JP2010267825A - Apparatus and method of supplying chemical - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a chemical supply apparatus and a chemical supply method capable of reducing use not contributing to production and efficiently supplying even a chemical containing a solid content such as slurry. <P>SOLUTION: The chemical supply apparatus calculates by a control unit 20, based on a chemical reception amount from preceding and following drums 1, 2 or the like which are sequentially replaced and installed to a dilution and supply unit 6 and a chemical supply amount for supplying the chemical in the dilution and supply unit 6 to production equipment 8, a residual ratio of the chemical from a previous chemical container in all of the chemical between the current drum 1 (or 2) and the production equipment 8, and also controls a chemical drain amount through a drain valve 13 so that the calculated value is no more than a threshold value predetermined for the residual ratio of the chemical. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a chemical solution supply apparatus and a chemical solution supply method for supplying a chemical solution to a semiconductor manufacturing apparatus or the like.

  Various chemical solutions are used in the manufacture of semiconductor devices. FIG. 8 shows a conventional chemical solution supply apparatus for supplying a chemical solution to a semiconductor manufacturing apparatus or the like. It is composed of a charge unit 3 for setting the drums 1 and 2 containing the chemical solution, a dilution / supply unit 6 having a dilution tank 4 and a supply tank 5, and a supply line 7. The product is transferred to the dilution tank 4 of the supply unit 6, diluted as necessary, added with additives, transferred to the supply tank 5, and supplied to the production facility 8 such as a semiconductor manufacturing apparatus through the supply line 7.

In the figure, 9, 10, 11, and 12 are pumps for circulating or supplying the chemical solution to the next unit, and 13 is a drain valve disposed on the drain line 14 from the supply line 7. Transfer between the drums 1, 2, dilution tank 4, and supply tank 5 is performed by instructing replenishment when the amount of the chemical in the dilution tank 4 or supply tank 5 falls below a preset lower limit. A fixed amount is replenished from 1, 2 or the dilution tank 4. The charge unit 3 is provided with a tank for receiving a low charge instead of the illustrated drums 1 and 2 (100 kg, 200 kg, 1 m ^3, etc.) depending on the delivery form of the chemical solution. Further, as means for transferring the chemical solution, N ₂ pumping is also used instead of the illustrated pumps 9 and 10.

  For a chemical solution whose components change with time, a chemical solution supply apparatus as shown in FIG. 9 has been proposed. The chemical solution from the bottle 31 is sent to the addition adjusting unit 33 through the storage tank 32, diluted with pure water by the addition adjusting unit 33, and an amount of modifier according to the degree of deterioration of the chemical solution is added. After being added by the controller 34, it is supplied onto the substrate 36 from the nozzle 35 (Patent Document 1).

JP 2008-147448 A

  Corresponding to the recent miniaturization of semiconductor devices, the chemicals used for semiconductor device manufacture are diversified. Some chemical solutions, as described in the above-mentioned Patent Document 1, have a reaction that progresses after the production and the components change, affecting the process performance.

  As long as the chemical change can be grasped and the chemical characteristics can be maintained by adding a modifier or the like according to the degree of deterioration, the method of Patent Document 1 is effective, but once the chemical reaction proceeds, the original state is obtained. It cannot be applied to chemicals that cannot be returned to All of the chemical components are not disclosed, and there are many cases where the user cannot prevent or improve the deterioration.

  Even if the preparation of a chemical solution, that is, the preparation of a material that causes a chemical reaction, is performed by the user's equipment, the problem of the expiration date still exists because the change of the chemical property starts immediately after the preparation. A just-in-time mixing method is also conceivable, but is impossible when the modifier itself is not disclosed by the manufacturer.

  In this situation, this type of chemical solution has a short expiration date. Some slurries and the like used in CMP have a period of use within one month after the slurry is manufactured. When such a slurry is used, it is necessary to discard the remaining amount, clean the piping, and replace with a new slurry every certain period, and use a large amount of slurry that does not contribute to production. In addition, since it is necessary to check the quality of the CMP apparatus after cleaning the pipes, all the units are stopped and production is stagnant.

