JPH0774143A - Substrate holder - Google Patents

Abstract

PURPOSE:To avoid the slippage of a substrate in the initial stage of acceleration of rotation and in the final stage of deceleration in which the slippage is easily produced by a method wherein a substrate pressure member is pressed against the substrate. CONSTITUTION:A substrate W is held on a horizontal rotary table 1. A pendulum type pressure member 11 which can be turned in a plane not perpendicular to the rotary table 1 is provided on the outer edge side of the rotary table 1. In a period in which the absolute value of the acceleration of the rotation is small, the pressure member 11 is separated from the substrate W. In the initial stage of the acceleration of the rotation and the final stage of the deceleration of the rotation in which the absolute value of the acceleration of the rotation is large, the pressing member 11 is turned and displaced significantly by an inertia and the predetermined part of the member 11 is brought into contact with the outer edge Wa of the substrate W to prevent the substrate W from slippage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substantially circular substrate such as a semiconductor wafer having a notch such as an orientation flat or notch, or a circular substrate having no notch such as an optical disk substrate. The present invention relates to a substrate holding device used in a rotary substrate processing apparatus that processes a substrate by supporting the substrate on a turntable and supplying various processing liquids such as cleaning liquid and etching liquid to the upper surface of the substrate.

[0002]

2. Description of the Related Art In a rotary substrate processing apparatus for processing a substrate such as a semiconductor wafer or a glass substrate for a photomask, which requires a high degree of cleanliness, a substrate between a member for holding the substrate during rotation of the substrate and the substrate. It is required to minimize slippage. When slippage occurs, the surface of the substrate is scraped, which not only damages the substrate, but also causes dust generation and contamination of the substrate itself. Further, since the flow of the processing liquid becomes non-uniform, there arises a problem in the quality of processing the substrate. Therefore, for example, in Japanese Unexamined Patent Publication No. 51-132927 and Japanese Patent Publication No. 3-77585,
A technique for suppressing slippage during rotation of a substrate is disclosed.
In these conventional devices, a centrifugal arm that can come into contact with the outer edge of a horizontally placed substrate is provided on the horizontal rotary table, and the arm is moved by the action of centrifugal force associated with the rotation of the horizontal rotary table. It is pressed and urged against the outer edge of the substrate. Due to the frictional force between the pressure-biased arm and the outer edge of the substrate,
The effect of preventing slippage of the substrate can be obtained.

[0003]

However, since these prior arts use the centrifugal force to sandwich the substrate, the period during which the rotation speed is not sufficiently high during rotation acceleration and rotation deceleration, That is, there is a problem that slip cannot be sufficiently suppressed in the initial stage of rotational acceleration and the final stage of rotational deceleration.

The present invention is aimed at eliminating the above-mentioned drawbacks of the prior art, and is capable of suppressing the slippage of the substrate including the initial stage of rotational acceleration and the final stage of rotational deceleration. The purpose is to provide.

[0005]

A substrate holding device according to the present invention holds a substrate when performing a predetermined process on a main surface of the substrate while horizontally rotating the substrate in a predetermined rotation direction around a vertical axis. A substrate holding device used for, (a) a horizontal rotary table, (b) a substrate holding member provided on the upper surface side of the horizontal rotary table to hold the substrate,
(c) a pressing member that is axially supported on the outer peripheral side of the horizontal rotary table, is bidirectionally rotatable within a non-vertical plane, and has a center of gravity at a position offset from the rotational axis, Only when the rotation angle of the center of gravity of the pressing member reaches the predetermined first and second critical angles, the predetermined portion of the pressing member contacts the outer edge of the substrate, and the first and second critical angles are reached. Is defined within a range deviated to the direction opposite to the predetermined rotation direction with reference to the direction connecting the rotation center of the horizontal rotary table and the position of the shaft support.

[0006]

