JPH1187288A - Substrate-cleaning method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove not only foreign particles attached to a substrate before cleaning but also a brush fibers which can cause short circuits to a pattern by a method, wherein the main surface of the substrate is cleaned being rubbed with the brush, and at the same time a cleaning solution oscillated by ultrasonic waves is supplied to the main surface of the substrate. SOLUTION: A substrate D held at the stage 4 of a substrate cleaning device is rotated, a cleaning solution is discharged at the substrate D from a cleaning solution supply nozzle 5, to coat all the main surface of the substrate D. Then, an arm 6 of a brush cleaning mechanism 13 and the arm 7 of an ultrasonic cleaning mechanism 14 are reciprocated in a horizontal direction at the center of the substrate D at the same time, and a brush 9 is made to descend so as to come into contact with the substrate D. At this point, the brush 9 is rotated, while ultrasonically oscillated pure water is spouted out from an ultrasonic nozzle 16, whereby brush cleaning and ultrasonic cleaning are carried out at the same time. A cleaning solution is discharged again to clean the main surface of the substrate D, after the simultaneous cleaning carried out with a brush and ultrasonically oscillated pure water has been finished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a substrate and a cleaning apparatus used for the method. More specifically, the present invention relates to a substrate cleaning method capable of effectively removing both dust adhering to the main surface of a substrate and fibers removed from a brush, and a cleaning apparatus used in the cleaning method.

[0002]

2. Description of the Related Art In the manufacturing process of semiconductors and liquid crystal display devices,
When forming a pattern in a photolithography process, it is essential to wash the substrate. As a conventional cleaning method, there is a method shown in a flowchart of FIG.

[0003] First, a substrate is carried on a rotatable stage, and then the substrate is rotated while rotating on the stage.
A cleaning liquid is supplied from a nozzle, and brush cleaning is performed by rubbing the main surface of the substrate with a cleaning brush.

After that, a nozzle for ultrasonic cleaning is moved onto the stage from the opposite direction to the cleaning nozzle, and the cleaning liquid is supplied while the cleaning liquid is vibrated by ultrasonic waves. This is a series of steps of removing a part of dust and finally supplying a cleaning liquid to wash out remaining dust.

[0005]

In the above-described series of steps, dust adhering before cleaning can be removed to some extent. However, since the brush comes into contact with the main surface of the substrate during brush cleaning, the brush fibers adhere to the substrate from the brush itself.

[0006] The brush fibers are generally made of nylon fibers or the like, and have the property of being difficult to remove if the substrate dries after being attached to the substrate. Therefore, even if the ultrasonic cleaning and the supply of the cleaning liquid are performed after the brush cleaning, there is a problem that the main surface of the substrate is dried during the time from the end of the brush cleaning to the start of the ultrasonic cleaning, and the fibers attached to the substrate cannot be removed. . When a pattern is formed in a state where fibers are attached to the main surface of the substrate, there is a case where a short circuit occurs in the pattern.

Further, in the conventional cleaning apparatus, the cleaning brush and the ultrasonic cleaning nozzle are arranged to face each other and move independently of each other. Therefore, it is impossible to use the cleaning nozzle and the ultrasonic cleaning nozzle simultaneously. It is possible.

The present invention has been made in order to solve such a problem, and a substrate cleaning method and a cleaning method capable of effectively removing both dust adhering to the main surface of the substrate and fibers removed from the brush. It is an object to provide a cleaning device used in the method.

[0009]

SUMMARY OF THE INVENTION Brush fibers made of nylon or the like have the characteristic that they cannot be easily removed if they adhere once before the substrate dries. Therefore, it is necessary to remove the brush fibers together with dust while the cleaning liquid remains on almost the entire surface of the substrate so as not to dry the substrate.
Therefore, the present inventors have paid attention to such a point, and have invented a substrate cleaning method capable of suitably removing the fiber of the brush and a cleaning apparatus used therein.