  In order to avoid this, it is conceivable to prepare a plurality of slurry supply tanks and switch to a new slurry supply tank having a long remaining number of days until the expiration date. Eventually, however, the old slurry is discarded, and a tank cleaning slurry is required when a new slurry is introduced.

  It is also conceivable to take up the slurry by switching between a plurality of supply tanks and pipes. However, in this case, the time for which the wall surface of the supply tank and the inner wall of the pipe are exposed to air is prolonged, and the slurry adheres and the slurry contains solid content such as abrasive grains. Since it may cause an abnormality, a new slurry cannot be introduced as it is. That is, a chemical solution containing a solid content such as a slurry needs to be continuously circulated and used continuously.

  The present invention solves the above-described problem, and provides a chemical supply apparatus and a chemical supply method that can suppress and efficiently supply a chemical solution containing a solid content such as a slurry without contributing to production. Objective.

  In order to solve the above-described problems, the chemical solution supply apparatus of the present invention receives chemical solutions from previous and subsequent chemical solution containers that are sequentially replaced and adds a diluent or a modifier according to the properties of the chemical solution. A chemical adjustment unit, a supply piping system for supplying the chemical solution of the chemical adjustment unit to a production facility, a drain pipe communicating with the supply piping system via a valve device, an amount of chemical received from an existing chemical solution container, and the production facility And a control device connected to the valve device and the measuring device, the control device connected to the chemical solution receiving amount and the chemical solution supply. Based on the measured value of the amount, calculate the remaining rate of the chemical solution from the previous chemical solution container in the total chemical solution between the current chemical solution container and the production equipment, and this calculated value is the remaining rate of the previous chemical solution Pre-determined threshold And controlling the chemical drain amount through the valve device so as to lower.

  The control device further inputs an expiration date of the chemical solution in each chemical solution container, and when the lower limit of the supply amount of the chemical solution per unit time is set, within the period until the expiration date of the chemical solution in the current chemical solution container, The liquid is supplied so that the residual ratio of the chemical from the container is equal to or less than a predetermined threshold, and the forced drain is performed when the measured value of the chemical supply per unit time falls below the lower limit value. It is characterized by.

  The control device further inputs an expiration date of the chemical solution in each chemical solution container, and when the lower limit of the supply amount of the chemical solution per unit time is set, within the period until the expiration date of the chemical solution in the current chemical solution container, Calculate the required number of days until the remaining ratio of the chemical from the container falls below a predetermined threshold, and after the date obtained by subtracting the required number of days from the expiration date, a new chemical with the same expiration date as that of the current chemical container The container is configured to be regulated so as not to be charged.

  The chemical solution supply method of the present invention receives the chemical solution from the previous and subsequent chemical solution containers that are sequentially replaced and installed in a chemical solution adjustment unit that adds a diluting solution and a modifier according to the properties of the chemical solution, and this chemical solution adjustment In the chemical supply method for supplying to the production facility through the supply piping system, the amount of chemical received from the current chemical solution container and the amount of chemical supplied to the production facility are respectively measured, and based on the measured value, Calculate the residual ratio of the chemical solution from the previous chemical solution container in all the chemical solutions with the production equipment, and supply the chemical solution from the supply piping system so that the calculated value is equal to or less than a predetermined threshold value for the previous chemical solution. It is characterized by draining.

  According to the present invention, even when the expiration date of the chemical solution has elapsed, the residual rate is suppressed to a level at which the influence on the process can be ignored, and the additional operation can be performed. This eliminates the need for pipe cleaning and replacement for replacement with a new chemical container, minimizing the disposal of the chemical and reducing costs. In addition, since it is not necessary to check the quality of the production equipment when replacing the chemical container, there is no need to stop the equipment for that purpose, and there is no need to stop production. is there.

