JP2010245230A - Method and apparatus for diluting drug - Google Patents

Abstract

Concentration adjustment is facilitated by reducing an error in the amount of a drug to be diluted.
SOLUTION: A dilution tank 2, a circulation pipe 4 for circulating the liquid in the dilution tank 2, and a liquid in the dilution tank 2 are sucked from one end of the circulation pipe 4 and the liquid is put into the dilution tank 2 from the other end. A method of diluting a drug (for example, a stock solution of a developing solution) using a diluting device 1 including a pump 3 for returning to a vacuum, and at least a part of the diluent for diluting the drug is at least a suction tube 4 'A first diluent introduction step for introducing the diluent into the dilution tank 2 until the inside is filled; a drug introduction step for introducing the agent into the dilution tank 2; and a second portion for introducing the remainder of the diluent into the container. And a diluent introduction step.
[Selection] Figure 1

Description

  The present invention relates to a drug dilution method and a dilution apparatus.

  For example, Patent Documents 1 to 3 and the like are known as techniques for diluting a drug (for example, a stock solution of a developer used for manufacturing a semiconductor). Patent Document 1 describes a reagent adjusting device that adjusts to a working concentration by diluting a high concentration reagent and supplies it to a clinical examination apparatus. Patent Documents 2 and 3 describe an automatic developer dilution apparatus for producing an alkaline developer used when developing a positive resist in a semiconductor production process or the like.

Japanese Patent Laid-Open No. 9-33538 (published February 7, 1997) Japanese Patent Laid-Open No. 5-216241 (released on August 27, 1993) JP 6-61136 A (published March 4, 1994)

  When a chemical such as an alkaline developer stock solution is diluted at a high magnification, an error is likely to occur in the concentration after dilution, and a technique for suppressing this error is required. When a circulation pump is provided in the tank for diluting the drug and the liquid in the tank is mixed by the circulation pump, the drug is introduced into the suction pipe when the drug is first introduced into the tank as in Patent Documents 1 to 3. Will enter. In general, since the amount of the drug to be diluted is much smaller than the amount of the diluent, an error in the amount of the drug has a great influence on the error in the concentration of the diluent. In order to adjust the concentration based on this influence, complicated operations and apparatuses are required.

  An object of the present invention is to provide a method and apparatus for diluting a drug that facilitates concentration adjustment by reducing an error in the amount of the drug to be diluted.

  In order to solve the above problems, a method for diluting a drug according to the present invention (hereinafter simply referred to as “dilution method according to the present invention”) circulates a container for diluting a drug and a liquid in the container. A drug dilution method using a drug diluting device, comprising: a circulation pipe; and a pump for sucking the liquid in the container from one end of the circulation pipe and returning the liquid from the other end to the container. Then, a part of the diluting liquid for diluting the drug is introduced into the container until at least a suction pipe that is a pipe for leading the liquid sucked from the container to the pump is filled in the circulation pipe. A first diluent introducing step, a drug introducing step for introducing the drug into the container, and a second diluent introducing step for introducing the remainder of the diluent into the container.

  In the dilution method according to the present invention, it is more preferable that in the second diluent introduction step, the diluent is introduced from the bottom of the container.

  In the dilution method according to the present invention, the drug may be a developer and the diluent may be water.

  Further, a drug diluting device according to the present invention (hereinafter simply referred to as “diluting device according to the present invention”) includes a container for diluting the drug, a circulation pipe for circulating the liquid in the container, A pump for sucking the liquid in the container from one end of the circulation pipe and returning the liquid to the container from the other end, and a diluent supply pipe for allowing the diluent to flow from the bottom of the container Is.

  According to the present invention, it is possible to easily adjust the concentration by reducing an error in the amount of the drug to be diluted.

It is a figure which shows typically the structure of the dilution apparatus 1 which is one Embodiment of the dilution apparatus which concerns on this invention. It is a figure which shows the result of having confirmed the relationship between the frequency | count of pump circulation and the stability of a density | concentration in the Example of this invention.

