As compared with the state before polishing in FIG. 14B, the deposits are not completely removed, and the resist is receded from the position before polishing. However, since the rail width C and the rail groove depth after polishing shown in FIG. 14D do not change from those before polishing, the accuracy of the rail width is 99 μm ± 1.0 μm. FIG. 17 is an enlarged view of a corner of the rail cross section of FIG.
Shown in The protection film at the corners of the rail is no longer polished.

After the adhering matter removal polishing, the resist is removed, the block is peeled off from the head block fixing jig, and cut into individual magnetic head sliders 1 shown in FIG.
The magnetic head slider shown in FIG. 2 is obtained.

In the above-described process, the rail width accuracy was ± 1.0% when evaluated with 3σ.

[0028]

According to the present invention, since the etching of the rail in the lateral direction is suppressed, the accuracy of the rail width is greatly improved, and a magnetic head capable of extremely low flying can be stably supplied.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method of manufacturing a magnetic head slider according to the present invention.

FIG. 2 is an explanatory view showing a magnetic head slider of the present invention.

FIG. 3 is an explanatory diagram of a flying state of a magnetic head slider.

FIG. 4 is an explanatory diagram showing a dimensional shift.

FIG. 5 is an explanatory view showing a method for manufacturing a conventional magnetic head slider.

FIG. 6 is an explanatory diagram illustrating the method for manufacturing the magnetic head slider according to the first embodiment.

FIG. 7 is an explanatory view showing a method of manufacturing the magnetic head slider.

FIG. 8 is an explanatory view of a capacitive coupling type etching apparatus.

FIG. 9 is an explanatory view of a deposit removal polishing process.

FIG. 10 is a sectional view of the method for manufacturing the magnetic head slider according to the first embodiment;

FIG. 11 is a sectional view of a method for manufacturing a magnetic head slider of Comparative Example 1.

FIG. 12 is a sectional view of the method for manufacturing the magnetic head slider according to the second embodiment.

FIG. 13 is an explanatory view of an ion milling apparatus.

FIG. 14 is a sectional view of the method of manufacturing the magnetic head slider according to the third embodiment.

FIG. 15 is an explanatory diagram of the progress of etching.

FIG. 16 is an explanatory diagram of the progress of etching when a thick-film resist is used.

FIG. 17 is a sectional view of a slider rail according to the third embodiment.

[Explanation of symbols]

3 ... rail, 13 ... alumina titanium carbide, 15 ...
Protective film, 16: resist.

Continued on the front page (72) Inventor Hideki Sonobe 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside of Hitachi, Ltd. In-house Research Institute (72) Inventor Masayoshi Endo 2880 Kozu, Odawara-shi, Kanagawa Storage Systems Division, Hitachi, Ltd.

Claims (6)

[Claims] When a rail is formed on a floating surface of a magnetic head slider by reactive ion etching, sputter etching, or ion milling, the exhaust capacity of a processing chamber is reduced, and the processing speed of the side wall is reduced. A method of manufacturing a magnetic head slider, wherein the speed at which an object to be etched or a reaction product adheres is controlled to be the same or faster. 2. A process for forming a rail on a floating surface of a magnetic head slider by reactive ion etching, sputter etching, or ion milling so that a reaction product produced by an etching gas and a workpiece has a boiling point of 300 ° C. or more. A method for manufacturing a magnetic head slider, characterized in that the etching speed is controlled so that the rate at which an object to be etched or a reaction product adheres to the side wall is equal to or faster than the processing speed of the side wall by adding a suitable etching gas. 3. A method of forming a rail on a floating surface of a magnetic head slider by reactive ion etching, sputter etching, or ion milling, wherein the thickness of a mask material is set to be at least seven times the processing depth of a material to be processed. A method of manufacturing a magnetic head slider, wherein the processing speed is controlled so that the speed at which an object to be etched or a reaction product adheres to the side wall is the same or faster. 4. The method of manufacturing a magnetic head slider according to claim 1, wherein a part or all of the attached matter on the side wall is removed by washing with water or an organic solvent. 5. The method of manufacturing a magnetic head slider according to claim 1, wherein after the etching process is performed, a part or all of the deposits attached to the side wall by polishing are removed. 6. A magnetic head slider manufactured by using the method of claim 1, 2, 3, 4, 5, or 6.