JPH04303919A - Coating apparatus - Google Patents

Abstract

PURPOSE:To prevent the spray of a coating liquid such as a photo-resist or the like from adhering to a substrate again and to form a homogeneous coating film on the substrate by a method wherein the substrate is turned at high speed. CONSTITUTION:A substrate 3 onto which a coating liquid has been dripped by using a dripping means 2 is turned inside a casing 5 by using a motor 10. A multiwinged centrifugal fan 16 in which the side of the said substrate 3 is opened and whose lower part is provided with an annular ring part 15 widened toward the end is installed on the inner circumference of said casing 5; many fins 23 which have been curved radially along the outside from the turning direction of said substrate 3 are formed in the said annular ring part 15. The said annular ring part 15 is turned in the direction opposite to that of the substrate 3; the spray of the coating liquid is guided to parts between the fins 23 so as to prevent the spray from adhering to the substrate 3 again.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus for rotating a substrate such as a semiconductor wafer and coating it with photoresist or the like.

0002

[Prior Art] When applying photoresist on a substrate,
Usually, a dropping means for dropping photoresist onto the substrate using a nozzle, a mounting table for mounting the substrate within a casing, and an adsorption means for adsorbing the substrate to the mounting table by suction.
A coating device equipped with a motor that rotates a mounting table is used. In this coating device, photoresist is dropped onto a substrate and the substrate is rotated at high speed within a casing to form a thin film of photoresist.

However, in the coating device, the photoresist droplets scattered as the substrate rotates at high speed collide with the inner side wall of the casing, are reflected, and re-adhere to the substrate, so that a thin and uniform photoresist is not deposited on the substrate. Unable to form a coating film. If the photoresist film becomes non-uniform, it becomes impossible to accurately form a fine resist image.

0004

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to prevent droplets of coating liquid such as photoresist from re-adhering to the substrate even when the substrate is rotated at high speed, and to form a uniform coating film on the substrate. An object of the present invention is to provide a coating device that can form a coating.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a coating device having a dropping means for dropping a coating liquid onto a substrate, and a rotating means for rotating the substrate within a casing. , an annular ring portion that is open on the substrate side is provided on the inner periphery of the casing, and a large number of radial fins are provided on the annular ring portion along the outer side from the rotation direction of the substrate. Provides a coating device.

In a preferred coating device, the annular ring portion rotates in a direction opposite to that of the substrate. Preferably, the fins are curved radially outward from the direction of rotation of the substrate. Furthermore, it is preferable that the annular ring portion has a lower portion formed in a shape that widens toward the end.

[0007]

[Operation] In the coating apparatus having the above structure, when the coating liquid is dropped onto the substrate by the dropping means and the substrate is rotated by the rotating means within the casing, the excess coating liquid is scattered radially due to centrifugal force. The scattered coating liquid flies into the annular ring portion that is open on the substrate side. Since the annular ring portion is provided with a large number of fins radially outward from the rotational direction of the substrate, it is possible to guide the spray of the coating liquid due to centrifugal force between the fins, and It is possible to prevent splashes of the coating liquid from being reflected inward of the annular ring portion. Therefore, re-adhesion to the substrate can be prevented, and droplets of the coating liquid can be efficiently contained within the annular ring portion.

Furthermore, when the annular ring portion rotates in the opposite direction to the substrate, the flying coating liquid can be efficiently guided between the plurality of fins.

Furthermore, when the fins are curved outward from the direction of rotation of the substrate, the flying direction of the sprayed coating liquid can be made to substantially match the direction of the fins, so that the sprayed coating liquid can be The liquid can be more efficiently guided between the fins of the annular ring portion, and the reflection of droplets by the fins can be further suppressed.

Furthermore, when the lower part of the annular ring portion is formed in a shape that widens toward the end, the flying droplets can be reflected downward by the inclined side wall.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a coating apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic plan view showing the coating apparatus of FIG.

This coating device is arranged in a casing 5 equipped with a dripping means 2 for quantitatively supplying a coating liquid such as photoresist and dripping it onto a substrate 3 from a nozzle 1, and an exhaust flow path 4, 3.

