JP2742777B2 - Spin coating method and spin coating apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for applying a coating liquid such as a resist to a substrate such as a wafer or a liquid crystal substrate. More specifically, the present invention relates to a spin coating method and a spin coating apparatus in which a coating liquid is dropped on a central portion of a surface of a substrate, and then the substrate is rotated to apply the coating liquid to the entire surface of the substrate by centrifugal force. .

[0002]

2. Description of the Related Art In the production of large-scale integrated circuits (LSIs) and liquid crystal display panels, there is a step of applying a coating liquid to a substrate such as a wafer or a glass substrate. This step is a part of the photolithography step of forming a fine circuit on the surface of the substrate, in which a coating solution called a resist is applied to the surface of the substrate, and the fine circuit is formed through a post-exposure step, a development step, and the like. Will be formed. Conventional application of a coating liquid is generally performed by a spin coating method in which the coating liquid is dropped onto a central portion of the surface of the substrate, and then the substrate is rotated to cover the entire surface of the substrate by centrifugal force. is there.

FIG. 4 is a view for explaining a schematic configuration of a conventional spin coating apparatus. The rotary coating apparatus shown in FIG. 4 includes a rotary table 2 on which the substrate 1 is placed, a rotary shaft 3 for rotating the rotary table 2, a container body 401 disposed around the rotary table 2, and It mainly comprises a container lid 402 arranged to cover the upper opening of the container body 401. Further, inside the container body 401, a shielding plate 9 for shielding the coating liquid 10 scattered from the substrate 1 during rotation is arranged so as to surround the turntable 2.

[0004] In the spin coating apparatus according to the above configuration,
The substrate 1 is transported by a substrate transport mechanism (not shown) and the turntable 2
It is placed on. Then, the coating liquid 10 is dropped at the center of the surface of the substrate 1 from a dropping nozzle (not shown). afterwards,
The container lid 402 is closed, the turntable 2 rotates, and the coating liquid 10 spreads in four directions on the surface of the substrate 1 due to the centrifugal force generated by the rotation, and covers the surface of the substrate 1.

In the field of fine processing of a substrate surface, which is a main application field of the present invention, it is necessary to perform more uniform processing to improve the yield of finished products such as LSIs and liquid crystal display panels. It is necessary to uniformly apply a coating liquid such as the above-mentioned resist. This uniform coating can be achieved by, for example, increasing the degree of integration and function of LSI.
Speaking of liquid crystal display panels, the demands have become stricter year by year due to the increase in the density and color of pixels.

Here, when the cause of the inability to apply a coating liquid having a high degree of uniformity is pursued, the following factors are considered. First, it is caused by the interfacial tension of the coating liquid. That is, when the coating liquid is caused to reach the periphery of the substrate by centrifugal force as described above, the flowing coating liquid stays at the edge of the substrate due to interfacial tension. It will definitely be thick.

[0007] The coating thickness abnormality at the periphery of the substrate is as follows.
In particular, the effect is serious when applied to a rectangular substrate such as a liquid crystal substrate. That is, since the centrifugal force naturally acts isotropically from the rotation axis, the coating liquid tends to stay at the corners of the rectangular substrate and the coating thickness tends to be abnormal. LSI
In the case of the manufacture of, there is not much problem because a non-defective product is originally difficult to be formed from the peripheral portion of the wafer, but in the case of a liquid crystal substrate, the problem is essential because all the cells need to be lit uniformly. . That is, if the coating thickness is large, the integrated exposure amount of ultraviolet rays becomes insufficient, and this causes the line width after development to be non-uniform. For this reason, the lighting state of each cell is not uniform, and lighting unevenness of the same pattern as a pattern having an uneven coating thickness occurs.

[0008] The non-uniform coating is also caused by turbulence generated above the substrate during rotation. This is shown in FIG.
This will be described in detail with reference to FIG. Container body 4 as shown in FIG.
When the turntable 2 rotates inside 01, a turbulent airflow A, which surrounds the axis of the rotating shaft 3 and rises in a spiral, first occurs. At the same time, the turbulence A bounces off the upper container lid 402 and collides with the surface of the middle part of the substrate radius.
Also occurs. In addition, the turbulence A is drawn by the spiral turbulence A from the side of the substrate 1 toward the center.