<Dilution apparatus according to the present invention>
First, the configuration of the dilution apparatus according to the present invention will be described with reference to FIG. FIG. 1 is a diagram schematically showing a configuration of a dilution apparatus 1 which is an embodiment of a dilution apparatus according to the present invention. In the present embodiment, a case will be described in which a stock solution of a developer (hereinafter sometimes simply referred to as “stock solution”) is used as a drug to be diluted, and pure water is used as a diluent. In addition, the chemical | medical agent and dilution liquid which can apply the dilution apparatus which concerns on this invention, and the dilution method which concerns on this invention mentioned later are applicable not only to the combination of the undiluted | developer solution and pure water but to various chemical | medical agents and dilution liquids. In particular, it can be suitably used when diluting at a high magnification. For example, as a medicine, it can be applied to HF (for example, 50% -concentration used after being diluted 100-fold), a cleaning liquid (for example, diluted 50-fold with pure water), etc. It can be selected as appropriate according to the conditions. Note that a plurality of types of drugs may be used. That is, the present invention can be used for mixing a plurality of types of chemicals with pure water. For example, a mixed acid may be prepared. Examples of the mixed acid include a mixture of HF, H ₂ O ₂ and pure water. As an example of preparing a mixed acid according to the present invention, pure water is added until a suction pipe 4 ′ described later is filled, a predetermined amount of HF is introduced into the dilution tank 2, and then a predetermined amount of H ₂ O ₂ is added. There is a method of mixing the remaining pure water after introduction. When HF and H ₂ O ₂ are mixed with pure water, it is preferable to use a near-infrared spectrophotometer as the concentration meter.

  Examples of the developer include a positive resist developer and a negative resist developer, and examples of the positive resist developer include tetramethylammonium hydroxide (TMAH). In the present specification, the “diluent” refers to a liquid used as a solvent for diluting a drug.

  As shown in FIG. 1, the dilution device 1 includes a dilution tank (container) 2 and a programmable controller 9.

  The dilution tank 2 is a container for diluting the stock solution of the developer with pure water. The stock solution is diluted by mixing the stock solution and pure water in the dilution tank 2.

  A circulation pipe 4, a pure water supply pipe (diluent supply pipe) 6, and a stock solution supply pipe 7 are connected to the dilution tank 2. The dilution tank 2 is provided with a load cell 8. The circulation pipe 4 is provided with a pump 3 and a concentration meter 5. Note that the member for confirming (measuring) the amount of preparation in the dilution tank may not be a load cell. For example, a level meter may be used.

  The pump 3 sucks the liquid in the dilution tank 2 from one end of the circulation pipe 4 and returns the liquid into the dilution tank 2 from the other end. The pump 3 is provided between the one end and the other end of the circulation pipe 4. The pump included in the diluting device according to the present invention may be any pump that sucks and discharges the liquid. When semiconductor chemicals are prepared as in this embodiment, a bellows pump, a diaphragm pump, or the like can be suitably used as the pump.

  The circulation pipe 4 is a suction pipe 4 ′ that is a pipe for guiding the liquid sucked from the dilution tank 2 by the pump 3 to the pump 3, and a pipe 4 ′ that is a pipe for returning the liquid sucked by the pump 3 to the dilution tank 2. It is divided into 'and.

  The end of the suction pipe 4 ′ on the dilution tank 2 side is connected to the bottom of the dilution tank 2, and the end of the pipe 4 ″ on the dilution tank 2 side is connected to the top of the dilution tank 2. Note that the ends of the suction pipe 4 ′ and the pipe 4 ″ on the side of the dilution tank 2 may not be the bottom and the top, respectively, as long as the liquid in the dilution tank 2 is circulated.

  The densitometer 5 measures the concentration of the liquid developer flowing in the circulation pipe 4. The densitometer 5 displays the measured value and outputs the measured value to the programmable controller 9 described later.

  The pure water supply pipe 6 is a pipe through which pure water flows from the bottom of the dilution tank 2. A pure water storage tank (not shown) is provided at the end of the pure water supply pipe 6 opposite to the dilution tank 2. The pure water supply pipe 6 is connected to the bottom of the dilution tank 2. When pure water flows from the bottom, the inside of the dilution tank 2 is suitably stirred and mixed by the flow rate of the pure water. Thereby, the mixing time in the dilution tank 2 by the pump circulation using the pump 3 can be shortened. In the diluting apparatus according to the present invention, the position where the diluent is introduced into the container for diluting the drug may be at the bottom of the dilution tank 2 as in the present embodiment. The diluent may be introduced from the top or the like.

