JPH03190215A - Coating method for resist film - Google Patents

Abstract

PURPOSE:To form a resist film of uniform thickness by obliquely cutting a square-shaped board to be treated at the edge of its one side, and installing one side inclined between the rotating center on a spin holder and the edge in a state directed toward its rotating direction. CONSTITUTION:The edge of one side of a square-shaped board 21 to be treated is obliquely cut out, the board 21 is installed at the inclined one side, i.e., an oblique surface 21a in a state directed toward the rotating direction of a spin holder 23 between the rotating center on the holder 23 and the edge, resist liquid is then dropped on the board 21, and the holder is rotated. Accordingly, the substrate 21 is coated with the liquid to be extended on the entire surface by a rotating centrifugal force, the excess liquid is scattered externally from the peripheral edge, the liquid is scarcely retained on the surface 21a of the board 21, but rather easily scattered externally. Therefore, projection of a resist film on the surface 21a is eliminated. Thus, the resist film of uniform thickness can easily the formed on the entire surface except the oblique surface on the board 21.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for applying a resist film, particularly a method for applying a resist film to a uniform thickness on a rectangular substrate to be processed using a spin code method, the present invention relates to a method for applying a resist film using a spin code method. The purpose of this technology is to eliminate the phenomenon in which excess resist liquid remains at the edges of a rectangular substrate in the rotating direction, causing the resist film to thicken and bulge in that area, thereby making it possible to form a resist film with a uniform thickness. In a method in which a resist solution is dropped onto a rectangular substrate to be processed placed on a spin holder and a resist film is applied by rotating the spin holder, the rectangular to be processed substrate has an edge portion on one side thereof. is cut out in an inclined shape and installed between the center of rotation and the peripheral edge on the spin holder with one inclined side facing the direction of rotation.

[Industrial application field]

The present invention relates to a method for applying a resist film, and in particular, a method for applying a resist film to a uniform thickness on a rectangular processing target substrate in which a pair of parallel sides are longer than the other pair of sides using a spin code method. It is related to.

Photolithography, which selectively removes unnecessary parts by optical and chemical processing to form a desired pattern on a substrate, has high patterning accuracy and high productivity, so it is used for magnetic disks. It is widely used in the manufacturing process of thin film magnetic heads in devices, the manufacturing process of semiconductor devices, etc.

In order to form a desired pattern on a substrate with high precision,
It is required to form a resist film that forms a patterning mask with a uniform film thickness on the substrate, but when forming a resist film on a rectangular substrate by the spin code method, it is necessary to form a resist film that forms a patterning mask with a uniform thickness. Resist liquid tends to accumulate on the edge of the substrate facing in the rotational direction, and the thickness of the formed resist film tends to be non-uniform. Therefore, there is a need for a resist film coating method that can easily eliminate such non-uniformity in the thickness of the resist film.

[Conventional technology]

Conventionally, in manufacturing a thin film magnetic hent slider used in a magnetic disk device, for example, as shown in FIG. 7(a), a large number of pairs of thin film magnetic head patterns 2 are formed on a block substrate 1 made of ceramic, which becomes a slider, by a photolithography process. The block substrate 1 is separated into row units of the thin film magnetic head pattern 2, and a resist film is applied and formed on the processed surface 3a of the separated rectangular separated block substrate 3 on which the slider air bearing surface is to be formed. ,
By selectively exposing and developing the resist film to form a predetermined mask pattern, and selectively etching the substrate surface exposed from the mask pattern, a plurality of sliders corresponding to each thin film magnetic head pattern 2 are levitated. After forming the surface 4, the separation block substrate 3 is cut and separated into head slider units each having a slider air bearing surface 4 corresponding to the thin film magnetic head pattern 2, thereby forming a large number of thin film magnetic RAD sliders 5.

By the way, when forming a resist film by the spin code method on the processing surface 3a on which the slider air bearing surface 4 of the rectangular separation block substrate 3 described above is to be formed, a vacuum chuck mechanism (not shown) is provided as shown in FIG. spin holder 1
1, the rectangular separation block substrate 3 is suctioned and fixed with the processed surface 3a, which is to form the slider flying surface, facing upward, and then a predetermined amount of resist liquid is dropped onto the surface 3a, and the substrate is spun. A resist film is formed by rotating the holder 11 at high speed in the rotational direction A indicated by the arrow to diffuse the resist solution from the center to the periphery by centrifugal force and scattering the excess resist solution from the periphery to the outside. There is.

[Problem to be solved by the invention]

However, in such a method of applying a resist liquid onto the processing surface 3a of the rectangular separation block substrate 3 in which one pair of parallel sides is longer than the other pair of sides, the resist liquid is applied by a spin code method, as shown in FIG. As shown in the figure, the resist liquid applied onto the processed surface 3a of the rotating separation block substrate 3 moves in the rotating direction on the processed surface 3a due to the balance between its surface tension and centrifugal force. There was a drawback that the resist solution remained and a resist film 6 with an uneven thickness was formed in the region B (having a raised film thickness).