First, the above-mentioned spiral turbulence A generates a coating thickness abnormality which is concentric about the axis of the rotating shaft 3.
Further, depending on the physical properties of the coating liquid, the coating liquid may rise due to the turbulence A and adhere to the container lid 402, then peel off, and fall on the surface of the substrate 1 to cause a local coating thickness abnormality. . Next, the turbulent airflow B that rebounds from the container lid 402 and collides with the substrate 1 collides with a middle portion of the substrate radius to make the coating thickness relatively thin. On the other hand, the central portion 13 of the substrate becomes thick as if slightly raised. Furthermore, the coating liquid scattered and adhered to the shielding plate 9 is carried by the airflow C and adheres again to the substrate 1, which may also cause a local abnormality in the coating thickness. Due to the various turbulences described above,
The thickness of the coating solution after the application causes gentle unevenness and local bumps, which promotes non-uniform application. In particular, local coating thickness abnormalities due to turbulence are likely to cause short-circuit failures in both LSIs and liquid crystal display panels.

In order to solve such a problem, Japanese Patent Laid-Open Publication No.
In the invention described in Japanese Patent Publication No. 20030034, the space facing the substrate is made a closed space, and an airflow that flows from the central portion of the substrate to the peripheral portion of the substrate along the surface of the substrate when the substrate is rotated is generated. The application liquid is applied to the surface. The differential pressure generating section is an opening provided in the turntable or the closed space forming section.

[0011]

[Technical problems to be solved by the invention]
When the airflow is generated using the differential pressure generated in the opening as in the invention described in the above-mentioned publication, there is a problem that the airflow flows backward from the opening when the rotation is reduced or stopped. . That is, in the invention disclosed in the above publication, a differential pressure tube that generates a differential pressure due to rotation is attached to the opening, but when the rotation is reduced or stopped, the differential pressure generated in the differential pressure tube is reduced or eliminated. In this case, the space facing the center of the substrate is
Since the pressure is reduced due to the airflow flowing from the center to the peripheral portion of the surface of the substrate, the pressure is lower than the opening due to the reduction or elimination of the pressure reduction in the differential pressure tube portion.
As a result, the airflow flows backward from the opening to the space facing the center of the substrate.

[0012] Such a backflowing airflow carries droplets and the like inside and outside the closed space forming section, and the carried droplets and the like adhere to the surface of the coating liquid applied to the substrate. is there. If such droplets adhere, the coating thickness becomes non-uniform, causing the same problem as described above. The invention of the present application has been made in order to solve such a problem, and provides a method and an apparatus capable of preventing a reverse flow of an air current from an opening and performing uniform application of a coating liquid without adhesion of a droplet or the like. The purpose is to:

[0013]

In order to achieve the above object, according to the first aspect of the present invention, an application liquid is dropped on a surface of a substrate placed on a turntable, and the turntable is rotated. In the spin coating method of applying a coating liquid on the surface of a substrate, the substrate is placed in a closed container having an opening, and when the substrate is rotated, an airflow flowing out of the container through the opening causes the substrate to flow from the center of the surface of the substrate. Spreading the air along the periphery to promote the air flow, and then, when the rotation is decelerated or stopped, introducing a pressurizing gas into the closed container to prevent the back flow of the air flow from the opening Having a configuration.
Similarly, in order to achieve the above object, an invention according to claim 2 includes a hermetically sealed container, a turntable on which a substrate disposed on the hermetically sealed container and on which a substrate for applying a coating liquid is placed, and a turntable are rotated. A rotary coating device having a rotation mechanism, wherein the closed container generates an airflow that flows from inside the closed container to outside the container when the substrate is rotated, and spreads from the central portion of the surface of the substrate to the peripheral portion. A gas introduction mechanism for introducing a pressurizing gas into the container to prevent a backflow of the airflow from the opening when the rotation is decelerated or stopped. It has the structure of. Similarly, in order to achieve the above object, according to the third aspect of the present invention, in the configuration of the second aspect, the gas introducing mechanism includes a pressurizing gas so that the flow of the pressurizing gas does not directly collide with the surface of the substrate. The gas is introduced into the space facing the surface of the substrate.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a schematic front sectional view illustrating an embodiment of the spin coating apparatus of the present invention, and FIG.
FIG. 2 is a schematic plan view of the device shown in FIG. The apparatus shown in FIGS. 1 and 2 includes a closed container 4, a turntable 2 placed in the closed container 4, on which a substrate 1 for applying a coating liquid on a surface is mounted, and a turntable 2 mounted on the turntable 2. A coating liquid supply mechanism 5 for supplying a coating liquid to the surface of the substrate 1, and a rotating mechanism 20 for rotating the turntable 2 to apply the coating liquid to the surface of the substrate 1.