According to a first aspect of the present invention, there is provided a method of cleaning a substrate, wherein the main surface of the substrate is cleaned by rubbing with a brush, and at the same time, a cleaning liquid vibrated by ultrasonic waves is supplied to the main surface of the substrate for cleaning. Accordingly, dust adhering to the main surface of the substrate and fibers removed from the brush are removed.

According to a second aspect of the present invention, in the method for cleaning a substrate, the main surface of the substrate is cleaned by rubbing with a brush, and at the same time, a high-pressure cleaning liquid is supplied to the main surface of the substrate for cleaning. It is characterized in that dust attached to the main surface of the substrate and fibers removed from the brush are removed.

The "brush" according to claims 1 and 2 is a brush in a broad sense, and does not particularly limit the shape and structure of the brush and the brush and the roll brush according to claims 4 to 8. It is a concept that includes both.

It is preferable that the main surface of the substrate is washed before a resist coating step at the time of pattern formation.

According to a fourth aspect of the present invention, there is provided a substrate cleaning apparatus comprising: (a) a substrate holding / rotating mechanism for holding and rotating a substrate around a rotation axis extending in a vertical direction; A brush extending downward, a brush cleaning mechanism having a drive unit for rotating and horizontally moving the brush, (c) an ultrasonic cleaning nozzle including an ultrasonic vibrator for ultrasonically vibrating the cleaning liquid, and And an ultrasonic cleaning mechanism having a drive unit for moving the ultrasonic cleaning nozzle in the horizontal direction.

According to a fifth aspect of the present invention, there is provided a substrate cleaning apparatus comprising: (a) a substrate holding and rotating mechanism for holding and rotating a substrate around a rotation axis extending in a vertical direction; A brush extending downward, a brush cleaning mechanism having a drive unit for rotating and horizontally moving the brush, (c) a high-pressure jet nozzle for jetting a cleaning liquid at high pressure, and moving the high-pressure jet nozzle in the horizontal direction And a high-pressure cleaning mechanism having a drive unit.

Preferably, the ultrasonic cleaning nozzle or the high-pressure jet nozzle is linked to the brush.

According to a seventh aspect of the present invention, there is provided a substrate cleaning apparatus comprising: (a) a substrate driving mechanism for rotating or horizontally moving a substrate; and (b) fibers extending radially from a mandrel extending in a horizontal direction. A roll brush cleaning mechanism having a roll brush, a drive unit for rotating the roll brush around the mandrel, (c) an ultrasonic cleaning nozzle including an ultrasonic vibrator for ultrasonically vibrating the cleaning liquid, and the ultrasonic cleaning nozzle And an ultrasonic cleaning mechanism having a drive unit for moving the ultrasonic cleaning nozzle in the horizontal direction.

The substrate cleaning apparatus according to claim 8 of the present invention comprises (a) a substrate driving mechanism for rotating or horizontally moving the substrate, and (b) fibers extending radially from a mandrel extending in the horizontal direction. A roll brush cleaning mechanism having a roll brush and a drive unit for rotating the roll brush around the mandrel; (c) a high-pressure jet nozzle for jetting a cleaning liquid at a high pressure; and a drive unit for moving the high-pressure jet nozzle in a horizontal direction. And a high-pressure cleaning mechanism having:

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a substrate cleaning method and a cleaning apparatus used in the cleaning method of the present invention will be described in detail with reference to the drawings. FIG. 1 is a flowchart showing a cleaning method according to the first embodiment of the present invention. FIG. 2 is a perspective view of a substrate cleaning apparatus according to the first embodiment of the present invention.
4 is an exploded perspective view of an arm of the brush cleaning mechanism of FIG. 2, FIG. 4 is an enlarged perspective view of the ultrasonic cleaning mechanism of FIG. 2, and FIG. 5 is a plan view of a substrate cleaning apparatus according to Embodiment 2 of the present invention.

Embodiment 1 The substrate cleaning method according to Embodiment 1 of the present invention shown in FIG. 1 is different from the conventional substrate cleaning method shown in FIG. 6 in the steps of brush cleaning and ultrasonic cleaning. Differently, the other steps are common.

