JPH08141532A - Batch type brush cleaning device and cleaning method - Google Patents

Abstract

(57) [Summary] [Purpose] Batch-type brush cleaning that can simultaneously clean foreign substances of big size and fine particle size and in a hybrid manner, and that does not promote deterioration of parts equipped in the cleaning device. The purpose is to provide a device. A batch type brush cleaning apparatus 1 includes a cleaning tank 2 for storing a cleaning liquid, and a cleaning substrate holder 4 for fixing a plurality of cleaning substrates 3 arranged in the cleaning tank 2.
And an ultrasonic transducer 5 provided on the side surface and the bottom surface in the cleaning tank 2 for propagating ultrasonic waves to the substrate 3 to be cleaned, and the cleaning tank 2
And a brush support 7 having a brush 6 for cleaning the surface of the substrate 3 to be cleaned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a batch type brush cleaning apparatus intended to be used for high precision cleaning of fine processed products such as semiconductor devices and glass substrates for liquid crystal displays which are highly integrated.

[0002]

2. Description of the Related Art Conventionally, a plurality of substrates to be cleaned are placed in a cleaning liquid in a cleaning tank in order to remove surface stains during the manufacturing process of the semiconductor device or the glass substrate for liquid crystal display as described above. A batch-type cleaning method of immersing and cleaning with ultrasonic waves or a single-wafer cleaning method of cleaning a substrate to be cleaned one by one with a brush or the like is performed.

The single-wafer cleaning method using a brush is generally effective in removing big size dust and dirt adhering to the substrate to be cleaned. That is, in the single-wafer cleaning method, as shown in FIG. 3, the substrate 30 to be cleaned is sandwiched by the transport rollers 11 rotating in the direction of the arrow in the drawing, and the substrate 30 to be cleaned is flowed one by one in one direction. The cleaning brush 12 is provided on the upper and lower portions of the substrate 30 to be cleaned at regular intervals. Therefore, since the brushes 12 are provided on the upper and lower portions of the substrate 30 to be cleaned, it is possible to clean not only the front surface of the substrate 30 to be cleaned but also dust and dirt attached to the back surface thereof at the same time.

Further, the batch type cleaning method using ultrasonic waves has been generally used for degreasing cleaning of oils and fats adhering to an object to be cleaned, but nowadays it is highly integrated. Accordingly, it is used for cleaning semiconductor devices, glass substrates for liquid crystal display elements, etc., which require clean surfaces. While it is desired to improve the ability to remove fine particles and the like in the substrate cleaning process, the batch type ultrasonic cleaning apparatus equipped with an ultrasonic oscillation mechanism has been attracting attention as one of the effective methods for removing fine particles.

An example of a batch type ultrasonic cleaning apparatus is shown in FIG. The batch type ultrasonic cleaning device 13 is provided with a cleaning tank 14 that stores a cleaning liquid, and an ultrasonic transducer 15 that generates ultrasonic waves according to the output is provided on the bottom and side surfaces of the cleaning tank 14. ing. Further, inside the cleaning tank 14, a substrate receiving base 17 for fixing the substrate 16 to be cleaned is disposed. The substrate receiving base 17 is
The substrate-to-be-cleaned 17 is moved up and down so that the ultrasonic waves generated by the ultrasonic oscillator 15 are uniformly propagated to the substrate 16 to be cleaned through the cleaning liquid.

An overflow tank 18 for receiving the cleaning liquid overflowing from the cleaning tank 14 is provided above the outer periphery of the cleaning tank 14, and the bottom of the overflow tank 18 is connected to the cleaning tank 14 by a pump 19 and a filter 20. Then, an overflow system in which the cleaning liquid is circulated is configured. By this overflow system, fine particles in the cleaning liquid are efficiently filtered by the filter 20, and the clean cleaning liquid is returned to the cleaning tank 14 again by the discharge force of the pump 19 and circulated.

