JP3664856B2 - Rotary substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary substrate processing apparatus that performs predetermined processing on a substrate while rotating the substrate while sucking and holding the substrate.
[0002]
[Prior art]
A rotary substrate processing apparatus is used to apply a coating solution such as a photoresist solution to a substrate such as a semiconductor wafer, a glass substrate for a liquid crystal display device, a glass substrate for a photomask, or a glass substrate for an optical disk.
[0003]
FIG. 3 is a schematic sectional view showing an example of a conventional rotary substrate processing apparatus. In FIG. 3, the rotary substrate processing apparatus includes a substrate holding unit 4 that holds a substrate W in a horizontal posture. The substrate holder 4 is attached to the tip of the rotating shaft 2 of the motor 1 and is driven to rotate about the vertical axis.
[0004]
Around the substrate W held by the substrate holding unit 4, a cup 6 for preventing the processing liquid from scattering is disposed.
[0005]
The motor 1 is fixed to the base member 8 by a motor holding member 7 so that the rotating shaft 2 faces in the vertical direction. The motor holding member 7 includes a holding flange 7 a that holds the upper surface of the motor 1 and a fixing member 7 b that fixes the holding flange 7 a to the base member 8.
[0006]
The substrate holding unit 4 includes a vacuum chuck that sucks and holds the back surface of the substrate W. A suction port 5 is formed at the center of the substrate holder 4, and the suction port 5 communicates with a suction path 3 formed in the rotating shaft 2 of the motor 1. The suction path 3 of the rotary shaft 2 is connected to an intake pipe line 33 via a connecting member 30. Further, the intake pipe 33 is connected to a vacuum suction power facility in the factory.
[0007]
The connecting member 30 has an annular communication space 32 that communicates the end of the suction passage 3 of the rotating shaft 2 and the end of the intake pipe 33, and is a contact type comprising oil seals on both upper and lower sides of the communication space 32. A seal member 31 is disposed. The sealing member 31 keeps the airtightness of the communication space 32 of the connecting member 30.
[0008]
By sucking air through the suction port 5, the suction path 3 of the rotating shaft 2 and the suction pipe 33, the back surface of the substrate W is sucked and held on the upper surface of the substrate holding part 4.
[0009]
[Problems to be solved by the invention]
However, in the conventional rotary substrate processing apparatus, the contact-type seal member 31 is used to keep the communication space 32 of the connection member 30 airtight. The rotating shaft 2 of the motor 1 performs a high-speed rotation operation several hundred to several thousand times per minute. For this reason, in the contact-type seal member 31, the portion in contact with the rotating shaft 2 rotating at high speed is heavily worn.
[0010]
When the airtightness of the seal member 31 is reduced due to wear, the holding force of the substrate W by the substrate holding part 4 is reduced. In particular, in recent years, the substrate W has become larger and heavier. For this reason, a decrease in the holding power of the substrate W easily causes an accident of detachment of the substrate W from the substrate holding portion 4. A large-sized substrate is expensive, and if a substrate W detachment accident occurs, the damage becomes large. For this reason, it is necessary to periodically replace the seal member 31 to maintain airtightness, and maintenance work is complicated.
[0011]
In the contact-type seal member 31, particles are likely to be generated from the contact portion with the rotating shaft 2. The generated particles float in the atmosphere and may adhere to the surface of the substrate W and contaminate the substrate W. For this reason, as shown in FIG. 3, it is necessary to provide an exhaust device 10 on the base member 8 and remove floating particles by suctioning from the exhaust port 10a, which complicates the structure of the rotary substrate processing apparatus. There was an inconvenience.
[0012]
An object of the present invention is to provide a rotary substrate processing apparatus excellent in maintainability of a connection portion between a suction path and an intake pipe line in a rotation shaft of a motor.
