JPH10154679A - Substrate cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adverse influence to the surface of a substrate while the readhesion of particles to the surface is prevented by supplying a cleaning solution to the surface of from the downside sop that the solution can form a hollow film toward the peripheral edge of the surface only. SOLUTION: A substrate cleaning device which cleans the back surface of a substrate W by supplying a cleaning solution to the backside from a cleaning solution supplying nozzle 7 while the substrate W is rotated through a mechanical spin chuck 1 with the front surface of the substrate W on the bottom side forms a film of the cleaning solution on the surface over the full circumference by supplying the cleaning solution to the peripheral section of the surface from the downside through a nozzle 9 for liquid film and a cleaning solution guiding section 15. The film of the cleaning solution is formed in a hollow state and does not come into contact with the surface of the substrate W on the inside of the peripheral section.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. 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, a substrate for an optical disk (hereinafter, simply referred to as a substrate). In particular, the present invention relates to a substrate cleaning apparatus that performs a cleaning process on a substrate by supplying a cleaning liquid toward the back surface of the substrate while rotating the substrate with the surface of the substrate facing downward.

[0002]

2. Description of the Related Art Particles adhering to a substrate during processing may adversely affect the substrate itself or cause the particles to adhere to another substrate to cause cross-contamination. Is performed to remove adhering particles.
In particular, when the substrate is transported, the back surface of the substrate is often abutted and supported, so that the cleaning process of the back surface of the substrate is important in order to prevent cross-contamination between the substrates. As a substrate cleaning apparatus for cleaning a substrate in this way, for example, a rotation support unit configured to be rotatable and supporting the substrate with the front surface of the substrate facing downward, and a cleaning liquid flowing from above the substrate toward the back surface of the substrate. And a first cleaning liquid supply unit for supplying the cleaning liquid. Examples of the form of the first cleaning liquid supply unit include a jet method in which the cleaning liquid is supplied as a jet jet at a strong flow rate, and a method in which a rotating brush is brought into contact with the back surface of the substrate to perform brush cleaning.
There are a method of supplying a cleaning liquid to the back surface of the substrate and an ultrasonic method of supplying a cleaning liquid to which ultrasonic vibration is applied.

[0003] In the apparatus configured as described above, first, the substrate is supported by the rotation support portion, and while the substrate is rotated, the cleaning liquid is supplied from the first cleaning liquid supply portion toward the rear surface to adhere to the rear surface. Cleaning particles are removed.

However, while the back surface of the substrate can be cleaned by the above-described cleaning process, particles removed from the back surface of the substrate are scattered together with the cleaning liquid, wrap around the surface, and reattach to the surface of the substrate. Risk of contamination. Therefore, in order to prevent such particles from re-adhering, a second cleaning liquid supply unit for supplying a cleaning liquid from below to the surface of the substrate is provided, and the cleaning liquid is supplied to the surface of the substrate to clean the entire surface. The cleaning liquid is supplied to the back surface of the rotating substrate to remove particles while protecting the substrate by covering with the cover.

[0005]

However, the prior art having such a structure has the following problems. In other words, since various processes are performed on the surface of the substrate, if the cleaning liquid is supplied from the second cleaning liquid supply unit to the surface of the substrate, the surface of the substrate may be adversely affected. For example, when processing a substrate having a surface coated with a coating film, the cleaning liquid supplied to the surface may have adverse effects such as swelling of the coating film. When the coating film swells in this way, the pattern of the coating film is broken or the degree of adhesion to the substrate surface is reduced, adversely affecting the subsequent steps such as etching, and ultimately lowering the product yield. Will be.

In particular, when the first cleaning liquid supply unit is of the above-described ultrasonic type, the ultrasonic vibration of the cleaning liquid supplied to the back surface of the substrate is transmitted to the front surface of the substrate, and the second cleaning liquid supply unit. However, there is a problem that the cleaning liquid supplied from the substrate and covering the entire surface of the substrate also vibrates, thereby causing a remarkable adverse effect such that the pattern of the coating film is broken.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and prevents the particles from re-adhering by forming a hollow cleaning liquid film that extends from below the substrate surface to only the peripheral edge thereof. It is an object of the present invention to provide a substrate cleaning apparatus capable of preventing an adverse effect on a substrate surface while doing so.

