JP2004273715A - Substrate washing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make preventable a substrate from being contaminated by the droplets of a treatment liquid stuck to the discharging part of a treatment liquid supplying means by preventing the droplets of the treatment liquid from being scattered. <P>SOLUTION: While washing the substrate W rotated together with a supporting plate 1 with a washing liquid nozzle 41, a rinsing liquid is supplied to the lower surface of the substrate W. Even when the rinsing liquid is stuck to the discharging part of a back rinse nozzle 32 in the case, the rinsing liquid is collected by a liquid accumulation part 33. Consequently, inconvenience that the droplets of the rinsing liquid is scattered by the supporting plate 1 and stuck to the lower surface of the substrate W is eliminated, thereby the substrate W can be prevented from being contaminated by the droplets. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a substrate cleaning apparatus for cleaning a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal display device, a substrate for an optical disk (hereinafter, simply referred to as a substrate), and particularly to rotating a substrate. The present invention relates to a substrate cleaning apparatus for supplying a processing liquid to a lower surface of a substrate when a cleaning liquid is supplied toward an upper surface of a substrate while performing a cleaning process.
[0002]
[Prior art]
As a conventional type of substrate cleaning apparatus, one having a configuration as disclosed in Japanese Patent Application Laid-Open No. 9-290197 is exemplified.
[0003]
[Patent Document 1]
JP-A-9-290197 (columns 4 to 6, FIG. 1)
[0004]
This apparatus has a disk-shaped bottom plate slightly larger than the diameter of the substrate, a plurality of support pins erected on the upper surface of a peripheral portion of the bottom plate, and a back rinse nozzle for supplying a processing liquid from the center of the bottom plate to the lower surface of the substrate. And a motor for driving the bottom plate to rotate.
[0005]
In the apparatus having such a configuration, the substrate is locked to the plurality of support pins, and the motor is driven to rotate the substrate while supplying the cleaning liquid to the upper surface thereof to act as a brush or to supply the high-pressure cleaning liquid. Thus, a cleaning process is performed on the upper surface of the substrate.
[0006]
At this time, if the processing liquid scattered from the upper surface of the substrate, the removed dirt, particles, and the like come around and adhere to the lower surface of the substrate, the lower surface of the substrate is contaminated. Therefore, during the cleaning process, the processing liquid is supplied from the back rinse nozzle to cover the entire lower surface of the substrate to prevent such inconvenience.
[0007]
[Problems to be solved by the invention]
However, the conventional example having such a configuration has the following problem.
That is, in the conventional apparatus, the back rinsing is stopped at the end of the cleaning process, but the processing liquid from the back rinsing nozzle does not run out instantaneously, and a part of the processing liquid is discharged and adheres slightly near the back rinsing nozzle. is there. In addition, when the processing liquid is first supplied from the back rinse nozzle, a part of the processing liquid that rebounds on the lower surface of the substrate may slightly adhere to the vicinity of the back rinse nozzle. Further, a part of the processing liquid that has been moved from the back rinse nozzle toward the substrate surface may not fall upward due to the stop of the supply, and may fall downward and adhere to the tip of the back rinse nozzle.
[0008]
After the cleaning process for the substrate, the substrate is rotated at a high speed to perform a drying process. At this time, droplets attached to the vicinity of the back rinse nozzle flow down to the bottom plate rotating at a high speed due to vibration or the like. Then, there is a problem that the droplets are repelled by the bottom plate, become fine droplets, and adhere to the lower surface of the substrate, and become residues to contaminate the substrate.
[0009]
The present invention has been made in view of such circumstances, and by preventing the droplets of the processing liquid attached to the discharge unit of the processing liquid supply unit from scattering, it is possible to reduce the number of processing liquid droplets. It is an object of the present invention to provide a substrate cleaning apparatus capable of preventing a substrate from being contaminated.
[0010]
[Means for Solving the Problems]
The present invention has the following configuration to achieve such an object.
That is, according to the first aspect of the present invention, there is provided a rotation supporting means for abuttingly supporting a peripheral portion of a substrate and rotating the substrate in a horizontal posture, a cleaning means for cleaning an upper surface of the substrate, and a processing liquid on a lower surface of the substrate. In a substrate cleaning apparatus provided with a processing liquid supply means for supplying, the processing liquid supply means is provided with a liquid pool portion opened toward the lower surface of the substrate at a discharge portion thereof.
[0011]
(Action / Effect)
The cleaning liquid is supplied to the lower surface of the substrate rotated by the cleaning unit while the substrate is being rotated by the rotation support unit. Even if the processing liquid adheres to the discharge unit of the processing liquid supply unit, the processing liquid may be removed. Is collected by the liquid pool. Therefore, the inconvenience that the droplets of the processing liquid are scattered by the rotation support means and adhere to the lower surface of the substrate is eliminated, so that contamination of the substrate due to the droplets can be prevented.
