JPH0817707A - Spin coating apparatus - Google Patents

Abstract

PURPOSE:To obtain a spin coating apparatus which prevents a surplus treatment liquid from being stuck to an upper-part rotating plate in a spin coating operation by a method wherein, in a closed space, a boundary part between a spacer and the upper-part rotating plate is situated in the upward outer direction at a prescribed set angle with reference to the horizontal direction as viewed from the outer circumference of a substrate. CONSTITUTION:A through hole whose shape is similar to that of a substrate and whose outward-shape size is a little larger than the outward-shape size of the substrate is made on the surface of a spacer 16. As a result, when a boundary part 26 is viewed from the outer circumference of the substrate, it is situated in the direction at an angle theta which is close to nearly 90 deg. with reference to the horizontal direction. As a result, when the substrate is turned after a treatment liquid has been supplied, a surplus treatment liquid L is discharged to the outer circumferential direction from the substrate due to a centrifugal force F generated by its rotation. However, even when the treatment liquid L is scattered to the upward outer direction at an angle PHIwith reference to the horizontal direction, the treatment liquid L is received wholly by a slope 28 on the spacer 16 so as to prevent it from being scattered and stuck to the boundary part 26 and a top plate 14. The set angle is set within a range of 45 to 90 deg..

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention rotates a substrate such as a glass rectangular substrate for liquid crystal, a semiconductor wafer, a substrate for color filter (hereinafter simply referred to as "substrate"), and supplies a photoresist to the surface of the substrate. The present invention relates to a spin coater that diffuses a treatment liquid such as a liquid over the entire surface and applies the treatment liquid to a substrate.

[0002]

2. Description of the Related Art Conventionally, as a spin coating apparatus of this type, there is one described in, for example, Japanese Patent Laid-Open No. 4-61955. FIG. 4 is a sectional view showing the spin coating apparatus described in that publication. In this spin coater, the substrate 60
There is provided a turntable 62 that rotates while horizontally supporting. Substrate support pins 64 are erected on the turntable 62, and engaging pins 66 are engaged with the four corners of the substrate 60.
Is provided, and the substrate 60 can be rotated integrally with the turntable 62 in a state where the substrate 60 is horizontally supported by the substrate support pins 64.

An upper rotary plate 68 is disposed above the substrate 60 supported by the rotary table 62, and the upper support plate 7 is provided.
0, the ring plate 72, and the ring-shaped spacer 74 are connected to the turntable 62. And turntable 6
The substrate 60 is placed on the substrate 2, the processing liquid is further dropped on the central portion of the upper surface of the substrate 60, and then the upper rotary plate 68 is lowered to bring the substrate 60 into close proximity to the upper surface of the substrate 60. The processing solution can be expanded by rotating the turntable 62 in this state to form a uniform thin film on the upper surface of the substrate 60.

Although not shown, the ring plate 7
2 between the spacer 74 and the spacer 74 and the turntable 62.
A washer is inserted between and to form a gap.
Therefore, when the turntable 62 is rotated while the substrate 60 is horizontally supported, the centrifugal force generated by the rotation and the wind in the rotation direction cause the substrate 60 to be discharged outward from the outer periphery of the substrate 60, and the surplus processing is performed via the gap. The liquid flows out and scatters.

In the spin coating apparatus of FIG. 4, the rotary table 6
2 is provided with a waste liquid recovery case 80, and the processing liquid scattered from the gap as described above is collected by the waste liquid recovery case 80.

[0006]

By the way, a part of the excess processing liquid discharged from the substrate 60 by the rotation is upward with respect to the horizontal direction and is scattered outward (hereinafter referred to as "upward outward"). And adheres to the upper rotary plate 68. And
When the adhered processing liquid is dried and solidified, fine dust (particles) is floated around the rotary table 62 due to vibration or the like caused by the opening / closing operation or the rotating operation of the upper rotary plate 68, and adheres to the substrate 60 to reduce the yield. Cause problems such as letting.

Therefore, the present invention has been made to solve the above problems, and it is an object of the present invention to provide a spin coating apparatus capable of preventing excess processing liquid from adhering to an upper rotary plate during spin coating. To aim.