First, the turntable 2 is for mounting the substrate 1 on its upper surface, and has a diameter of 200 mm to 400 mm.
It is formed from a disc-shaped member of the order. On the upper surface of the turntable 2, a mechanism (not shown) for fixing the substrate 1 by a mechanism such as vacuum suction during rotation is provided. The turntable 2
Are supported by the rotating shaft 3 in a vertical posture. The rotating shaft 3 is connected to a rotating mechanism 20 including a motor and the like, and is configured to rotate the rotating shaft 3 at a predetermined rotation speed. The turntable 2 is configured to be able to move up and down as needed to transfer the substrate 1 and the like.

The closed container 4 includes a container main body 41 accommodating the turntable 2 and a container lid 42 for closing an upper opening of the container main body 41. The container body 41 is a cylindrical member having a bottom plate 411 and a diameter of about 600 mm to 1200 mm. At the center of the bottom plate 411 of the container body 41,
A through hole is provided for allowing the rotation shaft 3 of the turntable 2 to pass therethrough. The rotating shaft 3 is fixed to the bottom plate 411 while penetrating the through hole, and the container main body 41 also rotates with the rotation of the rotating shaft 3.

Further, an opening 40 for generating an air flow at the time of coating is provided in the periphery of the bottom plate 411. The opening 40 is a circular opening having a diameter of about 10 mm to 20 mm, and is formed at regular intervals along the periphery of the bottom plate 411.
About twelve are provided. In the device of the present embodiment,
The differential pressure pipe 43 is connected to the bottom plate 411 at each of the openings 40. The differential pressure tube 43 is for promoting the generation of a differential pressure in the opening 40, and extends downward from the opening 40. The differential pressure tube 43 has a shape obtained by diagonally cutting a cylindrical pipe, and the cut surface is oriented in a direction opposite to the direction in which the turntable 2 rotates. It is connected to the.

The differential pressure tube 43 has the same function as a so-called pitot tube. That is, when the turntable 2 rotates, the differential pressure tube 43 also rotates integrally. Of the differential pressure tube 43, a side surface portion opposite to the cut surface (hereinafter, a front surface)
Is a part that directly receives a “head wind” during rotation, whereas the diagonal cut surface is located rearward. And, while the pressure in the space near the front surface rises due to gas molecules colliding, the pressure in the vicinity of the rear cut surface is
The pressure drops because the front surface has separated gas molecules. As a result, a differential pressure is generated in the differential pressure pipe 43, and an airflow flows from the inside of the closed container 4 to the outside through the opening 40. In addition, even when only the opening 40 is not provided and the differential pressure tube 43 is provided, an airflow is generated from the inside of the closed container 4 to the outside through the opening 40 with the rotation, but the airflow is further increased by providing the differential pressure tube 43. Promoted.

On the other hand, the container lid 42 constituting the closed container 4 together with the container main body 41 is formed of a disk-shaped member having a size substantially corresponding to the diameter of the container main body 41, and is arranged to be openable and closable. At the upper edge of the container body 41, a ring-shaped lid receiving plate 412 is extended inward, and the container lid 42 is placed on the lid receiving plate 412 so that the container lid 42 is placed on the container main body 41.
The upper opening is closed in a horizontal position. A peripheral sealing member 44 such as an O-ring is disposed on the upper surface of the lid receiving plate 412. When the container lid 42 closes the upper opening of the container main body 41, the gap between the two is sealed by the sealing member 44. It is supposed to. In addition, a sealing member 4 such as an O-ring
Of course, 4 may be provided on the lower surface of the container lid 42.

