JPH0536666A - Cleaning device - Google Patents

Abstract

PURPOSE:To provide a cleaning device which can prevent the floating of dust and impurity ions on the surface of a cleaning liquid and the adhesion of foreign matters to wafers. CONSTITUTION:This cleaning device is used for washing wafers with water in an LSI manufacturing process and is equipped with a cleaning tank 2 in which the wafers 1 are washed with flowing water with a lid 4 which is provided on the top of the tank 2 so that the lid 4 can be brought into contact with the surface of a cleaning liquid 3, namely, pure water contained in the tank 2. The wafers 1 are cleaned while the wafers contained in a wafer cassette 5 are dipped in the cleaning water 3 contained in the tank 2. Because of the lid 4, invasion of foreign matters into the liquid 3 can be minimized and, at the same time, the floating of foreign matters on the surface of the liquid 3 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus, and more particularly, to a cleaning apparatus capable of preventing foreign substances from adhering to a semiconductor wafer (hereinafter simply referred to as a wafer) in a water washing process and a wet etching process in LSI manufacturing. And about effective technology.

[0002]

2. Description of the Related Art Conventionally, as a wafer cleaning apparatus in an LSI manufacturing process, for example, a wafer is immersed in a cleaning tank while being stored in a wafer cassette which is used for both transportation and cleaning, and an ascending laminar flow from the lower part of the cleaning tank. The wafer is being cleaned by.

For example, in the conventional cleaning tank, the wafer 1 is immersed in the cleaning liquid 3 in the cleaning tank 2 as shown in FIG. 5, and the cleaning process is efficiently performed by an ascending laminar flow from below the cleaning tank 2. . In this case, in order to improve the use efficiency of the cleaning liquid 3, the overflow system in which the cleaning liquid 3 is repeatedly used is adopted.

A technique similar to this is described, for example, in "LSI Handbook" P238 to P239, published by the Institute of Electronics and Communication Engineers, November 30, 1984.

[0005]

However, in the prior art as described above, even though the cleaning liquid overflows, it floats depending on the flow direction of the cleaning liquid in the cleaning tank as shown in FIG. There is a problem that the object 11, for example, dust ions in the air or impurity ions such as ionic contaminants stay on the surface of the cleaning liquid.

Therefore, in the conventional cleaning apparatus, when the wafer is taken in and out of the cleaning tank, floating dust and impurity ions adhere to the surface of the wafer, which causes a decrease in device yield.

Therefore, an object of the present invention is to provide a cleaning apparatus capable of preventing foreign matters from adhering to a wafer by eliminating retention of dust and impurity ions on the surface of the cleaning liquid.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0009]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

That is, the cleaning apparatus of the present invention comprises a chemical liquid treatment tank for chemical chemical treatment, and a running water washing tank for washing with running water after the chemical liquid treatment. A cleaning device for cleaning, wherein at least one of the chemical liquid treatment tank and the running water cleaning tank is provided with a covering member so as to come into contact with the liquid surface of the chemical liquid and the running water stored in the chemical liquid processing tank and the running water cleaning tank. is there.

In another cleaning apparatus of the present invention, at least one of the chemical solution treatment tank and the running water cleaning tank has a predetermined direction on the surface of the chemical solution and the running water stored in the chemical solution processing tank and the running water cleaning tank. It creates an air flow to.

Further, in another cleaning apparatus of the present invention, in at least one of the chemical solution treatment tank and the running water cleaning tank, the chemical solution stored in the chemical solution processing tank and the running water cleaning tank and the surface of the running water are directed in a predetermined direction. Is what makes the flow of.

[0013]

According to the above-mentioned cleaning device, by the installation of the covering member in contact with the liquid surface of the chemical liquid and the flowing water, the generation of the air flow in the predetermined direction on the liquid surface, or the generation of the flow in the predetermined direction on the liquid surface, Foreign substances and impurity ions mixed in the cleaning liquid do not stay on the liquid surface. As a result, it is possible to prevent foreign matter from adhering to the object to be cleaned.

Further, when the covering member is provided, invasion of foreign matter can be minimized. As a result, it becomes possible to prevent foreign matter from adhering to the object to be cleaned.

[0015]

Embodiment 1 FIG. 1 is a sectional view showing a cleaning tank used in a cleaning apparatus which is an embodiment of the present invention, and FIG. 2 is a sectional view showing a modification of the cleaning tank lid in this embodiment.

First, the construction of the cleaning tank in the cleaning apparatus of this embodiment will be described with reference to FIG.