In the substrate holding device according to the present invention, in the initial stage of the process in which the rotary base accelerates the rotation, the holding member is rotated so that the center of gravity of the holding member approaches the direction of rotation rearward by the action of the inertial force associated with the acceleration. Move. Therefore, the center of gravity is located closer to the rear in the rotational direction of the first and second critical angles (for example, this is the first critical angle), and the predetermined portion of the pressing member contacts the outer edge of the substrate. Press and urge. As a result, a frictional force is generated between the predetermined portion and the outer edge of the substrate, so that the substrate is prevented from slipping. On the other hand, when acceleration is sufficient and the turntable rotates at a relatively high speed, centrifugal force acts more strongly than inertial force, so the center of gravity of the pressing member approaches the rotation axis radially outward of the rotation. The pressing member rotates so as to move. Therefore, the center of gravity is located at another critical angle (for example, the second critical angle), and the predetermined portion comes into contact with the outer edge of the substrate and presses and biases it. As a result, a frictional force is generated between the predetermined portion and the outer edge of the substrate, so that the substrate is prevented from slipping. Further, when the rotary table performs rotational deceleration, the inertial force associated with deceleration is added to the centrifugal force, so that the center of gravity is
Is also positioned at the critical angle of, and a predetermined portion comes into contact with the outer edge of the substrate and presses and biases it. As a result, a frictional force is generated between the predetermined portion and the outer edge of the substrate, so that the substrate is prevented from slipping. As described above, in the apparatus of the present invention, the slippage of the substrate can be suppressed including the initial stage of rotational acceleration and the final stage of rotational deceleration.

When the center of gravity is located between the first critical angle and the second critical angle, the pressing member releases the outer edge of the substrate. Therefore, by setting the rotation position of the pressing member to this position, the substrate can be placed on the substrate holding member,
Also, it can be easily removed from the substrate holding member.

[0008]

[Example] <Rotary substrate processing apparatus 10>

Prior to the description of the structure and function of the substrate holding apparatus in the embodiment of the present invention, a rotary substrate processing apparatus equipped with the apparatus of the embodiment will be described. The side view of FIG. 2 partially having a notch schematically shows the general configuration of the rotary substrate processing apparatus.

The rotary substrate processing apparatus 10 includes a substrate holding device 100 that is driven to rotate by a motor 6 and an upper surface of a substrate W held by the substrate holding device 100. The cleaning liquid containing the cleaning liquid, the processing liquid supply nozzle 7 for supplying various processing liquids such as the photoresist liquid, the developing liquid, and the etching liquid, and the rotary drive shaft 6a of the motor 6 are inserted to surround the side and the lower side of the substrate W. And a processing liquid recovery cup 8 for recovering the processing liquid scattered from the substrate W. The motor 6 is provided such that its rotation drive shaft 6a is vertical, and the substrate holding device 10
Reference numeral 0 denotes a rotary table 1 which is horizontally rotated by a motor 6, a plurality of substrate holding members 2 fixedly arranged on the peripheral edge of the rotary table 1, and a pressing member which is also rotatably attached to the peripheral edge. And a member (not shown in FIG. 2).

The surface treatment of the substrate W is performed by supplying a required treatment liquid to the upper surface of the substrate W which is horizontally rotated while being held by the substrate holding device 100. The processing liquid recovery cup 8 can be lifted and lowered in the vertical direction, in other words, in the direction of the rotation axis of the substrate holding device 100, by a lifting means (not shown).
When the substrate W is placed on the substrate holding device 100 and taken out from the substrate holding device 100, the processing liquid recovery cup 8 is used.
Is relatively lower, and is relatively higher in the process of rotating the substrate W to perform processing. FIG. 2 shows the treatment liquid recovery cup 8 in the step of performing the latter treatment.

<Structure of Substrate Holding Device 100>

FIG. 1 is a perspective view of a substrate holding device 100 used in a rotary substrate processing apparatus 10. The substrate holding member 2 and the pressing member 1 are provided on the upper surface of the turntable 1 that rotates about a vertical rotation axis A that coincides with the rotation drive shaft 6 a of the motor 6.
1 and 1 are arranged around a circular substrate W to be placed. The substrate holding member 2 is a member that holds the substrate W at a predetermined position, and is formed by integrally forming the substrate supporting portion 3 and the horizontal position regulating portion 4. The pressing member 11 has a rotating shaft 12a.
The turntable 1 is rotatably supported around (details will be described later).

FIG. 3 is a plan view of the substrate holding device 100. The substrate holding member 2 preferably has a center C of a circle R defined so as to be in contact with the horizontal position restricting portions 4 on the side of the rotating shafts A when viewed from the plurality of horizontal position restricting portions 4 such that the center of rotation C of the rotary table is the rotational axis. It is arranged so as to be displaced from A by a predetermined distance L in the horizontal direction. That is, when the substrate W is held by the substrate holding member 2, in the case of a circular substrate W having no notch (shown in FIG. 3), the center position of the outer edge Wa, a notch, etc. are formed in a substantially circular shape. In the case of the substrate (not shown), the position of the center of the arc portion of the outer edge thereof coincides with C and is displaced from the rotation axis A in the horizontal direction. Holding member 1
1 is installed on the side opposite to the center C described above with respect to the rotation axis A, that is, at a position where the outer edge Wa of the substrate W is closest to the rotation axis A.