The lid receiving plate 412 is provided with a lid locking rod 45 for preventing the container lid 42 from shifting during rotation. The lid locking rod 45 is fixed to the upper surface of the lid receiving plate 412 so as to extend upward as shown in FIG. The lid locking rods 45 are provided at equal intervals on the circumference as shown in FIG. In FIG. 2, the lid locking rod 45
Are four, but are appropriately selected and provided within a range of about 3 to 8 pieces. On the other hand, as shown in FIG. 2, the side end surface of the container lid 42 has a concave portion 42 at a position corresponding to the position of the lid locking rod 45.
When the container lid 42 closes the upper opening of the container body 41, the lid locking rod 4 is inserted into the recess 422.
5 is located. Thereby, the container body 41
The container lid 42 is also rotated in conjunction with the rotation of.

The container lid 42 has a lid opening / closing mechanism 4.
21 are provided. The lid opening / closing mechanism 421 is composed of an opening / closing arm whose tip is fixed to the container lid 42 and a drive mechanism for driving the opening / closing arm to open / close the lid. Is what you do.

The application liquid supply mechanism 5 supplies the application liquid by dropping it to the center of the substrate 1 placed on the turntable 2, and sends out the application liquid from an application liquid tank (not shown). , A coating liquid supply pipe 51 for guiding the coating liquid delivered by the delivery pump, a valve 52 provided on a supply path of the coating liquid supply pipe 51, and the like. A moving mechanism (not shown) is attached to a tip of the coating liquid supply pipe 51, and the tip is movable between an upper position in the center of the rotary table 2 in the sealed container 4 and a predetermined position outside the sealed container 4. ing.

Next, the gas introducing mechanism 6, which is one of the major features of the apparatus of the present embodiment, will be described. The gas introduction mechanism 6 includes a gas introduction pipe 61 for introducing a pressurizing gas into the closed container 4.
And a solenoid valve 62 provided on the gas introduction path of the gas introduction pipe 61. One end of the gas introduction pipe 61 is connected to a gas cylinder (not shown) that stores the pressurized gas to be introduced. A gas inlet 420 is provided at the center of the container lid 42, and the other end of the gas inlet pipe 61 is connected to the gas inlet 420. At least a part of the gas introduction pipe 61 is configured to be extendable and contractable like a bellows. In the device of the present embodiment, a part of a portion on the downstream side of the electromagnetic valve 62 is configured to be able to expand and contract.

The gas inlet pipe 6 to the gas inlet 420
A mechanical seal 63 is provided at the connection portion 1. The mechanical seal 63 is for achieving airtight sealing of the connection portion while allowing rotation of the container lid 42. That is, the container lid 42 rotates with the rotation of the turntable 2, but the gas introduction pipe 61 needs to be kept stationary.

On the other hand, a gas dispersion plate 64 is disposed below the container lid 42. The gas dispersion plate 64 is connected to the container lid 42.
It is slightly smaller than the disk shape and provided horizontally coaxially with the container lid 42. On the lower surface of the container lid 42, a dispersion plate holding rod 65 is provided so as to extend downward,
The gas dispersion plate 64 is held by the container lid 42 by being fixed to the lower end of the dispersion plate holding rod 65. The gas dispersion plate 64 has a shape slightly larger than the substrate 1 placed on the turntable 2. For example, the substrate 1 is 300 mm × 3
450mm-500m for a square of about 00mm
A diameter of about m is used. In addition, the gas dispersion plate 6
The distance between the rotary table 4 and the turntable 2 is about 5 mm to 8 mm.

Such a gas dispersion plate 64 is for introducing the pressurizing gas into the space facing the surface of the substrate 1 so that the pressurizing gas does not directly collide with the surface of the substrate 1. That is, the gas that has flowed in from the gas inlet 420 is horizontally dispersed by the gas dispersion plate 64, and is made to go around the periphery of the gas dispersion plate 64, before reaching the space facing the surface of the substrate 1.

