JPH0758000A - Rotary substrate processing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To suppress the generation of particles in the space around the rotation axis and prevent unnecessary mist from adhering to the back surface of the substrate or the back side of the substrate holding unit that holds the substrate. [Structure] The substrate cleaning apparatus 1 is a rotary type that processes the surface of the substrate W with a processing liquid while rotating the substrate W.
The device 1 includes a substrate holding portion 2, a brush cleaning mechanism 3, an outer cover 21, and an intake pipe 27. Substrate holding unit 2
Has a rotating shaft 7 extending vertically and a lateral substrate holding surface 4 arranged at the upper end of the rotating shaft 7, and holds the substrate W by the substrate holding surface 4. The brush cleaning mechanism 3 supplies the cleaning liquid to the substrate W held by the substrate holder 2. Outer cover 21
Are arranged so as to cover the substrate holding surface 2 from below and laterally. The intake pipe 27 supplies clean air to the space 28 around the rotation axis surrounded by the outer cover 21 below the substrate holding surface 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a substrate processing apparatus, and more particularly to
The present invention relates to a rotary substrate processing apparatus that processes a surface of a substrate with a processing liquid while rotating the substrate.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process or a liquid crystal display device manufacturing process, when a pattern is formed by a photo process, a process of applying a photoresist to a substrate, a process of developing the substrate with a developing solution, A substrate processing step using a processing liquid such as a step of cleaning with a cleaning liquid is indispensable.

A rotary substrate processing apparatus used in this type of substrate processing process includes a substrate holding unit for vacuum holding or mechanically holding a substrate, a processing liquid supply unit for supplying a processing liquid to the substrate holding unit, and a supply unit. And an exhaust unit for discharging the air containing the treated liquid. In addition, a spin cup is arranged around the substrate holder to prevent the processing liquid from scattering. The substrate holding part has a central axis extending vertically and a lateral substrate holding surface arranged at an upper end of the central axis. This central axis penetrates the spin cup and is connected to the motor.

In this type of rotary substrate processing apparatus, the substrate held on the substrate holding surface is rotated around the central axis while the processing liquid supply unit supplies the processing liquid to perform the substrate processing. And
In the substrate cleaning apparatus, the substrate is rotated at a high speed for draining and drying after cleaning. Further, in the photoresist coating device and the developing device, the substrate is rotated at a high speed in order to uniformly coat the processing liquid.

[0005]

SUMMARY OF THE INVENTION In the above conventional configuration,
When the substrate is rotated at high speed, the flow of air from the center of rotation toward the outer peripheral edge of the substrate occurs due to the rotation of the substrate and the substrate holder, so the space around the central axis is more negative pressure than the space on the outer peripheral edge side. (Low pressure). As a result, outside air flows into the space around the central axis from the outside of the spin cup through the penetrating portion of the central axis. In addition, a circulation flow is generated which goes toward the outer peripheral end portion and then hits the spin cup and returns to the space around the central axis again.

The flow of air from the outside causes the inflow of particles as foreign matter. The generated circulating flow also circulates liquid droplets, floating mist, etc., which cause the generation of particles. Then, these particles adhere to the back surface of the substrate or the substrate holding portion holding the substrate as mist. An object of the present invention is to suppress the generation of particles in the space around the central axis and prevent the mist from adhering to the back surface of the substrate or the substrate holding portion holding the substrate.

[0007]

A substrate processing apparatus according to the present invention is of a rotary type which processes a surface of a substrate with a processing liquid while rotating the substrate. This apparatus includes a substrate holding means, a processing liquid supply means, a cover member, and a gas supply means. The substrate holding means has a central axis extending vertically and a lateral substrate holding surface arranged at the upper end of the central axis, and holds the substrate by the substrate holding surface. The processing liquid supply unit supplies the processing liquid to the substrate held by the substrate holding unit. The cover member is arranged so as to cover the substrate holding surface from below and from the side. The gas supply unit supplies a clean gas to the space around the central axis surrounded by the cover member below the substrate holding surface.

[0008]

In the substrate processing apparatus according to the present invention, the substrate held on the substrate holding surface rotates about the central axis, and the processing liquid is supplied to the substrate by the processing liquid supply means to perform the substrate processing. The processing liquid supplied to the substrate diffuses and scatters from the center to the outer peripheral side by the rotation. The scattered processing liquid is received by the cover member. During the rotation of the substrate, the gas supply unit supplies clean gas to the space around the central axis below the substrate holding surface. The supplied gas is discharged outward from the space around the central axis.

Here, since clean gas is supplied to the space around the central axis, even if the substrate rotates, particles are less likely to enter the space around the central axis from the outside. Moreover,
It is difficult for the air flow hit by the cover member to return to the space around the central axis. Therefore, it is possible to prevent the generation of particles in the space around the central axis.