[0012]
Further, it is preferable that the liquid reservoir has a “mortar shape” in which an opening area increases toward an upper portion (claim 2).
[0013]
(Action / Effect)
As the opening area of the liquid reservoir increases toward the top, the more it is "mortar-shaped," the greater the probability of collecting the processing liquid droplets. Therefore, the contamination of the substrate due to the droplet can be further prevented.
[0014]
Further, it is preferable that the angle of the inclined surface at the opening of the liquid reservoir is not less than “20 °” (claim 3).
[0015]
(Action / Effect)
If the angle of the inclined surface at the opening of the liquid reservoir is equal to or more than “20 °”, even if vibrations or the like are applied, it is possible to prevent the droplets of the processing liquid once collected in the liquid reservoir from flowing down.
[0016]
Preferably, the processing liquid supply means is provided near the center of rotation of the substrate.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
1 and 2 relate to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing a schematic configuration of a substrate cleaning apparatus, and FIG. 2 is an enlarged view of a discharge section in a back rinse nozzle.
[0018]
The support plate 1 having a diameter slightly larger than the diameter of the substrate W is provided with a plurality of support pins 3 around the periphery thereof. Each support pin 3 has a cylindrical shape, and has a downwardly inclined surface 3a on the upper surface thereof on the rotation center side. On the downward inclined surface 3a, a projection 3b for regulating the edge position of the substrate W is provided upright.
[0019]
Note that the support plate 1 corresponds to the rotation support means in the present invention.
[0020]
A mounting portion 5 protruding downward is formed on a lower surface of the rotation center portion of the support plate 1.
A loose insertion hole 7 is formed in the mounting portion 5, and a locking portion 9 is formed around the opening to the support plate 1. A mounting hole 11 is formed in the lower part.
[0021]
The upper part of the rotating shaft 13 is attached to the attachment hole 11. The rotating shaft 13 is hollow, and is driven to rotate by a motor 15. The motor 15 is of a penetrating type in which the rotating shaft 13 protrudes from the bottom.
[0022]
A back rinse pipe 17 is inserted through the rotating shaft 13, and the bottom thereof is connected to a connecting portion 19 a of the T-tube 19. A supply pipe 23 communicating with the rinse liquid supply source 21 is connected to one of the connection sections 19 b of the T-shaped pipe 19 via an on-off valve 25. A drain pipe 29 is connected to the other connecting portion 19 c of the T-shaped pipe 19 via an on-off valve 27.
[0023]
The rinsing liquid corresponds to the processing liquid in the present invention.
[0024]
The back rinse pipe 17 is attached with its upper end projecting slightly above the surface of the support plate 1. On the other hand, the lower end is fitted to the connecting portion 19a of the T-tube 19. Further, a nozzle cap 31 is fitted on the outer peripheral surface of the back rinse pipe 17 at the upper end corresponding to the “discharge section” in the present invention. The back rinse pipe 17 and the nozzle cap 31 constitute a back rinse nozzle 32.
[0025]
The back rinse nozzle 32 corresponds to a processing liquid supply unit in the present invention.
[0026]
The nozzle cap 31 has a circular shape in plan view and is formed to be thin. A liquid reservoir 33 communicating with the upper end of the back rinse pipe 17 is formed at the center. The liquid reservoir 33 opens toward the lower surface of the substrate W, and has a linearly inclined surface 34 surrounding the upper end of the back rinse tube 17. Further, the opening area has a “mortar shape” that increases toward the top. Further, a gentle peripheral inclined surface 35 is formed from the liquid reservoir 33 to the peripheral portion.
[0027]
The distance d1 between the upper surface of the support plate 1 and the lower surface of the substrate W is, for example, about 13 mm, and the distance d2 between the upper portion of the nozzle cap 31 and the lower surface of the substrate W is determined in the horizontal direction of the rinsing liquid on the lower surface of the substrate W. The distance is such as not to disturb the flow to the outside, for example, about 6 mm. The interval d2 and the opening area of the liquid reservoir 33 in plan view are set in consideration of the number of revolutions when processing the substrate W, the flow rate of the rinsing liquid, the time required for completely stopping the rinsing liquid, and the like. Is preferred. Thereby, the probability that the splash of the rinsing liquid can be collected in the liquid pool 33 can be increased.
[0028]
It is preferable that the above-mentioned straight inclined surface 34 is configured as shown in FIG. FIG. 3 is an enlarged view of the liquid pool 33.