The block diagram of the chemical | medical solution supply apparatus of the 1st Embodiment of this invention The block diagram of the chemical | medical solution supply apparatus of the 2nd Embodiment of this invention The figure explaining the calculation method of the residual ratio of the old liquid in the chemical | medical solution supply apparatus of this invention The figure which shows transition of the residual ratio of the old liquid in the chemical | medical solution supply apparatus of FIG. The figure explaining the transition of the residual ratio of the old liquid in the chemical | medical solution supply apparatus of FIG. The figure which shows transition of the residual ratio of the old liquid in the chemical | medical solution supply apparatus of FIG. The figure explaining operation | movement of the chemical | medical solution supply apparatus of FIG. Configuration of conventional chemical supply device Configuration diagram of another conventional chemical supply device

Embodiments of the present invention will be described below with reference to the drawings. The same members as those in the conventional chemical supply apparatus described above with reference to FIG.
(First embodiment)
The chemical solution supply apparatus shown in FIG. 1 includes a charge unit 3 for charging the drums 1 and 2 containing the chemical solution, a dilution / supply unit 6 having a dilution tank 4 and a supply tank 5, and a supply line 7. Then, the chemical solution of the charge unit 3 is transferred to the dilution tank 4 of the dilution / supply unit 6, diluted with pure water or the like as necessary, added with additives, transferred to the supply tank 5, and supplied to the supply line 7. To supply production equipment 8 such as semiconductor manufacturing equipment. Note that charging means replacing a used drum with a new drum.

9, 10, 11, and 12 in the figure are pumps for circulating or transferring the chemical solution to the next unit, and 13 is a drain valve disposed on the drain line 14 from the supply line 7. In the charge unit 3, depending on the delivery form of the chemical solution, instead of the illustrated drums 1 and 2 (100 kg, 200 kg, 1 m ^3, etc.), a low charge receiving tank or the like is also used. Further, as means for transferring the chemical solution, N ₂ pumping is also used instead of the illustrated pumps 9 and 10.

  This chemical solution supply apparatus is different from the conventional one in that the hook-up lines 15 and 16 from the supply line 7 to the production facility 8 are provided with integrated flow meters 17 and 18 for measuring the chemical supply amount to the production facility 8, respectively. The drain line 14 includes an integrating flow meter 19 for measuring the drain flow rate, and further includes the following control unit 20. The “supply piping system” described in the claims is a concept including the supply line 7, the hook-up lines 15 and 16, and the pump 12 referred to here. The “chemical solution adjusting unit” corresponds to the dilution / supply unit 6.

  The control unit 20 performs management of the chemical solution supply amount and management of the expiration date of the chemical solution. That is, the expiration date is recognized for each drum installed in the charge unit 3, and the chemicals are supplied in order from the drum with the shorter number of days until the expiration date. As a result, chemicals with different expiration dates can be mixed from the drum that is currently being delivered to the production facility (hereinafter, the chemicals that are closer to the expiration date will be referred to as old liquids and the other liquids will be referred to as new liquids as necessary. In this case, the remaining rate of the old solution is obtained, and a drain instruction or the like is performed in order to achieve a preset threshold value (a level at which the influence on the process can be ignored).

  For this purpose, the control unit 20 obtains information on the expiration date of the charged chemicals in the drums 1 and 2 from the charge unit 3 and obtains batch transfer information to the dilution / supply unit 6.

  Further, the control unit 20 obtains the batch transfer information of the chemical solution from the dilution tank 4 to the supply tank 5 from the dilution / supply unit 6, and supplies the chemical solution supply amount to the production facility 8 by the integrating flow meter 17 of the hookup lines 15 and 16. 18, and when necessary, an instruction to open / close the drain valve 13 can be issued, and the drain amount information can be obtained from the integrated flow meter 19 of the drain line 14.