FIG. 4 shows the substrate holding device 100 on the line BB (FIGS. 1 and 3) which coincides with the rotating shaft 12a, that is, on the surface including the rotating shaft 12a and the center of gravity G in the mounting portion of the pressing member 11. FIG. The substrate support portion 3 that constitutes the substrate holding member 2 supports the substrate W horizontally away from the rotary table 1 by abutting the upper surface thereof on the bottom surface portion Wb near the outer edge of the substrate W. The side surface of the horizontal position regulating portion 4 contacts the outer edge Wa of the substrate W to regulate the horizontal position of the substrate W. Note that the substrate W to the substrate holding device 100 is
In order to facilitate the placement of the substrate W, the horizontal position restricting portion 4 may have some play with respect to the outer edge Wa of the substrate W so that the horizontal position of the substrate W is substantially restricted. It should be done.

In the substrate holding apparatus 100, the upper surface of the rotary table 1 is formed substantially in the horizontal plane, and the inclined surface 1a is formed on a portion of the rotary table 1 on the side opposite to the center C when viewed from the rotation axis A.
Are formed. The inclined surface 1a is an angle deviated from the upper surface of the rotary table 1 in the clockwise direction by an angle α when viewed from the upper side of the rotary table 1 with respect to a direction opposite to the center C from the rotation axis A, and is lowered outward in the radial direction. Is formed. The pressing member 11 has a twisted positional relationship with the rotation axis A on the extended inclined surface 1a extending from the center C toward the rotation axis A and is perpendicular to the inclined surface 1a, that is, from the rotation axis A of the turntable 1 toward the upper side. It is rotatably provided around a rotating shaft 12a inclined so as to separate. According to the present invention, the rotating shaft 1
It is sufficient that the direction of 2a is inclined with respect to the horizontal plane. In other words, the rotation surface of the pressing member 11 that rotates around the rotation shaft 12a may be a non-vertical surface that is inclined with respect to the vertical surface.

The pressing member 11 is supported by the rotary table 1 so as to be bidirectionally rotatable via a rotary bearing member 12. The pressing member 11 includes a resin pressing member main body 11a, a metal weight member 11b, and a resin connecting member 1 that connects the pressing member main body 11a and the weight member 11b.
1d and. The surface of the weight member 11b is covered with a thin resin film (not shown) for rust prevention. The pressing member main body 11a has a pressing surface 11c that is a surface that can come into contact with the substrate outer edge Wa. The pressing member main body 11a is fixedly coupled to the connecting member 11d by a nut 14. The pressing member main body 11a and the rotary bearing member 12 are
By using, for example, a fluororesin, the rotational frictional force acting between the pressing member main body 11a and the rotational bearing member 12 can be reduced.

The weight member 11b is the center of gravity G of the pressing member 11.
Is the rotation shaft 12 defined by the rotation bearing member 12.
It is provided so as to be displaced from a. Rotation axis 1
2a is inclined with respect to the rotation axis A at a predetermined inclination angle as described above, and the upward direction thereof is the outer radial direction Rd of rotation.
It is directed in a predetermined direction P0 between (FIG. 3) and the backward direction Bd in the rotational direction. The rotary table 1 has an inclined surface 1a at a position where the pressing member 11 is installed so as not to hinder the rotation of the pressing member 11.

<Operation of Substrate Holding Device 100>

FIG. 5 is a schematic view for explaining the operation of the substrate holding device 100. Before and after the processing of the substrate W, that is, when the substrate W is placed on the substrate holding member 2 and when it is removed from the substrate holding member 2, the rotary table 1 is stationary and does not rotate. At this time, the rotating shaft 12a
Is inclined, the center of gravity G of the pressing member 11 is positioned in the upwardly inclined direction P0 of the rotating shaft 12a by the action of gravity. The pressing surface 11c is formed so as not to contact the substrate outer edge Wa when the center of gravity G is at this position (FIG. 5A). Therefore, the substrate W can be easily placed and removed.