In addition, the gas introduction mechanism 6 includes a gas introduction pipe 6
It has a flow controller, a filter, and the like provided on one gas introduction path. As the gas to be introduced, an inert gas such as nitrogen or argon, or clean air is preferably used.

Next, the operation of the spin coating apparatus according to the above-described embodiment will be described together with the description of the spin coating method according to the embodiment of the present invention. FIG. 3 is a timing chart for explaining the operation of the apparatus of FIG. 1 and the embodiment of the invention of the spin coating method. In FIG. 3, the solid line indicates the rotation speed of the turntable 2, and the dashed line indicates the pressure in the closed container 4. First, when the substrate 1 transported by a substrate transport system (not shown) such as an arm of a transport robot reaches a predetermined position near the container lid 42, a lid opening / closing mechanism 421 (not shown) operates to open the lid, The substrate 1 is placed on the turntable 2 by the arm holding. At this time, the turntable 2 moves up and down as needed, and the substrate 1
To help the placing operation. The mounted substrate 1 is fixed on the upper surface of the turntable 2 by a vacuum suction mechanism or the like.

Then, a moving mechanism (not shown) operates to move the tip of the coating liquid supply pipe 51 located outside the closed container 4 to a position above the center of the rotary table 2 in the closed container 4.
In this state, the application liquid supply mechanism 5 operates to open the valve 52 for a predetermined time, and a predetermined amount of the application liquid is dropped on the surface of the substrate 1 from the tip of the application liquid supply pipe 51. After that, the tip of the coating liquid supply pipe 51 retreats outside the closed container 4.

Next, the lid opening / closing mechanism 421 operates to close the container lid 42 and close the upper opening of the container main body 41. Then, the rotation mechanism 20 operates to drive the rotation shaft 3 and rotate the turntable 2. The container body 41 also rotates with this,
The container lid 42 locked by the lid locking rod 45 also rotates.
The coating liquid on the substrate 1 placed on the turntable 2 is diffused to the periphery by rotation, spreads to the periphery, and covers the entire surface of the substrate 1.

At this time, a differential pressure is generated in the opening 40 provided in the bottom plate 411 of the container main body 41 as described above, and an airflow flowing from the inside of the container to the outside of the container through the opening 40 is generated. This air flow promotes an air flow that diffuses from the central portion of the surface of the substrate 1 to the peripheral portion thereof, and the coating liquid that tends to accumulate in the peripheral portion of the surface of the substrate 1 is swept away by the air current that diffuses along the peripheral portion. The coating solution is applied with a uniform thickness. At this time, the inside of the closed container 4 is reduced in pressure as compared with the outside by the airflow flowing outside the closed container 4.

When the rotation is performed for a predetermined time and the uniform coating is substantially completed, the gas introducing mechanism 6 is operated before the rotation of the turntable 2 is decelerated. That is, the solenoid valve 62 is opened to introduce the pressurizing gas into the closed container 4. The pressurizing gas flows from the gas inlet 420 and is dispersed in four directions by the gas dispersion plate 64, and reaches the space facing the surface of the substrate 1 so as to surround the periphery of the gas dispersion plate 64.

With the introduction of the gas, the pressure in the closed container 4 gradually increases as shown by a dashed line in FIG. 3, and when the pressure in the closed container 4 becomes almost equal to the pressure outside the container, the electromagnetic pressure is reduced. The valve 62 is closed to terminate the gas introduction. At the same time, the rotation mechanism 20 reduces the rotation of the turntable 2 and after a predetermined time,
Stop completely. After the rotation of the turntable 2 is decelerated and stopped while introducing the pressurizing gas in this manner, the container lid 42
Is opened, and the substrate 1 is carried out of the container body 41 by a substrate transport system (not shown). Thus, a series of application operation of the application liquid is completed.

In the above operation, the pressure increase in the closed container 4 due to the introduction of the pressurizing gas operates so as to compensate for the decrease in the flow of the airflow outside the container due to the reduction in rotation. Therefore, the backflow of the airflow from the opening 40 due to the rotation deceleration is prevented.