[0013]
[Means for Solving the Problems and Effects of the Invention]
A rotary substrate processing apparatus according to a first aspect of the present invention is a motor having a rotary shaft that is disposed in a vertical direction and has a suction path that penetrates from the upper end to the lower end, and is attached to the upper end of the rotary shaft. A substrate holding portion that has a suction port that communicates and sucks and holds the substrate; an intake port that is disposed below the lower end portion of the rotating shaft; and an intake pipe that guides air to the outside from the lower end of the suction passage; A connection member having a communication space in which the intake port of the intake pipe is connected and the lower end portion of the rotating shaft is loosely fitted, an inner peripheral surface forming a communication space of the connecting member, and an outer peripheral surface of the lower end portion of the rotating shaft And a magnetic fluid seal provided in a clearance between the rotating shaft and the connecting member, which has an annular recess surrounding the lower end of the rotating shaft and holding the magnetic fluid seal, and is attached to the lower end surface of the motor Connected to the lower end of the member and the seal holding member, A suction passage of the inlet of the road and the rotary shaft is intended to include a connection member having a space for communicating.
[0014]
In the rotary substrate processing apparatus according to the first aspect of the invention, the suction path of the rotating shaft that rotates at high speed and the intake pipe are connected by a connecting member, and the airtightness between the suction path and the intake port of the intake pipe is magnetic. It is held by a fluid seal. The magnetic fluid seal is a non-contact type seal member, and there is no portion to be worn by contact with the rotating shaft. For this reason, it is not necessary to periodically replace the seal member, and the maintainability of the rotary substrate processing apparatus is improved. Further, the magnetic fluid seal has no possibility of generating dust due to contact with the rotating shaft. This prevents the substrate from being contaminated by the dusting material from the magnetic fluid seal.
[0015]
Furthermore, by arranging the connecting member at the lower end portion of the rotating shaft, the configuration around the rotating shaft from the upper end surface of the motor to the substrate holding portion is simplified.
[0016]
In addition, after attaching the seal holding member holding the magnetic fluid seal to the lower end surface of the motor, adjusting the attachment state of the magnetic fluid seal, attaching the connecting member to the seal holding member, the suction path and the intake pipe of the rotating shaft of the motor The inlet of the road is communicated. Thereby, the attachment position of the magnetic fluid seal can be easily adjusted.
[0017]
A rotary substrate processing apparatus according to a second aspect of the present invention is the rotary substrate processing apparatus according to the first aspect of the present invention, further comprising a flat base member that divides the atmosphere up and down, and the motor is located below the base member. It is fixed to the base member so that the lower end of the rotating shaft is located in the atmosphere.
[0018]
In this case, the atmosphere in the rotary substrate processing apparatus is partitioned in the vertical direction by the base member, the substrate holding part is disposed in the atmosphere above the base member, and the connecting member is disposed in the atmosphere below the base member. And a magnetic fluid seal is disposed. Therefore, it is possible to prevent the magnetic fluid seal from deteriorating due to the solvent floating around the substrate holder acting on the magnetic fluid of the magnetic fluid seal.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic sectional view of a rotary substrate processing apparatus according to an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view of the rotary substrate processing apparatus of FIG.
[0020]
1 and 2, the rotary substrate processing apparatus includes a substrate holding unit 4 that holds a substrate W in a horizontal posture. The substrate holding unit 4 is attached to the tip of the rotating shaft 2 of the motor 1 and is driven to rotate around the vertical axis. Around the substrate W held by the substrate holding unit 4, a cup 6 for preventing the processing liquid from scattering is disposed.
[0021]
The motor 1 is fixed to the base member 8 by a motor holding member 7. The motor holding member 7 includes a holding flange 7 a that holds the upper surface of the motor 1 and a cylindrical fixing member 7 b that surrounds the outer periphery of the main body of the motor 1 and fixes the holding flange 7 a to the base member 8. . The base member 8 is formed in a flat plate shape that isolates the atmosphere in the rotary substrate processing apparatus vertically. The base member 8 and the motor holding member 7 block the main body of the motor 1 from the atmosphere above the base member 8.