The cleaning tank of the present embodiment is, for example, a cleaning device in a water cleaning step of LSI manufacturing, and is provided with a cleaning tank 2 for cleaning the wafer (object to be cleaned) 1 after chemical treatment with running water. A lid (covering member) 4 is provided so as to come into contact with the liquid surface of the pure water cleaning liquid 3 to be stored.

Then, the plurality of wafers 1 are immersed in the cleaning liquid 3 in the cleaning tank 2 while being stored in the wafer cassette 5, and the plurality of wafers 1 are simultaneously cleaned by the rising laminar flow from below the cleaning tank 2. It is supposed to be done.

Next, the operation of this embodiment will be described.

First, a plurality of wafers 1 which have undergone the chemical solution treatment are transferred to the upper part of the cleaning tank 2 by a transfer mechanism (not shown) while being stored in the wafer cassette 5. Then, the lid 4 of the cleaning tank 2 is opened, the transfer mechanism is lowered, and the wafer cassette 5 containing the wafer 1 is immersed in the cleaning liquid 3 in the cleaning tank 2.

Further, after raising the transfer mechanism, the lid 4 is closed and an ascending laminar flow is generated from below the cleaning tank 2 to clean the wafer 1 with the cleaning liquid 3 overflowing. In this case, even if dust particles in the air or impurity ions such as ionic contaminants are mixed in the cleaning liquid 3 and the dust particles or impurity ions float on the liquid surface, the cleaning liquid 3 and the cleaning liquid 3 will be discharged through the lid 4 on the liquid surface. The foreign matter does not stay on the surface of the cleaning liquid 3 since it flows down to the surface.

After the cleaning is completed, the lid 4 is opened again and the wafer cassette 5 is lifted from the cleaning tank 2 by the transfer mechanism and transferred to the next processing position. The above operation is repeated to clean the wafer 1 in units of wafer cassettes 5.

Therefore, according to the cleaning apparatus of the present embodiment, by providing the cleaning tank 2 with the lid 4, the invasion of foreign matter is minimized as compared with the conventional case, and even if it invades, the cleaning liquid 3
At the same time, the overflow can be performed, so that the foreign matter does not stay on the surface of the cleaning liquid 3, and the foreign matter can be prevented from adhering to the cleaning tank 2 when the wafer 1 is taken in and out.

Regarding the shape of the lid 4, for example, as shown in FIG. 2, a through hole 6 may be provided in the central portion of the lid 4a, and the cleaning liquid 3 and the foreign matter may overflow together through the through hole 6. .

[0025]

[Embodiment 2] FIG. 3 is a sectional view showing a cleaning tank used in a cleaning apparatus according to another embodiment of the present invention.

The cleaning tank of this embodiment has the same L capacity as in the first embodiment.
A washing tank 2a which is used as a washing device in a water washing step of SI production and which carries out washing of the wafer (object to be cleaned) 1 after chemical treatment with running water.
The difference from the first embodiment is that an air flow in a predetermined direction is created on the liquid surface instead of providing the cleaning tank 2a with a lid.

That is, in this embodiment, as shown in FIG. 3, an inert gas or the like is blown from one direction to the liquid surface of the cleaning liquid 3 to generate an air flow 7 on the liquid surface and float on the liquid surface. Dust, impurity ions, etc. can be washed off together with the cleaning liquid 3.

Therefore, according to the cleaning apparatus of the present embodiment, foreign matter does not remain on the liquid surface of the cleaning liquid 3 by forming the air flow 7 on the liquid surface of the cleaning liquid 3, as in the first embodiment. It becomes possible to prevent foreign matter from adhering to the wafer 1.

[0029]

[Embodiment 3] FIG. 4 is a sectional view showing a cleaning tank used in a cleaning apparatus according to still another embodiment of the present invention.

The cleaning tank of the present embodiment is a cleaning device in the water washing step of LSI manufacturing, as in the first and second embodiments.
A cleaning tank 2b for cleaning the wafer (object to be cleaned) 1 after chemical treatment with running water is provided, and the difference from the first and second embodiments is that a flow of the cleaning liquid 3 in a predetermined direction is created on the surface.

That is, in this embodiment, as shown in FIG. 4, an outflow nozzle 8 for outflowing the same pure water as the cleaning liquid 3 is provided on the surface of the cleaning liquid 3, and the pure water is made to flow from this outflow nozzle 8 to cause the surface to flow. It is possible to generate a flow 9 and to drop dust and impurity ions floating on the liquid surface together with the cleaning liquid 3.

Therefore, according to the cleaning apparatus of this embodiment, by forming the flow 9 on the liquid surface of the cleaning liquid 3, foreign matters do not remain on the liquid surface of the cleaning liquid 3 as in the first and second embodiments. Therefore, it becomes possible to prevent foreign matter from adhering to the wafer 1.