That is, the substrate cleaning method of the present invention is characterized in that the main surface of the substrate is cleaned by rubbing with a brush, and at the same time, ultrasonic cleaning is performed by supplying a cleaning liquid vibrated by ultrasonic waves to the main surface of the substrate. I have. Thus, the fibers removed from the brush by the brush cleaning are quickly removed by the ultrasonic cleaning together with dust adhering to the main surface of the substrate. Therefore, the substrate does not dry after the brush cleaning and the fibers remain attached.

When the main surface of the substrate is cleaned, if the cleaning is performed before the resist coating step at the time of pattern formation, the capability of removing foreign substances is high by the simultaneous operation of brush cleaning and ultrasonic cleaning. There is no problem of applying the resist while leaving the resist.

FIG. 2 shows a substrate cleaning apparatus according to the first embodiment of the present invention. The substrate cleaning apparatus shown in FIG. 2 includes a substrate holding and rotating mechanism 12 for holding and rotating the substrate D, a brush cleaning mechanism 13 for contacting the main surface of the substrate D and cleaning the main surface of the substrate D, An ultrasonic cleaning mechanism 14 that operates simultaneously with the brush cleaning mechanism 13.

The substrate holding and rotating mechanism 12 has a rotating shaft 1 that is driven to rotate by a driving mechanism (not shown), and a substrate holding unit 2 that holds the substrate D on the rotating shaft 1 by vacuum. A stage 4 having a plurality of pins 3 for positioning the four corners of the substrate D is disposed on the substrate holding unit 2.

The cleaning liquid supply nozzles 5 are nozzles for discharging the cleaning liquid to the entire main surface of the substrate D, and are disposed at about two positions outside the stage of the substrate holding and rotating mechanism 12.

The brush cleaning mechanism 13 has an arm 6. As the arm 6, a conventionally used robot arm is used, and its tip can reciprocate horizontally from the center of the substrate D toward the outer periphery and can move up and down with respect to the substrate D.

As shown in FIG. 3, the cleaning unit 15 includes a brush driving motor 8 and a cleaning brush 9 connected by a belt 10, and the driving motor 8 circulates the belt 10 to rotate the cleaning brush 9. The brush 9 is, for example,
Fiber 9b of nylon resin or the like downward from brush body 9a
A stretched one is used.

The ultrasonic cleaning mechanism 14 also includes the brush cleaning mechanism 1.
Like FIG. 3, it has an arm 7 composed of a robot arm and has the same movement direction. If the ultrasonic cleaning mechanism 14 is always linked with the brush cleaning mechanism 13, the brush 9 and the ultrasonic nozzle 11 can be used at the same time without interfering with each other. Moreover, the fibers removed from the brush can be quickly removed by ultrasonic cleaning.

The ultrasonic nozzle 11 is, as shown in FIG.
It comprises a nozzle body 16 and an ultrasonic transducer 17 arranged inside the nozzle body 16.

In the substrate cleaning apparatus thus configured, the cleaning liquid is discharged from the cleaning liquid supply nozzle 5 toward the substrate D at the same time as the substrate D held on the stage 4 of the substrate cleaning apparatus rotates. Cover the entire surface with the cleaning solution.

Next, the arm 6 of the brush cleaning mechanism 13 and the arm 7 of the ultrasonic cleaning mechanism 14 simultaneously reciprocate in the horizontal direction to the center position of the substrate D, and further lower the brush 9 to a position where it contacts the substrate D. At that time, the ultrasonic nozzle 1
6. Pure water subjected to ultrasonic vibration is ejected from 6. By rotating the brush while jetting pure water, brush cleaning and ultrasonic cleaning are performed simultaneously. After the completion of the simultaneous cleaning, the main surface of the substrate D is cleaned again by discharging the cleaning liquid.

By the above operation, not only the existing dust but also the fibers of the brush are ultrasonically cleaned at the same time, thereby improving the removing ability.

In the present embodiment, pure water has been described as an example of the cleaning liquid used in the ultrasonic cleaning. However, the present invention is not limited to this, and the present invention is not limited thereto. A cleaning liquid such as a solution of carbon dioxide or ozone dissolved in water can also be used.

