JPH07185445A - Rotary coating device - Google Patents

Abstract

PURPOSE:To prevent contamination from generating due to a coating liquid mist near the exhaust port of a cup. CONSTITUTION:An annular current rectifying member consisting of a current rectifying plate 55 and a bottom plate 35 is installed inside a cup 22, with an opening part 32 running along the inner circumference of the cup 22. One end of an exhaust pipe 30 is conneced to the bottom plate 35. As the air in the cup 22 is exhausted from the opening part 32, the current of the air following the exhaust is hardly allowed to spread as far as the lower surface of a rotary table 6. For this reason, it is possible to inhibit the attachment of the mist to the lower surface of the rotary table 6. Further, a cleaning liquid 53 is discharged toward the upper surface of the current rectifying plate 55 from a cleaning Liquid discharge nozzle 52 provided in the current rectifying plate. Consequently, the mist can be prevented from accumulating on the inner wall of the current rectifying plate 55 which is always exposed to an exhaust gas containing the mist. Thus the normal functioning of the current rectifying member contributes to the constant inhibition of a contamination near the exhaust port of the cup.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface of a substrate (hereinafter simply referred to as "substrate") such as a glass substrate for a liquid crystal display panel, a semiconductor wafer, a mask substrate for semiconductor production, etc. The present invention relates to a rotary type coating device for coating the coating liquid.

[0002]

2. Description of the Related Art Conventionally, as a rotary coating apparatus of this type, there is one described in, for example, Japanese Patent Application Laid-Open No. 4-61955. FIG. 9 is a sectional view showing the rotary coating device described in that publication. FIG. 10 is a partially enlarged view of the rotary coating apparatus of FIG. This rotary coating apparatus is provided with a rotary table 62 that rotates the substrate 60 while supporting it horizontally. Substrate support pins 64 are provided upright on the turntable 62, and engagement pins 66 that engage with the four corners of the substrate 60 are provided.
The substrate 60 can be rotated integrally with the turntable 62 in a state where the substrate is horizontally supported.

An upper rotary plate 68 is arranged above the substrate 60 supported by the rotary base 62, and is further connected to the rotary base 62 via an upper support plate 70, a ring plate 72 and a spacer 74. Then, as shown in FIG. 10, a washer 76 is inserted between the ring plate 72 and the spacer 74 and between the spacer 74 and the turntable 62 to form a gap 78. Then, the substrate 60 is placed on the turntable 62, the coating liquid is dropped on the central portion of the upper surface of the substrate 60, and then the upper rotary plate 68 is lowered to bring it into a state of being close to the upper surface of the substrate 60. By rotating the rotary table 62 while the substrate is mounted, the coating liquid can be expanded and dispersed, and a uniform thin film can be formed on the upper surface of the substrate 60.

At this time, when the turntable 62 is rotated while the substrate 60 is horizontally supported, as shown by the dotted line in FIG.
Excess coating liquid flows out and scatters through this gap 78.

In the rotary coating apparatus of FIG. 9, a waste liquid collecting case 80 is provided as a cup surrounding the rotary table 62, and the coating liquid scattered from the gap 78 as described above is collected in the waste liquid collecting case 80. It is configured to be. At the bottom of the waste liquid collection case 80, a waste liquid discharge port for discharging the collected coating liquid to the outside is opened. Further, an exhaust port communicates with the space surrounded by the waste liquid recovery case 80, and the air inside the device is exhausted to the outside through this exhaust port. As a result, the solvent gas evaporated from the coating liquid and the coating liquid mist are exhausted to the outside without drifting inside the device for a long period of time, and after these mists adhere to each part of the device and dry and solidify, they become dusty. Therefore, the contamination of the substrate 60 can be suppressed.