[0010]

1 and 2, a substrate cleaning apparatus 1 as an embodiment of the present invention is an apparatus for brush cleaning the surface of a rectangular substrate W for liquid crystal display. The cleaning apparatus 1 is a substrate W
And a brush cleaning mechanism 3 that supplies a cleaning liquid to the substrate W held by the substrate holding unit 2 and brush-cleans the substrate W.

The substrate holding portion 2 has a circular substrate holding surface 4 on the top. The diameter of the substrate holding surface 4 is longer than the diagonal length of the substrate W. Positioning pins 5 for positioning the four corners of the substrate W and support pins 6 (FIG. 2) for supporting the substrate W from below are arranged on the upper surface of the substrate holding surface 4.
A rotating shaft 7 is fixed to the center of the lower surface of the substrate holding surface 4. The rotating shaft 7 is rotatably supported by ball bearings 16 and 17 which are vertically spaced apart from each other. Ball bearing 1
6 and 17 are housed in a bearing portion 8 provided upright on the device frame 10. The upper ball bearing 16 has a magnetic fluid seal 18 on its top so that particles generated in the ball bearings 16 and 17 do not flow into the substrate holding surface 4 side.

A pulley 11a is attached to the lower end of the rotary shaft 7. A belt 12 is wound around the pulley 11a, and the pulley 12 is attached to the other end of the belt 12.
1b is arranged. The pulley 11b is the motor 13
It is attached to the output shaft of. As a result, the rotating shaft 7
Are driven to rotate by the motor 13. The rotary shaft 7 is a hollow shaft, and a cleaning liquid supply pipe 14 for cleaning the back surface of the substrate W and a nitrogen gas supply pipe 15 for injecting nitrogen gas onto the back surface of the substrate W are concentrically provided inside the rotary shaft 7. It is arranged. At the tips (upper ends) of these pipes 14 and 15,
Nozzles (not shown) are provided respectively, and the cleaning liquid and the nitrogen gas can be ejected from the nozzles toward the center of the substrate W.

A spin cup 2 is provided around the substrate holding surface 4.
0 is placed. The spin cup 20 is arranged so as to cover the outer peripheral edge of the substrate holding surface 4 from the side to the upper side thereof, and the upper portion is curved inward (center side). The spin cup 20 is supported by an inner peripheral portion of an outer cover 21 fixed on the apparatus frame 10 so as to be vertically adjustable.

The outer cover 21 has a bottomed cylindrical shape with a stepped portion having a small diameter at the bottom. A low pressure nozzle 29 for ejecting the rinse liquid onto the substrate W at a low pressure is arranged at the upper left portion of the inner peripheral surface of the outer cover 21 in FIG. As shown in FIG. 3, an exhaust duct 22 protruding downward is provided on the outer peripheral portion of the small-diameter bottom surface 23 of the outer cover 21. Exhaust duct 22
Are provided at equal intervals in the circumferential direction of the small-diameter bottom surface 23. The lower end of the exhaust duct 22 opens into the collecting duct 24. The collecting duct 24 has a hollow ring shape, and is arranged in parallel below the small-diameter bottom surface 23. Collecting duct 2
4 is supported by the device frame 10 and is also connected to an equipment exhaust duct (not shown).

Between the small-diameter bottom surface 23 and the substrate holding surface 4,
The rectification unit 25 is arranged. The rectifying unit 25 has a flat washer-shaped rectifying surface 26 on the upper portion. The rectifying surface 26 is arranged parallel to the substrate holding surface 4, and
6 and the lower surface of the substrate holding surface 4 have a gap of 5 mm to 20 m.
m, preferably 10 mm or less. On the inner peripheral side of the rectifying section 25, the small diameter bottom surface 23 has, for example, six tips of intake pipes 27 open. The intake pipe 27 has a bent shape as shown in the drawing, and its tip has a large-diameter bottom surface 33.
Also, it penetrates through the outer cover 21 and is directed to a clean downflow outside the apparatus. As a result, the clean air flowing outside the outer cover 21 flows as a downflow into the intake pipe 27, and the clean air that has flowed in is supplied to the space 28 around the rotating shaft 7.

As shown in FIG. 1, the brush cleaning mechanism 3 includes
It has an arm 31 that can swing in parallel with the substrate holding surface 4 and that can move up and down in a direction toward and away from the substrate holding surface 4, and a brush 30 arranged downward at the tip of the arm 31. An ultrasonic nozzle 32 is arranged in a downward direction inside the brush 30. The brush cleaning mechanism 3 cleans the substrate W with the brush 30 that swings on the substrate W, and also cleans the substrate W with cleaning water from the ultrasonic nozzle. Although the ultrasonic nozzle 32 is arranged inside the brush 30 in the present embodiment, the brush 30 and the ultrasonic nozzle 32 are fixed to separate arms so that they individually act on the substrate. May be. In this case, when cleaning the substrate with the brush 30, the cleaning liquid may be supplied from a nozzle provided separately.

