JPS63156323A - Wafer washing apparatus used in manufacture of semiconductor - Google Patents

Abstract

PURPOSE:To obtain a wafer washing apparatus adapted such that chemical solution is never leaked out of the washing apparatus even if leakage is caused in a circulation system, by arranging various devices related to the circulation of the solution within the same container with the washing tank. CONSTITUTION:Chemical solution overflowing from the top of a washing tank is introducted to an inlet 7 of a circulation system, and is guided to a filter 4 via a circulation pump 5. The chemical solution filtered by the filter 4 is returned to the washing tank from the bottom of the tank. All of such circulation is performed within the container of the washing tank 1. Therefore, if some chemical solution is leaked at some place of the circulation system, that solution is never leaked out of the washing tank 1. In this manner, leakage of the chemical solution is prevented completely by arranging various devices and piping of the circulation system within the same container with the washing tank.

Description

[Detailed description of the invention] This is related to the cleansing process.

b) Removal of unnecessary coatings used in the semiconductor manufacturing process (resist, oxide film, etc.); C) Removal of salts, organic substances, and other foreign substances that degrade the characteristics of devices on gold; 9. Pattern formation Etching of time.

[Conventional technology]

Fig. 3 shows a conventional device, of which Fig. 3 (al is a front view, Fig. 3 fb) is a side view, and Fig. 3 (3) is a top view. In the figure, (1) is a wafer cleaning tank, (2) is a wafer to be cleaned, (3) is a wafer cassette that stores the wafers, (4) is a filter, (5) is a chemical circulation pump, and (6) is a wafer cleaning tank.
(8) is a rectifying plate which also serves as a bottom plate for installing a wafer cassette and maintains the liquid flow in a laminar state, and (8) is an overflow receiving tank. Among these devices, cleaning tank (1), wafer cassette (
3) All parts that come into contact with the chemical solution, including the filter (5) and the bottom plate (6), are made of Teflon or coated with Teflon to prevent them from being attacked by the chemical solution.

Next, the operation will be explained.

A wafer cleaning tank (1) is filled with a chemical solution, and a wafer stored in a wafer cassette is immersed in the chemical solution. As a result, the wafer surface is eroded by the chemical solution, and harmful substances and foreign substances are removed or a circuit pattern is formed. At this time, various coating fragments and foreign substances adhering to the wafer surface move into the liquid. When this chemical solution is circulated and the wafer is repeatedly cleaned, film fragments and foreign matter (hereinafter collectively referred to as "dust" in the sense of substances that are undesirable for the wafer) that are present in the chemical solution adhere to the wafer again. This can lead to serious defects in the product. Conventionally, in such cleaning tanks, the chemical solution is constantly guided out of the tank using a circulation pump, and then passed through a filter to remove dirt.
I have been working on putting it back into the cleaning tank (1). As a result, the concentration of dust in the cleaning tank (1) is kept low, and dust is prevented from adhering to the wafer during the wafer cleaning process.

[Problem that the invention seeks to solve]

In conventional wafer cleaning equipment, the circulation pump and filter are placed outside the cypress as described above, so there is no temperature stress at the joint between the circulation pump, filter, etc. and their piping.
Pressure stress is applied, resulting in a risk of leakage from the seams. Furthermore, it was predicted that the leaked chemical solution could harm surrounding equipment and cause a serious accident, so the development of a safer circulation system was awaited.

This invention was made to solve the above-mentioned problems, and its purpose is to provide a device with a structure that will never allow liquid to leak out of the cleaning device even if a liquid leak occurs in the circulation system. do.

[Means for solving problems]

In the wafer cleaning apparatus according to the present invention, devices related to chemical circulation such as circulation pumps and filters were conventionally placed outside the cleaning tank, but now they are housed inside the same tank as the cleaning tank, and the chemical liquid is supplied to the cleaning tank. It has been closed so that nothing from the inside can go outside.