[0006]

However, the conventional device has the following problems. In other words, in the process of exhausting solvent gas and coating liquid mist along with the internal air from the exhaust port communicating with the waste liquid recovery case to the outside of the device, these mists carried by the air flow adhere to the vicinity of the exhaust port. I may end up doing it. These mists adhering to the vicinity of the exhaust port are difficult to remove because the solvent component volatilizes and the viscosity increases as the inside of the waste liquid recovery case 80 is exhausted. As a result, the exhaust from the exhaust port is obstructed, or the attached mist or the like becomes dust after drying and solidifying and drifts in the air when the exhaust is stopped. Had become a factor that pollutes.

The present invention has been made to solve the above problems, and prevents the mist of the processing liquid from adhering to and solidifying in the vicinity of the exhaust port, preventing the substrate from being contaminated, and rotating the turntable. An object of the present invention is to provide a rotary coating device capable of keeping the inside of the cup surrounding the container clean.

[0008]

A rotary coating apparatus according to the present invention is an apparatus for coating a coating liquid on the surface of a substrate while rotating the substrate, which is a rotary table for rotating the substrate while horizontally supporting it. And an outer peripheral portion that surrounds the outer peripheral side of the rotary table and an inner peripheral portion that surrounds the lower surface of the rotary table near the center of rotation of the rotary table, and prevents the coating liquid supplied to the substrate surface from scattering to the outside. An exhaust means for exhausting the inside of the cup, having an exhaust port opening to the cup and the inner peripheral portion of the cup;
A straightening vane that is arranged close to the inner circumferential portion of the cup so as to cover the exhaust port formed on the inner circumferential portion of the cup and that has an opening that opens into the cup; and the inner circumferential surface of the straightening vane and the cup. And a cleaning liquid nozzle that discharges the cleaning liquid toward the inner wall of the straightening vane.

[0009]

In the rotary coating apparatus of the present invention, the air in the cup is exhausted from the vicinity of the current plate through the exhaust port formed in the inner peripheral portion of the cup. Since the inner wall of the straightening vane is constantly exposed to the exhaust gas containing the coating liquid mist, the coating liquid mist easily adheres to this inner wall, but since the cleaning liquid nozzle discharges the washing liquid toward the inner wall of the straightening plate. The treatment liquid mist attached to the inner wall of the straightening vane is washed away. Therefore, in the device of the present invention, the mist can be prevented from solidifying on the inner wall of the straightening vane, and the normal functions of the straightening vane and the exhaust means are always guaranteed. As a result, the contamination of the rectifying plate is suppressed, the substrate is prevented from being contaminated by the mist adhered and solidified on the inner wall of the rectifying plate, and the contamination by the coating liquid mist of each part of the apparatus is always suppressed.

[0010]

【Example】

 <1. First embodiment>

First, the apparatus of the first embodiment of the present invention will be described.

<1-1. Overall configuration of device>

FIG. 1 is a sectional view of a rotary type coating apparatus according to the first embodiment. In this rotary coating apparatus, for example, a rectangular substrate 2 can be mounted, and a rotary table 6 that is rotatable around a rotary shaft 4 is provided. That is, a rotary shaft 8 is vertically provided along the rotary shaft 4, and a rotary base 6 is horizontally attached to an upper end of the rotary shaft 8 via a connecting boss 10, and a motor (not shown) is connected to a lower end thereof. . Further, the pin 1 for supporting the substrate is provided on the upper surface side of the turntable 6.
A plurality of 4 are projected to support the back surface of the substrate 2 and
Four sets of engagement pins 16 erected on the rotary table 6 are engaged with the four corners of the board 2 to horizontally fix the board 2. Thus, the turntable 6 can horizontally rotate the substrate 2 while supporting the substrate 2 horizontally.

On the upper side of the rotary table 6, an upper rotary plate 18 is arranged in parallel with the substrate 2 supported by the rotary table 6 at a predetermined distance above the substrate 2. It should be noted that the upper rotary plate 18 can be moved in the vertical direction by an elevating means (not shown).
It is adapted to rotate around the rotary shaft 4 while being integrated with the rotary table 6 and the spacer 20.

