JPH09250698A - Chemical feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mix plural sorts of chemicals at a desired mixing ratio efficiently without providing a storage tank of the mixture chemical beforehand. SOLUTION: The first and the second chemical tanks 5a and 5b housing a pure water 4a and a hydrofluoric acid 4d respectively; a semiconductor wafer 1 to receive the feeding of a mixture chemical mixing the pure water 4a and the hydrofluoric acid 4b; plural flow regulator valves 9a and 9b provided corresponding to the chemical tanks 5a and 5b respectively, and to regulate the flow rate of the chemicals flowing from the chemical tanks 5a and 5b to the semiconductor wafer 1; and a controller 16 to control the openings of the flow regulator valves 9a and 9b; are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical liquid supply device for performing a predetermined process on a work such as a semiconductor wafer.

[0002]

2. Description of the Related Art For example, in the manufacture of semiconductor devices, there are many steps in which a semiconductor wafer, which is a workpiece, needs to be brought into contact with a chemical solution. As an example, there are a cleaning process such as cleaning before ion diffusion and cleaning before CVD, a wet etching process for removing a predetermined portion such as various oxide films or silicon nitride films, and a residue cleaning process for removing etching reaction products. Further, various chemicals are required for these treatments. Currently used chemicals include hydrofluoric acid,
There are hydrogen peroxide, ammonia, hydrochloric acid, sulfuric acid, phosphoric acid, buffered hydrofluoric acid, acetic acid, nitric acid, pure water, and the like (here, pure water is also included in the chemical liquid in this specification).

As an example in which a chemical liquid supply device for supplying such a chemical liquid to a semiconductor wafer is described in detail, for example, "VLSI manufacturing / testing device guidebook <1994 version>", published by the Industrial Research Board (1993) Issued on November 20), P157 ~
There is P162.

These chemicals are often used by mixing them into a chemical having desired characteristics, for example, by mixing two or more chemicals at a certain mixing ratio or by diluting with pure water.

[0005]

In the use form premised on such preparation, it is necessary to provide a dedicated processing tank or prepare a dedicated processing device for each chemical solution. Alternatively, it is necessary to store in advance a drug solution having a desired concentration in a tank. Therefore, the space of the device is increased and the time for preparation is required.

Further, it is desirable that the mixed chemicals are prepared in various mixing ratios so as to prepare the mixed chemicals having the optimum concentration for the purpose of use. However, since the mixing ratios are innumerable, such a countermeasure is taken. Not realistic.

Therefore, an object of the present invention is to provide a chemical liquid supply device which does not require a storage tank for mixed chemical liquids in advance.

Another object of the present invention is to provide a chemical liquid supply device which can efficiently mix a plurality of types of chemical liquids at an arbitrary mixing ratio.

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

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the chemical liquid supply device according to the present invention is
A plurality of chemical liquid tanks containing different types of chemical liquids, a work for receiving a mixed chemical liquid mixed with two or more kinds of chemical liquids contained in these chemical liquid tanks, and a work corresponding to each chemical liquid tank The present invention is characterized by having a plurality of flow rate adjusting valves for adjusting the flow rate of the chemical liquid from the chemical liquid tank to the work, and a control unit for controlling the openings of the plurality of flow rate adjusting valves.

In this case, a spiral groove is formed in the inner periphery of the flow path from the chemical liquid tank to the work, and a stirring unit for stirring different kinds of chemical liquids and sending the chemical liquid to the work can be provided. A semiconductor wafer can be applied as the work. Furthermore, a wet etching solution or a wet cleaning solution can be applied as the mixed chemical solution.

Further, these chemical liquid supply devices are of a single-wafer processing type in which the works are housed in the processing chamber and processed one by one, or a batch processing type in which the works are immersed in the processing tank and a plurality of the works are simultaneously processed. You can

According to such a chemical liquid supply apparatus, the control unit controls the openings of the plurality of flow rate adjusting valves to mix different kinds of chemical liquids in a desired mixing ratio on the way from the chemical liquid tank to the work. Therefore, the mixed chemical liquid can be directly supplied to the work.