For this reason, when exposing the resist film 6, it becomes difficult to place a photomask in close contact with the resist film 6, which reduces the resolution of exposure and significantly reduces the patterning accuracy of the resist film 6 after exposure. There was a problem with the decline.

In view of the above-mentioned conventional problems, the present invention has been developed to address the phenomenon in which excess resist solution remains at the edges of a rectangular substrate in the rotational direction when applying a resist solution using a spin code method, and the resist film in that area thickens and swells. It is an object of the present invention to provide a novel method for coating a resist film, which makes it possible to form a resist film with a uniform thickness by eliminating the process.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a method for applying a resist film by dropping a resist solution onto a rectangular substrate placed on a spin holder and rotating the spin holder. The processing substrate is configured such that the edge of one side thereof is cut out in an inclined shape, and the substrate is placed between the rotation center on the spin holder and the peripheral edge with the inclined one side facing in the direction of rotation.

[For production]

In the present invention, the edge of one side of a rectangular substrate to be processed is cut out in an inclined shape, and the substrate to be processed is placed between the rotation center and the peripheral edge on the spin holder. After setting the spin holder in a direction facing the rotation direction of the spin holder, the resist solution is dropped onto the substrate to be processed and the spin holder is rotated, so that the resist solution spreads over the entire surface of the substrate due to rotational centrifugal force. The excess resist liquid is scattered from the periphery to the outside, but at this time, the resist liquid that has flowed to the edge of one side in the rotational direction of the substrate to be processed is scattered to the outside from the inclined surface. The resist liquid is left on the surface of the coating surface, and a small amount remains so as not to protrude from the surface on which the resist solution is applied.

That is, the resist liquid is difficult to remain on the sloped surface of the substrate to be processed, and is more likely to be scattered to the outside, so that the swelling of the resist film on the sloped surface is eliminated, and the sloped surface of the substrate to be processed is removed. A resist film having a uniform thickness can be easily formed on the entire surface except for the resist film. Therefore, the patterning accuracy of the resist film by subsequent exposure and development is also significantly improved.

〔Example〕

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

FIG. 1 is a perspective view showing an embodiment of a substrate to be processed used in the resist film coating method according to the present invention, and FIG. 2 is a plan view for explaining an embodiment of the resist film coating method according to the present invention. It is a diagram.

In this embodiment, as shown in FIG. 1, a substrate to be coated with a resist film is used, for example, a rectangular substrate to be processed, which is used as a thin film magnetic nod slider, in which one pair of parallel sides is longer than the other pair of sides, as in the conventional case. The edge of one short side of the substrate 21 is cut off in an inclined shape at a small angle of about 15 to 30 degrees to form an inclined surface 21a. ) The inclined surface 21a is installed between the center of rotation and the peripheral edge of the spin holder 23 provided with the spin holder 23, with the inclined surface 21a facing in the rotation direction A of the spin holder 23.

Thereafter, a predetermined amount of resist liquid is dropped onto the substrate 2 to be processed, and the spin holder 23 is heated to a
It is rotated at a rotational speed of 0 rpm to diffuse the resist solution from the center to the periphery of the surface of the substrate 21 to be processed by rotational centrifugal force, and scatter the excess resist solution from the periphery to the outside. At this time, the resist liquid that has flowed to the inclined surface 21a facing the rotational direction of the substrate 21 to be processed is scattered to the outside from the inclined surface 21a, and remains slightly to the extent that it does not protrude from the surface on which the resist liquid is applied. The rise of the resist film on this inclined surface 21a is eliminated.

Therefore, as shown in FIG. 3, it is possible to easily form a resist film 22 having a uniform thickness on the entire surface of the substrate 21 to be processed except for the inclined surface 21a.

As shown in FIG. 2, the substrate 21 to be processed is provided with a plurality of inclined surfaces 21a between the rotation center and the peripheral edge of the spin holder 23. By installing the resist liquid in the rotational direction A and applying the resist solution by rotation, it is possible to easily form a resist film 22 with a uniform thickness on a plurality of substrates 21 to be processed at the same time.

Furthermore, FIG. 4 is a perspective view showing another embodiment of the substrate to be processed used in the resist film coating method according to the present invention, and FIG. 5 explains another embodiment of the resist film coating method according to the present invention. 1, and parts equivalent to those in FIGS. 1 and 2 are given the same reference numerals.

The difference between the embodiment shown in these figures and the embodiment shown in FIGS. 1 and 2 is that, as shown in FIG. The edge of one long side of the rectangular substrate 31 that is longer than
Cut the inclined surface 31 at a small angle of about 30 degrees.
a, and as shown in FIG. 5, a plurality of substrates 31 to be processed are placed on the spin holder 23 equipped with a vacuum chuck mechanism (not shown) between the center of rotation and the peripheral edge thereof. The spin holder 23 is oriented in the rotational direction A, and the spin holders 23 are arranged radially at regular intervals.