An annular cup 22 is arranged around the rotary table 6. This cup 22 is a turntable 6
The inner cup 24 arranged at a position below the outer periphery of the rotary table 6
And an outer cup 26 disposed on the outer peripheral side of the. The bottom of the cup 22 is provided with a waste liquid discharge port 28 for discharging the waste liquid.

Further, inside the inner cup 24, a rectifying member composed of a rectifying plate 55 and a bottom plate 35 is annularly arranged along the inner periphery thereof. The straightening member defines an annular exhaust passage 45 therein. Further, the rectifying member has an opening 32 that opens along the inner circumference of the inner cup 24, and the exhaust passage 45 has the opening 22 through which the cup 22 passes.
It communicates with the inner space. Further, the bottom plate 35 is provided with exhaust ports 34 at four locations, and one end of the exhaust pipe 30 is connected to the exhaust ports 34. The space defined inside the exhaust pipe 30 has an exhaust passage 45 through the exhaust port 34.
Is in communication with. The other end of the exhaust pipe 30 has an opening / closing valve 3
It is connected to the suction pump 38 via 9. A bottom plate 31 is integrally connected to the inside of the bottom plate 35, and the bottom plate 31 and the flow straightening plate 55 both cover the lower surface of the rotary table 6 with a certain gap.

FIG. 2 is a partially enlarged view of the rotary coating apparatus of FIG. As shown in the figure, an annular spacer 20 is arranged on the outer peripheral portion of the upper surface of the turntable 6. The spacer 20 is attached by being connected to the rotary table 6 by a connecting member (not shown), and an outflow path 48 is formed between the rotary table 6 and the spacer 20 for outflowing the excess coating liquid to the outside. There is. On the other hand, the upper rotary plate 18 is attachable / detachable to / from the spacer 20 by fitting the pins P. When the upper rotary plate 18 descends and is mounted on the spacer 20, the rotary base 6 and the upper rotary plate 18 are attached. And spacer 2
With 0, a semi-enclosed space S for applying the substrate 2 is formed.

<1-2. Configuration of baffle plate cleaning mechanism>

This apparatus is equipped with a straightening plate cleaning mechanism. That is, as shown in FIGS. 1 and 2, the cleaning liquid discharge nozzle 52 is installed on the bottom plate 35 that constitutes the flow regulating member. The cleaning liquid ejection nozzle 52 ejects the cleaning liquid 53 from the tip of the ejection port 52a toward the inner wall of the rectifying member provided so as to cover the upper portion of the exhaust port 34, that is, the inner wall of the rectifying plate 55. One end of a connecting pipe 51 is connected to the cleaning liquid discharge nozzle 52.
The other end of the cleaning liquid supply source 48 is connected via an opening / closing valve 50.
Connected to. The cleaning liquid 53 delivered from the cleaning liquid supply source 48 passes through the opening / closing valve 50 and the connecting pipe 51 and is supplied to the cleaning liquid discharge nozzle 52.

FIG. 3 is a perspective view of the cleaning liquid discharge nozzle 52. The cleaning liquid discharge nozzle 52 has an annular main body and an ejection port 52a arranged on the upper surface thereof. One end of the connecting pipe 51 is opened at the bottom surface of the main body portion, and the cleaning liquid 53 supplied from the connecting pipe 51 passes through the annular path defined inside the main body portion and then from the tip end portion of the ejection port 52a. Is ejected. The cleaning liquid discharge nozzle 52 shown in FIG. 3 is arranged inside the exhaust port 34.

<1-3. Device operation>

Next, the operation of the rotary coating apparatus having the above-mentioned structure will be described. First, as shown by the alternate long and short dash line in FIG. 1, the upper rotary plate 18 is lifted to open the central opening greatly, and the substrate 2 is horizontally mounted on the substrate supporting pins 14, and the substrate for the turntable 6 is mounted. Complete the set.

