JPH09232269A - Rotary substrate treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary substrate treatment device short in the treatment time while having a simple device structure. SOLUTION: When a ring-like magnet 23 ascends, a repulsive force of a magnetic force affecting a permanent magnet 8 integral in a push-up member 10 is increased, and when the repulsive force is presently greater than gravity acting on the push-up member 10, the push-up member 10 starts rotating with a support shaft 7a serving as a rotation shaft and a plate 6 also starts ascending together therewith. When the ring-like magnet 23 further ascends, the push-up member 10 rotates until a position where its vertical member 10b comes into contact with a pin 9a, and the plate 6 ascends to the vicinity of a substrate W. At this time, an ascending position of the plate 6 is restricted by using a bolt 11 so that the plate 6 does not come into contact with a pattern face Wa of the substrate W. If the ring-like magnet 23 is at a position for ascending, as the ring-like magnet 23 is annular, the repulsive force always affects the permanent magnet 8 during a rotation processing and it is possible to maintain stably the plate 6 at an ascending position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary substrate processing apparatus for rotating a thin substrate (hereinafter referred to as "substrate") such as a semiconductor substrate or a liquid crystal glass substrate to perform various treatments such as cleaning treatment.

[0002]

2. Description of the Related Art Generally, in a rotary substrate processing apparatus as described above, a plurality of substrate holding members are provided on a turntable on which the substrates are placed, and the substrates are positioned and held by the substrate holding members. ing. If the substrate is supported horizontally by being separated from the turntable by the substrate holding member, it is possible to prevent the lower surface of the substrate (the surface facing the turntable) from being damaged. However, since the substrate is held apart from the turntable, there is a problem that the mist of the processing liquid scattered during the rotation process goes around and adheres to the lower surface of the substrate to contaminate the lower surface. Therefore, during rotation processing of the substrate, pure water or the like is sprayed onto the lower surface to prevent the mist from flowing around to the lower surface (hereinafter referred to as "back rinse").

By the way, the lower surface of the substrate is the rear surface of the substrate (the side opposite to the resist-coated pattern surface) in the chemical coating process and the like. Contamination of the rear surface of the substrate which cannot be sufficiently prevented by back rinse is performed by the exposure process. When performing the above, it may hinder the normal exposure of the pattern on the substrate surface (pattern surface coated with resist). For this reason, the back surface of the substrate is cleaned before the exposure process. At this time, the back surface of the substrate is supported by the substrate holding member, and the cleaning brush is brought into contact with the back surface of the substrate, or the high pressure jet is used. The back surface of the substrate is cleaned by rotating the substrate while spraying water.

If back rinse is performed for the purpose of preventing the mist from adhering to the substrate surface during such cleaning, there is a problem that the resist film formed on the substrate surface is damaged. In order to solve this problem, as shown below, a rotary substrate cleaning device (spin scrubber) is provided that prevents the mist from adhering to the substrate surface by providing a vertically movable plate between the substrate surface and the turntable. Proposed.

FIG. 6 shows a conventional rotary substrate cleaning apparatus SS6.
6 is a partial front view for explaining the operation of FIG. The rotary substrate cleaning apparatus SS6 includes a turntable 101, a substrate holding member 105, and a plate 106, and the substrate holding member 105 causes the substrate W to have its pattern surface Wa as its lower surface (that is, the back surface Wb (On the upper surface) and is horizontally held apart from the turntable 101.

The rotary table 101 is also provided with a plate driving means 107. The plate driving means 107 is provided with an inverted L-shaped lifting member 107a composed of an operating piece 107a ₁ and a hanging piece 107a _2, and a weight 107b is attached to the lower end of the hanging piece 107a ₂ . An intermediate bent portion of the push-up member 107a is inserted into and supported by a pin 107c provided on the bearing 107d. At this time, the push-up member 107a is rotatably supported with the pin shaft of the pin 107c as a rotation shaft.