[0008]

The present invention has the following configuration in order to achieve the above object. That is, the substrate cleaning apparatus according to claim 1 rotates the substrate by the rotation support means with the surface of the substrate facing downward,
In a substrate cleaning apparatus for cleaning a back surface of a substrate by supplying a cleaning liquid from a top of the rotation support unit toward a back surface of the substrate by a first cleaning liquid supply unit, the cleaning solution is supplied from below the substrate to a peripheral portion of the front surface thereof. And a liquid film forming means for supplying a cleaning liquid to form a film of the cleaning liquid over the entire circumference.

Further, the substrate cleaning apparatus according to claim 2 is
2. The substrate cleaning apparatus according to claim 1, wherein the liquid film forming unit is disposed near a rotation center of the rotation supporting unit,
Second cleaning liquid supply means for supplying a cleaning liquid from below the substrate toward the surface thereof, and cleaning liquid guiding means for guiding the cleaning liquid supplied from the second cleaning liquid supply means toward a peripheral portion of the surface of the substrate And characterized in that:

Further, the substrate cleaning apparatus according to claim 3 is
The substrate cleaning apparatus according to claim 1 or 2, wherein the first cleaning liquid supply unit includes an ultrasonic vibration applying unit that applies ultrasonic vibration to the cleaning liquid.

[0011]

The operation of the first aspect of the invention is as follows. The front surface of the substrate is supported downward by the rotation supporting means, and the substrate is rotated from the top toward the rear surface while rotating the substrate.
The cleaning liquid is supplied from the cleaning liquid supply means. The cleaning liquid is supplied to the periphery of the substrate directed downward by the liquid film forming means, and a film of the cleaning liquid is formed over the entire circumference. That is, the cleaning liquid is supplied only to the peripheral portion so as to prevent the cleaning liquid from touching the rotation center side of the peripheral portion of the substrate surface, and the cleaning liquid film is formed in a hollow shape. Particles adhering to the back surface of the substrate are scattered around the substrate together with the cleaning liquid supplied from the first cleaning liquid supply means and float around the substrate. However, since a hollow film of the cleaning liquid is formed on the peripheral portion of the substrate surface, it is possible to prevent particles from entering the inside from the peripheral portion.

According to the second aspect of the present invention, the direction of the cleaning liquid supplied from the second cleaning liquid supply means toward the surface of the substrate is guided to the peripheral portion of the substrate surface by the cleaning liquid guide means. Accordingly, the cleaning liquid can be supplied only to the peripheral portion so that the cleaning liquid does not come into contact with the vicinity of the center of the substrate surface. Therefore, it is possible to form a hollow film of the cleaning liquid, and it is possible to prevent particles from entering the inside of the film.

According to the third aspect of the present invention, since the ultrasonic vibration is applied to the cleaning liquid supplied from the first cleaning liquid supply means by the ultrasonic vibration applying means, the particles adhered to the back surface of the substrate. Can be efficiently removed. Furthermore, the ultrasonic vibration is transmitted to the surface of the substrate, but since the cleaning liquid is not supplied to the substrate surface from the periphery to the rotation center side, the ultrasonic vibration is prevented from acting on the substrate surface. it can.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 and 2, a description will be given of a substrate cleaning apparatus according to an embodiment. 1 is a longitudinal sectional view showing a schematic configuration of the substrate cleaning apparatus, and FIG. 2 is a partially cutaway perspective view showing a cleaning liquid guide. The substrate cleaning apparatus according to the present embodiment employs an ultrasonic method in which ultrasonic vibration is applied to a cleaning liquid to supply the cleaning liquid.

In FIG. 1, reference numeral 1 denotes a mechanical spin chuck for supporting the substrate W in contact therewith. The mechanical spin chuck 1 has a plurality of support pins 1b erected on a peripheral edge of an upper surface of a rotary plate 1a having a diameter slightly larger than the substrate W. The plurality of support pins 1b abut the edge of the substrate W to perform horizontal positioning, and abut the peripheral edge of the lower surface of the substrate W to perform positioning in the height direction, thereby holding the substrate W. It has become. In this apparatus, in order to wash and remove particles adhering to the back surface of the substrate W, the substrate W with the front surface facing downward is supported by the support pins 1b. The mechanical spin chuck 1 has a connecting portion 1c protruding downward from the center of the lower surface thereof is fitted on the upper end of the hollow rotary shaft 3a, and rotates with the hollow rotary shaft 3a by rotating the motor 3. Has become. Note that the mechanical spin chuck 1, the motor 3, and the hollow rotary shaft 3a correspond to the rotation support means of the present invention.