That is, the pressure inside the sealed container 4 is lower than the pressure outside the container as described above due to the airflow flowing through the opening 40 to the outside of the sealed container 4 during the rotation of the turntable 2. In this case, if the pressurizing gas is not introduced, the airflow weakens due to the rotation deceleration, and eventually the airflow flows backward from the opening 40 due to the reduced pressure in the container and flows into the container. The airflow flowing backward in this manner tends to flow from the opening 40 toward a space near the center of the surface of the substrate 1. Therefore, the closed container 4
Substrate 1 removes the evaporation liquid called mist or mist of the coating liquid existing inside and outside, and the dust existing outside the sealed container 4.
As a result. If such droplets or dust are attached, there is a problem that a local abnormal coating thickness occurs or a circuit failure occurs.

However, when the pressurizing gas is introduced,
As shown in FIG. 3, the rotation is decelerated in a state where the pressure inside the closed container 4 is reduced, and the opening 40
There is no backflow of the air flow in the above, and there is no danger that splashes and dusts inside and outside the sealed container 4 adhere to the substrate 1. The timing of the introduction of the pressurizing gas is preferably before the rotation of the turntable 2 starts to decelerate. However, even if the gas is introduced within the period until the rotation is stopped after the deceleration, the backflow may be similarly prevented.

In the method and the apparatus according to the present embodiment according to the above-described operation, the pressurizing gas is dispersed and introduced by the gas dispersion plate 64, so that the coating thickness abnormality caused by the air current temporarily generated when the pressurizing gas is introduced. Is prevented beforehand.
That is, when the flow of the pressurizing gas from the gas inlet 420 directly collides with the surface of the substrate 1 directly, the flow may cause the coating liquid on the surface of the substrate 1 to rise abnormally or to be depressed. However, as described above, the gas distribution plate 64
When the pressurizing gas is dispersed and introduced in the above, such an abnormal coating thickness does not occur.

As a configuration for "preventing the pressurized gas from directly colliding with the surface of the substrate 1", a mesh-like member is disposed in place of the plate-like member in the same position as the gas dispersing means. And the like. Incidentally, even when the pressurizing gas directly collides with the surface of the substrate 1 directly, by reducing the flow rate of the pressurizing gas or increasing the distance from the gas inlet 420 to the surface of the substrate 1,
Abnormal coating thickness can be prevented. However, if the flow rate of the pressurizing gas is reduced, backflow at the opening 40 may not be sufficiently prevented.
If the distance to the surface is increased, the size of the airtight container 4 may be increased, and turbulence as in the related art may be easily generated. The configuration using the gas dispersing means has an advantage in that there is no such a fear.

As can be seen by comparing FIGS. 1 and 4, in the spin coating apparatus of the present embodiment, the distance from the turntable 2 to the upper container lid 42 is smaller than in the prior art. This is to prevent the generation of turbulence as described in the description of the related art. That is, if the distance from the turntable 2 to the container lid 42 is reduced as shown in FIG. 1, turbulence as in the conventional apparatus is less likely to occur, and the airflow due to the opening 40 is not disturbed. It will flow on the surface of the substrate 1. Such an effect of preventing turbulence is preferably obtained when the distance from the turntable 2 to the container lid 42 is 20 mm or less.

Further, since the turbulence is hard to generate, the rising of the coating liquid at the center of the substrate 1 and the drop at the middle of the radius of the substrate 1 as shown in FIG. 4 are naturally eliminated. The spin coating device of the present embodiment can perform coating with high uniformity. In the spin coating apparatus of the present embodiment, the air flow from the vicinity of the center of the surface of the substrate 1 to the vicinity of the periphery of the substrate 1 to the opening portion 40 carries the mist-like coating liquid scattered from the substrate 1 and It is carried out of the closed container 4 from the part 40. Accordingly, unlike the conventional case, the coating liquid does not adhere to the container body 41 or the like, and then separates and adheres again to the surface of the substrate 1 without causing a local coating thickness abnormality. Can be performed.

