JPH11207274A - Substrate treatment solution tank and substrate treatment solution apparatus using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly and accurately weigh a treatment soln. without wasting the treatment soln. SOLUTION: A chemical soln. is supplied to a storage tank 15 from a chemical soln. supply valve 13. When the liquid surface in the storage tank 15 reaches the discharge port 41 provided to the upper end of a leveling weighing pipe 40, an overflow is generated and the liquid surface does not rise to the level of the upper end of the weighing pipe or more. A chemical soln. detection sensor 50 is arranged to the overflow piping 42 connected to the leveling weighing pipe 40 and, when the chemical soln. is detected by the chemical soln. detection sensor 50, a control unit 35 closes a chemical soln. supply valve 13 to stop the supply of the chemical soln. to the storage tank 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a semiconductor wafer,
A substrate processing liquid for storing a processing liquid for performing various processing on one or more substrates at once, such as a glass substrate for a liquid crystal display device and a glass substrate for a PDP (plasma display panel). The present invention relates to a tank and a substrate processing liquid apparatus for preparing a processing liquid using the substrate processing liquid tank.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor device or a liquid crystal display device, a substrate to be processed such as a semiconductor wafer or a glass substrate is subjected to processing using various processing liquids. The treatment liquid is, for example, a predetermined liquid obtained by mixing one or more kinds of chemical liquids (such as hydrofluoric acid, sulfuric acid, hydrochloric acid, nitric acid, acetic acid, ammonia or hydrogen peroxide solution) and pure water at a constant mixing ratio. It is a diluted chemical solution with a concentration. An example of the mixing ratio of the chemical and pure water is shown below.

NH ₄ OH: H ₂ O ₂ : pure water = 1: 2: 7 HCL: H ₂ O ₂ : pure water = 1: 1: 8 HF: pure water = 1: 100 Appropriate processing of the substrate Therefore, it is important to strictly control the mixing ratio when mixing the chemical solution and the pure water.
Therefore, each type of chemical solution and pure water are respectively weighed in a weighing tank, and the weighed chemical solution and pure water are led to a mixing tank so that a processing solution having an appropriate concentration is prepared in the mixing tank. .

FIG. 3 is a simplified sectional view showing the configuration of a typical conventional weighing tank. A chemical solution or pure water is supplied to a stock solution storage tank 1 for storing a stock solution (chemical solution or pure water) from a stock solution tank (not shown) via a stock solution supply valve 2. A mixing tank (not shown) is provided on the bottom of the stock solution storage tank 1.
A stock solution input pipe 3 for supplying a stock solution is connected to the stock solution, and a stock solution input valve 4 is interposed in the stock solution input pipe 3.

[0005] Inside the stock solution storage tank 1, there is provided a weighing pipe 5 having an open upper end, and the lower end of the weighing pipe 5 is connected to an overflow pipe 7 by an elbow 6.
It is connected to the. The overflow pipe 7 is guided to the outside from the side wall of the stock solution storage tank 1, and discharges the stock solution from the upper end opening 5 a of the weighing pipe 5. A level sensor 8 (for example, a capacitance sensor) for detecting the liquid level of the undiluted solution is disposed on the side wall of the undiluted solution storage tank 1 at a position slightly lower than the opening 5a at the upper end of the weighing tube 5. The opening and closing of the stock solution supply valve 2 is controlled based on the output signal of the level sensor 8.

That is, the stock solution supply valve 2 is opened while the stock solution input valve 4 is closed. As a result, the undiluted solution is stored in the undiluted solution storage tank 1, and the liquid level inside the undiluted solution rises and finally reaches the detection height of the level sensor 8. After a lapse of a predetermined time (for example, 60 seconds), the stock solution supply valve 2 is closed. The liquid level of the stock solution in the stock solution storage tank 1 reaches the upper end of the scouring weighing tube 5 earlier than the stock solution supply valve 2 is closed. Therefore, after that, by the supply of the stock solution from the stock solution supply valve 2,
The undiluted solution in the undiluted solution storage tank 1 overflows into the weighing tube 5, so that no further rise in the liquid level occurs.
Therefore, if the stock solution supply valve 2 is closed after the above-mentioned overflow occurs, a certain amount of the stock solution is always stored in the stock solution storage tank 1, and thus the stock solution is weighed. Achieved.

[0007] The weighed stock solution is entirely discharged by opening the stock solution input valve 4 for a certain period of time and guided to the mixing tank.