Then, a predetermined amount of resist liquid is dropped onto each of the plurality of substrates 31 to be processed, and the spin holder 23 is rotated at a rotation speed of, for example, 2000 to 3000 rpm, so that the resist liquid is applied to the center of the surface of the substrate 31 to be processed. By spreading the resist liquid from the peripheral part to the peripheral part by rotational centrifugal force and scattering the excess resist liquid from the peripheral part to the outside, the resist that has flowed to the inclined surface 31a facing the rotation direction of the substrate 31 to be processed is removed. The liquid is scattered to the outside from the inclined surface 31a and remains slightly to the extent that it does not protrude from the surface to which the resist liquid is applied, as shown in FIG. 6, similar to the embodiment shown in FIGS. 2 and 3 described above. The substrate to be processed 31
It becomes possible to easily form the resist film 32 with a uniform thickness on the entire surface except the upper inclined surface 31a.

Therefore, as a substrate to be processed to which a resist film is applied, for example, as in the conventional case, a pair of parallel sides is longer than the other pair of sides, and a plurality of thin film magnetic head patterns are arranged in a row, as shown in FIG. 7(a). When forming a resist film on the processed surface 3a on which the slider air bearing surface of the rectangular separation block substrate 3 shown in FIG. The edge of the slider is cut off at a shallow angle of about 15 to 30 degrees to form an inclined surface at the same position as the inclined surface 31a on the substrate 31 to be processed, as an airflow inflow part when the slider floats. Therefore, by utilizing this inclined surface and applying a resist solution to the processed surface 3a of the rectangular separation block substrate 3 on which the slider air bearing surface is to be formed, according to the embodiment shown in FIG. 5, a resist film having a uniform thickness can be obtained. can be easily formed.

In addition, in the above embodiment, an example in which a resist solution is applied by a spin code method onto a rectangular substrate to be processed in which one pair of parallel sides is longer than the other pair of sides has been described.
The present invention is not limited to this example, and similar effects can be obtained, for example, when the resist solution is applied to a rectangular substrate to be processed whose four sides are equal in length.

Further, in the above embodiment, the edge of one side of the rectangular substrate to be processed is inclined 7 at a small angle of about 15 to 30 degrees to form an inclined surface. Similar effects can be obtained by chamfering 8 chamfers or C chamfering.

〔Effect of the invention〕

As is clear from the above description, according to the resist film coating method according to the present invention, it is possible to apply a resist film on a substrate having a rectangular shape in which a pair of parallel sides are longer than the other pair of sides, or On a rectangular processing substrate with equal lengths,
This method has an excellent advantage of being able to easily form a resist film with a uniform thickness by coating, and improves the patterning accuracy of the subsequent exposure and development of the resist film.

Therefore, the present invention is extremely advantageous when applied to the process of coating and forming a resist film on a rectangular substrate to be processed, and the manufacture of a magnetic rad slider using such a process.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of a substrate to be processed used in the resist film coating method according to the present invention, and FIG. 2 is a plan view for explaining an embodiment of the resist film coating method according to the present invention. 3 is a perspective view illustrating a state of coating a resist film according to an embodiment of the present invention, and FIG. 4 is a perspective view illustrating another embodiment of a substrate to be processed used in the method of coating a resist film according to the present invention. FIG. 5 is a plan view for explaining another embodiment of the resist film coating method according to the present invention, and FIG. 6 is a perspective view for explaining a resist film coating state according to another embodiment of the present invention. , FIGS. 7(a) to (C) are schematic perspective views illustrating a part of the manufacturing process of a thin film magnetic radar slider using a resist film coating process, and FIG. 8 is a diagram illustrating a conventional resist film coating method. FIG. 9 is a perspective view for explaining the points of interest in the conventional resist film coating method. 1 to 6, 21.31 is a substrate to be processed, 21a and 31a are inclined surfaces, 22.32 is a resist film, and 23 is a spin holder. 5. Sakaki ventricle O = r shi U) Su U horse # Benmisaki 1] Suko wing Figure 6 Figure 6 Wato Hakken-Ba 7F Kasuri Sensei-kata] k-Ichisho 於Se question hanging 2nd Figure
#q; #f=g State'=tlBEnt"H1lnFigure 3Figure

Claims (1)

[Claims] A resist solution is dropped onto a rectangular substrate to be processed (21) placed on a spin holder (23), and the spin holder (23) is
In the method of applying a resist film by rotating the substrate (23), the rectangular substrate to be processed (21) has one edge thereof cut off in an inclined manner, and the center of rotation on the spin holder (23) is A method for applying a resist film, the method comprising: installing the resist film between the resist film and the peripheral edge so that the inclined side faces in the direction of rotation.