The rotating means includes a mounting plate 6 on which the substrate 3 is mounted, a hollow portion is opened on the upper surface of the mounting plate 6, and the substrate 3 mounted on the mounting plate 6 is moved by suction. It includes a hollow shaft 7 for adsorption, and bearings 8a and 8b that rotatably hold the hollow shaft 7 at an end extending inward at the lower part of the casing 5. Further, the rotating means includes the hollow shaft 7 between the bearings 8a and 8b and the motor 1.
A pulley 9a attached to the rotating shaft 11 of the motor 10, a belt 9b provided under tension between the pulleys 9a, and the motor 10.
It has a bearing 12 that rotatably supports a rotating shaft.

Therefore, when the substrate 3 is attracted to the mounting plate 6 by suction through the hollow shaft 7 and the motor 10 is rotated, the rotational motion is transmitted to the hollow shaft 7 via the belt 9b, and the substrate 3 is attracted to the mounting plate 6. Plate 6 and substrate 3 rotate.

A multi-blade centrifugal fan 16 is disposed on the inner periphery of the casing 5 and is open on the substrate 3 side and rotates without contacting the substrate 3. This multi-blade centrifugal fan 1
6 is formed at the bottom plate part 13 in the casing 5, a cylindrical part 14 extending from the center of the bottom plate part 13 and rotatably housing the hollow shaft 7, and a peripheral edge part of the bottom plate part 13. , and an annular ring portion 15 that is open on the substrate 3 side.

Further, in order to reflect downward the coating liquid scattered as the substrate 3 rotates, the annular ring portion 15 has a lower portion that widens toward the end, that is, a vertical section having a V-shape. . Furthermore, an opening 17 is formed at the outer end of the annular ring portion 15 to allow the stored coating liquid to flow out.

The cylindrical portion 14 is rotatably held by a bearing 19 at the end of a liquid receiving portion 18 formed integrally with the casing 5 at the lower part of the casing 5 . Further, a gear 20 is attached to the lower end of the cylindrical portion 14, and this gear 20 meshes with a gear 21 attached to the rotating shaft 11 of the motor 10. Note that the end of the rotating shaft 11 is rotatably held by a bearing 22.

Therefore, the rotational motion of the motor 10 is transmitted to the multi-blade centrifugal fan 16 by the gears 20 and 21, and the multi-blade centrifugal fan 16 rotates in a direction opposite to the direction of rotation of the substrate 3. In this example, the substrate 3 rotates counterclockwise and the multi-blade centrifugal fan 16 rotates clockwise.

The annular ring portion 15 is provided with a large number of fins 23, and these fins 23 are curved outward from the direction of rotation of the substrate 3. Therefore,
By rotating the multi-blade centrifugal fan 16 in the opposite direction to the substrate 3, the flying direction of the droplets that fly as the fan 16 rotates can be made to substantially match the direction of the fins 23, and the fins 23 in the annular ring portion 15 It can efficiently guide and contain droplets in between. Furthermore, since the fins 23 are curved, droplets flying between the fins 23 can be prevented from being reflected from the annular ring portion 15 toward the substrate 3.

Furthermore, a drain pipe 24 is connected to the liquid receiving portion 18 for discharging or collecting the coating liquid flowing out from the opening 17 of the annular ring portion 15.

[0022] Note that the fins are arranged in the direction in which the droplets of the coating liquid fly;
That is, if it is provided along the outward direction from the rotational direction of the substrate, the flying droplets can be guided between the fins and accommodated in the annular ring part, so the annular ring part does not necessarily need to be rotated. Furthermore, the fins do not need to be curved along the flight direction of the droplets, and may be flat or twisted.

[0023] The fin may be swingably provided within the annular ring portion. FIG. 3 is a partial schematic plan view of an annular ring portion according to another embodiment of the present invention.

In this example, pins 32 for rotatably supporting the fins 33 are provided at the upper and lower portions of the inward open side of the annular ring portion 31, and fins are provided in the upper circumferential direction of the annular ring portion 31. A regulating pin 34 is provided to define the swinging range of 33. The regulation pin 34 is arranged on the lower surface of an annular member (not shown) that is slidable within an annular slit (not shown) formed in the upper circumferential direction of the annular ring portion 31 and fixed at a predetermined position. It protrudes into the annular ring portion 31 from the inside.