Ultrasonic waves exert a great effect in removing fine particles adhering to the substrate 16 to be cleaned. The high-frequency electric vibration generated by the oscillator is converted into mechanical vibration by the ultrasonic vibrator 15, and the ultrasonic wave is generated by the vibration of the ultrasonic vibrator 15. Then, this vibration propagates to the substrate 16 to be cleaned via the cleaning liquid. When the frequency is below several tens of KHz, it is mainly due to the erosion effect, and also in the megasonic region (M
(Hz range), the substrate to be cleaned 16 is caused by the vibration acceleration effect.
Dissociates the fine particles adhering to the surface of the. The cleaning liquid containing the dissociated particles flows from the cleaning tank 14 to the overflow tank 18
And is efficiently filtered by the filter 20.

[0008]

However, in the above-mentioned conventional single-wafer cleaning method, it is difficult to thoroughly control the gap of the brush (the distance between the brush and the substrate to be cleaned), that is, the brush is always even on the substrate to be cleaned. Since it is difficult to control whether or not the gap has been hit, there is a disadvantage that the gap interval must be regularly measured and dealt with so as to prevent defective cleaning or uneven cleaning.

Further, at the time of conveyance, the substrate to be cleaned must be sandwiched between the upper roller and the lower roller with respect to the traveling direction by the conveying roller. Therefore, when the transfer roller is dirty, the transfer roller may be contaminated on the substrate to be cleaned, and the distance between the upper roller and the lower roller may be narrowed due to deterioration of the transfer roller. Therefore, there is a possibility that cleaning failure and cleaning unevenness may occur.

On the other hand, the conventional batch type cleaning method using ultrasonic waves is suitable for removing minute size foreign matters and dirt, but it is necessary to increase the ultrasonic wave intensity for removing big size dust. is there. However, when the ultrasonic wave intensity is increased, the deterioration of the ultrasonic vibrator progresses, and in particular, the degree of adhesion between the ultrasonic vibrator and the tank wall of the cleaning tank decreases. Therefore, ultrasonic waves may not be sufficiently propagated to the substrate to be cleaned 16, which causes a problem that cleaning unevenness or the like occurs.

Further, in order to uniformly propagate the ultrasonic wave,
The pedestal to be cleaned vibrates, but as mentioned above, the cleaning level is lower than the initial setting value due to the decrease in adhesion between the ultrasonic transducer and the tank wall of the cleaning tank due to the increase in ultrasonic intensity. As a result, there is a possibility that the substrate to be cleaned may not be uniformly cleaned and cleaning unevenness may occur, and the cleaning level cannot be improved. Further, if the cleaning level is low in one step, it is necessary to perform recleaning, which makes it difficult to simplify the process.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and it is possible to simultaneously perform a batch-type cleaning system and a single-wafer cleaning system, that is, a foreign matter of a big size and a fine particle size. At the same time, or
It is an object of the present invention to provide a batch-type brush cleaning device that can be hybrid-cleaned and that does not promote deterioration of parts included in the cleaning device.

[0013]

The present invention is to solve the above-mentioned problems by the following constitutions. The invention of claim 1 is
A cleaning tank for storing the cleaning liquid, a substrate to be cleaned for fixing a plurality of substrates to be cleaned arranged in the cleaning tank, and an ultrasonic wave provided on the tank wall of the cleaning tank A batch-type brush cleaning apparatus comprising: an ultrasonic wave generating unit; and a brush cleaning unit disposed above the cleaning tank and having a brush for cleaning the surface of the substrate to be cleaned.

According to a second aspect of the present invention, in the first aspect, the brush cleaning means has one or more brushes between the substrates to be cleaned, and the brushes are movable. This is a batch type brush cleaning device.

According to a third aspect of the present invention, in the batch type brush cleaning apparatus according to the first aspect, the substrate receiving base to be cleaned is movable while holding the substrate to be cleaned.

According to a fourth aspect of the present invention, in the first or second aspect, the brush pushes out the bristles from the inside of the brush according to the abrasion of the piezoelectric element and the bristles recognized by the piezoelectric element. A batch-type brush cleaning device comprising a mechanism.