Next, an experimental example performed to verify the cleaning effect of the substrate cleaning method according to the present invention will be described.

In this experiment, a nylon brush was used as a washing brush for the washing treatment, and after the initial washing, the washing treatment was performed under the conditions of Experimental Examples 1, 2, and 3, the number of fibers of the brush was measured by a measuring device.

The conditions are as follows. First, when only the brush is operated as the initial, the number of brush fibers is measured. In Experimental Example 1, when the supply of the cleaning liquid before the brush cleaning and then only the brush cleaning were performed, in Experimental Example 2, the cleaning method of the present invention was used. When ultrasonic cleaning is performed, Experimental Example 3 is a cleaning method of the present invention, in which brush cleaning and supply of a cleaning liquid before and after ultrasonic cleaning are performed, and brush fibers when brush cleaning and ultrasonic cleaning are used simultaneously are used. The number was measured.

The results are shown in Table 1. In Experimental Example 1, supplying the cleaning liquid and brushing before the brush cleaning had no effect. However, when the brush cleaning and ultrasonic cleaning in Experimental Example 2 were performed simultaneously, the number of fibers was reduced without supplying the cleaning liquid. I do.
Further, it is apparent that the number of brush fibers attached is drastically reduced by adding the cleaning liquid before and after the brush cleaning and the ultrasonic cleaning in Experimental Example 3 and simultaneously using the brush cleaning and the ultrasonic cleaning.

[0038]

[Table 1]

Embodiment 2 A mandrel 1 extending horizontally as shown in FIG.
A roll brush 18 in which the fibers 18b extend radially from 8a may be used. In this case, the contact area of the brush is increased, so that the cleaning ability is improved. Roll brush 1
8, the drive unit (not shown) is the roll brush 1
8 is rotated around the mandrel 18a. The roll brush 1
The roll brush cleaning mechanism is constituted by the drive unit 8 and the driving unit.

In the second embodiment, the substrate D
The present invention is not limited to washing by rotating the washing machine, and the present invention may be implemented in a conveyor-type washing apparatus as shown in FIG.

That is, instead of the substrate holding and rotating mechanism 12 shown in FIG. 2, a substrate driving mechanism for rotating or horizontally moving the substrate D may be used. Ultrasonic cleaning mechanism 1 of FIG.
As for No. 4, a common one is used. In the apparatus shown in FIG. 5, the substrate D is transported in the direction of the arrow in the figure by a substrate driving mechanism such as a roller conveyor that transports the substrate while supporting the edge. In this case, the cleaning liquid supply nozzle 5 and the ultrasonic cleaning nozzle 11 are arranged before and after in the traveling direction of the substrate D so that the cleaning liquid is always applied to the roll brush 18. The ultrasonic cleaning nozzle 11 can reciprocate along the longitudinal direction of the roll brush 18.

Third Embodiment As an application example of the first embodiment, the brush 9 shown in FIG.
The number of rotations of the stage 4 for rotating the substrate D is, for example, 50 to 100 rpm.
In order to prevent the brush 9 from contacting the substrate end face at a high speed and generating fibers of the brush 9 such that the rotation speed of the stage 4 is 100 rpm to 300 rpm, the rotation speed of the brush 9 is reduced. Is good.

Fourth Embodiment Instead of the ultrasonic cleaning in the above-described first to third embodiments, high-pressure jet cleaning using pure water or the like can also suitably remove dust and brush fibers.

That is, the ultrasonic cleaning nozzle 11 is
A high-pressure cleaning mechanism may be provided by replacing the high-pressure jet nozzle which injects the cleaning liquid at a high pressure (about 10 to 15 kgf / cm ² ). Other configurations are common to those of the first to third embodiments.

[0045]

According to the present invention, the brush cleaning and the ultrasonic cleaning are simultaneously used, so that not only the dust adhering before the cleaning but also the brush fibers which cause the short-circuit of the pattern are removed. And the cleaning ability is further improved.

The use of high-pressure jet cleaning instead of ultrasonic cleaning also has the effect of removing both dust and brush fibers, as in ultrasonic cleaning.