[0022]
The substrate holding unit 4 includes a vacuum chuck that sucks and holds the back surface of the substrate W. The vacuum suction path from the substrate holding unit 4 includes a suction port 5 of the substrate holding unit 4, a suction path 3 that penetrates the rotating shaft 2 of the motor 1, and an intake pipe 25, and is a vacuum suction force installed in a factory. Connected to equipment (not shown). Further, the suction path 3 and the intake pipe 25 of the rotating shaft 2 are connected via a connecting member 14.
[0023]
As shown in FIG. 2, the connecting member 14 includes a seal holding member 15 connected to the lower end surface of the motor 1 and a connecting member 21 connected to the seal holding member 15.
[0024]
The seal holding member 15 holds a magnetic fluid seal 17 into which the lower end 2 a of the rotating shaft 2 of the motor 1 is inserted into a cylindrical recess 15 a and is fixed to the lower end surface of the motor 1 by a screw 16. The magnetic fluid seal 17 includes a plurality of annular magnetic pole pieces 18 having an inner diameter slightly larger than the outer diameter of the lower end portion 2 a of the rotating shaft 2, and a plurality of annular permanent magnets 19 inserted between the magnetic pole pieces 18. The magnetic fluid 20 is injected into the gap between the surface of the lower end 2 a of the rotating shaft 2 and the magnetic pole piece 18. The magnetic fluid 20 is made of a colloidal solution in which solid fine particles of a ferromagnetic material are dispersed in a liquid at a high density.
[0025]
In the magnetic fluid seal 17, the permanent magnet 19 forms a magnetic field between the pole piece 18 and the rotating shaft 2 made of a magnetic material. The magnetic fluid 20 is held in the gap between the magnetic pole piece 18 and the rotating shaft 2 by the magnetic field. For this reason, even when the rotating shaft 2 rotates at a high speed, the magnetic fluid 20 stops in the gap between the magnetic pole piece 18 and the rotating shaft 2, and the gap between the rotating shaft 2 and the magnetic pole piece 18 is sealed.
[0026]
The connecting member 21 has a space that forms a communication space 22 that receives the lower end 2 a of the rotating shaft 2, and is fixed to the seal holding member 15 by screws 24. An O-ring 23 is attached to the joint surface between the seal holding member 15 and the connection member 21. Thereby, airtightness between the communication space 22 and the outside is maintained. An intake pipe 25 is connected to the communication space 22 in the connection member 21. With such a structure, the suction path 3 of the rotating shaft 2 of the motor 1 and the intake port of the intake pipe line 25 communicate in an airtight manner through the communication space 22.
[0027]
In the rotary substrate processing apparatus having the above configuration, when the substrate W is placed on the substrate holding unit 4, the suction port 5 of the substrate holding unit 4, the suction path 3 of the rotating shaft 2, and the communication space 22 of the connecting member 14. Then, the air is sucked through the intake pipe 25 toward the vacuum suction power facility. Thereby, the back surface of the substrate W is vacuum-sucked and held by the substrate holding part 4. At this time, the magnetic fluid seal 17 of the connecting member 14 prevents outside air from entering the communication space 22 along the lower end portion 2a of the rotating shaft 2 and lowering the degree of vacuum.
[0028]
As described above, in the rotary substrate processing apparatus of the present invention, the suction path 3 and the intake pipe 25 in the rotary shaft 2 are connected via the connecting member 14 on the lower end surface of the motor 1. For this reason, the suction path 3 in the rotating shaft 2 is formed so as to penetrate the rotating shaft 2 linearly, whereby the processing of the suction path 3 is facilitated.