[0041]

EXAMPLES Examples of the spin coating method and apparatus according to the above embodiment will be described. Size of substrate 1: 370 mm x 480 mm Thickness of substrate 1: 1.1 mm Material of substrate 1: Glass Inner diameter of container main body 41: diameter 800 mm Height of container main body 41: 28 mm Distance from turntable 2 to container lid 42 : 15 mm Size of the opening 40: diameter 20 mm Number of the openings 40: 8 distances between the openings 40: arcs of 45 ° each Type of coating liquid: negative type color resist Dropping amount of coating liquid: 15 cc Rotation speed ( V): 800 rpm t1: 5 seconds in FIG. 3 t2: 11 seconds in FIG. 3 t3: 14 seconds in FIG. 3 t4: 15 seconds in FIG. 3 t5: 22 seconds in FIG. 3 Type of pressurizing gas: dry air When the spin coating was actually performed under the conditions of the flow rate of the pressurizing gas: 120 L / min to 150 L / min, the coating was performed with a coating thickness uniformity of ± 3% on average. Also, no droplets or dust adhered to the surface.

The spin coating method and apparatus of the present invention having the above-described embodiments and examples can be configured as follows. First, the opening 40 may be provided not on the bottom plate 411 of the container body 41 but on the side surface. In this case, if the position of the opening 40 is much higher than the height of the upper surface of the turntable 2, the flow of the air current flows away from the surface of the substrate 1 and the effect of pushing the coating liquid by the air flow is reduced. Therefore, it is preferable that the position of the opening 40 be a position that is not higher than the substrate surface on the upper surface of the turntable 2. It is preferable to provide a back surface opening for generating an airflow flowing along the back surface of the substrate 1 as in the invention described in the above-mentioned publication. Also in this case, since the inside of the closed container 4 is pressurized by the pressurizing gas, the backflow of the airflow from the back surface opening is also prevented.

[0043]

As described above, according to the first or second aspect of the present invention, the backflow of the air current from the opening is prevented, and the uniform coating liquid free of the splash and the like caused by the backflow is provided. Can be applied. According to the third aspect of the invention, in addition to the effect of the second aspect, an abnormality in the coating thickness due to the collision of the flow of the pressurizing gas is prevented, and the apparatus is more preferable in this respect.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view illustrating an embodiment of a spin coating apparatus according to the present invention.

FIG. 2 is a schematic plan view of the apparatus shown in FIG. 1 as viewed from above.

FIG. 3 is a timing chart illustrating the operation of the apparatus of FIG. 1 and an embodiment of the invention of the spin coating method.

FIG. 4 is a view for explaining a schematic configuration of a conventional spin coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 10 Coating liquid 2 Rotating table 20 Rotating mechanism 3 Rotating shaft 4 Airtight container 40 Opening 41 Container main body 42 Container lid 421 Lid opening / closing mechanism 5 Coating liquid supply mechanism 6 Gas introduction mechanism

Claims (3)

(57) [Claims] 1. A rotary coating method in which a coating liquid is dropped on a surface of a substrate placed on a turntable, and the rotary table is rotated to apply the coating liquid to the surface of the substrate. When the substrate is rotated, the airflow flowing out of the container through the opening when the substrate is rotated promotes the airflow that spreads from the central portion of the surface of the substrate to the peripheral portion, and then the rotation is reduced. Alternatively, when stopped, a pressurizing gas is introduced into the closed container to prevent a backflow of the airflow from the opening, and a spin coating method. 2. A closed container, and a turntable which is disposed in the closed container and on which a substrate on which a coating solution is applied is placed, and
A rotation mechanism for rotating a turntable, wherein the hermetic container generates an airflow that flows from the inside of the hermetic container to the outside of the container during rotation of the substrate, and the central portion of the substrate surface to the peripheral portion. A gas inlet for introducing a pressurizing gas into the container to prevent a backflow of the air flow from the opening when the rotation is decelerated or stopped when the rotation is reduced or stopped. A spin coating device comprising a mechanism. 3. The gas introduction mechanism according to claim 2, wherein the gas introduction mechanism introduces the gas for pressurization into a space facing the surface of the substrate so that the flow of the gas for pressurization does not directly collide with the surface of the substrate. The spin coating device according to claim 2, wherein