[0029]
That is, the linearly inclined surface 34 of the liquid reservoir 33 is configured such that the angle θ upward and obliquely from the upper end of the back rinse pipe 17 to the horizontal axis is 20 ° or more.
[0030]
With such an angle, even if vibrations or the like are applied by the motor 15 or the like, it is possible to prevent the droplets of the rinse liquid once collected in the liquid reservoir 33 from flowing down to the surroundings.
[0031]
The lower surface of the nozzle cap 31 is formed with a concave portion 37 having a larger shape than the locking portion 9 so as not to interfere with the locking portion 9 of the support plate 1. Therefore, the nozzle cap 31 is independent of the support plate 1, is fixed to the back rinse pipe 17, and is non-rotating.
[0032]
Above the support plate 1, a cleaning liquid nozzle 41 movable between a standby position (not shown) and the processing position shown in FIG. 1 is provided. The cleaning liquid nozzle 41 has a swingable arm 43 and a discharge nozzle 45 on the tip side.
[0033]
Note that the above-described cleaning liquid nozzle 41 corresponds to a cleaning unit in the present invention.
[0034]
Next, the operation of the substrate cleaning apparatus having the above configuration will be described.
[0035]
First, the substrate W to be processed is transported by a transport arm (not shown), and is placed on the support plate 1 with the cleaning surface facing upward. At this time, the peripheral edge of the substrate W comes into contact with the support pins 3 so that the position of the substrate W is regulated. Note that the cleaning surface of the substrate W here is generally the back surface of the substrate W where no circuit pattern or the like is formed.
[0036]
Next, the motor 15 is driven to rotate the support plate 1 at a low speed. The rotation speed at this time is, for example, about 500 to 1000 rpm. Then, the on-off valve 27 is closed and the on-off valve 25 is opened, so that the rinsing liquid is supplied from the rinsing liquid supply source 21 to the back rinse pipe 17. Thus, the rinsing liquid is supplied from the back rinse nozzle 32 toward the lower surface of the substrate W that rotates at a low speed together with the support plate 1.
[0037]
At this time, a part of the rinsing liquid colliding with the lower surface of the substrate W may rebound and return to the back rinse nozzle 32 side without being scattered around by the centrifugal force. Then, the droplets fall on the nozzle cap 31, but are received by the liquid reservoir 33.
[0038]
Thereafter, a process of swinging the upper surface of the substrate W while supplying the cleaning liquid from the cleaning liquid nozzle 41 is performed for a predetermined time. As a result, a cleaning process is performed on the upper surface of the substrate W, and dirt such as particles attached to the upper surface is removed.
[0039]
The rinsing liquid from the back rinse nozzle 32 and the cleaning liquid from the cleaning liquid nozzle 41 may be supplied simultaneously.
[0040]
After a lapse of a predetermined time, the discharge of the cleaning liquid from the cleaning liquid nozzle 41 is stopped, and the cleaning liquid is retracted to the standby position. Further, the opening and closing valve 27 is opened, and the opening and closing valve 25 is closed, so that the supply of the rinsing liquid from the back rinse nozzle 32 is stopped. At this time, the rinsing liquid in the back rinsing pipe 17 flows down in the pipe and is discharged, but a part of the rinsing liquid discharged from the upper end of the back rinsing pipe 17 toward the lower surface of the substrate W is located at the rotation center. For this reason, since the centrifugal force is not applied or the centrifugal force is extremely small as compared with the rinsing liquid that spreads by touching the lower surface of the substrate, the liquid drops downward without scattering to the surroundings along the lower surface of the substrate W. However, the droplet is received by the liquid reservoir 33 of the nozzle cap 31.
[0041]
The cleaning liquid from the cleaning liquid nozzle 41 and the rinsing liquid from the back rinsing nozzle 32 may be stopped simultaneously.
[0042]
Next, the rotation speed of the motor 15 is increased and maintained for a predetermined time, whereby the cleaning liquid adhering to the substrate W is shaken off and dried. The rotation speed at this time is, for example, about 3000 rpm.
[0043]
In this drying step, the substrate W is rotated at a high speed. However, the droplets dropped on the nozzle cap 31 may be vibrated due to the high-speed rotation of the motor 15 or the like because the liquid reservoir 33 employs the above-described structure. Even when a negative pressure is applied due to the rotation or rotation, the droplet does not climb up and move on the linearly inclined surface 35 of the non-rotating nozzle cap 31.