Subsequently, the coating liquid supply nozzle 46
Is moved to the center of the central opening and is lowered to an appropriate height on the substrate 2, as shown by the alternate long and short dash line in FIG. Then, a predetermined amount of the coating liquid is dropped on the central portion of the upper surface of the substrate 2. In this way, the coating liquid is supplied to the substrate 2.

After that, the coating liquid supply nozzle 46 is retracted to an appropriate place, and the upper rotary plate 18 is attached to the spacer 20.
Attach and fix to and complete the preparation for spin coating. And
A motor (not shown) is driven to rotate the rotary table 6, the spacer 20 and the upper rotary plate 18 at a high speed integrally while keeping the substrate 2 horizontally supported (rotation speed N = N3).
By this rotation, the coating liquid on the substrate 2 is diffused outward and is applied thinly on the upper surface of the substrate 2. At this time, as shown by the dotted line in FIG. 2, a part of the coating liquid as a surplus coating liquid passes through the gap between the rotary table 6 and the spacer 20, that is, the outflow path 48 by the centrifugal force F, and then from the rotary table 6 to the surroundings. Scatter. Since the excess coating liquid that has been scattered is captured by the cup 22,
It does not scatter to the outside of the device.

When the spin coating on the substrate 2 is completed, the rotation of the turntable 6 is stopped. After that, the upper rotary plate 18 is moved upward (one-dot chain line in FIG. 1), and then the substrate 2 on which the coating process is completed is taken out from the rotary table 6.

While the substrate 2 is being processed, the suction pump 38 operates and the open / close valve 39 is set to the open state. Therefore, the air in the cup 22 is exhausted by sequentially passing through the opening 32, the exhaust passage 45, the exhaust port 34, and the exhaust pipe 30. As the air in the cup 22 is exhausted, the solvent gas evaporated from the coating liquid and the coating liquid mist are exhausted and removed. Therefore, it is possible to prevent the mist or the like from adhering to each part of the apparatus, drying and solidifying, and then becoming dust and contaminating the substrate 2. Especially, since the rectifying member is provided, the cup 2
Since the air in the inside of 2 is exhausted through the opening 32 that opens to the inner circumference of the cup 22, the air flow accompanying the exhaust is unlikely to go around to the lower surface of the turntable 6. Therefore, there is an advantage that mist and the like can be prevented from adhering to the lower surface of the rotary table 6.

On the other hand, a straightening plate 55 that defines the exhaust passage 45.
Since the inner wall of is constantly exposed to exhaust gas containing mist,
Mist or the like is easily attached to the inner wall. The rectifying plate cleaning mechanism described above is provided to remove the deposits on the inner wall of the rectifying plate 55 that causes contamination of the substrate 2. Ie 1
The inner wall of the straightening vane 55 is cleaned using the straightening vane cleaning mechanism every time the processing of one or a certain number of substrates 2 is completed, or every time the series of processing of the substrates 2 is completed. That is, by opening the opening / closing valve 50, the cleaning liquid 53
Is supplied to the cleaning liquid discharge nozzle 52. As a result, the cleaning liquid 53 is discharged to the inner wall of the straightening vane 55. This cleaning liquid 53
Infiltrates the inner wall of the straightening vane 55 and dissolves the deposit 54 such as the coating liquid mist attached to the inner wall. The cleaning liquid 53 and the dissolved deposit 54 are discharged to the cup 22 through the opening 32. As a result, the deposit 54 is washed and removed from the inner wall of the straightening vane 55. The upper surface of the straightening vane 55 is inclined so that it becomes lower toward the opening 32 so that the cleaning liquid 53 and the deposit 54 can be easily discharged to the opening 32.

Further, as shown in the timing chart of FIG. 4, when the opening / closing valve 50 is opened to supply the cleaning liquid 53 to the cleaning liquid discharge nozzle 52, the opening / closing valve 39 is closed to stop the exhaust of the air in the cup 22. It is desirable to do. This can prevent the cleaning liquid 53 that wets the inner wall of the current plate 55 and the discharge of the dissolved deposit 54 to the opening 32 from being hindered by the flow of the exhausted air.