A splash prevention cup 5 is provided around the mechanical spin chuck 1 to prevent the cleaning liquid from splashing around. This scattering prevention cup 5 has an opening at the top and an upper cup 5a having an inclined surface on the side,
And a lower cup 5b into which the outer peripheral portion of the lower end of the upper cup 5a is fitted. An annular drainage zone 5c is formed at the bottom of the lower cup 5b, and is supplied to the substrate W and scatters, and stores the cleaning liquid guided downward by the inclined surface of the upper cup 5a. The cleaning liquid stored in the drainage zone 5c is discharged through the drain 5d and collected. Further, an elevating mechanism (not shown) for raising and lowering the scattering prevention cup 5 and the motor 3 relative to each other is provided, and the mechanical spin chuck 1 advances and retreats with respect to the scattering prevention cup 5 by moving these up and down relatively. It is supposed to. When transferring the substrate W between a substrate transport mechanism (not shown) and the mechanical spin chuck 1, an elevating mechanism operates.

A cleaning liquid supply nozzle 7 for supplying a cleaning liquid is provided above the substrate W. The cleaning liquid supply nozzle 7 moves to a side standby position away from the scattering prevention cup 5 when transferring the substrate W, and when cleaning processing is performed on the substrate W, it is shown in the drawing. It is configured to descend to a cleaning position indicated by a two-dot chain line in the figure via an upper standby position. In the cleaning process, the cleaning liquid supply nozzle 7 is driven to swing along the diameter direction of the substrate W by a swing mechanism (not shown). The cleaning liquid supply nozzle 7 supplies the cleaning liquid downward by applying ultrasonic vibration to the cleaning liquid supplied from the supply unit 7a by the ultrasonic application unit 7b. As the cleaning liquid, pure water, alcohol, or the like is used. The ultrasonic wave applying section 7b is a diaphragm formed by shaping a material having a piezoelectric effect or an electrostriction effect into a shape capable of obtaining a desired mechanical resonance frequency (for example, a frequency called an ultrasonic wave of about 1.5 MHz). In addition, a high-frequency voltage having a frequency substantially equal to the mechanical resonance frequency is applied and excited. The cleaning liquid supply nozzle 7 corresponds to a first cleaning liquid supply unit in the present invention, and the ultrasonic wave application unit 7b corresponds to an ultrasonic vibration applying unit in the present invention.

A liquid film nozzle 9 is disposed in the hollow portion of the hollow rotary shaft 3a so as to penetrate through the motor 3 and protrude slightly above the upper surface of the rotary plate 1a.
A cleaning liquid is supplied to the liquid film nozzle 9 from a cleaning liquid supply unit (not shown). Pure water or alcohol is used as the cleaning liquid as described above. Rotating plate 1
A circular diffusion plate 11 in a plan view is attached to the rotation center side of the liquid film nozzle 9 by four support members 11a so as to be spaced apart from the tip of the liquid film nozzle 9 by a predetermined distance. The cleaning liquid supplied upward from the front end of the nozzle 9 is diffused in the horizontal direction. The liquid film nozzle 9 corresponds to a second cleaning liquid supply unit in the present invention.

Around the diffusion plate 11, an annular deflection plate 13 having an inner diameter smaller than the outer diameter of the diffusion plate 11 and having an outer diameter larger than the outer diameter of the diffusion plate 11 is provided. ing. Further, the deflecting plate 13 has an inclined surface such that an inner peripheral portion thereof is located below the diffusion plate 11 and an outer peripheral portion thereof is located above the diffusion plate 11, that is, an upwardly inclined surface from the inner peripheral portion to the outer peripheral portion. Is formed. Further, the deflection plate 13 is supported by the support member 11 such that the outer peripheral portion is located below the surface of the substrate W supported by the support pins 1b.
a. When the outer peripheral portion of the deflecting plate 13 is extended, the tip of the deflecting plate 13 reaches the peripheral edge of the surface of the substrate W. The cleaning liquid supplied from the liquid film nozzle 9 and diffused in the horizontal direction by the diffusion plate 11 is deflected obliquely upward toward the peripheral edge of the surface of the substrate W by the deflection plate 13. Thus, the liquid film nozzle 9
Is supplied to the peripheral portion of the surface of the substrate W to form a film of the cleaning liquid over the entire circumference. That is, the cleaning liquid is formed in a hollow inverted conical shape, and the cleaning liquid does not touch the rotation center side from the peripheral edge of the substrate W. The above-described diffusion plate 11, support member 11a, and deflection plate 13 are connected to the cleaning liquid guide portion 1.
5. The liquid film nozzle 9 and the cleaning liquid guide 15 correspond to the liquid film forming means of the present invention, and the cleaning liquid guide 15 corresponds to the cleaning liquid guiding means of the present invention.