According to a fifth aspect of the invention, a step of immersing a plurality of substrates to be cleaned in the cleaning liquid stored in the cleaning tank, and the step of immersing the substrate to be cleaned in a cleaning tank A step of fixing the substrate to be cleaned, a step of moving a brush support installed above the cleaning tank and having a plurality of brushes downward, and inserting the brush between the substrates to be cleaned; Mainly consists of a step of moving the support to clean the substrate to be cleaned, and a step of removing ultrasonic particles generated by ultrasonic wave generation means provided on the tank wall in the cleaning layer to remove foreign matters adhering to the substrate to be cleaned. Is a batch-type brush cleaning method.

[0018]

According to the invention of claim 1, a brush for fixing the substrate to be cleaned to the substrate to be cleaned disposed in the cleaning tank and cleaning the surface of the substrate to be cleaned above the cleaning tank. The single-wafer cleaning is performed by arranging the brush cleaning means having the above, and the batch cleaning is performed by ultrasonic waves.

According to the invention of claim 2, since the brush cleaning means is provided with one or more brushes between the substrates to be cleaned, the cleaning power is enhanced and at the same time one brush fails. Even in this case, the substrate to be cleaned can be uniformly cleaned. Further, since the brush is movable and moves along the cleaning surface of the substrate, for example, the end surface of the substrate can be uniformly cleaned. Further, both sides of the substrate can be cleaned at the same time, and a plurality of substrates can be cleaned at the same time.

According to the third aspect of the present invention, since the substrate to be cleaned base is movable while holding the substrate to be cleaned and moves, for example, in the vertical direction, the ultrasonic waves generated by the ultrasonic wave generating means generate the cleaning liquid. And uniformly propagate to the substrate to be cleaned.

According to the invention of claim 4, the brush is provided with a piezoelectric element and a brush bristle pushing-out mechanism for pushing the brush bristle out of the inside of the brush in accordance with the abrasion of the brush bristle recognized by the piezoelectric element. Therefore, the length of the brush hair is always kept uniform. Further, when the brush bristles of a predetermined length are pushed out from the inside of the brush and are no longer pushed out, and when the brush bristles are worn out, the output from the piezoelectric element is lost, so that it is possible to know when to replace the brush.

According to the fifth aspect of the present invention, in the cleaning step, the step of cleaning the substrate to be cleaned fixed in the cleaning tank with a brush, and the ultrasonic wave generating means provided on the tank wall of the cleaning tank are used to generate ultrasonic waves. Is combined with the step of removing foreign matter adhering to the substrate to be cleaned, the single-wafer cleaning and the batch cleaning are performed simultaneously or in a hybrid manner.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic sectional view of a batch type brush cleaning apparatus according to an embodiment of the present invention. The present apparatus is an apparatus used for cleaning semiconductor devices, glass substrates for liquid crystal display elements, and the like.

As shown in FIG. 1, the batch type brush cleaning apparatus 1 according to the embodiment of the present invention is capable of simultaneously performing single-wafer cleaning and batch cleaning. That is, a plurality of substrates 3 to be cleaned are placed in the cleaning tank 2 for storing the cleaning liquid.
A substrate receiving base 4 for fixing the substrate is disposed, and an ultrasonic transducer 5 for converting a high frequency electric signal generated by an oscillator (not shown) into mechanical vibration to generate ultrasonic waves.
Are provided on the side surface and the bottom surface in the cleaning tank 2. Further, above the cleaning tank 2, a brush support 7 having a brush 6 for cleaning the front surface and the back surface of the substrate 3 to be cleaned is arranged. The brush 6 itself rotates by the driving force of a motor or the like.

