JPH08905A - Washing apparatus and method having defoaming function - Google Patents

Abstract

PURPOSE:To realize a washing apparatus and method having defoaming function capable of removing air bubbles in a washing soln. CONSTITUTION:This washing apparatus consists of an overflow type washing tank and a circulating filter mechanism containing a filter and a defoaming device 11 and the defoaming device 11 is constituted by partially inserting a liquid inlet pipe 13 and an exhaust pipe 12 in the upper part of a hermetically closed container 12, and a liquid outlet pipe 15 is provided to the lower part of the container 12 and the leading end of the liquid inlet pipe 13 is closed, and a plurality of small holes 16 allowing a liquid to flow out are provided to the upper circumferential part of the pipe 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning device having a defoaming function and a cleaning method.

2. Description of the Related Art Conventionally, semiconductor devices have been highly integrated with the progress of semiconductor technology, and their patterns have become finer. It has become an important issue to prevent contamination due to poor removal of metal and particles and redeposition.

[0003]

2. Description of the Related Art FIG. 4 is a schematic view showing a conventional semiconductor substrate cleaning apparatus. In the figure, 1 is an overflow type cleaning tank, and 1b is an overflow receiver for storing the cleaning liquid overflowing from the cleaning tank 1a. The overflow receiver 1b is connected to the suction port of the liquid feed pump 3 by the pipe 2, and the discharge port of the liquid feed pump is connected to the cleaning tank 1 by the pipe 4, the filter 5, and the pipe 6, which form a circulation filtration mechanism. It is configured.

Then, the semiconductor substrate 7 is immersed in the cleaning liquid 8 filled in the cleaning tank 1 for cleaning. The cleaning liquid 8 for cleaning the semiconductor substrate 7 overflows from the cleaning tank 1a,
The cleaning liquid sent to the filter 5 through the pipe 2 by the liquid supply pump 3 and filtered for particles and the like therein is returned to the cleaning tank 1 by the pipe 6. In this way, the cleaning liquid 8 is circulated and used.

[0005]

In the conventional semiconductor substrate cleaning apparatus described above, bubbles are generated in the cleaning liquid 8 due to the influence of the processing liquid remaining in the chemical treatment process performed before the cleaning process (especially when a foaming agent is included). 9 is generated. In addition, the gas dissolved in the cleaning liquid is separated into bubbles by the pressure change when passing through the filter 5.

When such bubbles are present in the cleaning tank, the bubbles adhere to the semiconductor substrate. Due to the property that particles tend to collect at the boundary between the gas phase and the liquid phase, the particles adhere to the semiconductor substrate together with the air bubbles and cause a problem of contaminating the semiconductor substrate.

The present invention aims to realize a cleaning device and a cleaning method having a defoaming function capable of removing bubbles in a cleaning liquid.

[0008]

In a cleaning apparatus having a defoaming function of the present invention, an overflow type cleaning tank 1 is provided,
The defoaming device 11 is provided with a liquid inlet pipe 13 and an exhaust pipe 14 which are partially inserted in the upper part of a closed container 12, and the circulation filtering mechanism includes a filter 5 and a defoaming device 11. A liquid outlet pipe 15 is provided in the lower portion, the tip of the liquid inlet pipe 13 is closed, and a plurality of small holes 16 for liquid outflow are formed on the upper circumference thereof.

Further, the cleaning method of the present invention is characterized in that the object to be cleaned is immersed in the cleaning liquid 8 for cleaning while the air bubbles 9 generated in the cleaning liquid 8 are removed by the defoaming means 11.

By adopting this configuration, it is possible to obtain a cleaning device and a cleaning method having a defoaming function capable of removing bubbles in the cleaning liquid.

[0011]

As shown in FIG. 1, the cleaning liquid 8 overflowing from the cleaning tank 1a passes through the pipe 2, the liquid feed pump 3, the pipe 4, the filter 5, and the pipe 10 to remove the defoaming device 1
Sent to 1. In the defoaming device 11, as shown in FIG. 3, the cleaning liquid flows out from the plurality of small holes 16 provided in the liquid inlet pipe 13 to the lower part through the space of the closed container 12, and is defoamed during this time. Further, air bubbles also float from the cleaning liquid accumulated in the lower part of the closed container 12 and are defoamed. The degassed gas is discharged to the outside through the exhaust pipe 14. The defoamed cleaning liquid is returned to the cleaning tank 1a through the pipe 6. Thus, the cleaning liquid is defoamed by the defoaming device 11 while circulating.