After the substrate W is placed on the substrate holding member 2,
In the process in which the rotary table 1 starts rotating counterclockwise in FIG. 5B and the rotational speed increases at a predetermined rotational acceleration, the center of gravity G is affected by the acceleration during the initial period when the rotational speed is not sufficiently high. The inertial force mainly acts. Therefore, the position of the center of gravity G moves from the direction P0 toward the rearward direction Bd in the rotational direction. When the center of gravity G is in a predetermined direction P1 (for example, a direction corresponding to the first critical angle) between the direction P0 and the backward direction Bd of the rotational direction, the pressing surface 11c abuts the outer edge Wa of the substrate (FIG. 5 (b). )). Therefore, the pressing surface 11c presses the substrate outer edge Wa with a certain amount of pressing force corresponding to the rotational acceleration. Due to the frictional force between the pressing surface 11c and the substrate outer edge Wa generated by this pressing force, the relative slip between the substrate W and the turntable 1 is suppressed.

When the rotational speed of the rotary table 1 exceeds a certain value, the centrifugal force rather than the inertial force acts mainly on the pressing member 11, so that the center of gravity G moves outward in the radial direction Rd. The center of gravity G is a predetermined direction P between the direction P0 and the radially outward Rd.
2 (for example, the direction corresponding to the second critical angle), the pressing surface 11c contacts the substrate outer edge Wa (see FIG. 5).
(C)). Therefore, the pressing surface 11c presses and urges the substrate outer edge Wa with a centrifugal force, that is, a certain pressing force corresponding to the rotation speed. Due to the frictional force between the pressing surface 11c and the outer edge Wa of the substrate generated by this pressing force, the substrate W
The relative slip between the rotary table 1 and the rotary table 1 is suppressed.

The center of gravity G is still in the same direction P2 after the rotational acceleration of the rotary table 1 is completed and the rotation of the rotary table 1 is changed to the constant speed rotation, and the pressing member 11 presses and biases the outer edge Wa of the substrate. Further, in the process in which the constant speed rotation is completed and the rotation speed of the rotary table 1 decreases at a predetermined rotation deceleration, the inertial force and the centrifugal force due to the deceleration reinforce each other. Therefore, the center of gravity G is also located in the same direction P2, and the pressing member 11 has the substrate outer edge W.
Press and urge to a.

FIG. 6 is a graph showing the above operation of the pressing member 11. FIG. 6 shows the rotation speed V
However, in the acceleration period T1, the acceleration is increased with a constant acceleration, the constant speed period T2 is maintained with a constant value, and the deceleration period T3 is decreased with a constant deceleration. The centrifugal force F caused by the rotation speed V is the acceleration period T
1 increases parabolically with time, and the constant speed period T
At 2, it maintains a constant value, and during the deceleration period T3, it decreases in a parabolic shape. Inertial force H due to rotational acceleration and deceleration
Is a constant negative value during the acceleration period T1, and the constant speed period T2
Is zero and has a positive constant value during the deceleration period T3.

The sum F + H of the inertial force H and the centrifugal force F (strictly speaking, the sum of the values weighted with each other) is a parabolic curve with time from a negative value to a positive value during the acceleration period T1. To a constant constant value during the constant speed period T2,
In the deceleration period T3, the value is parabolic from a high positive value to a low positive value. The sum F + H has a value of zero at some point in time t0 within the acceleration period T1. Sum F + H is time t
With 0 as a boundary, it is negative before time t0, and is consistently positive after time t0 until the deceleration period T3 ends. The center of gravity G is located in the direction P1 when the sum F + H is negative, and in the direction P2 when the sum F + H is positive. That is, the pressing member 11 does not apply sufficient pressing force to the outer edge Wa of the substrate at a certain time t0 or a certain period before and after the time when the rotation of the rotary table 1 is accelerated. In the period before that and the period after that, the pressing member 11 exerts a sufficiently large pressing force on the outer edge Wa of the substrate to prevent the substrate W from slipping.

In the apparatus 100 of this embodiment, since the center C is deviated from the rotation axis A with a predetermined distance, the centrifugal force corresponding to the rotation speed acts on the substrate W. As a result, if the rotation speed of the turntable 1 is higher than a certain level,
The horizontal position restricting portion 4 suppresses slippage of the substrate W. Therefore, when the rotation speed is sufficiently high, slip does not occur even if the pressing force of the pressing member 11 is weak. On the contrary, when the rotation speed of the turntable 1 is not sufficiently high, for example, in the initial stage of rotation acceleration and the final stage of rotation deceleration, the slip prevention effect due to the deviation of the center C cannot be obtained.

Therefore, preferably, in the acceleration period T1, the magnitude of the deviation L and the rotating shaft 1 are set so that the effect of preventing the slip due to the deviation of the center C appears before the time t0.
The distance between 2a and the center of gravity G, the directions P0, P1, P2, etc. are set. As a result, the effect of the center C displacement and the effect of the pressing member 11 pressing the outer peripheral edge Wa of the substrate C complement each other, preventing the substrate W from slipping over the entire period from the acceleration period T1 to the deceleration period T3. To be done.