[0008]

If the supply of the stock solution is stopped before the overflow occurs, accurate weighing cannot be performed. Therefore, the stock solution supply valve 2 is closed after the level sensor 8 detects the liquid level. It is necessary to set a sufficiently long time before the setting is completed. On the other hand, if the set time is too long, a large amount of undiluted solution overflows and is wasted, and the time required for weighing becomes long. Therefore, it is important to set the set time as short as possible.

However, the pressure on the stock solution supply source side for feeding the stock solution to the stock solution supply valve 2 is not always constant.
Stock solution 1 for weighing stock solution at a constant flow rate from stock solution supply valve 2
Can not be put into Therefore, in order to surely cause the overflow, it is necessary to increase the above-mentioned set time in view of a certain margin. Therefore, according to the above-described conventional technology, waste of the stock solution cannot be effectively prevented, and there is a limit in shortening the time required for weighing.

Accordingly, an object of the present invention is to solve the above-mentioned technical problems, and to provide a substrate processing liquid tank and a substrate processing liquid apparatus using the same, which can prevent waste of the stored processing liquid as much as possible. That is. Another object of the present invention is to
An object of the present invention is to provide a substrate processing liquid tank that can accurately measure a processing liquid in a short time and a substrate processing liquid apparatus using the same.

[0011]

Means for Solving the Problems and Effects of the Invention According to the first aspect of the present invention, there is provided a storage tank for storing a processing liquid for performing processing on a substrate, and a storage tank for storing a processing liquid. A discharge pipe having a discharge port for discharging the processing liquid stored in the storage tank out of the storage tank in the vicinity of the liquid level, and a processing provided in connection with the discharge pipe and detecting the processing liquid flowing through the discharge pipe A substrate processing liquid tank comprising a liquid detecting means.

The treatment liquid stored in the storage tank may be, for example, a stock solution of a chemical solution or pure water, or a mixed solution of a chemical solution and pure water. Is also good. Further, the discharge port may be formed at the upper end of the discharge pipe, or may be formed at an intermediate portion of the discharge port.
According to the above configuration, when the level of the processing liquid stored in the storage tank reaches the height of the discharge port, even if more processing liquid is supplied to the storage tank, overflow occurs via the discharge pipe. The liquid level does not rise. If an overflow occurs, the processing liquid detecting means detects the processing liquid flowing in the discharge pipe.If the supply of the processing liquid to the storage tank is stopped accordingly, the processing liquid is stored in the storage tank. Thus, the amount of the processing solution can be reliably set to a constant amount.

Further, if the supply of the processing liquid to the storage tank is stopped immediately after the processing liquid detecting means detects the processing liquid flowing in the discharge pipe, useless processing liquid consumption does not occur. The time for storing a certain amount of the processing solution is also short. Further, even when the supply of the processing liquid to the storage tank is stopped after a predetermined time that has been set after the processing liquid detecting unit detects the processing liquid, the setting of the predetermined time is easy. Because if the processing liquid detecting means detects the processing liquid,
This is because the storage of a certain amount of the processing liquid in the storage tank is definitely completed, so that the time can be set without considering the influence of the pressure fluctuation on the processing liquid supply source side. In this case, for example, the predetermined time may be determined in consideration of, for example, an early overflow to the discharge pipe due to the effect of the waving of the processing liquid level in the storage chamber.

According to a second aspect of the present invention, the substrate processing liquid tank is a weighing tank, and the storage tank is for storing the weighed processing liquid. Substrate processing liquid tank. According to this configuration, the weighing of the processing liquid can be performed without excess or deficiency, and the supply of the processing liquid to the storage tank is stopped in response to the processing liquid detecting unit detecting the processing liquid, The processing solution can be quickly weighed.

The third aspect of the present invention provides the first or second aspect.
In response to the substrate processing liquid tank described in the above, a processing liquid supply mechanism for supplying a processing liquid to the storage tank, in response to outputting a detection signal indicating that the processing liquid detecting means has detected the processing liquid And a supply stop control unit for stopping the supply of the processing liquid to the storage tank by the processing liquid supply mechanism.

According to the above arrangement, since the supply of the processing liquid to the storage tank is stopped in response to the detection of the processing liquid by the processing liquid detecting means, the weighing and preparation of the processing liquid can be performed quickly and accurately. It can be carried out. This allows accurate weighing,
Since a plurality of types of processing liquids can be prepared at an accurate mixing ratio, a high-quality substrate processing liquid can be provided. As a result, the substrate can be satisfactorily processed, and as a result, a high-quality substrate can be provided.