[For production]

By arranging the circulation pump, filter, and piping in the same tank as the cleaning tank, the temperature stress and pressure stress occurring between the inside and outside of the circulation system can be drastically reduced.

This eliminates leakage of chemical solutions from joints in the circulatory system due to stress. Furthermore, even in the unlikely event that the chemical solution leaks from the circulation system to the outside, it will only diffuse within the cleaning tank and will not leak to the outside at all.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figure, (1) is a wafer cleaning tank, and each process (above items A, C, and C) is inside this tank.
The wafer cassette (3) containing the wafers (2) to be processed is immersed in this tank. As a result, the wafer (2) is treated with the molten liquid, and a clean wafer can be obtained (the above is the same as in the conventional apparatus). The filter (4) filters the chemical solution in the tank,
This removes dirt that has moved into the chemical solution during cleaning work. A circulation pump (5) performs feeding of the chemical liquid to the filter (4) and sending it to the cleaning tank (in short, circulation). As can be seen from Figure 2, the circulation pump, filter, and circulation piping are all placed inside the cleaning tank. Thus, wafer cleaning and chemical circulation are carried out in exactly the same manner as in the prior art, but the improvement in this invention is that the circulation pump, filter, related piping, etc. are all placed inside the cleaning tank (1). Furthermore, all parts that come into contact with the chemical solution are coated with Teflon to prevent corrosion caused by the chemical solution.

The circulation of the chemical solution, which is the essence of this invention, will be explained above. The chemical solution that overflows from the upper part of the cleaning tank is guided from the circulation system inlet (7) through the circulation pump (5) to the filter (A), where the chemical solution is filtered.The filtered chemical solution is returned to the bottom of the tank. The essence of this invention is that all of these circulations are carried out in a single tank called the cleaning tank (1).Therefore, in the unlikely event that the chemical solution leaks somewhere in the circulation system, Even if this occurs, there is no risk of the chemical solution leaking to the outside of the cleaning tank (1).

It is clear that the present invention is not limited to wafer cleaning in semiconductor manufacturing, but can also be used in liquid processing using a circulation system.

〔Effect of the invention〕

As described above, according to the present invention, each device and piping of the circulation system are placed in the same tank as the cleaning tank, which eliminates the risk of chemical leakage, which is very significant in terms of safety measures and the arrangement of other equipment. It is something.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of this invention, of which the first
Figures (al is a front view, Figure 1 (b) is a side view, Figure 1 (c) is a front view, Figure 1 (b) is a side view,
) shows a top view. Fig. 2 shows the inside of the embodiment shown in Fig. 1 when the cassette is loaded, of which Fig. 2 (a) is a front view taken along the cross-sectional line u (a) II (a) of Fig. 1 (a). Cross section, 2nd
Figure (b) is the cross-sectional line n (b) -II of Figure 1 (C).
FIG. 2(C) is a top sectional view taken along section line II(c)-n(c)G in FIG. 2. Fig. 3 shows a conventional device, Fig. 3(a) is a partially sectional front view, Fig. 3(b) is a partially sectional side view, Fig. 3(C)
is a top view. In the drawings, (1) is a wafer cleaning tank, (2) is a wafer, (3) is a wafer cassette, (4) is a filler, and (5) is a wafer cassette.
indicates the circulation pump, (6) indicates the bottom plate/straightening plate, and (7) indicates the circulation system inlet. Note that the same reference numerals in each figure indicate the same members or parts. Agent: Masuo Oiwa, Patent Attorney Figure 1 Figure 2

Claims (2)

[Claims] (1) In the process of immersing a wafer in a chemical solution and cleaning it, all systems that perform circulation filtration, such as circulation pumps, filters, and piping, are placed inside the cleaning tank to prevent the risk of the chemical solution leaking out of the tank. A cleaning device used in semiconductor manufacturing that is characterized by the fact that it has been lost. (2) The wafer cleaning apparatus according to claim (1), wherein the circulation pump, filter, piping, etc. arranged in the cleaning tank are all coated with Teflon.