In the rotary substrate cleaning apparatus SS6, when the substrate rotation process is started, the rotary base 101 is rotationally driven by a motor (not shown). Then, as the rotary table 101 rotates, centrifugal force begins to act on the weight 107b. The centrifugal force acting on the weight 107b increases as the rotation speed of the turntable 101 increases, and eventually the push-up member 107a starts to rotate clockwise in the figure, and as a result, the operating piece 107a ₁ moves to the plate 1a.
Gradually push 06 upward. Thus, the turntable 10
When the rotation speed of 1 reaches a predetermined speed, the plate 106
Is lifted to a position (a position indicated by a chain double-dashed line in the figure) where it abuts on the lower surface of the stopper 105a of the substrate holding member 105, and then a cleaning liquid is sprayed from a nozzle (not shown) to clean the back surface Wb of the substrate. This state is maintained during the rotation process.

When the rotation process ends, the rotation speed of the turntable 101 gradually decreases, and the centrifugal force acting on the weight 107b also decreases. Then, the push-up member 107a rotates counterclockwise in the figure, and as a result, the plate 106 descends,
Return to the original position (the position shown by the solid line in the figure).

With the above arrangement, the plate 106 rises during the rotation process and the gap between the substrate W and the plate 106 is narrowed, so that the mist hardly wraps around the pattern surface Wa side of the substrate W. Therefore, it is possible to prevent the mist from adhering to the pattern surface Wa.

[0010]

However, in the rotary substrate cleaning apparatus SS6 as described above, the weight 10 is provided while the rotation speed of the rotary table 101 is low at the initial stage of processing.
Since a sufficient centrifugal force does not act on 7b, the push-up member 107
It is not possible to raise the plate 106 to the position where the plate 106 contacts the lower surface of the stopper 105a. When the cleaning liquid is sprayed before the plate 106 has risen to the position, the mist wraps around the pattern surface Wa side of the substrate and adheres to the pattern surface Wa because the gap between the substrate W and the plate 106 is wide. become.

Therefore, in the rotary substrate cleaning apparatus SS6, it is necessary to provide an interlock so that the cleaning liquid is not ejected until the rotary table 101 reaches a predetermined rotation speed, which makes the apparatus as a whole complicated. Moreover, since the cleaning process cannot be performed until the rotary table 101 reaches a predetermined rotation speed,
There is a problem that the processing time becomes long.

In view of the above problems, it is an object of the present invention to provide a rotary substrate processing apparatus having a simple apparatus configuration and a short processing time.

[0013]

In order to solve the above-mentioned problems, the invention of claim 1 is a rotary substrate processing apparatus for applying a processing liquid to the upper surface of the substrate to perform a predetermined processing while rotating the substrate. In (a) a turntable for rotating the substrate, (b) a substrate holding member which is provided on an upper surface of the turntable and holds the substrate at a predetermined distance from the turntable, ) A plate having at least the same size as the substrate, provided within the predetermined interval, and movable up and down within the predetermined interval, (d)
A plate driving unit that has a first magnetic member, is provided on the rotary table, and moves the plate up and down; and (e) along a predetermined rotation locus about the rotation axis of the rotary table, A substantially annular second magnetic member arranged below the turntable, and (f) relative raising / lowering means for moving the turntable and the second magnetic member relative to each other. The plate driving means is driven by the increase and decrease of the magnetic force acting between the first and second magnetic members due to the relative elevation with respect to the second magnetic member, and the plate is raised to the vicinity of the substrate; It is possible to lower the rotation table to the vicinity thereof.

According to a second aspect of the invention, in the rotary substrate processing apparatus according to the first aspect of the invention, the plate is
In addition to being larger than the planar size of the substrate, a thickness of a region of the plate outside the outer periphery of the substrate is larger than a thickness of a region facing the substrate.

According to a third aspect of the present invention, in the rotary substrate processing apparatus according to the first aspect of the present invention, the plate is
The size is approximately the same as the planar size of the substrate, and the thickness of the region of the plate facing the outer periphery of the substrate is thicker than the thickness of the region inside the region.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional front view of essential parts of a rotary substrate cleaning apparatus SS1 which is an embodiment of the rotary substrate processing apparatus according to the present invention. This rotary substrate cleaning apparatus SS1 includes a rotary table 1 for rotating a substrate W, a plate 6 movable up and down between the substrate W and the rotary table 1, and a nozzle 50 for injecting a cleaning liquid such as pure water onto the substrate W. And a cup 20 for collecting the cleaning liquid scattered from the substrate W during the rotation process, a motor 40 for rotationally driving the rotary base 1, and an air cylinder 30 for raising and lowering the cup 20.

