JPH1161447A - Formation of multi-step profile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reduction in manufacturing process and formation of a high precision irregular-profiled magnetic head slider by subjecting first and second resists formed on a substrate to exposure with different two masks, respectively, subjecting the resulting two resist layers together to development and drying, and thereafter, successively subjecting the resulting substrate provided with resist patterns to dry etching, ashing and dry etching, in this order. SOLUTION: This formation comprises: forming a first resist 2 on a raw far 1 (slider material); irradiating the first resist 2 with ultraviolet rays 4 through a first mask 3 to cure an irradiated part 2a of the resist 2; forming a second resist 5 on the first resist 2; irradiating the resist 5 with ultraviolet rays through a second mask 6 different from the first mask 3 to cure an irradiated part 5a of the second resist 5; subjecting the resulting laminated resist layers together to development and, thereafter, to drying; dry-etching the substrate 1 provided with resist patterns 7 and 8 to form a first cavity 9; introducing gaseous argon contg. oxygen to form a plasma from the gas and performing resist ashing with the plasma; then, performing reactive ion etching to form a second cavity 10; and finally, performing resist removal with acetone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-step forming method using an etching method for forming a step on a substrate made of silicon, ceramics, glass, or the like used as various sensors and actuators. The present invention relates to a method for forming a plurality of steps having a height, and a method for manufacturing a magnetic head slider using the method.

[0002]

2. Description of the Related Art In recent years, as represented by micromachine technology, silicon and various ceramic substrates are finely processed into a predetermined shape using semiconductor manufacturing technology, in particular, photolithography and dry etching, and are applied to sensors and actuators. Many examples have been seen.
In this case, it is necessary to form a plurality of steps having different depths, such as a group having various depths or a part of the thickness of the substrate for controlling rigidity.
In describing these operations and forming methods, a floating magnetic head used in a magnetic disk drive will be described here as an example.

In a flying magnetic head used in a magnetic disk drive, the spacing between the disk and the magnetic head, that is, the flying height, keeps decreasing in order to minimize the so-called spacing loss with the increase in recording density. In addition, it is required that the disk be constant from the outer circumference to the inner circumference. As a magnetic head slider that can meet such demands, a modified slider designed based on the fluid dynamics of air has been proposed and put into practical use. The odd-shaped slider is characterized in that it has a concave portion called a cavity and generates a pressure lower than the atmospheric pressure, and is also called a negative pressure slider. Such cavities are difficult to produce by conventional mechanical grinding, and are generally made by photolithography and dry etching processes.

Further, in recent years, in order to more accurately and precisely control the flying height, there is a tendency that the magnetic head slider has a cavity or a step having a plurality of depths as shown in FIG.

In order to form a slider having such a plurality of cavities, alignment and adhesion of row bars (slider material), application of resist, exposure, development, dry etching, peeling of resist and row bar, and cleaning are performed. A series of steps is repeated as many times as the depth of the cavity.

[0006]

However, in the above-mentioned conventional method, since the same process is repeated a plurality of times,
The problem of halving the production capacity of the production line, the problem of defects occurring due to the increase in the number of processes for handling low bars (slider materials) that require careful handling, and the problem of laminating resist In order to repeat a series of steps of application, exposure, and development, the resist must be applied to the surface of the resist once developed, and the adhesion between the resists is poor. There is a problem that dry etching cannot be performed.

[0007] In order to solve this problem, an object of the present invention is to provide an inexpensive and high-precision method of manufacturing a slider with a deformed shape of a magnetic head, which greatly reduces the number of manufacturing steps.
Consequently, it contributes to the realization of a high recording density magnetic disk drive.

[0008]

In order to achieve the above-mentioned object, the present invention provides a row-type slider having an array of sliders.
Apply the first resist on the bar (slider material)
After exposing this through a predetermined mask, a second resist is applied thereon, and this is exposed using a mask different from that exposing the first resist. After collectively developing the resist laminated in two layers, the resist is dried. When this is dry-etched using ion milling or reactive ion etching, the low bar surface not covered with the resist is etched to form a first cavity. Next, ashing is performed in a plasma using a mixed gas of argon and oxygen, and then dry etching is performed again using ion milling or reactive ion etching. Is etched. A second cavity having a depth different from the cavity formed by the first dry etching process is formed.

In the present invention, the step of repeating the dry etching and the ashing can be performed in the same dry etching apparatus, so that the number of steps can be significantly reduced as compared with the conventional step. Also, the number of steps for handling the low bar is reduced, and furthermore, by performing the batch development, the separation between the stacked resists is completely eliminated, and the yield can be improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing one example of a manufacturing process of a magnetic head slider according to the present invention. First, as shown in FIG. 2A, a first resist 2 is attached on a low bar (slider material) 1. Here, a photosensitive dry film resist manufactured by Tokyo Ohka Kogyo Co., Ltd., Odile α series (thickness: 30 μm) is used as the resist. However, any negative dry film can be used. The thickness of the resist is not limited to 30 μm. The attachment of the dry film resist was performed by setting the upper and lower roll temperatures of the laminator apparatus to 105 ° C. and the pressure between the upper and lower rolls to 3 kgf / cm ² .