[0008]

According to a first aspect of the present invention, there is provided a spin coater for coating a substrate by rotating the substrate and diffusing the treating liquid supplied to the surface thereof over the entire surface of the substrate. In order to achieve the above object, the rotation supporting means for horizontally supporting and rotating the substrate, and the upper rotation for rotating together with the substrate are arranged in parallel with the substrate supported by the rotation supporting means at a predetermined distance. The plate and the upper rotary plate are placed on the plate to form a space for accommodating the substrate together with the rotation support means and the upper rotary plate to rotate together with the substrate and the upper rotary plate, and are supported by the rotary support means. A spacer having an opening formed in the upper center of the substrate, the opening having its outer periphery arranged in an upward outward direction at an installation angle of 45 ° to 90 ° with respect to the radial direction and the horizontal direction during rotation from the outer periphery of the substrate; The it has.

According to a second aspect of the present invention, the installation angle is set to an angle equal to or larger than a maximum value of a horizontal scattering angle of the processing liquid scattered upward and outward from the outer periphery of the substrate when the substrate is rotated. It is set.

According to a third aspect of the invention, the installation angle is set to 70 ° to 80 °.

According to a fourth aspect of the present invention, the substrate has a rectangular shape, and the opening portion of the spacer has a short shape similar to the rectangular substrate.

[0012]

According to the invention of claim 1, a closed space is formed by the rotation support means, the upper rotation plate and the spacer, and the substrate is horizontally supported in the closed space, and the rotation support means and the upper rotation are provided. The plate and the spacer are rotated as a unit, and the treatment liquid is applied to the surface thereof. In this closed space, the boundary between the spacer and the upper rotary plate is located upward and outward at an installation angle of 45 ° to 90 ° with respect to the horizontal direction when viewed from the outer periphery of the substrate. All the processing liquid scattered outward from the outer periphery of the substrate when the substrate is rotated is received by the spacer, and the upper rotating plate is prevented from being contaminated by the processing liquid.

According to a second aspect of the present invention, the installation angle is set to an angle equal to or greater than a maximum value of a horizontal scattering angle of the processing liquid scattered upward and outward from the outer periphery of the substrate when the substrate is rotated. Therefore, it is possible to prevent the processing liquid from the outer periphery of the substrate from scattering over the boundary portion to the upper rotary plate.

According to the invention of claim 3, the installation angle is 70.
The processing liquid discharged from the outer periphery of the substrate is scattered to the spacers to prevent the upper rotary plate from being contaminated.

In the invention of claim 4, since the substrate has a rectangular shape and the opening of the spacer has a short shape similar to the rectangular substrate, the installation angle is substantially constant.

[0016]

1 is a sectional view showing an embodiment of a spin coating apparatus according to the present invention, FIG. 2 is a partial perspective view of the spin coating apparatus, and FIG. 3 is a portion of the spin coating apparatus. It is an expanded sectional view. In this spin coater, an under plate 6 that can support the rectangular substrate 2 and that is rotatable about the rotation axis 4 is provided. That is,
A rotating shaft 8 is vertically provided along the rotating shaft 4, and an under plate 6 having a size equal to or larger than the outer shape of the substrate 2 is horizontally attached to an upper end of the rotating shaft 8 via a connecting boss 10, while an under plate 6 is attached to a lower end thereof. A motor (not shown) is connected. A suction chuck 12 is fixed to the tip of the rotary shaft 8 to support the substrate 2 by suction. With these configurations, a rotation supporting unit that rotates the substrate 2 while horizontally supporting the substrate 2 is configured.

On the upper side of the under plate 6, a top plate 14 is arranged parallel to the substrate 2 supported by the under plate 6 at a predetermined distance above the substrate 2. The top plate 14 can be moved in the vertical direction by an elevator device (not shown) (FIG. 2). When the top plate 14 is lowered, the top plate 14 is fitted with a spacer 16 which will be described later, and is integrated with the under plate 6 and the spacer 16 so as to rotate around the rotary shaft 4. It is designed to rotate.

A rectifying plate 18 having the rotating shaft 4 as a concentric center is fixed to the upper surface of the under plate 6 so as to rotate integrally with the substrate 2 and the under plate 6. By providing this straightening plate 18, as shown in FIG. 2, only a small gap exists on the outer peripheral lower surface of the substrate 2, and even when the substrate 2 is rotated, a spiral shape is formed near the outer peripheral portion of the substrate 2. It is possible to suppress the generation of an air flow, and it is possible to prevent the inconvenience that the processing liquid such as the resist liquid flows around to the back surface side of the substrate 2.