The stop control means may stop the supply of the processing liquid by the processing liquid supply mechanism immediately after the processing liquid detecting means detects the processing liquid. After detecting the liquid, the supply of the processing liquid by the processing liquid supply mechanism may be stopped after a predetermined time has elapsed. In this case, it is preferable that the predetermined time is determined in consideration of, for example, an early overflow due to the effect of waving of the liquid surface in the processing liquid tank.

According to a fourth aspect of the present invention, there is provided a substrate processing liquid tank for storing a processing liquid of a type different from the processing liquid stored in the storage tank of the substrate processing liquid tank, the substrate processing liquid tank and the substrate processing liquid tank. 4. The substrate processing liquid apparatus according to claim 3, further comprising a preparation tank into which the processing liquid stored in each of the liquid tanks is charged and prepared. According to this configuration, accurate weighing can be performed in the substrate processing liquid tank, so that the mixing ratio of a plurality of types of processing liquids in the preparation tank can be made accurate. Accordingly, a plurality of types of processing liquids can be prepared at an accurate mixing ratio, so that a high-quality substrate processing liquid can be provided. As a result, the substrate can be satisfactorily processed, and as a result, a high-quality substrate can be provided.

[0019]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a system diagram showing an overall configuration of a substrate processing liquid apparatus according to an embodiment of the present invention. The substrate processing liquid apparatus mixes the chemical solution from the chemical solution supply source 11 and the pure water from the pure water supply source 21 at a predetermined mixing ratio in the mixing tank 30.
This is an apparatus for preparing a processing solution obtained by diluting a chemical solution to a predetermined concentration.

For example, in a single-wafer substrate processing apparatus for processing substrates one by one, the processing liquid stored in the preparation tank 30 is pumped to a substrate processing station by a pump, and is directed from a nozzle toward a substrate to be processed. Is discharged. Further, in a batch-type processing apparatus that performs substrate processing by immersing a plurality of (for example, 25) substrates in a processing liquid at a time, the preparation tank 30 is transferred to a substrate processing tank for immersing the substrates. A processing liquid is supplied. Of course, the preparation tank 30 itself may be used as the substrate processing tank.

In order to accurately mix pure water and a chemical solution at a predetermined mixing ratio, a chemical solution from a chemical solution supply source 11 is weighed in a chemical solution weighing tank 10, and then gravity is reduced through a chemical solution input valve 12. The mixture is put into the mixing tank 30 by utilizing. Similarly, with respect to pure water, pure water from a pure water supply source 21 is weighed in a pure water weighing tank 20,
Mixing tank 30 using gravity through pure water input valve 22
It is to be thrown into.

However, for example, when a large amount of pure water is mixed with a small amount of a chemical such as when the mixing ratio of the chemical to pure water is 1:20 to 1: 200, With respect to water, for example, pure water may be supplied to the mixing tank 30 by a pump without providing a weighing tank, and the amount of pure water supplied may be controlled by controlling the driving time of the pump. . Further, in this embodiment, the chemical solution weighing tank 10 and the pure water weighing tank 20 have the same basic configuration. However, for weighing the chemical solution and pure water, weighing tanks having different configurations are applied. Is also good. In this case, it is preferable that the present invention be applied to a weighing tank on the side that weighs a small amount of liquid.

A chemical supply valve 13 is interposed between the chemical weighing tank 10 and the chemical supply source 11, and a pure water supply valve 23 is provided between the pure water weighing tank 20 and the pure water supply source 21. Is interposed. The opening and closing of the chemical solution supply valve 13 and the pure water supply valve 23, and the chemical solution supply valve 12 and the pure water supply valve 22 are controlled by the control device 35. The control device 35 closes the chemical liquid supply valve 12 and opens the chemical liquid supply valve 13 when the chemical liquid measuring tank 10 is empty, and supplies the chemical liquid to the chemical liquid measuring tank 10. After a sufficient amount of the chemical solution is supplied for weighing in the chemical solution weighing tank 10, the control device 35 closes the chemical solution supply valve 13. Similarly,
The control device 35 supplies the pure water to the pure water weighing tank 20 by closing the pure water charging valve 22 and opening the pure water supply valve 23 when the pure water weighing tank 20 is empty. Then, the pure water weighing tank 20
After a sufficient amount of pure water has been supplied for the weighing at, the control device closes the pure water supply valve.