Although the invention made by the present inventor has been specifically described based on the first to third embodiments, the present invention is not limited to the above-mentioned embodiments and various modifications are possible without departing from the scope of the invention. It goes without saying that it can be changed.

For example, the cleaning apparatus according to the first embodiment is not limited to the shapes of the lids 4 and 4a as shown in FIGS. 1 and 2, but various modifications are possible. Considering the laminar flow of the cleaning liquid, it is particularly desirable that the foreign matter has a shape that allows the foreign matter to easily flow down.

Also in the second and third embodiments, it goes without saying that the method of producing the air flow 7 and the flow 9 can be changed.

In the above description, the invention mainly made by the present inventor is applied to the cleaning apparatus used in the water washing step of the LSI manufacturing which is the field of use of the invention, but the invention is not limited to this. For example, it can be widely applied to a cleaning device for a wet etching process including a chemical treatment tank.

[0037]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.
It is as follows.

That is, at least one of the chemical solution treatment tank and the running water cleaning tank is provided with a covering member so as to come into contact with the liquid surface of the chemical solution and the running water stored in the chemical solution processing tank and the running water cleaning tank, or the chemical solution and the running water. By creating an air flow in the specified direction on the liquid surface or by creating a flow in the specified direction on the liquid surface, foreign substances and impurity ions mixed in the cleaning liquid do not stay on the liquid surface, so the object to be cleaned It is possible to prevent foreign matter from adhering to the.

When a covering member is provided,
Since it is possible to minimize the intrusion of foreign matter, it becomes possible to prevent foreign matter from adhering to the object to be cleaned.

As a result, it is possible to prevent foreign matter from adhering to the wafer in the water washing process and the wet etching process in the LSI manufacturing, so that it is possible to obtain a cleaning apparatus capable of improving the cleaning efficiency and the yield.

[Brief description of drawings]

FIG. 1 is a sectional view showing a cleaning tank used in a cleaning apparatus that is Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view showing a modified example of the lid of the cleaning tank in the first embodiment.

FIG. 3 is a cross-sectional view showing a cleaning tank used in a cleaning apparatus that is Embodiment 2 of the present invention.

FIG. 4 is a cross-sectional view showing a cleaning tank used in a cleaning apparatus that is Embodiment 3 of the present invention.

FIG. 5 is a cross-sectional view showing a cleaning tank used in a cleaning device which is an example of a conventional technique.

[Explanation of symbols]

1 Wafer (semiconductor wafer; object to be cleaned) 2,2a, 2b Cleaning tank 3 cleaning liquid 4,4a Lid (cover member) 5 wafer cassette 6 through holes 7 airflow 8 outflow nozzle 9 flow 11 suspended matter

Continued front page    (72) Inventor Tatsumi Shirasu             Nishinachiman, Ryuo-cho, Nakakoma-gun, Yamanashi Prefecture (no address)               Hitachi, Ltd. Musashi Factory Kofu Branch Factory             Within (72) Inventor Masato Kazuno             5-22-1 Kamimizuhonmachi, Kodaira-shi, Tokyo Stock             Inside the Hitachi Microcomputer System

Claims (3)

[Claims] 1. A cleaning device comprising a chemical liquid treatment tank for performing chemical chemical liquid treatment, and a running water washing tank for performing running water washing after the chemical liquid treatment, for washing an object to be cleaned by the chemical liquid treatment tank and the running water washing tank. At least one of the chemical solution treatment tank and the running water cleaning tank is provided with a covering member so as to come into contact with a liquid surface of the chemical solution and the running water stored in the chemical solution processing tank and the running water cleaning tank. apparatus. 2. A cleaning device, comprising: a chemical liquid treatment tank for performing chemical chemical liquid treatment; and a running water washing tank for performing running water washing after the chemical liquid treatment, for washing an object to be cleaned by the chemical liquid treatment tank and the running water washing tank. A cleaning, characterized in that in at least one of the chemical solution treatment tank and the running water cleaning tank, an air flow in a predetermined direction is created on a liquid surface of the chemical solution and the running water stored in the chemical solution processing tank and the running water cleaning tank. apparatus. 3. A cleaning device, comprising: a chemical liquid treatment tank for performing chemical chemical liquid treatment; and a running water washing tank for performing running water washing after the chemical liquid treatment, for washing an object to be cleaned with the chemical liquid treatment tank and the running water washing tank. A cleaning device, characterized in that in at least one of the chemical solution treatment tank and the running water cleaning tank, a flow in a predetermined direction is created on a liquid surface of the chemical solution and the running water stored in the chemical solution processing tank and the running water cleaning tank. .