Since the rotatable brush 6 is inserted between the substrates 3 to be cleaned, it is possible to effectively remove the large size foreign matter adhering to the surface of the substrate 3 to be cleaned, and Not only the front surface of the cleaning substrate 3 but also the back surface can be uniformly cleaned. Although only one brush 6 is shown between the substrates in FIG. 1, two or more brushes may be provided, and in this case, the cleaning power is further enhanced, and furthermore, one brush fails. Even in this case, the substrate to be cleaned can be uniformly cleaned. Further, since the brush support 7 provided with the brush 6 is movable and is configured to move in the vertical direction along the cleaning surface of the substrate, for example,
The end surface of the substrate 3 to be cleaned can be uniformly cleaned.
The movement direction of the brush support base 7 is not limited to the above, and may be, for example, up and down, left and right, or even oblique.

As described above, since the ultrasonic transducers 5 are attached to the side surface and the bottom surface in the cleaning tank 2, the foreign matter of the particle size adhering to the substrate 3 to be cleaned is removed as in the conventional batch type cleaning. Since it can be removed, hybrid cleaning becomes possible in combination with the brush cleaning. Further, the substrate-to-be-cleaned 4 is movable, and is configured to move in the vertical direction, for example, so that the ultrasonic vibration from the ultrasonic transducer 5 is uniformly propagated to the substrate to be cleaned through the cleaning liquid. There is.
As a result, cleaning of fine particles and the like can be performed more efficiently.
The movement direction of the substrate to be cleaned 4 is not limited to the above, and for example, horizontal movement may be applied.

FIG. 2 is an explanatory diagram showing the change over time of the brush used in the batch type brush cleaning apparatus according to the present invention. As shown in FIG. 2, the brush 6 has a brush bristle pushing machine 6 that pushes out the piezoelectric bristle 6a provided on the piezoelectric element 6d and the bristle mounting base 6c from the inside of the brush rotary shaft 6b.
e is built in, and the brush 6 rotates about the brush rotating shaft 6b by a driving force (not shown) such as a motor. As is clear from FIG. 2, the length of the brush bristles 6a becomes non-uniform due to abrasion with the substrate to be cleaned. As it is, it becomes impossible to provide a stable cleaning level to the substrate to be cleaned. Therefore, the piezoelectric element 6d is provided inside the brush rotation shaft 6b to recognize the contact condition between the substrate to be cleaned and the brush 6. When a problem occurs in the contacting condition between the two, the brush bristle pushing machine 6e is operated (rotating operation), and the brush bristle 6a is pushed out from the inside of the brush rotary shaft 6b by the amount of wear. This manages the gap (separation distance) between the brush and the substrate to be cleaned. as a result,
The length of the bristles is always kept constant and a stable cleaning level can be provided.

Further, in order to make up for the shortage between the gaps caused by the abrasion of the brush bristles 6a, the brush bristle extruder 6
Although the brush bristles 6a are extruded from the inside of the brush rotation shaft 6b only by the amount e, the length of the bristles 6a is finite. Is impossible. At this time, since the output from the piezoelectric element 6d inside the brush rotation shaft 6b disappears, it is possible to know the replacement time of the brush and to secure a more stable cleaning level.

Next, the substrate cleaning using the batch type brush cleaning apparatus according to this embodiment will be outlined. First, a plurality of substrates 3 to be cleaned are dipped in the cleaning liquid stored in the cleaning tank 2, and the tips of the substrates 3 are fixed to the substrate receiving base 4. Then, the brush support 7 arranged above the cleaning tank 2 is moved downward to immerse the brush 6 in the cleaning liquid so that the brush 6 provided on the brush support 7 is inserted between the respective substrates. .

At the same time as the brush 6 rotates by itself, it moves up and down or up and down and left and right, for example, along the cleaning surface of the substrate 3 to be cleaned, so that the big size dust adhering to the surface of the substrate 3 to be cleaned is removed to clean The front surface and the back surface of the substrate 3 are uniformly cleaned. After a certain time has passed after this cleaning, the cleaning liquid containing the foreign matter floating in the cleaning tank 2 is discharged from the cleaning tank 2 to the overflow tank 8. The bottom of the overflow tank 8 is connected to the bottom of the cleaning tank 2 by a pump 9 and a filter 10 to form an overflow system in which the cleaning liquid circulates. Therefore, the cleaning liquid containing the foreign matter and the like passes through the pipe 9 and the pump 9 and the filter 10 to effectively remove the foreign matter and the like, and the clean cleaning liquid returns to the tank.