The rotary base 1 has a motor 4 via a rotary shaft 41.
It is connected to 0 and is rotatable in association with the rotation of the motor 40. FIG. 2 is a top view of the turntable 1. Two rotary holding members 4 and four fixed holding members 5 are erected on the upper surface of the peripheral portion of the rotary table 1. The rotatable holding member 4 includes a cylindrical support portion 4b and the support portion 4b.
A cylindrical holding portion 4a provided eccentrically from the central axis of the support portion 4b is provided on the upper surface of b. Further, the fixed holding member 5 includes a cylindrical support portion 5b and a cylindrical holding portion 5a provided on the upper surface of the support portion 5b. The holding member holds the substrate W horizontally away from the turntable 1. The mechanism will be described later.

Further, the rotary table 1 is provided with three plate driving means 7, and the plate driving means 7 vertically moves the plate 6. The holding of the substrate W and the vertical movement of the plate 6 are performed as the cup 20 is moved up and down, which will be described in detail later. The numbers of the rotary holding members 4 and the fixed holding members 5 are not limited to the above-mentioned forms, and one or more may be provided so that the substrate W can be stably held. Further, the plate driving means 7 is not limited to three, and may be any number that can stably move the plate 6 up and down.

The plate 6 is a disk-shaped member that is larger than the planar size of the substrate W, and its peripheral edge portion 6a is an area outside the area facing the substrate W and the inside 6b.
Is an area facing the substrate W. Further, the thickness of the peripheral edge portion 6a is formed to be thicker than the thickness of the inside 6b. Then, in the plate 6, guide holes having a diameter slightly larger than those of the support portions 4b and 5b are formed at positions facing the rotary holding member 4 and the fixed holding member 5. The plate 6 is movable in the vertical direction by being provided in the rotary holding member 4 and the fixed holding member 5 so as to pass through the guide holes.

Returning to FIG. 1, a cup base 21 is provided on the lower surface of the bottom of the cup 20, and the cup base 21 is connected to the air cylinder 30 via a piston 31. Further, a ring 22 containing a ring-shaped magnet 23 is provided on the upper surface of the bottom of the cup 20. The ring-shaped magnet 23 is an annular permanent magnet centered on the rotation shaft 41, and has, for example, an S pole on the inner diameter side and an N pole on the outer diameter side. By moving the cup 20 up and down by the air cylinder 30, the ring-shaped magnet 23
Can be raised and lowered. The means for raising and lowering the cup 20 is not limited to the air cylinder 30, and may be an electromagnetic actuator, for example.

When the rotation cleaning process is performed on the substrate W, first, the pattern surface Wa is on the lower side and the back surface Wb is on the upper side, and the supporting portion 4b of the rotary holding member 4 and the fixed holding member 5 are first. It is placed on the supporting portion 5b of the. At this time, the cup 20 is in the lowered position (the position indicated by the chain double-dashed line in FIG. 1).

Next, the air cylinder 30 is operated to raise the cup 20 to the position shown by the solid line in FIG. As the cup 20 rises, the ring-shaped magnet 23
Also rises to the position indicated by the solid line in FIG. As a result, the ring-shaped magnet 23 approaches the permanent magnet 14a built in the magnet holding member 14 and the permanent magnet 8 provided in the plate driving means 7.

By the way, the fixed holding member 5 is the rotary table 1.
In contrast to the fixed arrangement of the rotary holding member 4
Is rotatably arranged on the turntable 1 and is further connected to the magnet holding member 14 below the turntable 1. When the ring-shaped magnet 23 approaches or separates from the permanent magnet 14a contained in the magnet holding member 14, the direction of the magnetic force lines acting on the permanent magnet 14a is reversed, and the permanent magnet 1
A turning force is generated in 4a, and the rotary holding member 4 rotates accordingly. That is, when the ring-shaped magnet 23 is descending, the holding portion 4 a of the rotary holding member 4 moves to the substrate W.
When the ring-shaped magnet 23 is raised, the holding portion 4a abuts on the peripheral end portion of the substrate W and presses and urges the substrate W away from the peripheral end portion of the substrate W. It is configured. The position of the substrate W that has been pressed and biased is regulated by the holding portion 5 a of the fixed holding member 5. In this way, the substrate W is separated from the turntable 1 and held horizontally by the rise of the ring-shaped magnet 23.