Next, the operation of the apparatus configured as described above will be described with reference to FIGS.
Note that these drawings are schematic diagrams showing the configuration near the substrate W, and the symbol P in the drawings indicates particles.

First, the substrate cleaning apparatus drives a lifting mechanism (not shown) to cause the mechanical spin chuck 1 to protrude upward with respect to the scattering prevention cup 5. In this state, after the substrate W to be cleaned is received by the mechanical spin chuck 1 from a substrate transport mechanism (not shown), the mechanical spin chuck 1 is stored in the scattering prevention cup 5. Then, the cleaning liquid supply nozzle 7 at the side standby position is moved to the cleaning position via the upper standby position.

Next, the substrate W is rotated by driving the motor 3, and before the cleaning liquid is supplied from the cleaning liquid supply nozzle 7 to the back surface of the substrate W, the supply of the cleaning liquid from the liquid film nozzle 9 is started. FIG. 3 shows the state at this time.
It is. The cleaning liquid supplied from the liquid film nozzle 9 is diffused in the peripheral direction of the substrate W by the diffusion plate 11 positioned above the liquid, and is supplied toward the peripheral edge of the surface of the substrate W by the deflection plate 13. As a result, a film of a cleaning liquid having a hollow inverted conical shape as shown in FIG. 3 is formed. Therefore, the cleaning liquid does not touch the surface of the substrate W that has been subjected to various processes. For example, when a coating film is applied to the surface of the substrate W, the coating film swells by contact with the cleaning liquid, and the formed pattern is easily broken or peeled, which adversely affects subsequent processes. However, this device can prevent such adverse effects.

After the cleaning liquid film is formed on the surface of the substrate W, the cleaning liquid is supplied from the cleaning liquid supply nozzle 7 to the back surface of the substrate W, and the cleaning liquid supply nozzle 7 is moved in the horizontal direction as shown by a two-dot chain line in FIG. To wash the back surface of the substrate W. Since ultrasonic vibration is applied to the cleaning liquid by the ultrasonic wave application unit 7b, the particles P attached to the back surface of the substrate W are easily removed from the back surface of the substrate W, and the particles P Scatter. As described above, since the ultrasonic vibration is applied to the cleaning liquid supplied to the back surface of the substrate W, the vibration is transmitted to the front surface of the substrate W to some extent. However, the cleaning liquid from the liquid film nozzle 9 is prevented from touching the rotation center side from the peripheral edge of the surface of the substrate W by the operation of the cleaning liquid guide portion 15, so that the action of ultrasonic vibration can be suppressed and the substrate W can be suppressed. It is possible to prevent the surface of W from being adversely affected.

After a predetermined time has passed since the supply of the cleaning liquid from the cleaning liquid supply nozzle 7, the supply is stopped. The particles P removed from the back surface of the substrate W and floating around the surface of the substrate W are drawn by a negative pressure generated on the rotation center side of the surface of the substrate W as shown by a dotted line in FIG. However, since a film made of the above-described cleaning liquid is formed by the cleaning liquid guide portion 15 on the rotation center side from the peripheral edge, the invasion can be prevented. Therefore, the particles P removed from the back surface of the substrate W can be prevented from re-adhering to the surface of the substrate W. The substrate W thus cleaned is supplied to the motor 3
The liquid is drained and dried by rotating at a high speed to complete the washing process.

In the conventional apparatus, a nozzle corresponding to the above-described liquid film nozzle 9 is provided for supplying a cleaning liquid to the center of the surface of the substrate W to cover and protect the entire surface of the substrate W with the cleaning liquid. May have been. In such an apparatus, the above-described effects can be obtained only by attaching the above-described cleaning liquid guide section 15 to the mechanical spin chuck 1 of the conventional apparatus. Can be.

Further, in order to reduce the area where the cleaning liquid comes into contact with the surface of the substrate W, the cleaning liquid supplied from the cleaning liquid guide 15 is supplied to a position near the edge of the substrate W.
It is preferable to adjust the mounting angle of the deflection plate 13 and the like.

Further, the apparatus of the above embodiment employs an ultrasonic system, but a jet system in which a cleaning liquid is supplied by a strong jet without applying ultrasonic vibration, or a cleaning liquid is supplied to the back surface of a substrate for brush cleaning. The same effect can be obtained even if the method is used.