  The stock solution supply pipe 7 is a pipe for introducing the stock solution into the dilution tank 2. A stock solution storage tank is provided at the tip of the stock solution supply pipe 7 opposite to the dilution tank 2 (not shown).

  Further, the pure water supply pipe 6 and the stock solution supply pipe 7 are each provided with a valve for adjusting the introduction of the stock solution and the pure water into the dilution tank 2. Is controlled.

  The load cell 8 is for measuring the amount of liquid in the dilution tank 2. As a result, the user can recognize that the desired amount of developer and pure water have entered the dilution tank 2. The liquid amount measured by the load cell 8 is output to the programmable controller 9.

  The programmable controller 9 is for controlling the operation of the dilution apparatus 1. A user can operate the diluting device 1 via the programmable controller 9. For example, the user inputs a desired concentration and liquid amount in advance into the programmable controller 9, and the programmable controller 9 automatically performs pure water supply piping based on the concentration measured by the concentration meter 5 and the liquid amount measured by the load cell 8. 6 and a valve provided in the stock solution supply pipe 7 may be opened and closed.

<Dilution method according to the present invention>
The dilution method according to the present invention includes a container for diluting a drug, a circulation pipe for circulating the liquid in the container, a liquid in the container from one end of the circulation pipe, and the liquid from the other end. A method for diluting a drug using a drug diluting device, wherein at least a part of the diluent for diluting the drug is sucked from the container in the circulation pipe A first diluent introduction process for introducing the liquid into the container until a suction pipe, which is a pipe for guiding the liquid to the pump, is filled; a drug introduction process for introducing the drug into the container; A second diluent introduction step for introducing the remaining portion into the container.

  The case where the diluting apparatus 1 described above is used for the diluting method according to the present invention and a stock solution of a developer is used as a drug and pure water is used as a diluting solution will be described.

[First Diluent Introduction Step]
In the first diluent introduction step, a portion of pure water for diluting the developer is introduced into the dilution tank 2 until at least the suction pipe 4 'is filled.

  The amount of stock solution used is small compared to the amount of pure water used. If the stock solution is first introduced into the dilution tank 2, the stock solution enters the suction pipe 4 '. Since it is difficult to measure the amount of the stock solution that has entered the suction tube 4 ′, the user tries to adjust the concentration based on the amount of the stock solution outside the suction tube 4 ′ and in the dilution tank 2. This causes a large error in the amount of the stock solution used in a small amount. Therefore, the density adjustment becomes complicated. On the other hand, according to the present invention, since the suction pipe 4 'is first filled with pure water, no error occurs in the amount of the stock solution. Further, since the amount of pure water used is enormous, the influence of errors due to the amount of pure water entering the suction pipe 4 'is small. Therefore, it is easy to adjust the concentration of dilution at a high magnification.

[Drug introduction process]
In the drug introduction step, the stock solution is introduced into the dilution tank 2. Here, the whole amount of the stock solution used for dilution may be added, or a part thereof may be used. In some cases, the remainder may be added after the second diluent introduction step described later. In that case, a third diluent introduction step is further provided, and the diluent is introduced after the remaining stock solution is introduced. Further introduction is preferable. By introducing pure water from the bottom of the dilution tank 2 through the pure water supply pipe 6 after introducing all the stock solutions, stirring and mixing can be performed, and the number and time of pump circulation can be reduced. .

[Second diluent introduction step]
In the second diluent introduction process, the remaining pure water is introduced into the dilution tank 2. By introducing pure water after introducing the stock solution, stirring and mixing occur, and the number and time of pump circulation can be reduced. Further, if the diluting device 1 is used, pure water is allowed to flow from the bottom of the dilution tank 2 through the pure water supply pipe 6, so that the efficiency of this stirring / mixing is further improved, and as a result, the number and time of pump circulation can be reduced. It can be further reduced.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

[Example 1]
In the present embodiment, in diluting the developer using the diluting device 1, the density error between the case where pure water was previously added to the suction pipe 4 ′ and the case where no pure water was added was examined.