On the other hand, the plate driving means 7 containing the permanent magnet 8 is also driven by raising and lowering the ring-shaped magnet 23.
FIG. 3 is a partial front view for explaining the operation of the plate driving means 7.

The plate driving means 7 includes a support shaft 7a fixed to the rotary table 1, a push-up member 10 rotatably supported by the support shaft 7a, and a bearing 9 fixed to the rotary table 1. The bearing 9 includes a pin 9a whose both ends are held. The permanent magnet 8 is built in the push-up member 10, and its position is substantially above the ring-shaped magnet 23 in the vertical direction. At this time, the polarities of the permanent magnets 8 match the polarities of the ring magnets 23 facing each other, as shown in FIG. 3, that is, the N pole is on the outer diameter side of the ring magnet 23 and the S pole is on the inner diameter side. When the poles are formed, the N pole is formed on the side farther from the rotation center of the rotary table 1 in the permanent magnet 8 and the S pole is formed on the closer side. Therefore, a repulsive force due to the magnetic force acts between the ring-shaped magnet 23 and the permanent magnet 8.

When the ring-shaped magnet 23 is in the lowered position (the position shown by the solid line in FIG. 3), the ring-shaped magnet 2 is
Since the distance between the magnet 3 and the permanent magnet 8 is relatively large, the gravity acting on the push-up member 10 is larger than the repulsive force acting between the two magnets, and the push-up member 10 is rotated counterclockwise in FIG. Power is generated. Then, the tip of the operating piece 10a of the push-up member 10 is in a state of being locked to the pin 9a (the state shown by the solid line in FIG. 3). At this time, the plate 6 has three minute projections 12 (see FIG. 2) provided on the upper surface of the turntable 1.
It becomes a state supported by the reference).

Next, in the process of raising the ring-shaped magnet 23, as the distance between the ring-shaped magnet 23 and the permanent magnet 8 becomes smaller, the repulsive force acting between the two magnets increases, and eventually the repulsive force is increased. When it becomes larger than the gravity acting on the push-up member 10, a clockwise turning force in FIG. 3 starts to act on the push-up member 10, and the push-up member 10 gradually starts to rotate with the support shaft 7a as the rotation shaft. As a result, the push-up member 10 gradually pushes up the plate 6, and the plate 6 supports the support portion 5 of the fixed holding member 5.
b and is guided by the support portion 4b of the rotary holding member 4 to ascend along the vertical direction.

Next, when the ring-shaped magnet 23 is further raised, the push-up member 10 is further rotated accordingly,
Eventually, the hanging piece 10b of the push-up member 10 comes into contact with the pin 9a, and the push-up member 10 is restricted to the position shown by the chain double-dashed line in FIG. Along with that, the plate 6 is also supported in a state of being raised to the vicinity of the substrate W. At this time, the plate 6 comes into contact with the substrate W and the pattern surface Wa
To prevent damage to the
1 is provided. The bolt 11 has a washer 11a below the rotary table 1 through which the rotary table 1 is inserted. When the washer 11a contacts the lower surface of the rotary table 1, the plate 6 contacts the pattern surface Wa of the substrate W. Are prevented. At this time, even if the plate 6 is too far from the pattern surface Wa of the substrate W, the mist during the cleaning process wraps around between the pattern surface Wa and the plate 6. Pattern surface W
It is desirable to bring the pattern surface Wa as close to the pattern surface Wa as possible without contacting a. Further, the regulation of the rising position of the plate 6 is not limited to the use of the bolt 11, but may be provided, for example, by providing the fixed holding member 5 and the rotary holding member 4 with stoppers.

Next, when the ring-shaped magnet 23 rises to a predetermined position (position indicated by a chain double-dashed line in FIG. 3) during the rotation processing, a larger repulsive force acts on the push-up member 10,
The push-up member 10 can stably maintain the posture of the chain double-dashed line in the figure, and as a result, the plate 6 is also stably supported in the raised position. Then, when the rotation process is started, the cleaning liquid is sprayed from the nozzle 50, and the rotary table 1 starts the rotation operation. However, since the ring-shaped magnet 23 has an annular shape, the plate is stably maintained during the rotation process. The state where 6 is raised is maintained.