After the completion of the weighing of the chemical and the pure water, the controller 35 sets the chemical injection valve 12 when necessary.
Then, the pure water charging valve 22 is opened, and all the chemicals in the chemical liquid measuring tank 10 and all the pure water in the pure water measuring tank 20 are charged into the mixing tank 30. Thereby, in the mixing tank 30, a processing solution having an accurate concentration can be obtained. When the chemical solution supply valve 12 and the pure water supply valve 22 are opened, for example, the level sensor provided in connection with the preparation tank 30 detects that the level of the processing liquid in the preparation tank 30 is lower than a predetermined height. May be performed in response to the detection of the event. Further, for example, when the entire processing liquid in the mixing tank 30 is exchanged, for example, when the mixing tank 30 is used as a substrate processing tank, the chemical liquid supply valve is used after the processing liquid in the mixing tank 30 is completely discharged. 12 and the pure water supply valve 22 may be opened to supply the chemical and pure water.

It is not necessary to open the chemical liquid supply valve 12 and the pure water supply valve 22 at the same time, but before all the liquids weighed in the two weighing tanks 10 and 20 are poured into the mixing tank 30, It cannot be expected that the processing solution in the preparation tank 30 is controlled to an accurate concentration. FIG. 2 is a sectional view showing a detailed configuration of the chemical solution weighing tank 10. The chemical weighing tank 10 includes a storage tank 15 for storing a chemical supplied from a chemical supply source 11 via a chemical supply valve 13 and a chemical supply pipe 14.
The storage tank 15 has a bottom portion 16, and the bottom portion 16
Is connected to a charging pipe 17 for charging a chemical solution into the mixing tank 30. The liquid supply valve 12 is interposed in the supply pipe 17.

In the storage tank 15, a weighing pipe 40 is set up. The upper end of the weighing pipe 40 is opened, and an outlet 41 for discharging the chemical in the storage tank 15 near the liquid level is provided. Is formed. The weighing pipe 40 penetrates through the bottom 16 of the storage tank 15 and communicates with the overflow pipe 42. The overflow pipe 42 discharges the chemical from the opening 41 of the weighing pipe 40. Thus, the weighing pipe 40 and the overflow pipe 42 function as a discharge pipe for discharging a predetermined amount or more of the chemical solution in the processing tank 15.

In relation to a predetermined position of the overflow pipe 42 (for example, a position close to the lower surface of the bottom portion 16),
A chemical liquid detection sensor 50 for detecting a chemical liquid flowing in the overflow pipe 42 is arranged. The chemical liquid detection sensor 50 includes, for example, a capacitance sensor that detects a change in capacitance due to the presence or absence of a chemical in the overflow pipe 42, generates an ultrasonic wave toward the overflow pipe 42, An ultrasonic sensor for detecting a change in the degree of reflection / absorption of light, an optical transmission type sensor for detecting a change in light transmittance due to the presence or absence of a liquid in the overflow pipe 42, and irradiating light to the overflow pipe 42, An optical reflection sensor or the like that detects a change in light reflectance due to the presence or absence of a liquid by detecting reflected light can be applied. However, when an optical sensor is used, at least the chemical liquid detection sensor 50
, The overflow pipe 42 needs to be made of a material (for example, glass or transparent resin) that can transmit light for detection.

The output signal of the chemical liquid detection sensor 50 is input to the control device 35 and is used for controlling the opening and closing of the chemical liquid supply valve 13. Specifically, the control device 35
During the process of opening the chemical supply valve 13 and storing the chemical in the storage tank 15, the output of the chemical detection sensor 50 is monitored. Then, in response to outputting the detection signal indicating that the chemical liquid detection sensor 50 has detected the liquid surface of the chemical liquid,
The chemical supply valve 13 is closed. As long as the chemical solution detection sensor 50 does not detect the chemical solution unless overflow occurs via the weighing tube 40, a certain amount of the chemical solution is surely stored in the storage tank 15 when the chemical solution detection sensor 50 detects the chemical solution. It will be stored.