  Based on the batch transfer information to the dilution / supply unit 6 (the amount of chemical received in the dilution / supply unit 6) and the measured value of the amount of chemical supplied to the production facility 8, the control unit 20 The remaining ratio of the old liquid in all the chemicals during the period (from the current drum to the pipe connected to the production facility 8) is calculated, and this calculated value is equal to or less than a predetermined threshold for the remaining ratio of the old liquid. Thus, the chemical solution drain amount is controlled through the drain valve 13.

  In addition, the control unit 20 is present in the entire supply system in several days from the current amount of chemical solution supplied per day and the capacity of the entire supply system (from the current drum to the pipe connected to the production facility 8). It is calculated whether the old liquid is replaced with the new liquid and the remaining ratio of the old liquid is equal to or less than a predetermined threshold, and the calculated number of days is subtracted from the expiration date of the currently charged drum chemical. If the current date is later than the date after the subtraction, the monitoring of the expiration date and the supply amount of the chemical solution is continued. If the current date is before the date after the subtraction, the chemical solution supply amount is managed and the remaining rate of the old solution is monitored.

  The management of the chemical supply amount means that a lower limit of the chemical supply amount per day is set and forced draining is performed when the actual chemical supply amount falls below the lower limit value. The lower limit depends on the number of days until the expiration date of the chemical solution and the supply amount per day (use amount in the production facility). Forcible draining may be performed every day, or the necessary amount may be forcibly drained on the last day of use. You may set a lower limit for several days. Thereby, the remaining rate of the old liquid can be managed.

  Further, a restriction is imposed on the supply system so that a new drum having the same expiration date as the currently charged drum cannot be charged. For example, information on the drum to be charged is taken into the system using bar code management or the like, and if a non-chargeable drum is mounted, the liquid cannot be fed and an alarm is issued.

  In addition, by managing the number of batch transfers from the dilution tank 4 to the supply tank 5 and the supply amount of the chemical liquid to the production facility 8 even for chemical liquids that have an expiration date after adjustment in the dilution tank 4, Similarly, the remaining rate of the old liquid can be managed.

By doing as described above, even if the expiration date of the chemical solution has elapsed, the residual rate is suppressed to a level at which the influence on the process can be ignored, and the additional operation can be performed. This eliminates the need for pipe cleaning and replacement for replacement with a new chemical container, minimizing the disposal of the chemical and reducing costs. In addition, since it is not necessary to check the quality of the production equipment when replacing the chemical container, there is no need to stop the equipment for that purpose, and there is no need to stop production, and it is possible to reduce the number of chemicals to be supplied for quality check, such as wafers. is there.
(Second Embodiment)
The chemical supply apparatus shown in FIG. 2 includes a liquid level sensor 21 that can detect the liquid level in the supply tank 5, and measures the chemical supply amount and the drain amount from the amount of change in the detected value of the liquid level sensor 21. be able to.

  The control unit 20 receives information on the chemical supply amount and the drain amount from the liquid level sensor 21, and issues a drain instruction to the drain valve 13 when necessary. Others are the same as those described in the first embodiment. The resolution of the liquid level sensor 21 is desirably 1/10 or less of the amount of the chemical solution for one batch transferred from the dilution tank 4 to the supply tank 5.

Next, the calculation principle of the remaining ratio of the old liquid when the chemical liquids having different expiration dates are mixed as described above will be described with reference to FIG.
In the chemical solution supply apparatus including the charge unit 3, the dilution / supply unit 6, the supply line 7 to the production facility 8, and the supply pump 12, the dilution / supply unit 6 (only the supply tank 5 is considered for simplicity) If the replenishing amount V ₃₁ per fresh solution one batch to be transferred from the charge unit 3 and the remaining amount V ₃₂ of the old liquid is present, when the batch transport number of new liquid to the supply tank 5 is n times, the former The residual ratio of the liquid is calculated by the following formula (1).