When the annular ring portion 31 provided with such fins 33 is rotated in the same direction as the substrate or in the opposite direction, the fins 33 are rotated against the pins 32 due to the flow resistance accompanying the rotation of the annular ring portion 31. The movement of the fin 33 is directed outward from the direction of rotation of the board with
regulated by. Therefore, the fins 33 can be arranged in a predetermined direction, and droplets of the coating liquid can be guided between the fins 33. In addition, together with the annular member, the regulating pin 34
By moving the fins 33 in the circumferential direction along the annular slit, the swing range of the fins 33 can be easily defined.

In the embodiment shown in FIG. 3, the pins for pivotally supporting the fins 33 can be formed at appropriate positions depending on the rotational direction of the substrate and the annular ring section, and the pins that pivot the fins 33 can be formed at appropriate positions depending on the rotation direction of the substrate and the annular ring section. The fins may be attached to pins that are provided. Further, instead of the regulating pin 34, the swinging range of the fin may be defined by a pin or a convex portion formed on the annular ring portion.

[0027] In each of the above embodiments, the annular ring portion is
It may be rotated in the same direction as the substrate. In this case, for example,
Gears may be used in place of the pulley 9a and the belt 9b. Gears that mesh with each other are attached to the rotating shaft 11 and the hollow shaft 7 of the motor 10, and the gear 21 of the rotating shaft 11 and the cylindrical portion 14 are connected to each other. A gear may be interposed between the gear 20 and the gear 20. Furthermore, the rotational speed of the substrate and the rotational speed of the annular ring portion may be controlled by adjusting the gear ratio and pulley ratio.

Further, the side wall of the annular ring portion may be provided upright, but it is preferable that the side wall be formed to be inclined downwardly and spread out as described above. The angle of the side wall of the annular ring portion can be selected depending on the rotation speed of the substrate, etc.

The coating apparatus of the present invention is suitably used when manufacturing fine circuit patterns using photoresist, but it can also be used when coating various coating liquids other than photoresist.

[0030]

According to the coating device of the present invention, the annular ring portion is provided with a large number of fins oriented in a specific direction, so even if the substrate is rotated at high speed, the coating liquid is not splashed between the fins. In addition, it is possible to control the inward reflection of the annular ring portion, prevent droplets of coating liquid such as photoresist from adhering to the substrate again, and form a uniform coating film on the substrate.

[0031] When the annular ring portion rotates in the opposite direction to the substrate, the sprayed coating liquid droplets can be efficiently guided between the plurality of fins, further preventing the droplets from re-adhering to the substrate. .

Furthermore, when the fins are curved outward from the direction of rotation of the substrate, the flying direction of the splashed coating liquid can be made to match the direction of the fins, so that the flying direction of the flying coating liquid can be made to match the direction of the fins. can be guided more efficiently between the fins of the annular ring portion, and reflection of droplets by the fins can be further suppressed.

Furthermore, when the annular ring portion is formed so that its lower part widens toward the end, droplets of the coating liquid can be reflected downward, thereby preventing the droplets from re-adhering to the substrate.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a coating device according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing the coating device of FIG. 1;

FIG. 3 is a partial schematic plan view of an annular ring portion according to another embodiment of the invention.

[Explanation of symbols]

2...Dripping means 3...Substrate 5...Casing 10...Motor 15, 31...Annular ring part 16...Multi-blade centrifugal fan 23, 33...fin

Claims (4)

[Claims] 1. A coating device comprising a dropping means for dropping a coating liquid onto a substrate and a rotating means for rotating the substrate within a casing, the coating device having an annular ring on the inner periphery of the casing that is open on the substrate side. The coating device is provided with a ring-shaped ring portion, and a large number of radial fins are provided on the annular ring portion along the outer side from the rotation direction of the substrate. 2. The coating apparatus according to claim 1, wherein the annular ring portion rotates in a direction opposite to that of the substrate. 3. The coating device according to claim 1, wherein the fin is curved outward from the direction of rotation of the substrate. 4. The coating device according to claim 1, wherein the lower part of the annular ring portion is formed in a shape that widens toward the end.