By appropriately cleaning the inner wall of the straightening vane 55 in this manner, the extraneous deposit 54 can be removed before the solidified deposit 54 attached to the inner wall of the straightening vane 55 is dried and solidified. Therefore, it is possible to prevent the solidified deposit from becoming dust and contaminating the substrate 2, and the solidified deposit 54 of the mist or the like causes the solidified deposit 54 to be exhausted.
Since it does not narrow the mist, mist etc.
The function to exclude from can always be maintained normally.

<2. Second embodiment>

FIG. 5 is a plan view showing another structural example of the cleaning liquid discharge nozzle 52. In this example, the cleaning liquid discharge nozzle 52 is divided into four, and each is installed between the exhaust ports 34. In addition, the connecting pipes 51 are also individually connected to their bottom surfaces. In this configuration, since the cleaning liquid discharge nozzle 52 is installed between the exhaust ports 34,
The width of the bottom plate 35 can be set as narrow as the diameter of the exhaust port 34. That is, there is an advantage that the rectifying member can be downsized. On the other hand, it may be difficult to sufficiently supply the cleaning liquid 53 to the portion of the inner wall of the straightening vane 55 above the exhaust port 34. Therefore, the shape of the jet outlet 52a is sprayed with the cleaning liquid. It is desirable that

<3. Third embodiment>

FIG. 6 is a front sectional view showing still another example of the structure of the cleaning liquid discharge nozzle 52. The cleaning liquid discharge nozzle 52 is different from the cleaning liquid discharge nozzle 52 of the first embodiment in that it is installed on the outer peripheral portion of the exhaust port 34.
Adhesion of mist or the like is prevented from occurring in the opening 3 inside the inner wall of the straightening vane 55.
It occurs most frequently in the area close to 2. Therefore, by configuring the cleaning liquid discharge nozzle 52 so as to intensively clean the portion near the opening 32 as in this embodiment,
The cleaning efficiency can be increased. However, the opening 32
It is conceivable that cleaning of a region away from the cleaning liquid may be insufficient, so that a cleaning mechanism is separately provided for a region that the cleaning liquid 53 does not reach, and the cleaning liquid is appropriately discharged at a lower frequency than the cleaning by the cleaning liquid discharge nozzle 52 shown in FIG. It is desirable to perform washing. For this purpose, two systems of cleaning mechanism having the cleaning liquid discharge nozzle 52 of the first embodiment and the cleaning liquid discharge nozzle 52 of this embodiment may be installed at the same time without sharing the opening / closing valve 50. .

<4. Fourth Embodiment>

FIG. 7 is a partial sectional perspective view showing another structural example of the cleaning liquid discharge nozzle. In the cleaning liquid discharge nozzle 56 in this example, a so-called fan-shaped nozzle 56a is arranged in an annular main body similar to the cleaning liquid discharge nozzle 52.
The fan-shaped nozzle 56a ejects the cleaning liquid 53 in a fan shape. For this reason, in this embodiment, the cleaning liquid 53 is uniformly discharged over the entire circumference of the inner wall of the straightening vane 55, so that the straightening vane 55 is discharged.
The advantage is that uniform cleaning over the entire circumference can be performed relatively easily.

<5. Fifth Example>

FIG. 8 is a partial cross-sectional perspective view showing still another configuration example of the cleaning liquid discharge nozzle. The cleaning liquid discharge nozzle 57 in this example has an annular shape formed by bending a readily available circular pipe and connecting both ends to each other. The cleaning liquid 53 supplied from the connecting pipe 51 connected to the lower side of the circular ring passes through the circular ring, and then passes through the through holes 57a formed in a row in the upper direction to form the straightening plate 5.
It spouts toward the inner wall of No. 5.