As a result, it is not necessary to previously provide a storage tank for storing the mixed chemical solution, and the apparatus can be downsized. Further, since the supply and the mixing of the chemicals are performed at the same time, the time for preparing the mixed chemicals becomes unnecessary. Further, since the desired mixing ratio can be realized in the process of supplying the mixed chemical liquid, it becomes possible to efficiently obtain the mixed chemical liquid having the optimum mixing ratio for the workpiece to be treated.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, the same members are denoted by the same reference numerals, and a repeated description thereof will be omitted.

(Embodiment 1) FIG. 1 is a schematic view showing a chemical liquid supply apparatus which is an embodiment of the present invention.

The chemical liquid supply apparatus of the present embodiment is used, for example, when supplying a wet etching solution to a semiconductor wafer (workpiece) 1, and the processing unit 2 has a first side from the left side to the right side in the drawing. Processing chamber 2a, second processing chamber 2b, and water washing chamber 2c. As described above, the chemical liquid supply apparatus is a single-wafer processing type in which the semiconductor wafers 1 are processed one by one in each of the chambers 2a, 2b, 2c. The number of chambers is not limited to three, but one, two, or four
There may be more than one.

In order to supply the mixed chemical liquid to the processing chambers 2a and 2b, the present apparatus is provided with two chemical liquid tanks 5a and 5b. Pure water (chemical liquid) 4a is stored in the first chemical liquid tank 5a, and hydrofluoric acid (chemical liquid) 4b is stored in the second chemical liquid tank 5b.
Are housed respectively. And the chemical liquid tanks 5a, 5b
The pressurizing parts 6a and 6b, which constantly pressurize the liquid surfaces of the pure water 4a and the hydrofluoric acid 4b in the tank, are attached respectively to the pure water 4a and the hydrofluoric acid 4b.
It is designed to be pumped to 2b. In addition, including the case of the following second embodiment, it is sufficient that two or more chemical liquid tanks are provided, and the chemical liquids are limited to pure water 4a and hydrofluoric acid 4b as long as different types of chemical liquids are stored. It is not something that will be done. Further, for example, three chemical liquid tanks are provided, two of which contain pure water 4a and the other one contains hydrofluoric acid 4b.
The same chemical liquid may be stored in a plurality of chemical liquid tanks.

In order to supply the pure water 4a and the hydrofluoric acid 4b to the processing chambers 2a and 2b, the chemical liquid tanks 5a and 5b and the processing chambers 2a and 2b are connected by a pipe 7 made of, for example, a fluororesin. And in the pipe 7, the chemical liquid tank 5
stop valves 8a and 8b for opening and closing the flow paths from a and 5b to the processing chambers 2a and 2b, and a flow rate adjusting valve 9 for adjusting the flow rates of the pure water 4a and the hydrofluoric acid 4b, respectively.
a and 9b are provided corresponding to the respective chemical liquid tanks 5a and 5b. Further, a stirring unit 10 is provided at a portion where the pipes 7 from the two chemical liquid tanks 5a and 5b are gathered. The stirring section 10 is configured by forming a spiral groove on the inner circumference, and pure water 4a and hydrofluoric acid 4b, which are different types of chemical liquids, are forcibly stirred and mixed and sent to the processing chambers 2a and 2b.
It should be noted that the structure of the pipe 7 automatically causes pure water 4a and hydrofluoric acid 4b to be present.
When and are mixed, the stirring unit 10 may not be provided.

As shown in the drawing, the pipe 7 gathered at the position of the stirring section 10 is branched again by the switching valve 11 into a pipe 7 directed to the first processing chamber 2a and a pipe 7 directed to the second processing chamber 2b. Has been done. Therefore, the mixed chemical liquid stirred by the stirring unit 10 is switched by the switching valve 11 to the first processing chamber 2a or the second processing chamber 2b.
Sent to any of. It should be noted that only pure water is supplied to the washing chamber 2c by another route.