FIG. 4 is a diagram for explaining how the plate 6 is raised. As shown in the drawing, when the plate 6 is in the raised position, the thickness of the peripheral edge portion 6a of the plate 6 is equal to that of the inside 6
Since it is thicker than the thickness of b, the peripheral portion 6a covers the periphery of the substrate W. Therefore, the mist of the processing liquid hardly wraps around between the pattern surface Wa of the substrate W and the plate 6, so that the mist can be prevented from adhering to the pattern surface Wa. As a result, conventionally, a processing liquid that causes a problem when mist adheres to the pattern surface Wa can also be used, so that the choice of substrate processing methods is expanded.

When the rotation process is completed, the motor 40 shown in FIG.
Stops and the rotation speed of the turntable 1 gradually decreases.
Even when the rotary table 1 is completely stopped, the repulsive force from the ring-shaped magnet 23 continues to act on the push-up member 10, so that the plate 6 continues to be kept in the raised state. Next, when the cup 20 descends, the ring-shaped magnet 23 descends accordingly, the repulsive force acting on the push-up member 10 weakens, and the push-up member 10 returns to the state before processing (the position indicated by the solid line in FIG. 3). . Then, with the rotation of the push-up member 10, the plate 6 also returns to the lowered position.

With the above arrangement, since the cup 20 is raised at the same time as the cup 20 is raised during the rotation process,
It is not necessary to wait for the injection of the treatment liquid until the rotary table 1 reaches a predetermined rotation speed, and the interlock for that can be eliminated. Therefore, the device configuration can be simplified and the cost can be reduced.

Furthermore, since the treatment liquid can be jetted at the same time when the rotation of the turntable 1 is started, the rotation treatment time can be shortened and the treatment efficiency can be improved.

[0035]

[Modification] The embodiment of the present invention has been described above. However, the present invention is not limited to the above embodiment,
For example, the shape of the plate may be as shown below.

FIG. 5 is a diagram for explaining another form of the plate. Note that FIG. 5 is similar to FIG.
6 has shown the state which rose. This plate 16
It is a disk-shaped member having a size substantially the same as the plane size of the substrate W, and the thickness of the peripheral edge portion 16a thereof is thicker than the thickness of the inside 16b. The rising position of the plate 16 is
Although the peripheral edge 16a is regulated by the bolts 11 (see FIG. 3) so as to approach the pattern surface Wa of the substrate W within a range that does not contact the peripheral surface 16a, the peripheral edge 16a may contact the pattern surface Wa. This is because the peripheral portion of the pattern surface Wa is not used finally.

According to the plate 16 described above, the distance between the pattern surface Wa of the substrate W and the peripheral edge portion 16a is extremely narrow, or the pattern surface Wa and the peripheral edge portion 16a are in contact with each other. The mist of the treatment liquid does not wrap around to the side, and it is possible to prevent the mist from adhering to the pattern surface Wa. Furthermore, even if the inside 16b of the plate 16 is slightly bent during the rotation process,
Since the thickened peripheral portion 16a is hard to be deformed, the substrate W
Will not damage. Therefore, the inner portion 16b can be thinned to reduce the mass of the plate 16 as a whole, and as a result, the inertia of the plate 16 can be reduced.

Further, in the above embodiment, the cup 2
Although the ring-shaped magnet 23 and the permanent magnet 8 are moved close to and away from each other by raising and lowering 0, this may be performed by raising and lowering the rotary table 1.

Further, in the above embodiment, the permanent magnet 8 built in the push-up member 10 which constitutes the plate driving means 7.
And the plate 6 is moved up and down by using the repulsive force of the ring-shaped magnet 23 built in the ring 22 provided on the upper surface of the bottom of the cup 20, but not limited to this, the push-up member 10 can be freely rotated. By changing the positions of the support shaft 7a and the permanent magnet 8 that are supported by the permanent magnet 8 and the ring-shaped magnet 23,
The plate 6 may be moved up and down by utilizing the quote.

Further, the rotary substrate processing apparatus according to the present invention can be applied not only to the rotary substrate cleaning apparatus but also to a rotary coating apparatus, a rotary developing apparatus and the like. In this case, the back surface Wb of the substrate W is set to the lower side, and the back surface Wb
Since the mist can be prevented from adhering to the surface, the subsequent cleaning process becomes easy.