<6. Modification>

The above-mentioned rotary coating apparatus is a hermetically sealed apparatus, and is provided with an upper rotary plate 18, and by covering the upper side of the substrate 2 with this upper rotary plate 18, the substrate 2 in the semi-closed space S is covered.
The application of the coating liquid is performed. However, the current plate 5
The rectifying member such as 5 and the rectifying plate cleaning mechanism such as the cleaning liquid discharge nozzle 52 do not include a closed-type device that makes the space S a completely enclosed space by the upper rotating plate 18 and the spacer 20, or the upper rotating plate 18 and the like. It can also be installed on an open top device. In these cases as well, similar to the apparatus of the above-described embodiment, the effect of dissolving and removing the adhering matter such as mist adhering to the inner wall of the flow regulating plate 55 and preventing the substrate 2 from being contaminated is obtained.

[0040]

In the rotary coating apparatus of the present invention, the air in the cup is exhausted from the vicinity of the straightening vane through the exhaust port formed in the inner peripheral portion of the cup, and the cleaning liquid nozzle causes the air to flow to the inner wall of the straightening vane. The attached mist can be washed and removed. Therefore, it is possible to prevent the mist from solidifying on the inner wall of the straightening vane, and at the same time, the normal functions of the straightening vane and the exhaust means are always guaranteed. As a result, the device of the present invention can suppress the pollution of the straightening vane itself, prevent the pollution of the substrate by the mist adhering and solidified on the inner wall of the straightening vane, and prevent the exhaust gas from being obstructed by the pollution of the straightening vane. Thus, it is possible to constantly suppress the contamination of the various parts of the apparatus with the coating liquid mist.

[Brief description of drawings]

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

FIG. 2 is a partially enlarged sectional view of the rotary coating device in FIG.

3 is a perspective view of a cleaning liquid discharge nozzle of the rotary coating apparatus of FIG.

4 is a timing chart showing the operation of two on-off valves of the rotary coating apparatus of FIG.

FIG. 5 is a plan view of a cleaning liquid discharge nozzle according to another embodiment.

FIG. 6 is a partially enlarged cross-sectional view of a rotary coating device according to still another embodiment.

FIG. 7 is a plan view of a cleaning liquid discharge nozzle according to still another embodiment.

FIG. 8 is a plan view of a cleaning liquid discharge nozzle according to still another embodiment.

FIG. 9 is a front sectional view of a conventional rotary coating device.

10 is a partially enlarged cross-sectional view of the conventional rotary coating device of FIG.

[Explanation of symbols]

 2 substrate 6 turntable 22 cup 30 exhaust pipe 32 opening 34 exhaust port 35 bottom plate 45 exhaust passage 52 cleaning liquid discharge nozzle 53 cleaning liquid 55 straightening plate

Front Page Continuation (72) Inventor Masahiro Mimahiro 1-chome, No. 1 Tenjin Kitamachi, 4-chome Tenjin Kitamachi, Teranouchi, Horikawa-dori, Kamigyo-ku, Kyoto

Claims (1)

[Claims] 1. A rotary coating apparatus for coating a coating liquid on the surface of a substrate while rotating the substrate, the rotary table rotating the substrate while horizontally supporting it, and the outer periphery surrounding the outer periphery of the rotary table. And an inner peripheral portion that surrounds the lower surface of the turntable in the vicinity of the center of rotation of the turntable,
A cup that prevents the coating liquid supplied to the surface of the substrate from splashing to the outside, an exhaust port that opens to the inner circumference of the cup, and an exhaust means that exhausts the inside of the cup, and a cup formed on the inner circumference of the cup. A straightening vane that is arranged close to the inner circumference of the cup so as to cover the exhaust port and has an opening that opens into the cup, and an area surrounded by the straightening vane and the inner circumference of the cup. A cleaning liquid nozzle that is disposed and that discharges the cleaning liquid toward the inner wall of the current plate.