First and second processing chambers 2a, 2b
The discharge side and the supply side of are connected by a pipe 12 and recovery circulation tanks 13a and 13b are respectively installed in the middle of them.
The chemical solution used in each of the processing chambers 2a and 2b is purified and reused. The recovery circulation tank 13
Pipe 12 from a, 13b to processing chambers 2a, 2b
Stop valves 14a and 14b are attached to each of the processing chambers 2, and the regenerated chemical liquid is supplied to the processing chamber 2 as needed.
It is designed to be returned to a and 2b.

Stop valves 8a, 8b, 14a, 14
b, the flow rate adjusting valves 9a and 9b, and the switching valve 11 are controlled by a control unit 16 which operates according to a command input to the input unit 15. As a result, the opening / closing operation of the stop valves 8a, 8b is controlled, and the chemical liquid tank 5
The outflow of pure water 4a and hydrofluoric acid 4b from a and 5b
The opening ratios of the two flow rate adjusting valves 9a and 9b are controlled, the mixing ratio of the pure water 4a and the hydrofluoric acid 4b is controlled, the switching operation of the switching valve 11 is controlled, the supply destination of the mixed chemical liquid is stopped, and the stop valve 14a is controlled. , 14b are controlled so that the timing of supplying the regenerant liquid can be freely set. Therefore, the mixed chemical liquid consisting of pure water 4a and hydrofluoric acid 4b is supplied at an arbitrary mixing ratio.

The processing of the semiconductor wafer 1 by the chemical liquid supply apparatus having such a structure is performed as follows.

First, each valve is set by the input section as follows.

A flow rate adjusting valve 9a corresponding to the first chemical liquid tank 5a and a flow rate adjusting valve 9 corresponding to the second chemical liquid tank 5b.
The opening ratio with respect to b is set to, for example, 5: 1, and the switching valve 11 is set so that the mixed chemical liquid is supplied to the first processing chamber 2a. And the stop valves 8a, 8
Open b. The stop valves 14a, 14
b is “closed”.

As a result, pure water 4a is "5", hydrofluoric acid 4
b is pressure-fed from each of the chemical liquid tanks 5a and 5b at a ratio of "1", merges, and then is stirred by the stirring unit 10 before the first
Is supplied to the processing chamber 2a.

Here, the switching valve 11 is adjusted so that the opening ratio of the flow rate adjusting valve 9a and the flow rate adjusting valve 9b is, for example, 100: 1, and the mixed chemical solution is supplied to the second processing chamber 2b. By setting, the chemical liquid having a mixing ratio of pure water 4a and hydrofluoric acid 4b of 100: 1 is supplied to the second processing chamber 2b. Therefore, as will be described later, either of the processing chambers 2a and 2b is properly used according to the film thickness of the thin film to be etched. However, only one processing chamber may be provided, and only the mixing ratio of the chemicals may be different. As described above, the pure water 4a is supplied to the washing chamber 2c by another route.

In this way, the first processing chamber 2a
5: 1 for the second and 100: 1 for the second processing chamber 2b.
Wet etching is performed so that the mixed chemical solution of pure water 4a and hydrofluoric acid 4b is supplied and pure water 4a is supplied to the water washing chamber 2c.

In the etching process, for example, 100 to
When etching a thin film having a thickness of about 800 nm, an etching process is performed in the first processing chamber 2a containing a higher concentration of the mixed chemical solution, and then pure water is washed in the water washing chamber 2c. For example, a thin film having a thickness of about 10 to 20 nm is etched. Second processing chamber 2 containing a thinner chemical mixture
After the etching process in b, pure water is washed in the water washing chamber 2c. If necessary, stop valve 14
"a" and "14b" are "opened" so that the regenerated chemical solution from the recovery circulation tanks 13a and 13b is supplied again to the processing chambers 2a and 2b.

As described above, according to the chemical liquid supply apparatus of the present embodiment, the control unit 16 controls the flow rate adjusting valves 9a and 9b.
By controlling the opening of the pure water 4a and the hydrofluoric acid 4b
Since different types of chemical liquids can be mixed at a desired mixing ratio on the way from the chemical liquid tanks 5a, 5b to the processing chambers 2a, 2b, the mixed chemical liquids can be directly mixed with the semiconductor wafer 1
Can be supplied to.