Further, so as to surround the substrate 2 and the current plate 18 which are suction-supported on the upper surface of the under plate 6,
The spacer 16 is fixed to the outer peripheral portion of the upper surface of the under plate 6. As shown in FIG.
As shown in FIG. 2, the through hole 22 having a shape similar to that of the substrate 2 and having an outer size slightly larger than the outer size of the substrate 2 is formed.
Is provided, and the substrate 2 can be carried in and out of the device through the through hole 22. Further, three pins P are provided on the upper surface 20 so as to project upward, and can be fitted into the positioning holes 24 provided on the outer peripheral portion of the top plate 14. Therefore, when the top plate 14 is lowered, as shown in FIG. 3, the pins P fit into the positioning holes 24 and the top plate 14 is fitted to the spacers 16, so that the substrate 2 is subjected to a predetermined treatment liquid. A closed space S for processing is formed. In this embodiment, the upper surface 20 of the spacer 16 is excluded, except for the through holes 22 that function for loading and unloading the substrate 2.
Since the top plate 14 is supported as a whole, the contact area between the two is increased as compared with the case where a ring-shaped spacer is used as in the conventional case, and the sealing property between the two can be improved.

When the top plate 14 is mounted on the spacer 16 in this way, as shown in FIG. 3, a boundary portion 26 between the top plate 14 and the spacer 16 is formed in the upward and outward direction of the substrate 2. The boundary 26 is formed in the same manner as in the conventional example, but differs greatly in the following points.
That is, in this embodiment, since the through hole 22 having a similar shape to the substrate 2 and having an outer size slightly larger than the outer size of the substrate 2 is provided on the upper surface 20 of the spacer 16, the boundary portion from the outer periphery of the substrate 2 is changed. As seen from 26, it is located in the angle θ with respect to the horizontal direction (hereinafter, this angle is referred to as “installation angle” for convenience of description), which is approximately 90 °. For this reason, when the substrate 2 is rotated after supplying the processing liquid, the excess processing liquid L is discharged from the substrate 2 in the outer peripheral direction by the centrifugal force F generated by the rotation, as shown in FIG. Even if the processing liquid L is scattered upward at an angle φ with respect to the horizontal direction, the processing liquid L is entirely received by the inclined surface 28 of the spacer 16,
It is possible to prevent scattering and adhesion to the boundary portion 26 and the top plate 14.

This angle φ varies depending on the spin coating conditions such as the viscosity of the treatment liquid and the number of revolutions. For example, a resist liquid (treatment liquid) having a viscosity of 20 cp has a size (300 mm × 400 mm).
After being supplied to the surface of the substrate 2, the rotational acceleration is 500 rpm.
When the spin coating process is performed at a rotation speed of 1500 rpm at a rotation speed of 1 / sec, the angle φ is about 20 °, and in this embodiment, the process from the substrate 2 is performed without causing the adhesion to the top plate 14. The liquid L can be reliably recovered. Further, the installation angle θ is not limited to this example, and as a result of examining various spin coating conditions,
By setting the angle in the range of 45 ° to 90 °, it is possible to prevent the treatment liquid from adhering to the top plate 14. In short, if the installation angle θ is set to be larger than the maximum value of the angle φ at which the processing liquid is scattered under the spin coating condition, that is, the maximum scattering angle φMAX, the surplus processing liquid L adheres to the top plate 14 during the spin coating. Can be prevented.

However, in order to carry in and carry out the substrate 2 through the through hole 22 as described above, it is preferable to provide a clearance of at least about 2 to 3 mm in order to carry out the work smoothly. Considering the above, it is preferable to set the installation angle θ to 70 ° to 80 °.

The spacer 16 thus constructed has
A groove 30 is formed at a predetermined position on the lower surface (see FIG. 3).
By reference to this groove 30, an outflow path 32 for outflowing the excess processing liquid L to the outside is formed between the under plate 6 and the spacer 16. A trap portion 34 having a trapezoidal cross section is provided at a position of the spacer 16 facing the outer peripheral side opening of the outflow passage 32. The trap portion 34 communicates with the closed space S via the outflow path 32. Further, an inclined surface 36 is formed on the lower side of the trap portion 34 so as to decrease inward in the radial direction of the under plate 6, and a discharge hole 38 is provided at the lower end of the inclined surface 36. Therefore, the substrate 2 and the under plate 6
Is rotated at a high speed and the centrifugal force F is applied, the excess processing liquid L from the substrate 2 is received by the inclined surface 28 of the spacer 16, further flows into the trap portion 34 through the groove 30, and It is stored in the trap section 34. And
When the rotation speeds of the substrate 2 and the under plate 6 drop and the centrifugal force F becomes less than a certain value or becomes zero,
The processing liquid stored in the trap portion 34 is discharged into the discharge hole 38.
Flows down from.