Cn = (Va × Ca + Vb × Cb (n−1)) / (Va + Vb) (1)
Va: Replenishment amount of new solution to the supply tank
Vb: Remaining supply tank + Old liquid chemical in the pipe
Ca: Concentration of new solution replenished to the supply tank
Cb: Supply tank remaining amount + concentration of old liquid in the pipe
Cn: Remaining ratio of old liquid in supply tank + entire pipe when n batches of new liquid is supplied For example, Va: 100L, Vb: 50L, Ca: 0%, Cb: 100% for the first batch As shown in FIG. 4, the remaining ratio Cn of the old solution decreases as the number of chemical transfer batches increases, and becomes 0.1% or less after the seventh batch.

  Based on this calculation principle, a method for calculating the remaining ratio of the old liquid in the chemical liquid supply apparatus of FIG. 1 will be described with reference to FIG. Charge unit 3, dilution tank 4 and supply tank 5 of dilution / supply unit 6, pump 11a for circulation of dilution tank 4, pump 11b for transfer from dilution tank 4 to supply tank 5, and production facility 8 Only the supply line 7 and the supply pump 12 are shown.

Charge unit 3 V ₄₁ the transfer of one batch to be transferred to the dilution tank 5 _is transferred to the chemical liquid fraction remaining in the dilution tank 4 also including the distribution pipe to the supply tank 5 V _42, to supply tank 5 The transfer amount for one batch is represented by V ₅₁ , and the chemical solution remaining in the supply tank 5 including the supply line 7 to the production facility 8 is represented by V ₅₂ .

The total chemical amount of the charge unit 3 is 1,000 L, the transfer amount V ₄₁ to the dilution tank 4 is 100 L, the chemical solution V ₄₂ remaining in the dilution tank 4 is 50 L, the transfer amount V ₅₁ to the supply tank 5 is 100 L, and the supply tank 5 a chemical component V ₅₂ is 150L remaining in, initially operating exist old medium throughout chemical supply system, it is assumed that the old solution is to charge the fresh liquid with the use in production facilities 8 .

  FIG. 6 shows the relationship between the supply amount of the chemical solution (the supply amount of the chemical solution to the production facility 8) and the remaining ratio of the old solution at this time. When the supply amount reaches 1,000L, the chemical solution in Charge Unit 3 is replaced with a new solution. When 1,200 L or more is supplied, the mixed liquid in which the new liquid is mixed with the old liquid is transferred from the dilution tank 4 to the supply tank 5, and the remaining ratio of the old liquid in the supply tank 5 starts to decrease. When 1,800 L or more is supplied, the remaining rate of the old liquid in the supply tank 5 becomes 10% or less.

Using the above relationship, the threshold value of the remaining ratio of the old liquid that has exceeded the expiration date and the supply amount corresponding to it are set.
For example, when the threshold is 10%, if 1,800L or more is supplied as described above, the remaining rate of the old liquid in the supply tank 5 will be 10% or less. When running, set the lower limit of daily supply to 300L. The lower limit of the supply amount may be determined by the capacity of the production facility using the chemical solution and the production amount at that time.

  Furthermore, when the total number of days that the remaining ratio of the old liquid in the supply tank 5 can be less than the set value (in this case, 6 days) exceeds the remaining expiration date when the entire chemical liquid supply apparatus is the old liquid, Restrictions that cannot be entered into the charge unit 3 are set.

FIG. 7 shows changes in the supply amount and the old liquid remaining rate with respect to the old liquid supply days at this time. When 1,000L supply 1 m ³ drum charge unit 3 is replaced with a new solution, new chemical is introduced to the downstream side of the drum, the former liquid residual ratio of the supply tank 5 starts to decrease from 100%. The decrease in the old liquid residual rate is theoretically from the point of use of 1,200L or more, but since the supply amount per day is 300L or more, the third day when the cumulative supply amount becomes 1,000L is the changing point. It has become.