TMAH stock solution (concentration 25% by weight) was used as the drug, and the target dilution concentration was 2.38% by weight (with an allowable error range of ± 0.003% by weight). The amount of the developer to be produced was 600 kg. That is, in order to achieve the target dilution concentration, theoretically, the TMAH stock solution was required to be 57.12 kg and pure water 542.88 kg. Further, the total length of the suction tube 4 ′ was 3 m 50 cm, the diameter was 22.22 mm, and the portion 3 m from the pump 3 was bent flexibly (specifically, a bellows structure). The area from the flexible part to the pump 3 is not measured by the load cell 9. Further, since 1/2 of this unmeasured volume remains without being replaced with nitrogen gas, the non-weighing weight part (weight not measured of the liquid introduced into the suction pipe) is 3.14 / 4 × (22. 22/1000) ² × 3 × 1/2 = 5.8 × 10 ⁻⁴ (m ³ ) That is, 0.58 kg.

(1: When pure water is put into the suction pipe first)
The concentration error when pure water was put into the suction tube first was as follows. The amount of the stock solution was 57.12 kg, the amount of pure water was 542.88 + 0.58 = 543.46 kg, and the total amount was 600.58 kg. Therefore, the concentration of the resulting developer was 57.12 × 0.25 / 600.58, and thus was about 2.378% by weight. Therefore, the error with respect to the target dilution concentration of 2.38 wt% was −0.002 wt% within the above allowable error range.

(2: When stock solution is put in the suction tube first)
The concentration error when the stock solution was put into the suction tube first was as follows. The amount of the stock solution was 57.12 + 0.58 = 57.70 kg, the amount of pure water was 542.88 kg, and the total amount was 600.58 kg. Therefore, the concentration of the resulting developer was 57.70 × 0.25 / 600.58, and thus was about 2.402% by weight. Therefore, the error with respect to the target dilution concentration of 2.38% by weight was + 0.022% by weight outside the allowable error range.

  From the above, when the stock solution was supplied first, the error was 10 times that of the case where pure water was supplied first.

[Example 2]
In this example, the number and concentration of pump circulations when pure water is added to some extent and then pure water is added after all of the stock solution has been added and when the pure solution is added after all of the pure water has been initially added. The stability relationship was confirmed. Amount of undiluted solution and pure water Same as (1) in Example 1. Further, as a diluting device, two lines of the circulation pipe 4 and the pump 3 are provided to increase the circulation amount, and the stock solution supply pipe 7 is connected so that the stock solution is also fed from the bottom of the dilution tank 2. The same as the dilution apparatus 1 described in the embodiment.

  The results are shown in FIG. FIG. 2 is a diagram showing the result of confirming the relationship between the number of pump circulations and the stability of concentration in the present example. The graph on the left shows the case where the stock solution is introduced after all the pure water is introduced, and the graph on the right shows The result is shown in the case where half of the total amount of pure water used is added (the suction pipe is filled with pure water), the whole stock solution is added, and then all the remaining pure water is added. In FIG. 2, the vertical axis represents the concentration index, and the horizontal axis represents the number of pump circulations.

  As shown in FIG. 2, when all the pure water was added first, the concentration was not constant unless the pump was circulated four times (stirring was not sufficient), but half of the pure water was added first. When the remaining pure water was introduced after the stock solution was introduced, the concentration became constant when the pump circulation was less than one time of the capacity of the dilution tank 2.

  The present invention can be used for the preparation of a developer stock solution, dilution of acid, etc., mixed acid, and the like.

1 Dilution device 2 Dilution tank (container)
3 Pump 4 Circulation pipe 4 'Suction pipe 6 Pure water supply pipe (Diluent supply pipe)

Claims (4)

A container for diluting the drug, a circulation pipe for circulating the liquid in the container, and a liquid for sucking the liquid in the container from one end of the circulation pipe and returning the liquid into the container from the other end A drug dilution method using a drug dilution device comprising a pump,
First, a part of the diluent for diluting the drug is introduced into the container until at least a suction pipe that is a pipe for leading the liquid sucked from the container to the pump is filled in the circulation pipe. A dilution liquid introducing step,
A drug introduction step of introducing the drug into the container;
A second diluent introduction step for introducing the remainder of the diluent into the container;
A dilution method comprising:   The dilution method according to claim 1, wherein in the second diluent introduction step, the diluent is caused to flow from the bottom of the container.   The dilution method according to claim 1, wherein the drug is a developer, and the diluent is water. A container for diluting the drug;
A circulation pipe for circulating the liquid in the container;
A pump for sucking the liquid in the container from one end of the circulation pipe and returning the liquid from the other end to the container;
A diluent supply pipe for allowing the diluent to flow from the bottom of the container;
A drug diluting device.

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