By replacing the brush with a roller brush, the area of contact of the roll brush with the main surface of the substrate increases, so that the cleaning ability of dust adhering before cleaning is further improved.

By using the present invention for pretreatment of the resist coating step at the time of pattern formation, not only dust but also fibers of the brush before the treatment can be removed, and short circuit of the pattern can be prevented.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a cleaning method according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the substrate cleaning apparatus according to the first embodiment of the present invention.

FIG. 3 is an exploded perspective view of an arm of the brush cleaning mechanism of FIG. 2;

FIG. 4 is an enlarged perspective view of the ultrasonic cleaning mechanism of FIG.

FIG. 5 is a plan view of a substrate cleaning apparatus according to Embodiment 2 of the present invention.

FIG. 6 is a flowchart showing a conventional cleaning process.

[Explanation of symbols]

 9 Brush 11 Ultrasonic nozzle 12 Substrate holding and rotating mechanism 13 Brush cleaning mechanism 14 Ultrasonic cleaning mechanism 15 Cleaning unit 18 Roll brush

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Yabushita, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo, Japan 2-3 Mitsubishi Electric Co., Ltd. (72) Inventor Kazuhiko Noguchi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Corporation

Claims (8)

[Claims] 1. A main surface of a substrate is cleaned by rubbing with a brush,
At the same time, a cleaning liquid vibrated by ultrasonic waves is supplied to the main surface of the substrate to perform cleaning, thereby removing dust adhering to the main surface of the substrate and fibers removed from the brush. 2. A main surface of the substrate is cleaned by rubbing with a brush,
At the same time, a substrate cleaning method in which a high-pressure cleaning liquid is supplied to the main surface of the substrate for cleaning, thereby removing dust adhering to the main surface of the substrate and fibers removed from the brush. 3. The substrate cleaning method according to claim 1, wherein the cleaning of the main surface of the substrate is performed before a resist coating step at the time of pattern formation. 4. A substrate holding and rotating mechanism for holding and rotating a substrate around a rotation axis extending in a vertical direction.
(B) a brush in which fibers extend downward from the brush body;
A brush cleaning mechanism having a driving unit for rotating and horizontally moving the brush; (c) an ultrasonic cleaning nozzle including an ultrasonic vibrator for vibrating the cleaning liquid with ultrasonic waves; A substrate cleaning apparatus comprising: an ultrasonic cleaning mechanism having a driving unit for moving the substrate. 5. A (a) substrate holding / rotating mechanism for holding and rotating a substrate about a rotation axis extending vertically.
(B) a brush in which fibers extend downward from the brush body;
A brush cleaning mechanism having a driving unit for rotating and horizontally moving the brush; (c) a high-pressure cleaning nozzle having a high-pressure jet nozzle for jetting a cleaning liquid at a high pressure; and a driving unit for moving the high-pressure jet nozzle in a horizontal direction. A substrate cleaning apparatus comprising: 6. The substrate cleaning apparatus according to claim 4, wherein the ultrasonic cleaning nozzle or the high-pressure jet nozzle is linked to the brush. 7. A substrate driving mechanism for rotating or horizontally moving a substrate, (b) a roll brush in which fibers extend radially from a mandrel extending in a horizontal direction, and the roll brush is moved around the mandrel. A roll brush cleaning mechanism having a rotating drive unit, and (c) an ultrasonic cleaning nozzle including an ultrasonic vibrator for vibrating the cleaning liquid with ultrasonic waves,
And an ultrasonic cleaning mechanism having a drive unit for moving the ultrasonic cleaning nozzle in a horizontal direction. 8. A substrate drive mechanism for rotating or horizontally moving a substrate, (b) a roll brush in which fibers extend radially from a mandrel extending in a horizontal direction, and the roll brush is moved around the mandrel. A substrate cleaning apparatus comprising: a roll brush cleaning mechanism having a driving unit for rotating; (c) a high pressure jet nozzle for jetting a cleaning liquid at high pressure; and a high pressure cleaning mechanism having a driving unit for moving the high pressure jet nozzle in a horizontal direction.