Next, the operation of the above embodiment will be described. When the substrate W is transported to the cleaning apparatus 1 by a transport mechanism (not shown), the substrate W is placed on the support pins 6 on the substrate holding surface 4 and positioned and held by the positioning pins 5. Next, the motor 13 rotates at a low speed, and the substrate holding surface 4 and the substrate W are
And rotate together at low speed. Subsequently, the arm 31 pivots to the center position of the substrate W, and the brush 30 is lowered to the position where it abuts on the substrate W. Then, the swinging of the arm 31 is started, and the pure water that has been ultrasonically vibrated is caused to flow out from the ultrasonic nozzle 32 toward the substrate W. As a result, brush 3
The cleaning with 0 and the cleaning with pure water vibrating ultrasonically from the ultrasonic nozzle 32 are simultaneously performed.

When the cleaning is finished, low-pressure pure water (rinse liquid) is ejected from the low-pressure nozzle 29 toward the substrate W, and the rinse process is performed. When the rinse process is completed, the motor 13 rotates at a high speed to rotate the substrate W at a high speed. As a result, the water adhering to the surface of the substrate W is scattered, and the draining and drying process is performed. At the time of this drainage drying, the substrate W
The cleaning liquid adhering to the substrate W is transferred from the four corners of the substrate W to the substrate holding surface 4.
And is scattered from the outer peripheral edge of the substrate holding surface 4 as indicated by an arrow in FIG. As a result, water drops and mist are generated in the spin cup 20. However, the substrate holding surface 4
The cleaning liquid is less likely to scatter from the corners of the rectangular substrate W because of the large size, and the water droplets and mist that are generated are less than when the substrate holding surface is small and the corners of the rectangular substrate project.

On the other hand, below the substrate holding surface 4, rotation causes air to flow outward between the flow straightening plate 26 and the substrate holding surface 4 as indicated by an arrow in FIG. As a result, the space 28 around the rotation shaft 7 of the substrate holding surface 4 tends to have a low pressure. However, here, clean air flows from the intake pipe 27 into the space 28 to compensate for the negative pressure. Here, since the clean air is supplied to the space 28 around the rotation axis, particles from the ball bearings 16 and 17 or particles generated by the circulating mist are unlikely to enter the space 28.
Therefore, generation of particles in the space 28 can be prevented. Further, the rectifying unit 25 is provided below the substrate holding surface 4, and the generation of a differential pressure between the periphery of the rotation axis and the outer peripheral portion by the clean air taken in through the intake pipe 27 is suppressed. Mist generated from the peripheral edge of the holding surface 4 is unlikely to enter the space 28. As a result, the space 28
It is possible to more reliably prevent the generation of particles in the.

Other Embodiments (a) The present invention may be carried out by a closed type or semi-closed type device such as a spin coater instead of the rotary cleaning device. In this case, the back side of the semi-hermetic substrate holding portion (so-called spin chuck) is controlled by suppressing the generation of particles around the central axis as in the above embodiment, without preventing the mist from adhering to the back surface of the substrate. It is possible to prevent mist from adhering to. Further, when the present invention is carried out by an open type spin coater or the like, it is possible to similarly suppress the generation of particles around the central axis and prevent the mist from adhering to the back surface of the substrate. (B) Instead of supplying clean air, another clean gas (for example, nitrogen gas) may be supplied. (C) In order to eliminate the negative pressure generated when the substrate holder is rotated, negative pressure detection means for detecting the generated negative pressure is provided, and the regulated clean gas is rotated according to the detection result. It may be forcibly supplied to the space around the axis.

[0021]

According to the rotary substrate processing apparatus of the present invention,
Since clean gas is supplied to the space around the central axis, it is possible to prevent the generation of particles in the space around the central axis and prevent unnecessary mist from adhering to the back surface of the substrate or the back side of the substrate holding part that holds the substrate. can do.

[Brief description of drawings]

FIG. 1 is a partial cutaway perspective partial view of a substrate cleaning apparatus as an embodiment of the present invention.

FIG. 2 is a partial vertical sectional view thereof.

FIG. 3 is an enlarged partial view of FIG.

[Explanation of symbols]

 1 Substrate Cleaning Device 2 Substrate Holding Section 3 Brush Cleaning Mechanism 4 Substrate Holding Surface 7 Rotation Axis 20 Spin Cup 21 Outer Cover 27 Intake Pipe 28 Space

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01L 21/304 341 B

Claims (1)

[Claims] 1. A rotary substrate processing apparatus for processing a surface of a substrate with a processing liquid while rotating the substrate, comprising: a central axis extending vertically; and a horizontal substrate holder disposed at an upper end of the central axis. A substrate holding means for holding the substrate on the substrate holding surface; a processing liquid supplying means for supplying the processing liquid to the substrate held by the substrate holding means; A rotary member provided with a cover member arranged so as to cover from the side, and a gas supply unit for supplying clean gas to a space around the central axis surrounded by the cover member below the substrate holding surface. Substrate processing equipment.