However, when the chemical liquid is supplied from the chemical liquid supply valve 13 to the storage tank 15 through the supply port 14a of the chemical liquid supply pipe 14, the liquid level in the storage tank 15 becomes wavy. Opening 41 of weighing tube 40
It is conceivable that an overflow occurs early before the pressure reaches, and a small amount of the chemical solution flows into the overflow pipe 42. Therefore, the chemical supply valve 1 by the control device 35
3 is closed after the chemical liquid detection sensor 50 detects the chemical liquid.
It is preferably performed after a lapse of a predetermined time (for example, after 1 to 10 seconds, preferably after 5 seconds) set in consideration of the waving of the liquid surface in the storage tank 15.

Further, in order to suppress the influence of the waving of the liquid level in the storage tank 15, it is preferable to keep the supply port 14a and the opening 41 of the scouring weighing tube 40 as far as possible. Thereby, the predetermined time can be reduced. Furthermore, if the supply port 14a is arranged at a position lower than the opening 41, the liquid surface in the storage tank 15 can be suppressed from waving, so that the predetermined time can be further reduced.

As described above, according to this embodiment, in response to the detection of the chemical by the chemical detection sensor 50 disposed in the overflow pipe 42, the control device 35 closes the chemical supply valve 13 and The supply of the chemical is stopped. For this reason, when overflow occurs through the opening 41 of the weighing pipe 40, the supply of the chemical solution is stopped immediately, so that a large amount of the chemical solution is not wasted. Further, the supply of the chemical is stopped after the overflow has occurred without fail. Therefore, even if the pressure on the side of the chemical supply 11 fluctuates, a certain amount of the chemical is stored in the storage tank 15. Also, the supply of the chemical solution is not stopped before. Therefore, accurate weighing can be achieved while minimizing waste of the chemical solution. Moreover, the supply of the chemical solution is stopped immediately after a certain amount of the chemical solution is stored, and as a result, the chemical solution can be weighed in a short time, thereby contributing to a reduction in substrate processing time. can do.

In addition, since the chemicals can be weighed quickly and accurately, the processing liquid can be prepared quickly and precisely, and the substrate can be processed with the processing liquid whose mixing ratio is precisely set. Thereby, a high-quality substrate can be provided. As mentioned above, although one Embodiment of this invention was described, this invention can be implemented in another form. For example, in the embodiment, in order to reuse the chemical discharged from the overflow pipe 42, the chemical may be returned to the chemical supply source. Further, in the above-described embodiment, an example has been described in which two types of liquids (chemical solution and pure water) are prepared to prepare a substrate processing liquid. Can also be applied to a substrate processing liquid apparatus for producing a substrate.

In addition, various design changes can be made within the scope of the technical matters described in the claims.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of a substrate processing liquid apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of a chemical solution weighing tank according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a configuration of a conventional chemical solution weighing tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Chemical solution weighing tank (substrate processing liquid tank) 20 Pure water weighing tank (substrate processing liquid tank) 30 Mixing tank 35 Control device (stop control means) 12 Chemical liquid input valve 13 Chemical liquid supply valve (processing liquid supply mechanism) 15 Storage tank 17 Injection pipe 40 Slice weighing pipe (discharge pipe) 41 Discharge port 50 Chemical liquid detection sensor (processing liquid detection means)

Claims (4)

[Claims] A storage tank for storing a processing liquid for performing processing on the substrate; and a discharge port for discharging the processing liquid stored in the storage tank near the liquid level to outside the storage tank. A substrate processing liquid tank comprising: a discharge pipe; and a processing liquid detection unit provided in relation to the discharge pipe and configured to detect a processing liquid flowing through the discharge pipe. 2. The substrate processing liquid tank according to claim 1, wherein said substrate processing liquid tank is a weighing tank, and said storage tank is for storing a processing liquid to be weighed. 3. A processing liquid tank according to claim 1 or 2, a processing liquid supply mechanism for supplying a processing liquid to the storage tank, and a processing liquid detection unit detecting that the processing liquid has been detected. A substrate processing liquid apparatus further comprising: a supply stop control unit configured to stop the supply of the processing liquid to the storage tank by the processing liquid supply mechanism in response to outputting the detection signal. 4. A substrate processing liquid tank for storing a processing liquid of a type different from a processing liquid stored in a storage tank of the substrate processing liquid tank; and a substrate processing liquid tank stored in the substrate processing liquid tank and the substrate processing liquid tank, respectively. 4. The substrate processing liquid apparatus according to claim 3, further comprising: a mixing tank into which the processing liquid is charged and mixed.