As a result, it is not necessary to provide a storage tank for storing the mixed chemical solution in advance, and the apparatus can be downsized. Further, since the supply and the mixing of the chemicals are performed at the same time, the time for preparing the mixed chemicals becomes unnecessary. Further, since the control unit 16 can realize a desired mixing ratio in the supply process,
It is possible to efficiently obtain the mixed chemical liquid having the optimum mixing ratio for the semiconductor wafer 1 to be processed.

The stirring portion 1 having a spiral groove formed on the inner circumference thereof
Since 0 is provided, the pure water 4a and the hydrofluoric acid 4b are evenly mixed.

(Embodiment 2) FIG. 2 is a schematic view showing a chemical liquid supply apparatus according to another embodiment of the present invention.

The chemical liquid supply apparatus of the present embodiment is of a batch processing type in which 50 semiconductor wafers 1 are accommodated in a cassette 3 at the same time. , First processing tank 22a, first
Water washing tank 22b, second water washing tank 22c, second treatment tank 2
It has six tanks of 2d, a third water washing tank 22e, and a fourth water washing tank. The number of tanks is not limited to six, and the number of semiconductor wafers 1 that can be accommodated at one time is not limited to 50.

As shown in the drawing, a pipe 7 for supplying the mixed chemicals to the first and second processing tanks 22a, 22d, stop valves 8a, 8b provided in this pipe 7, flow rate adjusting valves 9a, 9b, and a switching valve. 11, and the stirring unit 10 has the same configuration as that described in the first embodiment, and the valves 8a, 8b, 9a, 9b, 11 are control units that operate according to a command input to the input unit 25. 26
Is controlled by the Therefore, also in the chemical liquid supply device of the present embodiment, a mixed chemical liquid having an arbitrary mixing ratio can be obtained. It should be noted that only pure water is supplied to the first to fourth washing tanks 22b, 22c, 22e, 22f by another route.

The processing of the semiconductor wafer 1 by such a chemical supply device is performed as follows.

Flow rate adjusting valve 9a and flow rate adjusting valve 9b
And the switching valve 1 so that the mixed chemical liquid is supplied to the first processing tank 22a.
Set 1. Then, the stop valves 8a and 8b are opened. As a result, the chemical solution having a mixing ratio of 5: 1 is supplied to the first processing tank 22a.

After the supply of the mixed chemical solution to the first processing tank 22a is completed, the stop valves 8a and 8b are once closed, and the opening ratio of the flow rate adjusting valve 9a and the flow rate adjusting valve 9b becomes 100: 1, for example. So that the mixed solution is second
The switching valve 11 is set at a position where it is supplied to the processing tank 22d. Then, the stop valves 8a and 8b are opened. As a result, the chemical solution having a mixing ratio of 100: 1 is supplied to the second treatment tank 2
2d.

After supplying the chemical solution to the second processing tank 22d, the stop valves 8a and 8b are closed.

In this way, 5: 1 pure water 4a in the first treatment tank 22a and 100: 1 pure water 4a in the second treatment tank 22d.
And a hydrofluoric acid 4b are mixed, and the first to fourth washing tanks 22b, 22c, 22e, and 22f are filled with pure water 4a, respectively, and wet etching is performed.

Then, according to the film thickness of the thin film to be etched, the first processing tank 22a containing a denser chemical mixture is stored.
Then, the first and second water washing tanks 22b and 22c are washed with pure water, or the second treatment tank 22d containing a thinner mixed chemical solution is subjected to etching treatment. To the third and fourth processing tanks 22e,
Pure water cleaning is performed at 22f.

In this way, the control unit 26 controls the openings of the flow rate adjusting valves 9a and 9b to mix different kinds of chemical liquids to a desired mixing ratio on the way from the chemical liquid tanks 5a and 5b to the processing tanks 22a and 22d. The chemical liquid supply device can be realized by a batch processing type instead of a single-wafer processing type.