[0041]

According to the first aspect of the present invention, a plate movable up and down is provided between the turntable and the substrate held at a predetermined distance from the turntable, and the turntable has a magnetic member. And a plate drive means having a drive means for driving the plate drive means by increasing and decreasing the magnetic member having a substantially annular shape to increase or decrease the magnetic force between both magnetic members, and raising the plate to the vicinity of the substrate, and rotating the plate. Since it is possible to lower it to the vicinity of the table, it is not necessary to wait for the injection of the processing liquid until the rotary table reaches a predetermined rotation speed, and the interlock for that can be eliminated.
Therefore, the device configuration can be simplified and the cost can be reduced. Further, since the treatment liquid can be jetted at the same time as the rotation of the turntable is started, the rotation treatment time can be shortened and the treatment efficiency can be improved.

According to the second aspect of the present invention, since the thickness of the region outside the outer periphery of the plate of the plate which is larger than the plane size of the substrate is larger than the thickness of the region facing the substrate, the peripheral edge of the plate. Since the portion covers the periphery of the substrate and the mist of the processing liquid hardly wraps around between the substrate and the plate, it is possible to prevent the mist from adhering to the lower surface of the substrate. As a result, a treatment liquid that conventionally causes a problem when mist adheres to the substrate surface can be used, so that the choice of substrate treatment methods can be expanded.

According to the third aspect of the present invention, the thickness of the region of the plate having the same plane size as the substrate facing the outer peripheral portion of the substrate is made thicker than the thickness of the inner region. Even if the thickness of the region is reduced, the peripheral portion of the plate does not easily deform so that the substrate is not damaged during the rotation process. Therefore, it is possible to reduce the weight of the plate and reduce the inertia of the plate.

[Brief description of drawings]

FIG. 1 is a sectional front view of a main part of a rotary substrate cleaning apparatus that is an embodiment of a rotary substrate processing apparatus according to the present invention.

FIG. 2 is a top view of a turntable of the rotary substrate cleaning apparatus of FIG.

FIG. 3 is a partial front view for explaining the operation of the plate driving means of FIG.

FIG. 4 is a diagram for explaining how the plate is raised.

FIG. 5 is a diagram illustrating another form of the plate.

FIG. 6 is a partial front view for explaining the operation of the conventional rotary substrate cleaning apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary table 4 rotary holding member 5 fixed holding member 6 plate 7 plate driving means 8 permanent magnet 20 cup 23 ring magnet 30 air cylinder 40 motor W substrate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H01L 21/68 H01L 21/30 564C 569C

Claims (3)

[Claims] 1. A rotary substrate processing apparatus that applies a processing liquid to the upper surface of the substrate to perform a predetermined process while rotating the substrate, comprising: (a) a rotary table for rotating the substrate; ) A substrate holding member which is provided on the upper surface of the turntable and holds the substrate at a predetermined distance from the turntable, and (c) has at least the same size as the substrate and has the predetermined distance. A plate that is provided inside and that can move up and down within the predetermined interval; and (d) a plate drive means that has a first magnetic member and that is provided on the turntable and that moves the plate up and down. (e) A second substantially annular ring disposed below the rotary table along a predetermined rotation locus about the rotation axis of the rotary table.
(F) relative elevating means for relatively elevating and lowering the rotary base and the second magnetic member, and the first and second magnetic heads by relative elevation of the rotary base and the second magnetic member. It is possible to drive the plate driving means by increasing and decreasing the magnetic force acting between the second magnetic members to raise the plate to the vicinity of the substrate and to lower the plate to the vicinity of the rotary table. A rotary substrate processing apparatus characterized by the above. 2. The rotary substrate processing apparatus according to claim 1, wherein the plate is larger than a planar size of the substrate,
A rotary substrate processing apparatus, wherein a thickness of a region of the plate outside an outer periphery of the substrate is larger than a thickness of a region facing the substrate. 3. The rotary substrate processing apparatus according to claim 1, wherein the plate has a size substantially equal to a plane size of the substrate, and a thickness of a region of the plate facing the outer peripheral portion of the substrate. Is thicker than the region inside the region, the rotary substrate processing apparatus.