[0029]
Further, the magnetic fluid seal 17 maintains the airtightness of the communication space 22 that connects the suction path 3 of the rotating shaft 2 and the intake pipe line 25. The magnetic fluid seal 17 does not have a portion that is worn by contact with the rotating shaft 2. For this reason, deterioration of airtightness due to wear does not occur, and maintenance work such as replacement of the magnetic fluid seal 17 becomes unnecessary.
[0030]
Further, the magnetic fluid seal 17 has no fear of dust generation. For this reason, the substrate W held on the substrate holding part 4 is prevented from being contaminated by the dust generation material from the magnetic fluid seal 17. Therefore, it is not necessary to provide the exhaust device 10 as shown in FIG. 3 on the base member 8 in order to remove dust generated from the magnetic fluid seal.
[0031]
Further, the connecting member 14 includes a seal holding member 15 and a connecting member 21. For this reason, first, the seal holding member 15 is attached to the lower end surface of the motor 1, and the gap between the magnetic pole piece 18 of the magnetic fluid seal 17 and the lower end portion 2a of the rotating shaft 2 of the motor 1 is adjusted to be uniform. The magnetic fluid 20 is injected into this gap. Thereafter, the connecting member 21 can be fixed. For this reason, the adjustment work of the magnetic fluid seal 17 and the rotating shaft 2 of the motor 1 becomes easy, and the assembly work is simplified.
[0032]
Further, the connecting member 14 is disposed below the base member 8. The motor 1 is isolated from the atmosphere on the base member 8 by the motor holding member 7. For this reason, it is prevented that the solvent leaking around the cup 6 reaches the magnetic fluid seal 17 and adversely affects it.
[0033]
FIG. 2 shows the structure of the magnetic fluid seal in principle, and the shape and number of the pole pieces 18 and the permanent magnets 19 are appropriately selected depending on the airtight condition and the like. Further, when the rotating shaft 2 is not a magnetic material, a hollow shaft member made of a magnetic material may be attached to the rotating shaft 2 side, and a magnetic fluid seal may be mounted around the hollow shaft member.
[0034]
Further, the present invention can be applied to a rotary substrate processing apparatus such as a rotary coating apparatus, a rotary cleaning apparatus, and a rotary developing apparatus having a substrate holding unit 4 that sucks and holds the substrate W.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a rotary substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of the rotary substrate processing apparatus of FIG.
FIG. 3 is a schematic sectional view of a conventional rotary substrate processing apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Motor 2 Rotating shaft 3 Suction path 4 Substrate holding part 5 Suction port 7 Motor holding member 8 Base member 14 Connecting member 15 Seal holding member 17 Magnetic fluid seal 18 Magnetic pole piece 19 Permanent magnet 20 Magnetic fluid 21 Connection member 22 Communication space 25 Intake Pipeline

Claims (2)

A motor provided with a rotating shaft that is arranged in the vertical direction and has a suction path that penetrates from the upper end to the lower end;
A substrate holding part attached to the upper end of the rotating shaft, having a suction port communicating with the suction path, and holding the substrate by suction;
An intake pipe disposed below a lower end portion of the rotating shaft, and an intake pipe for guiding air to the outside from the lower end of the suction path;
A connecting member having a communication space to which the intake port of the intake pipe is connected and the lower end of the rotating shaft is loosely fitted;
A magnetic fluid seal provided in a gap between an inner peripheral surface forming the communication space of the connecting member and an outer peripheral surface of a lower end portion of the rotating shaft ;
The connecting member is
A seal holding member that has an annular recess surrounding the lower end of the rotating shaft and holding the magnetic fluid seal, and is attached to the lower end surface of the motor;
A rotary substrate processing apparatus comprising: a connecting member connected to a lower end of the seal holding member and having a space for communicating the intake port of the intake pipe and the suction path of the rotary shaft . It further comprises a flat base member that partitions the atmosphere up and down,
The rotary substrate processing apparatus according to claim 1, wherein the motor is fixed to the base member so that the lower end portion of the rotary shaft is positioned in an atmosphere below the base member.

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