After removing a big size foreign substance with the brush 6, an ultrasonic wave is generated from an ultrasonic vibrator 5 provided in the cleaning tank 2. This ultrasonic wave propagates to the substrate 3 to be cleaned, and the foreign matter of particle size adhering to the surface of the substrate 3 to be cleaned is removed from the surface of the substrate. However, this alone does not always mean that the ultrasonic waves hit the substrate 3 to be cleaned uniformly. For this reason, the substrate to be cleaned 4 is moved up and down, for example, for the purpose of further improving the cleaning level. As a result, the ultrasonic waves are uniformly propagated to the substrate 3 to be cleaned, the fine particles are removed more efficiently, and the substrate cleaning is completed.

By performing the batch type cleaning and the single-wafer cleaning alternately or simultaneously or in a hybrid manner as described above, the cleaning level in the process can be improved and the process can be shortened. That is, in the conventional brush cleaning method, the objects to be cleaned are cleaned one by one with the cleaning roller, but when cleaning is performed by this method, cleaning is performed with dust in the air adhering to the objects to be cleaned. To do
For example, when cleaning a high-definition device, scratches or the like are generated on the device surface, and in the case of a substance having a high oxidation rate, the function of the device surface, for example, as a transistor, is deteriorated. Also,
Since it is a single-wafer type, it takes a long time to clean, and loss occurs during mass production.

According to the present invention, the single-wafer type and the batch type (ultrasonic wave) can be performed in the tank at the same time, which was not possible in the past, and the cleaning can be performed by the hybrid type. Therefore, it is possible to perform high-level cleaning of an object to be cleaned under various conditions without unevenness. Further, according to the present invention, a plurality of brushes corresponding to the number of objects to be cleaned are provided, and a single-wafer type and a batch type (ultrasonic wave) can be performed simultaneously or in a hybrid manner in the tank. The stability, the cleaning power and the processing time can be shortened.

[0034]

According to the first aspect of the present invention, the substrate to be cleaned can be fixed on the substrate to be cleaned disposed in the cleaning tank, and the batch type cleaning can be performed by ultrasonic waves.
Since a single-wafer cleaning mechanism is provided by arranging a brush cleaning means having a brush for cleaning the surface of the substrate to be cleaned above the cleaning tank, it is possible to remove the big size adhered to the substrate to be cleaned. Further, the foreign matter having a particle size can be removed simultaneously or in a hybrid manner, the cleaning power can be improved, and the substrate to be cleaned can be uniformly cleaned. Therefore, it is not necessary to excessively increase the power of ultrasonic waves in order to improve the cleaning level, and there is no fear of accelerating the deterioration of the parts provided in the cleaning device. Further, as described above, since it becomes possible to remove the foreign matter of the big size and the fine particle size in a short time, the process can be shortened and the cost can be reduced. Further, the cleaning method can be selected or changed, and the process can be simplified.

According to the second aspect of the present invention, the brush cleaning means is provided with one or more brushes between the substrates to be cleaned, so that the cleaning power is enhanced and at the same time one brush fails. Also in this case, since the substrate to be cleaned can be uniformly cleaned, defective cleaning and uneven cleaning can be prevented. Further, not only the film surface of the substrate to be cleaned but also the back surface can be uniformly cleaned. further,
By moving the brush and moving it along the cleaning surface of the substrate to be cleaned, it is possible to uniformly clean the end surface of the substrate and prevent problems such as uneven cleaning and poor cleaning. In addition, since cleaning of a plurality of substrates can be performed simultaneously, cleaning time can be shortened.

According to the third aspect of the invention, the substrate to be cleaned is movable while holding the substrate to be cleaned, and is moved up and down, for example, so that the ultrasonic wave generated by the ultrasonic wave generating means is passed through the cleaning liquid. And evenly propagate to the substrate to be cleaned,
The fine particles can be removed more effectively, and the cleaning level can be improved.