[0012]

EXAMPLE FIG. 1 is a schematic view showing an example of a cleaning apparatus having a defoaming function of the present invention. In FIG. 1, reference numeral 1 denotes an overflow type cleaning tank, which has a cleaning tank 1a and an overflow receiver 1b for receiving the cleaning liquid overflowing from the cleaning tank 1a. There is. The liquid delivery pump 3 is connected to the filter 5 via the pipe 4 and the defoaming device 11 via the pipe 10, and the defoaming device 11 is connected to the cleaning tank 1 via the pipe 6.

As shown in FIG. 2, the defoaming device 11 is provided with a cylindrical hermetically sealed container 12, and a liquid inlet pipe 13 and an exhaust pipe 14 are provided on the upper portion thereof so as to communicate with the interior of the container, respectively, and hermetically sealed. A liquid outlet pipe 15 is provided at the bottom of the container 12 so as to communicate with the inside of the container. And, the liquid inlet pipe 13 has a part of the end thereof in the closed container 1.
2, and the tip is closed like a bag, and a plurality of small holes 16 for liquid outflow are formed on the upper circumference thereof.

The operation of this embodiment thus constructed will be described with reference to FIGS. In FIG. 1, the cleaning tank 1a
The cleaning liquid 8 that has overflowed from the overflow receiver 1b is sucked into the liquid feed pump 3 through the pipe 2 and sent out from the discharge port. The cleaning liquid sent out is sent to the filter 5 through the pipe 4, where contaminants such as metal and particles are removed. Next, the cleaning liquid from which contaminants have been removed is sent to the defoaming device 11 through the pipe 10.

In the defoaming device 11, as shown in FIG. 3, the cleaning liquid flows into the closed container 12 through the small hole 16 at the tip through the liquid inlet pipe 13, and passes through the space to the cleaning liquid 8 accumulated at the bottom. To fall. Air bubbles in the cleaning liquid separate from the cleaning liquid while falling in this space. Further, bubbles also float from the cleaning liquid 8 accumulated at the bottom of the closed container 12 and are separated from the cleaning liquid. These separated gases are discharged to the outside through the exhaust pipe 14.

This series of operations is constantly repeated by the pulsation of the liquid feed pump, and the defoamed cleaning liquid 8 is returned to the original cleaning tank 1a through the pipe 6. In this way, the cleaning liquid is circulated and used, and contaminants are removed and defoamed during the process. As a result, bubbles existing in the cleaning liquid 8 in the cleaning tank 1a are suppressed, and contamination of an object to be cleaned such as the semiconductor substrate 7 to be cleaned is prevented.

The defoaming device 11 always needs a space for performing a defoaming action in the closed container 12, and since this space is opened to the atmosphere through the exhaust pipe 14, the cleaning liquid 8 in the closed container 12 is opened. The liquid level 8a of the liquid is substantially the same as the liquid level of the cleaning tank 1a. Therefore, the defoaming device 11 needs to be installed in consideration of the required space.

[0018]

According to the present invention, by removing the bubbles generated in the cleaning tank or the circulation mechanism, it is possible to prevent contamination of the object to be cleaned by particles collected in the bubbles and improve the cleaning effect. It greatly contributes to.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of a cleaning device having a defoaming function of the present invention.

FIG. 2 is a perspective view showing a defoaming device in an embodiment of a cleaning device having a defoaming function of the present invention.

FIG. 3 is a cross-sectional view for explaining the operation of the defoaming device of FIG.

FIG. 4 is a schematic view showing a conventional semiconductor substrate cleaning apparatus.

[Explanation of symbols]

 1 ... Overflow type cleaning tank 2, 4, 6, 10 ... Pipe 3 ... Liquid feed pump 5 ... Filter 7 ... Semiconductor substrate 8 ... Cleaning liquid 11 ... Defoaming device 12 ... Airtight container 13 ... Liquid inlet pipe 14 ... Exhaust pipe 15 ... Liquid outlet pipe 16 ... Small hole

Claims (2)

[Claims] 1. An overflow type washing tank (1) and a circulation filtration mechanism including a filter (5) and a defoaming device (11), wherein the defoaming device (11) is an upper part of a closed container (12). Liquid inlet pipe (13) and exhaust pipe (1)
4) is provided, a liquid outlet pipe (15) is provided in the lower portion of the container (12), and the tip of the liquid inlet pipe (13) is closed, and a liquid outlet pipe (15) is provided on the upper circumference thereof. A cleaning device having a defoaming function, characterized in that a plurality of small holes (16) are formed. 2. A cleaning method characterized by immersing and cleaning an object to be cleaned while removing air bubbles (9) generated in the cleaning liquid (8) by a defoaming means (11).