After cooling at room temperature, the resist is irradiated with ultraviolet rays 4 through a first mask 3 to harden the resist, as shown in FIG. As shown in FIG. 1C, since a negative resist is used, a portion 2 exposed to the ultraviolet light 4 is used.
Only a hardens.

Next, as shown in FIG. 1C, a second resist 5 is further adhered on the first resist. As the second resist, an AUDIL α series (30 μm thick) was used. The bonding operation was performed under the same conditions as the first resist.

After cooling at room temperature, as shown in FIG. 1D, the resist is irradiated with ultraviolet rays 4 through a second mask 6 different from the mask used when exposing the first resist. To cure. As shown in FIG. 1 (e), since a negative resist is used, a portion 5 exposed to the ultraviolet light 4 is used.
Only a hardens.

Next, as shown in FIG. 1E, the first and second resists laminated in two layers are collectively developed.
As the developer, an aqueous solution of sodium carbonate is used. The developing operation was performed by setting the developing temperature of the spray developing device to 30 ° C. and the developing time to 40 seconds. After the development, washing with pure water at the same time as the development time is performed, and further, a drying treatment at 90 ° C. is performed to improve adhesion and dimensional accuracy. By developing the two-layered resist collectively, there is no peeling of the resist pattern from the substrate (row bar) and peeling between the laminated resists, which occurs after the developing step.
As shown in FIG. 2F, the dimensional variation is small (1
２2 μm or less) A good resist shape can be obtained.

In the conventional method, the surface of the resist once developed (the surface exposed to the developing solution) is inferior in adhesiveness. Therefore, when the resist is laminated in two layers,
Exposure, because a series of steps of development was repeated, peeling occurred at the interface between the first resist and the second resist,
This was the largest factor in the occurrence of poor dry etching accuracy.

Next, the row bar 1 having the first and second resist patterns 7 and 8 is put into a reactive ion etching apparatus, and the row bar is etched to obtain a structure shown in FIG.
As shown in (g), the first cavity 9 is formed.
Although the thickness of the second resist 8 is reduced, about 20 μm still remains.

Next, while holding the low bar in the etching apparatus, an argon mixed gas containing 10% oxygen was introduced, and this was turned into plasma, and as shown in FIG. The resist is ashed until the pattern is reflected on the low bar surface. The end point of the ashing of the resist was controlled by time by measuring the etching rate of the resist in advance. At this time,
A bias voltage of -300 V was applied to the substrate (low bar). Also, by increasing the oxygen concentration of the mixed gas of oxygen and argon, the etching rate of the resist can be increased in a proportional relationship. However, judgment is made based on the observation result of the resist surface after ashing (the state of void generation and discoloration). It is appropriate to use an argon mixed gas containing 10% oxygen. As in this embodiment, the removal (etching) of the resist can be made anisotropic by turning the argon mixed gas containing oxygen into plasma and applying a negative bias to the substrate (row bar), A resist pattern with good dimensional accuracy could be obtained.

Next, reactive ion etching was performed again to obtain a second cavity 10 as shown in FIG.

Finally, by dipping in acetone, the resist is completely removed as shown in FIG. 2 (j), and a cavity having two depths is completed. The low bar in which the cavities are formed as described above is cut into individual heads to complete a magnetic head slider having first and second cavities 9, 10 as shown in FIG.

As described above, in the embodiment of the present invention, the method of forming the two-stage cavity has been described. However, the step is not limited to two steps, and the substrate is also
It is not limited to the materials used in the embodiments, and silicon or various ceramics may be used.

[0021]

As described above, according to the present invention, a method of forming a multi-stage shape is provided. Specifically, a negative pressure slider having a plurality of cavities having different depths can be easily and stably manufactured. This contributes to the spread of high-density, high-capacity magnetic disk drives and the spread of computers with excellent information processing capabilities. In addition, when applied to the processing of silicon or various ceramic substrates, a multi-step shape required for a small sensor or actuator can be obtained, which contributes to its spread.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a manufacturing process of a magnetic head slider according to the present invention.

FIG. 2 is a schematic diagram showing an example of a magnetic head slider manufactured according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Row bar (slider material) 2 1st resist 3 1st mask 4 Ultraviolet light 5 2nd resist 6 2nd mask 7 1st resist pattern 8 2nd resist pattern 9 1st cavity 10th Second cavity

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/3065 H01L 21/302 H

Claims (4)

[Claims] 1. A step of applying a first resist on a predetermined substrate and exposing the first resist through a predetermined mask, and applying a second resist thereon and applying a second resist through a mask different from the aforementioned mask. The step of exposing, the step of repeating the same steps as many as the number of steps required, the step of collectively developing and drying the resist, the step of forming the first step by etching, and the step of forming a first step by ashing A method of forming a multi-step shape, comprising: removing a resist and forming a second step by etching again; and repeating the same step as many times as required. 2. The method according to claim 1, wherein the first resist and the second resist are photosensitive dry film resists. 3. The method according to claim 1, wherein the ashing of the resist is performed in a plasma using a mixed gas of argon and oxygen. 4. The method according to claim 1, wherein the resist ashing is performed by applying a negative bias voltage to the substrate.