[0028]

As is apparent from the above description, according to the first aspect of the present invention, the cleaning liquid is applied only to the peripheral edge of the substrate surface so that the cleaning liquid does not touch the rotation center side of the peripheral surface. Is supplied to form a hollow film of the cleaning liquid, so that particles can be prevented from entering the inside from the periphery. Therefore, the particles can be prevented from re-adhering to the substrate surface. Also, since the cleaning liquid does not touch the inside of the periphery of the substrate surface,
An adverse effect on the substrate surface, for example, an adverse effect due to swelling of the coating film applied on the substrate surface can be prevented.

According to the second aspect of the present invention, the direction of the cleaning liquid is guided to the peripheral portion of the substrate surface by the cleaning liquid guiding means, whereby a hollow cleaning liquid film can be formed. Particles can be prevented from invading. Therefore, there is an effect that the adverse effect on the substrate surface is prevented while preventing the particles from re-adhering. Further, since the second cleaning liquid supply means may be provided in the conventional apparatus in some cases, the same effect can be obtained only by attaching the cleaning liquid guide means.

According to the third aspect of the present invention, the ultrasonic vibration can be prevented from acting on the substrate surface.
While maintaining the particle removal efficiency on the back surface of the substrate as it is, it is possible to prevent an adverse effect due to ultrasonic vibration that may occur on the substrate surface.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating a schematic configuration of a substrate cleaning apparatus according to a first embodiment.

FIG. 2 is a partially cutaway perspective view showing a cleaning liquid guide.

FIG. 3 is a schematic diagram for explaining the operation.

FIG. 4 is a schematic diagram for explaining the operation.

FIG. 5 is a schematic diagram for explaining the operation.

[Explanation of symbols]

W: substrate P: particles 1: mechanical spin chuck (rotation support means) 3: motor (rotation support means) 5: scattering prevention cup 7: cleaning liquid supply nozzle (first cleaning liquid supply means) 7b: ultrasonic wave application unit ( Ultrasonic vibration applying means 9 Liquid nozzle (second cleaning liquid supply means, liquid film forming means) 11 Diffusion plate 13 Deflection plate 15 Cleaning liquid guide (cleaning liquid guiding means, liquid film forming means)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hideo Kinoshita 5-22-1, Kamizuhoncho, Kodaira-shi, Tokyo Inside Hitachi Microcomputer Co., Ltd. (72) Inventor Yasuki Yasuki 5-chome, Kamizuhoncho, Kodaira-shi, Tokyo 22-1 Inside Hitachi Microcomputer System Co., Ltd. (72) Inventor Shohiro Onishi 5-2-1, Josumihoncho, Kodaira-shi, Tokyo Intranet Co., Ltd. Hitachi Microcomputer System (72) Inventor Akihiro Tomozawa Kodaira, Tokyo 5-22-1, Kamizu Honcho Hitachi Microcomputer System Co., Ltd. (72) Inventor Masami Otani 322 Hashizushi Furukawacho, Fushimi-ku, Kyoto, Kyoto Japan Nippon Screen Manufacturing Co., Ltd. (72) Inventor Nobuyasu Hiraoka 322 Hashizushi Furukawa-cho, Fushimi-ku, Kyoto, Kyoto Prefecture Nippon Screen Manufacturing Co., Ltd.

Claims (3)

[Claims] A first cleaning liquid supply unit for supplying a cleaning liquid from above the rotation support unit to the back surface of the substrate by rotating the substrate with the rotation support unit with the front surface of the substrate facing downward; A substrate cleaning apparatus for cleaning the back surface of the substrate, further comprising a liquid film forming unit configured to supply a cleaning liquid from below the substrate toward a peripheral portion of the front surface and form a film of the cleaning liquid over the entire circumference. Substrate cleaning device. 2. The substrate cleaning apparatus according to claim 1, wherein said liquid film forming means is provided near a rotation center of said rotation support means, and supplies a cleaning liquid from below said substrate toward its surface. A substrate cleaning apparatus comprising: a second cleaning liquid supply unit; and a cleaning liquid guide unit that guides the cleaning liquid supplied from the second cleaning liquid supply unit toward a peripheral portion of the surface of the substrate. . 3. The substrate cleaning apparatus according to claim 1, wherein the first cleaning liquid supply unit includes an ultrasonic vibration applying unit that applies ultrasonic vibration to the cleaning liquid. Substrate cleaning equipment.