Although not shown in the drawings, an annular cup is arranged around the under plate 6 to collect the processing liquid discharged as described above, and a predetermined drain collecting part. It is designed to be discharged to.

As described above, according to this embodiment, the boundary portion 26 between the spacer 16 and the top plate 14 in the closed space S moves upward and outward with respect to the outer periphery of the substrate 2 with an appropriate installation angle θ. Since it is positioned, all of the processing liquid L scattered from the substrate 2 during the spin coating process is received by the inclined surface 28 of the spacer 16 and the excess processing liquid L is prevented from adhering to the top plate 14. You can

Although the substrate is rotated after the processing liquid is supplied in the above embodiment, it is needless to say that the present invention can be applied to an apparatus that rotates the substrate while supplying the processing liquid to the substrate. Nor.

Further, in the above embodiment, the case of the rectangular substrate 2 has been described. However, a processing liquid is supplied to a substantially circular substrate such as a semiconductor wafer, and the circular substrate is rotated to perform a predetermined processing. The present invention can also be applied to a spin coating device.

[0028]

According to the first aspect of the present invention, the boundary portion between the spacer and the upper rotary plate has an installation angle of 45.degree. Since it is configured to be located in, it is possible to receive all of the processing liquid scattered outward from the outer periphery of the substrate by the spacer when the substrate is rotated,
It is possible to prevent the upper rotary plate from being contaminated by the processing liquid.

According to the second aspect of the present invention, the installation angle is equal to or more than the maximum value of the scattering angle with respect to the horizontal direction of the processing liquid scattered upward and outward from the outer periphery of the substrate when the substrate is rotated. Therefore, it is possible to prevent the processing liquid from the outer periphery of the substrate from splashing over the boundary portion to the upper rotary plate.

According to the invention of claim 3, since the installation angle is set to 70 ° to 80 °, it is possible to prevent the upper rotary plate from being contaminated by the processing liquid discharged from the outer periphery of the substrate. .

According to the fourth aspect of the present invention, a square through hole is provided in the central portion of the spacer corresponding to the square substrate, and the rotation supporting means, the upper rotary plate and the spacer are provided. Since the boundary portion is formed along the outer periphery of the substrate when integrated, the installation angle can be made substantially constant.

[Brief description of drawings]

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

2 is a partial perspective view of the device of FIG. 1. FIG.

3 is a partially enlarged view of the device of FIG.

FIG. 4 is a cross-sectional view showing a conventional spin coating device.

[Explanation of symbols]

 2 Substrate 6 Underplate 12 Adsorption chuck 14 Top plate 16 Spacer 26 Boundary L Excessive processing liquid θ Installation angle

Claims (4)

[Claims] 1. A rotary coating apparatus for coating a substrate with a treatment liquid by rotating the substrate and diffusing the treatment liquid supplied to the surface of the substrate over the entire surface of the substrate. Means, an upper rotating plate which is arranged in parallel with the substrate supported by the rotation supporting means at a predetermined interval and is rotated together with the substrate, and an upper rotating plate is mounted on the upper rotating plate and the rotation supporting means and the upper rotation plate. A space for accommodating the substrate is formed together with the plate to be rotated together with the substrate and the upper rotary plate, and from the outer periphery of the substrate supported by the rotation supporting means to 45 ° to 90 ° with respect to the radial direction and the horizontal direction during rotation. And a spacer having an opening whose outer periphery is arranged in an upward and outward direction at an installation angle up to and including a spacer formed at the center of the upper portion. 2. The installation angle is set to an angle equal to or larger than a maximum value of a scattering angle with respect to a horizontal direction of a processing liquid scattered upward and outward from the outer periphery of the substrate when the substrate is rotated. 1. The spin coating apparatus according to 1. 3. The spin coating apparatus according to claim 1, wherein the installation angle is set to an angle of 70 ° to 80 °. 4. The spin coating apparatus according to claim 1, wherein the substrate is a rectangular substrate, and the opening of the spacer is a short form similar to the rectangular substrate. .