  In this example, since the lower limit of the supply amount is 300 L / Day, the forced drain of 100 L of the difference is performed on the fifth day when the actual supply amount was 200 L / Day. The management of the supply amount may be performed by Day or a moving average (such as 3 days). In actual operation, the moving average can absorb fluctuations in daily supply. In this example, the 6th day is the expiration date of the old liquid, and the remaining ratio of the old liquid in the supply tank 5 is 10% or less on the 6th day.

  In this case, if it is before the number of days to consume 1,800L of supply volume that can achieve the old liquid remaining rate 10% or less set from the expiration date of the old liquid, that is, before the date after subtracting 6 days, it is within the expiration date Even if the daily supply is 300L or less, there is no need to drain. The drain correspondence is only a means for keeping the remaining ratio of the old liquid that has exceeded the expiration date below the set value.

  INDUSTRIAL APPLICABILITY The present invention is useful for a manufacturing process that may affect the process quality when a chemical solution that has exceeded its expiration date is used, for example, a semiconductor wafer manufacturing process.

1, 2 Drum 3 Charge unit 4 Dilution tank 5 Supply tank 6 Dilution / supply unit 7 Supply line 8 Production equipment 9, 10, 11, 12 Pump
13 Drain valve
14 Drain line
17, 18, 19 Integrated flow meter
20 Control unit
21 Liquid level sensor

Claims (4)

Receives chemical solutions from previous and subsequent chemical solution containers that are replaced and installed sequentially, and supplies the chemical solution adjustment unit that adds diluents and modifiers according to the properties of the chemical solution, and supplies the chemical solution of the chemical solution adjustment unit to the production equipment Supply piping system, drain piping communicating with the supply piping system via a valve device, the amount of chemical received from the current chemical solution container, the amount of chemical supplied to the production facility, and the amount of chemical drain in the drain piping And a control device connected to the valve device and the measuring device,
The controller calculates the remaining rate of the chemical solution from the previous chemical solution container in the total chemical solution between the current chemical solution container and the production facility based on the measured value of the received chemical solution amount and the supplied chemical solution amount. The chemical solution supply device controls the drain amount of the chemical solution through the valve device so that the calculated value is equal to or less than a predetermined threshold for the remaining rate of the chemical solution.   The control device further inputs an expiration date of the chemical solution in each chemical solution container, and when the lower limit of the supply amount of the chemical solution per unit time is set, within the period until the expiration date of the chemical solution in the current chemical solution container, The liquid is supplied so that the residual ratio of the chemical from the container is equal to or less than a predetermined threshold, and the forced drain is performed when the measured value of the chemical supply per unit time falls below the lower limit value. The chemical solution supply apparatus according to claim 1, wherein:   The control device further inputs an expiration date of the chemical solution in each chemical solution container, and when the lower limit of the supply amount of the chemical solution per unit time is set, within the period until the expiration date of the chemical solution in the current chemical solution container, Calculate the required number of days until the remaining ratio of the chemical from the container falls below a predetermined threshold, and after the date obtained by subtracting the required number of days from the expiration date, a new chemical with the same expiration date as that of the current chemical container 2. The chemical solution supply apparatus according to claim 1, wherein the container is configured so as not to be charged. The chemical solution from the previous and subsequent chemical solution containers that are sequentially replaced and received is received in the chemical solution adjustment unit to which the diluent and modifier according to the properties of the chemical solution are added, and production equipment is supplied from this chemical solution adjustment unit through the supply piping system. In the chemical supply method for supplying to
Measure the amount of chemical liquid received from the current chemical liquid container and the amount of chemical liquid supplied to the production equipment, respectively, and based on the measured value, from the previous chemical liquid container in the total chemical liquid between the current chemical liquid container and the production equipment A chemical solution supply method comprising: calculating a residual ratio of the chemical solution and draining the chemical solution from the supply piping system so that the calculated value is equal to or less than a predetermined threshold value for the previous chemical solution.

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