Although the invention made by the inventor has been specifically described based on the embodiment, the invention is not limited to the embodiment, and various modifications may be made without departing from the gist of the invention. It goes without saying that it is possible.

For example, in the chemical liquid supply device of the present embodiment, the wet etching solution is supplied, but the present invention is not limited to this.
It can be applied to supply various other mixed chemicals such as a wet cleaning solution.

Further, in the above description, the case where the invention made by the present inventor is mainly applied to a chemical liquid supply device for manufacturing a semiconductor device which is a field of application which is the background of the invention has been described, but the invention is not limited thereto. However, the present invention can be applied to supply of mixed chemicals in various other fields. Therefore, the work to be processed is not limited to the semiconductor wafer 1.

[0047]

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

(1) That is, according to the chemical liquid supply apparatus of the present invention, the control unit controls the openings of the plurality of flow rate adjusting valves so that different kinds of chemical liquids are desired on the way from the chemical liquid tank to the work. Since the mixing can be performed at the mixing ratio of 1, the mixed chemical liquid can be directly supplied to the work.

(2) As a result, it is not necessary to previously provide a storage tank for storing the mixed chemical solution, and the apparatus can be downsized.

(3) Further, since the supply and mixing of the chemicals are performed at the same time, the time for preparing the mixed chemicals becomes unnecessary.

(4) Further, since the desired mixing ratio can be realized in the process of supplying the mixed chemical liquid, it becomes possible to efficiently obtain the mixed chemical liquid having the optimum mixing ratio for the workpiece to be treated. .

(5) Then, by providing the agitating portion having the spiral groove formed on the inner circumference, the two or more kinds of chemical liquids can be uniformly mixed.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a chemical liquid supply device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a chemical liquid supply device according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Semiconductor Wafer (Work) 2 Processing Section 2a First Processing Chamber 2b Second Processing Chamber 2c Rinsing Chamber 3 Cassette 4a Pure Water (Chemical Solution) 4b Hydrofluoric Acid (Chemical Solution) 5a First Chemical Solution Tank 5b Second Chemical Solution Tank 6a, 6b Pressurizing section 7 Piping 8a, 8b Stop valve 9a, 9b Flow rate adjusting valve 10 Stirring section 11 Switching valve 12 Piping 13a, 13b Recovery circulation tank 14a, 14b Stop valve 15 Input section 16 Control section 22 Processing section 22a 1st Treatment tank 22b First water washing tank 22c Second water washing tank 22d Second treatment tank 22e Third water washing tank 22f Fourth treatment tank 25 Input section 26 Control section

Claims (5)

[Claims] 1. A plurality of chemical liquid tanks containing different types of chemical liquids, a work to which a mixed chemical liquid mixed with two or more chemical liquids contained in the chemical liquid tanks is supplied, and each of the chemical liquid tanks A chemical liquid, which is provided correspondingly, and has a plurality of flow rate adjustment valves for adjusting the flow rate of the chemical liquid from the chemical liquid tank to the workpiece, and a control unit for controlling the openings of the plurality of flow rate adjustment valves. Supply device. 2. The chemical liquid supply device according to claim 1,
A chemical liquid supply device characterized in that a spiral groove is formed in an inner periphery of a flow path from the chemical liquid tank to the work, and a stirring unit for stirring different kinds of the chemical liquid and sending the chemical liquid to the work is provided. . 3. The chemical liquid supply device according to claim 1, wherein the work is a semiconductor wafer. 4. The chemical liquid supply device according to claim 1, 2 or 3, wherein the mixed chemical liquid is a wet etching solution or a wet cleaning solution. 5. The chemical liquid supply apparatus according to claim 1, 2, 3 or 4, wherein the chemical liquid supply apparatus accommodates the works in a processing chamber and processes them one by one, or processes the works. A chemical liquid supply device characterized in that it is of a batch processing type that is immersed in a tank and simultaneously processes a plurality of sheets.