Therefore, it is possible to prevent the droplets from flowing down on the surface of the rotating support plate 1, where the droplets scatter and contaminate the lower surface of the substrate W. As a result, the inconvenience that the droplets of the processing liquid are scattered and adhere to the lower surface of the substrate W is eliminated, so that contamination of the substrate W due to the droplets can be prevented.
[0044]
The nozzle cap 31 is not limited to the above-described embodiment, and may be implemented, for example, in an embodiment as shown in FIG.
[0045]
That is, the back rinse pipe 17 having a smaller diameter than the loose insertion hole 7 is attached so as to protrude from the upper portion of the nozzle cap 31. With the configuration in which the upper end of the back rinse pipe 17 is close to the lower surface of the substrate W, splash of the rinse liquid due to liquid return when the rinse liquid is stopped can be suppressed. The splash of the rinsing liquid is collected in the liquid reservoir 33 and flows down the gap between the back rinse pipe 17 and the gentle insertion hole 7. Therefore, it is preferable that the gap be communicated with the drain pipe 29. This can save the trouble of maintenance for periodically removing the stored rinse liquid.
[0046]
Further, the nozzle cap 31 may be embodied in a form as shown in FIG.
[0047]
That is, the liquid reservoir 33A of the nozzle cap 31A has a curved inclined surface 43 having a curved inclined surface. The curved inclined surface 43 is formed such that the angle of the inclined surface gradually increases toward the outside. Therefore, it is possible to make it more difficult for the droplets that have fallen into the liquid reservoir 33A to flow down to the surroundings.
[0048]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made as follows.
[0049]
(1) The liquid reservoirs 33 and 33A are not limited to the linear inclined surface 34 and the curved inclined surface 43. For example, an inclined surface having fine step-like projections may be used.
[0050]
(2) The back rinse nozzle 32 does not need to be provided at the center of rotation, and may be provided at a position eccentric from the center of rotation of the substrate W. Even in such a case, the same effect as in the above-described embodiment can be achieved by providing the above-described liquid pools 33 and 33A in the discharge unit of the back rinse nozzle 32.
[0051]
(3) A discharge pipe for discharging the rinse liquid dropped and stored in the liquid pools 33 and 33A may be connected to the liquid pipes 29 from the liquid pools 33 and 33A. This can save the labor of maintenance for periodically removing the rinsing liquid stored in the liquid pools 33 and 33A.
[0052]
(4) The cleaning means may include, for example, a brush or the like instead of the cleaning liquid nozzle 41.
[0053]
【The invention's effect】
As is apparent from the above description, according to the present invention, the processing liquid is supplied to the lower surface thereof while the substrate being rotated by the rotation supporting means is cleaned by the cleaning means. Even if the processing liquid adheres to the discharge unit, the processing liquid is collected by the liquid pool. Therefore, the inconvenience that the droplet of the processing liquid is scattered by the rotation support means and adheres to the lower surface of the substrate is eliminated, so that the contamination of the substrate due to the droplet can be prevented.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a schematic configuration of a substrate cleaning apparatus.
FIG. 2 is an enlarged view of a discharge unit in a back rinse nozzle.
FIG. 3 is an enlarged view of a liquid pool.
FIG. 4 is a longitudinal sectional view showing a modification.
FIG. 5 is a longitudinal sectional view showing a modification.
[Explanation of symbols]
W ... substrate 1 ... support plate (rotation support means)
3 ... Support pin 13 ... Rotating shaft 15 ... Motor 17 ... Back rinse pipe 19 ... T-tube 21 ... Rinse liquid supply source 31, 31A ... Nozzle cap 32 ... Back rinse nozzle (processing liquid supply means)
33, 33A: liquid pool portion 34: linear inclined surface 35: peripheral inclined surface 41: cleaning liquid nozzle (cleaning means)
43… curved inclined surface

Claims (4)

A substrate provided with rotation support means for abuttingly supporting a peripheral portion of the substrate and rotating the substrate in a horizontal posture, cleaning means for cleaning the upper surface of the substrate, and processing liquid supply means for supplying a processing liquid to the lower surface of the substrate In the cleaning device,
The substrate cleaning apparatus according to claim 1, wherein the processing liquid supply means includes a liquid pool portion opened toward a lower surface of the substrate at a discharge portion thereof. The substrate cleaning apparatus according to claim 1,
The substrate cleaning apparatus is characterized in that the liquid reservoir has a “mortar shape” in which an opening area increases toward an upper portion. The substrate cleaning apparatus according to claim 2,
The substrate cleaning apparatus according to claim 1, wherein the angle of the inclined surface at the opening of the liquid reservoir is not less than "20 °". 4. The substrate cleaning apparatus according to claim 1, wherein the processing liquid supply unit is provided near a rotation center of the substrate. 5.

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