According to the invention of claim 4, the brush is provided with the piezoelectric element and the brush bristle pushing mechanism for pushing the brush bristle from the inside of the brush in accordance with the abrasion amount of the brush bristle recognized by the piezoelectric element. , The piezoelectric element recognizes the contact of the brush against the substrate to be cleaned, and if a problem occurs with the contact, the brush pushing mechanism operates to compensate for the wear of the brush bristles, and the length of the bristles is always maintained. It can be kept uniform and the gap between the brush and the substrate to be cleaned can be managed. As a result, the brush to be cleaned is constantly and evenly applied to the substrate to be cleaned, so that defective cleaning and uneven cleaning can be prevented. In addition, when the bristles of a predetermined length are pushed out from the inside of the brush and are no longer pushed out, and when the bristles are worn out, the output from the piezoelectric element disappears, so it is possible to know when to replace the brush. It is possible to secure a stable cleaning level.

According to the fifth aspect of the present invention, a step of cleaning the substrate to be cleaned fixed in the cleaning tank with a brush, and ultrasonic waves are generated by the ultrasonic wave generating means provided on the tank wall of the cleaning tank. By incorporating a step of removing foreign matter adhering to the substrate to be cleaned into the cleaning step, it is possible to remove big size and fine particle size foreign matter adhering to the substrate to be cleaned at the same time or in a hybrid manner, improving the cleaning power, The substrate to be cleaned can be uniformly cleaned. Therefore,
It is not necessary to excessively increase the power of ultrasonic waves for improving the cleaning level, and there is no fear of accelerating the deterioration of the parts provided in the cleaning device. Further, as described above, since it becomes possible to remove the foreign matter of the big size and the fine particle size in a short time, the process can be shortened and the cost can be reduced. Further, the cleaning method can be selected or changed, and the process can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a batch type brush cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a change with time of the brush of FIG.

FIG. 3A is a schematic side view showing a cleaning process using a conventional single wafer cleaning apparatus. (B) is a plan view of (a).

FIG. 4 is a schematic sectional view of a conventional batch type cleaning apparatus.

[Explanation of symbols]

 1 Batch type brush cleaning device 2 Cleaning tank 3 Substrate to be cleaned 4 Substrate to be cleaned 5 Ultrasonic vibrator 6 Brush 7 Brush support

Claims (5)

[Claims] 1. A cleaning tank for storing a cleaning liquid, a substrate to be cleaned for fixing a plurality of substrates to be cleaned, which is arranged in the cleaning tank, and a tank wall of the cleaning tank. A batch-type brush cleaning apparatus comprising: an ultrasonic wave generating unit that generates ultrasonic waves; and a brush cleaning unit that is disposed above the cleaning tank and has a brush for cleaning the surface of the substrate to be cleaned. . 2. The batch type brush according to claim 1, wherein the brush cleaning means comprises one or more brushes between the substrates to be cleaned, and the brushes are movable. Cleaning device. 3. The batch type brush cleaning apparatus according to claim 1, wherein the substrate to be cleaned pedestal is movable while holding the substrate to be cleaned. 4. The brush has a piezoelectric element and a brush bristle pushing mechanism that pushes the bristle from the inside of the brush according to the amount of wear of the bristle recognized by the piezoelectric element. The batch type brush cleaning apparatus according to claim 1 or 2. 5. A step of immersing a plurality of substrates to be cleaned in a cleaning liquid stored in the cleaning tank, and fixing the substrate to be cleaned immersed in a substrate receiving base arranged in the cleaning tank. And a step of moving a brush support installed above the cleaning tank and having a plurality of brushes downward, inserting the brushes between the substrates to be cleaned, and moving the brush support. Mainly consists of a step of cleaning the substrate to be cleaned and a step of removing ultrasonic particles by ultrasonic waves generated by an ultrasonic wave generating means provided on a tank wall in the cleaning layer to remove foreign matters adhering to the substrate to be cleaned. Characteristic batch type brush cleaning method.