<Modification>

(1) The substrate holding member 2 does not have to have the substrate supporting portion 3 and the horizontal position regulating portion 4 integrally formed as shown in FIG. In other words, as shown in FIG.
And the horizontal position regulating portion 4 may be separately configured. Note that the pressing member 11 is omitted in FIG. 7.

(2) The shape of the pressing member 11 is not limited to the shape shown in FIG. Other shapes may be used as long as they can perform the predetermined functions described above. Preferably, a shape that can reduce the air resistance acting on the pressing member 11 when the rotary table 1 rotates is selected.

(3) The rotary substrate processing apparatus 10 is not only an apparatus for supplying a processing liquid to perform processing on the upper surface of a substrate, but also
For example, it may be a rotary substrate processing apparatus or the like that horizontally rotates the substrate while drying the substrate.

[0032]

According to the substrate holding apparatus of the present invention, the center of gravity of the pressing member approaches the rear side in the rotational direction at the beginning of the process of rotational acceleration of the rotary table, because the inertial force accompanying the acceleration mainly acts. The pressing member rotates, and the pressing member comes into contact with the outer edge of the substrate and presses and urges it. On the other hand, when acceleration is sufficiently performed and the turntable rotates at high speed, or during deceleration, the centrifugal force acts stronger than the inertial force, or the centrifugal force exerts an inertial force, so that the center of gravity of the pressing member is increased. The pressing member rotates so that the arrow approaches the rotation axis in the radially outward direction of rotation. Therefore, the pressing member also comes into contact with the outer edge of the substrate and presses and biases it. Since the pressing force of the pressing member causes a frictional force between the pressing member and the outer edge of the substrate, the substrate is prevented from slipping. That is, the apparatus of the present invention has the effect of preventing the substrate from slipping, including the initial stage of rotational acceleration and the final stage of rotational deceleration.

[Brief description of drawings]

FIG. 1 is a perspective view of a substrate holding device according to an embodiment of the present invention.

FIG. 2 is a partially cut front view of the rotary substrate processing apparatus according to the embodiment of the present invention.

FIG. 3 is a plan view of the substrate holding device according to the embodiment of the present invention.

FIG. 4 is a partial cross-sectional front view of the substrate holding device according to the embodiment of the present invention.

FIG. 5 is a schematic view of a substrate holding device according to an embodiment of the present invention.

FIG. 6 is a graph showing the operating principle in the embodiment of the present invention.

FIG. 7 is a front view of a substrate holding device according to a modified example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 rotary table 2 substrate holding member 10 rotary substrate processing apparatus 11 pressing member 12a rotation axis 100 substrate holding apparatus A rotation axis G center of gravity W substrate Wa substrate outer edge Bd rotation direction rear Rd radial direction outside P1 direction (first or first) 2 direction (corresponding to the critical angle) P2 direction (direction corresponding to the 2nd or 1st critical angle)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Katsuji Yoshioka, inventor Katsuji Yoshioka, 322 Hazushishi Furukawa-cho, Fushimi-ku, Kyoto Daini Nippon Screen Mfg. Co., Ltd. Rakusai factory Dainichi Main Screen Manufacturing Co., Ltd. Rakusai Factory (72) Inventor Masafumi Takeoka 322 Hazushishi Furukawacho, Fushimi-ku, Kyoto Dainichi Screen Manufacturing Co., Ltd. Rakusai Factory

Claims (1)

[Claims] 1. A substrate holding device used for holding a substrate when performing a predetermined process on a main surface of the substrate while horizontally rotating the substrate in a predetermined rotation direction around a vertical axis, comprising: a) a horizontal rotary table; (b) a substrate holding member provided on the upper surface side of the horizontal rotary table to hold the substrate; (c) axially supported on the outer peripheral side of the horizontal rotary table in a non-vertical plane. And a pressing member having a center of gravity at a position deviated from an axis of rotation on the rotation axis, and the rotation angle of the center of gravity of the pressing member is a predetermined first and second critical value. Only when the angle is reached, the predetermined portion of the pressing member abuts the outer edge of the substrate, and the first and second critical angles are the directions connecting the rotation center of the horizontal rotary table and the position of the shaft support. Is specified within the range deviated to the side opposite to the predetermined rotation direction. A substrate holding device comprising: