JP2005334755A - Detoxification apparatus and detoxification method for waste gas and system for fabricating electronic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detoxification apparatus and a detoxification method for a waste gas in which fluorine concentration of a washing solution used for washing the waste gas is precisely detected, and provide a system for fabricating an electronic device. <P>SOLUTION: The detoxification apparatus is used for a waste gas containing PFC (perfluorocarbon) gas which is suspected to be a cause of global warming, and comprises a second scrubber 22 for washing a waste gas discharged out of a semiconductor treatment apparatus 90 and thermally decomposed by a reaction cylinder 30 with water, or the like, and a fluorine densitometer 60 for measuring the fluorine concentration of water used for washing treatment of the waste gas by the second scrubber 22. The fluorine concentration of water used for the washing treatment of the waste gas can precisely be detected and the fluorine concentration in the water to be discharged out the detoxification apparatus can be prevented from exceeding a prescribed discharge standard. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an abatement apparatus and an electronic device manufacturing system, and more particularly to a technique for detoxifying (that is, detoxifying treatment) harmful components in exhaust gas discharged from a manufacturing apparatus such as an electronic device.

In recent years, SF ₆ and PFC gas have been pointed out to have a relationship with global warming, and there is a strong demand for reducing their emissions. In the manufacturing process of semiconductor devices and LCDs, generally, PFC gas such as SF ₆ , CF ₄ , and CHF ₃ is used as a process gas. The process gas is, for example, a raw material gas for film formation or an etching gas for thin film etching, and is a gas necessary for forming an IC circuit on a semiconductor wafer. In the manufacturing process of semiconductor devices and LCDs, an abatement device is provided in an exhaust line connected to the manufacturing apparatus in order to reduce the amount of PFC gas discharged to the outside.

The PFC gas abatement system detoxifies harmful components that are difficult to process at room temperature, and therefore a reaction cylinder that heats the exhaust gas to thermally decompose the harmful components, and a scrubber provided downstream of the reaction cylinder, Usually, it is composed of a combination of The PFC gas discharged from the manufacturing apparatus is thermally decomposed into CO ₂ (carbon dioxide), HF (hydrofluoric acid) and the like in the reaction cylinder. Of the exhaust gas that has been pyrolyzed, particularly HF, which is a harmful component, is dissolved in water by a scrubber at the rear stage of the reaction tube and removed from the exhaust gas. A specific configuration of the scrubber is described in Patent Document 1, for example.

Here, the scrubber described in Patent Document 1 has a pH meter for measuring the pH of the cleaning liquid used in circulation in the scrubber, and a new cleaning liquid is supplied to the scrubber based on the measured value of the pH meter. It is the structure which determines the replenishment amount. With such a configuration, Patent Document 1 discloses as an effect of the invention that “exhaust gas can be reliably cleaned and purified with a minimum replenishment amount of the cleaning liquid. In addition, the pH value of the cleaning liquid is managed. Therefore, it is described that the concentration of the harmful gas component after the exhaust gas cleaning process can be reliably maintained below the upper limit. "
JP-A-10-290918

By the way, in the manufacturing factory of a semiconductor device or LCD, NH ₃ , HCl, SiHCl ₃ , BCl ₃ , BF ₃ , PF ₅ , PF ₃ , SiCl ₄ , SiF are used with one scrubber for reasons of equipment cost and arrangement space. It is common to detoxify a plurality of types of gases such as ₄ , B ₂ H ₆ , SiH ₂ Cl ₂ , and WF ₆ . In general, one or a plurality of scrubbers that target a plurality of types of gases for the detoxification process are provided depending on the scale of the factory. Conventionally, this type of scrubber is considered to be sufficient if the pH of the entire cleaning liquid after use has cleared the discharge standard. To clear such a discharge standard, it is described in Patent Document 1. The configuration was considered sufficient.

  However, the present inventor stated that “when such a scrubber is used to detoxify a plurality of kinds of gases including PFC gas, the scrubber is not limited to HF generated by thermal decomposition of PFC gas, but also HCl or the like. Since other gases also flow, other gases such as HCl dissolve in the cleaning liquid, and the pH of the cleaning liquid varies greatly depending on the flow rate of each gas flowing to the scrubber. Therefore, the measured value of the pH meter cannot accurately grasp the HF concentration of the cleaning solution. ”

  The present invention has been made paying attention to such an unsolved problem of the conventional technology, and is an exhaust gas that can accurately grasp the fluorine concentration of the cleaning liquid used in the exhaust gas cleaning process. An object of the present invention is to provide an abatement apparatus, a detoxification method thereof, and an electronic device manufacturing system.

[Invention 1] In order to achieve the above object, the exhaust gas abatement apparatus of Invention 1 is an exhaust gas cleaning means for cleaning an exhaust gas discharged from a predetermined manufacturing apparatus and thermally decomposed by an exhaust gas heat treatment means with a predetermined cleaning liquid. And fluorine concentration measuring means for measuring the fluorine concentration of the cleaning liquid used for the exhaust gas cleaning treatment by the exhaust gas cleaning means.

Here, the exhaust gas is, for example, SF ₆ or PFC (perfluorocarbon compound) gas. SF ₆ and PFC gas have been pointed out to have a relationship with global warming, and there is a strong demand for reducing their emissions. In the manufacturing process of semiconductor devices and LCDs (liquid crystal displays), PFC gases such as SF ₆ (sulfur hexafluoride), CF ₄ (tetrafluoromethane), and CHF ₃ (methane trifluoride) are generally used as process gases. It is used as.

The predetermined cleaning liquid is, for example, tap water, industrial water, or an aqueous solution in which a chemical agent such as an absorbent is dissolved in water. PFC gas is thermally decomposed into CO ₂ (carbon dioxide), HF (hydrofluoric acid) and the like by the exhaust gas heat treatment means. Of these pyrolyzed gases, HF is particularly water-soluble. Therefore, HF can be removed from the gas by washing the pyrolyzed gas with water or the like.

Furthermore, the fluorine concentration measuring means of the present invention does not measure the pH of the cleaning liquid like a pH meter and indirectly estimate the fluorine concentration from the measured pH value, but directly measures the fluorine concentration of the cleaning liquid. Is.
According to the exhaust gas abatement apparatus of the first aspect, the fluorine concentration of the cleaning liquid used for the exhaust gas cleaning process can be accurately grasped.
[Invention 2] The exhaust gas abatement apparatus of the invention 2 is the exhaust gas abatement apparatus of the invention 1, wherein the fluorine concentration of the cleaning liquid is adjusted based on the fluorine concentration of the cleaning liquid measured by the fluorine concentration measuring means. Fluorine concentration adjusting means.

With such a configuration, it is possible to accurately grasp the fluorine concentration of the cleaning liquid used in the exhaust gas cleaning process, and the fluorine concentration of the cleaning liquid discharged outside the abatement apparatus does not exceed a predetermined emission standard. It is possible to do so.
For example, when the fluorine concentration of the cleaning liquid after being used for the exhaust gas cleaning process exceeds the upper control value, the cleaning liquid after use can be diluted until the fluorine concentration becomes equal to or lower than the upper control value. Thereby, the corrosion inside the abatement apparatus can be suppressed, and for example, the emission standards for fluorine concentration set in-house, which are stricter than the emission standards established by the country, can be strictly observed. Further, when the fluorine concentration of the cleaning liquid after being used for the exhaust gas cleaning process is equal to or lower than the upper control value, the cleaning liquid used for the exhaust gas cleaning process can be used again for the exhaust gas cleaning process (that is, Can be reused.) Since it is possible to prevent the cleaning liquid whose fluorine concentration has not reached the upper control value from being discharged to the outside, it is possible to reduce the amount of the cleaning liquid used.
[Invention 3] The exhaust gas abatement apparatus of Invention 3 is the pH measurement for measuring the pH of the cleaning liquid used in the exhaust gas cleaning process by the exhaust gas cleaning means in the exhaust gas abatement apparatus of Invention 1 or Invention 2. Means.

Here, the pH is a hydrogen ion concentration and is an index representing the acidity and alkalinity of the cleaning liquid. The pH is neutral at 7. Moreover, when the numerical value goes up, it shows that it is alkaline, and it becomes acidic when it becomes low.
According to the exhaust gas abatement apparatus of the third aspect of the invention, for example, even when the fluorine concentration of the cleaning liquid after being used for the exhaust gas cleaning treatment is less than a predetermined value, the pH of the cleaning liquid after being used is within a predetermined range. When it comes off, the cleaning solution can be diluted until the pH of the cleaning solution after use falls within a predetermined range. Thereby, corrosion inside the abatement apparatus by acids other than hydrofluoric acid or alkali can be suppressed. In addition, for example, it is possible to strictly observe the emission standards for acids and alkalis set by the company, which are stricter than the emission standards set by the government.
[Invention 4] The exhaust gas abatement apparatus of Invention 4 is the exhaust gas abatement apparatus according to any one of Inventions 1 to 3, wherein the cleaning liquid used for cleaning the exhaust gas by the exhaust gas cleaning means is stored. It has a tank and a liquid amount measuring means for measuring the amount of the cleaning liquid stored in the cleaning liquid tank.

With such a configuration, for example, when the amount of the cleaning liquid stored in the cleaning liquid tank is evaporated and the amount thereof is reduced, the amount of evaporation can be known, so the cleaning liquid corresponding to the amount of evaporation can be obtained. It is possible to newly supply the cleaning liquid tank.
[Invention 5] The exhaust gas abatement apparatus according to Invention 5 is the exhaust gas abatement apparatus according to any one of Inventions 1 to 4, further comprising an exhaust gas heat treatment means for thermally decomposing the exhaust gas discharged from the manufacturing apparatus. It is characterized by that. With such a configuration, for example, it is possible to thermally decompose PFC gas into CO ₂ and HF.
[Invention 6] The exhaust gas detoxification method of Invention 6 uses the exhaust gas detoxification apparatus according to any one of Inventions 1 to 5 to detoxify the exhaust gas discharged from a predetermined production apparatus. It is a feature. With such a configuration, any one of the exhaust gas abatement apparatuses according to the first to fifth aspects of the invention is applied, so that the fluorine concentration of the cleaning liquid after being used for the exhaust gas cleaning process can be accurately grasped. .
[Invention 7] The electronic device manufacturing system according to Invention 7 includes the exhaust gas abatement apparatus according to any one of Inventions 1 to 5, and one or more electronic device manufacturing apparatuses. It is a feature.

  Here, the electronic device is, for example, a semiconductor device or an LCD. The electronic device manufacturing apparatus is composed of one or two or more apparatuses. For example, an electronic device manufacturing apparatus includes a plurality of CVD (Chemical Vapor Deposition) apparatuses. Alternatively, the electronic device manufacturing apparatus may include a plurality of CVD apparatuses and a plurality of dry etching apparatuses.

  According to the electronic device manufacturing system of the seventh aspect of the invention, the exhaust gas discharged from the electronic device manufacturing apparatus can be detoxified using the exhaust gas abatement apparatus of any one of the first to fifth aspects. Therefore, it is possible to accurately grasp the fluorine concentration of the cleaning liquid after being used for the exhaust gas cleaning process.

Hereinafter, an exhaust gas abatement apparatus, a detoxification method thereof, and an electronic device manufacturing system according to the present invention will be described with reference to the drawings.
(1) 1st Embodiment FIG. 1: is a conceptual diagram which shows the structural example of the abatement apparatus 100 which concerns on 1st Embodiment of this invention. An abatement apparatus 100 shown in FIG. 1 is an apparatus for detoxifying SF ₆ and PFC gas contained in exhaust gas discharged from a manufacturing apparatus for manufacturing a semiconductor device, an LCD, or the like. Examples of the PFC gas include CF ₄ and CHF ₃ . As a manufacturing apparatus, for example, a semiconductor processing apparatus 90 such as a CVD apparatus or a dry etching apparatus is assumed.

  The abatement apparatus 100 includes a control unit 50 (see FIG. 2) including the exhaust pipe 10, the first scrubber 21, the reaction cylinder 30, the second scrubber 22, the water storage tank 40, a CPU (central processing unit), and the like. ), A fluorine concentration meter 60, a water supply line, a water supply valve SV1, a drainage line, a drainage valve SV2, and the like. In FIG. 1, three semiconductor processing apparatuses 90 are shown for convenience of drawing. However, any number of semiconductor processing apparatuses 90 may be used, and here, any number of semiconductor processing apparatuses 90 placed in a factory are all included. Are connected to the gas inlet of the exhaust pipe 10.

  In FIG. 1, the first scrubber 21 injects water (for example, tap water or industrial water) as a cleaning liquid into the gas sent through the exhaust pipe 10, and powder contained in the gas, An apparatus for removing water-soluble gas. In this abatement apparatus 100, the first scrubber 21 is provided between the gas inlet of the exhaust pipe 10 and the reaction tube 30, and mainly plays a role of powder removal. For example, in a CVD apparatus, a large number of fine particles are generated for reasons of the film forming process. Such fine particles enter the exhaust pipe 10 together with the exhaust gas from the gas inlet of the exhaust pipe 10. In the detoxifying apparatus 100, the first scrubber 21 can remove fine particles that have entered the exhaust pipe 10.

As shown in FIG. 1, the reaction cylinder 30 is connected to the exhaust pipe 10 and heat-treats the exhaust gas from which the powder is mainly removed by the first scrubber 21. Inside the reaction cylinder 30, for example, a catalyst (not shown) that promotes decomposition of harmful components in the exhaust gas is provided. Further, a heater (not shown) for heating the inside of the reaction cylinder 30 is provided outside the reaction cylinder 30, for example. In this reaction cylinder 30, the PFC gas in the exhaust gas is thermally decomposed mainly into CO ₂ and HF.

The reaction cylinder 30 is not limited to the above example. For example, a combustion system having a burner in the reaction cylinder, a heating system having a heater outside the reaction cylinder, and a catalyst in the reaction cylinder. Any one of a catalyst system, an adsorption system having an adsorbent in the reaction cylinder, or a combination thereof may be used.
In addition, the second scrubber 22 injects water (for example, tap water or industrial water) as a cleaning liquid into the gas sent through the exhaust pipe 10, and the powder contained in the gas or water-soluble This device removes the gas. In the abatement apparatus 100, the second scrubber 22 is provided at the rear stage of the reaction cylinder 30. HF produced by thermal decomposition of PFC gas has high solubility in water. Therefore, the second scrubber 22 dissolves HF contained in the exhaust gas into water and removes it from the exhaust gas.

  As shown in FIG. 1, a water supply line and a drain line are connected to the water storage tank 40. A water supply valve SV1 is provided in the water supply line. By opening this water supply valve SV1, water (for example, tap water or industrial water) as a cleaning liquid is supplied into the water storage tank 40. Yes. The drain line is provided with a drain valve SV2. By opening the drain valve SV2, water in the water storage tank 40 is discharged to the outside.

  Further, as shown in FIG. 1, a water circulation line is provided between the water storage tank 40 and the first scrubber 21, and water in the water storage tank 40 is used as an exhaust gas cleaning liquid by the first scrubber 21. It has come to be used. Similarly, a water circulation line is also provided between the water storage tank 40 and the second scrubber 22, and the water in the water storage tank 40 is used as the exhaust gas cleaning liquid in the second scrubber 22. .

  As shown in FIG. 1, a fluorine concentration meter 60 is attached to the water storage tank 40. The fluorine concentration meter 60 measures the fluorine concentration of the water stored in the water storage tank 40. In this abatement apparatus 100, the water supply valve SV1 and the drainage valve SV2 are closed during normal times, that is, when the measured value of the fluorine concentration by the fluorine concentration meter 60 is not more than the upper control limit (UCL). Yes. Here, the upper limit control value (UCL) is, of course, a value that is sufficiently lower than the emission standard of fluorine concentration set by the country, or a value that allows the fluorine removal treatment to be easily performed by the wastewater treatment facility installed in the subsequent stage. .

Further, this water storage tank 40 is provided with an overflow drain, and when the amount of water stored in the water storage tank 40 exceeds a certain amount for some reason, the water in the water storage tank 40 is caused to overflow and forced. It is designed to drain.
FIG. 2 is a block diagram showing a configuration example of a control system of the abatement apparatus 100. As shown in FIG. As shown in FIG. 2, the control unit 50 is connected to the fluorine concentration meter 60, the water supply valve SV1, and the drain valve SV2 via signal lines. Here, the signal line is, for example, wired or wireless. A RAM (random access memory) 52 stores the above-described upper limit management value (UCL), a control program for controlling the fluorine concentration in the water storage tank 40, and the like. In this abatement apparatus 100, the control unit 50 causes the fluorine concentration meter 60 to measure the fluorine concentration of water according to the control program stored in the RAM 52. Then, the control unit 50 receives the measured value of the fluorine concentration by the fluorine concentration meter 60 and compares the received measured value with the upper limit management value (UCL) stored in the RAM 52. Based on the result of this comparison, the controller 50 opens and closes the water supply valve SV1 and the drain valve SV2 simultaneously or alternately.

FIG. 3 is a flowchart showing a method for adjusting the fluorine concentration of water in the water storage tank 40. In this flowchart, it is assumed that both the water supply valve SV1 and the drain valve SV2 are closed at the time of the start.
First, in step S <b> 1 of FIG. 3, a signal instructing the start of measurement of fluorine concentration is transmitted from the control unit 50 to the fluorine concentration meter 60. The fluorine concentration meter 60 receives this signal and measures the fluorine concentration of the water in the water storage tank 40. Then, the measured value is transmitted from the fluorine concentration meter 60 to the control unit 50.

  Next, in step S <b> 2 of FIG. 3, the control unit 50 determines whether or not this measurement value is equal to or less than the upper limit management value (UCL) of the fluorine concentration. If the measured value is equal to or lower than the upper limit management value (UCL) of the fluorine concentration, the process proceeds to step S3 in FIG. In step S <b> 3, for example, the control unit 50 determines whether or not to continue the abatement process in the abatement apparatus 100. If the detoxification process is continued in step S3, the process returns to step S1. Further, when the abatement process is ended, this flowchart is ended.

  On the other hand, when the measured value by the fluorine concentration meter 60 exceeds the upper limit management value (UCL) of the fluorine concentration in step S2 of FIG. In step S4, the control part 50 transmits the control signal regarding valve opening / closing to the water supply valve SV1 and the drainage valve SV2, respectively, and opens / closes the water supply valve SV1 and the drainage valve SV2 simultaneously or alternately. Moreover, the control part 50 can adjust the opening degree separately, when opening a valve | bulb. In this way, a part of the water in the water storage tank 40 is replaced. Then, it progresses to step S5 of FIG.

  In step S <b> 5, a signal instructing the start of measurement of the fluorine concentration is transmitted from the control unit 50 to the fluorine concentration meter 60. The fluorine concentration meter 60 receives this signal and measures the fluorine concentration of water in the water storage tank 40. Then, the measured value is transmitted from the fluorine concentration meter 60 to the control unit 50. Next, the process proceeds to step S6 in FIG. In step S6, the control unit 50 determines whether or not the measurement value is equal to or lower than the upper limit management value (UCL) of the fluorine concentration. If the measured value is not more than the upper limit management value (UCL) of the fluorine concentration, the process proceeds to step S3. If the measured value exceeds the upper limit management value (UCL) of the fluorine concentration in step S6, the process returns to step S4.

With such a configuration, in the abatement apparatus 100, the fluorine concentration of water discharged to the outside of the abatement apparatus 100 is, for example, less than or less than the emission standards set by the company, which is stricter than the emission standards established by the government It is possible to set the value so that the fluorine removal treatment can be easily performed in the wastewater treatment facility to be installed.
FIG. 7 is a diagram showing the timing of opening and closing operations of the water supply valve SV1 and the drain valve SV2 connected to the water storage tank 40. The horizontal axis in FIG. 7 indicates time. The vertical axis in FIG. 7 indicates the fluorine concentration of water in the water storage tank 40.

  As shown in FIG. 7, immediately after the water in the water storage tank 40 is completely replaced and the detoxification process is resumed, the water in the water storage tank 40 is new and its fluorine concentration is low. Therefore, it is not necessary to replace the water in the water storage tank 40 until the fluorine concentration of the water in the water storage tank 40 reaches the upper control value (UCL) after the detoxification process is restarted. The drain valve SV2 (hereinafter also simply referred to as “valve”) is closed. As shown in FIG. 7, by closing the valve, the fluorine concentration of water in the water storage tank 40 gradually increases with time.

  Next, when the fluorine concentration of the water in the water storage tank 40 reaches UCL, the valve is opened and the replacement of the water in the water storage tank 40 is started. Then, as shown in FIG. 7, the fluorine concentration of the water in the water storage tank 40 becomes low, and the fluorine concentration eventually reaches the central control value (CL). Next, when the fluorine concentration of the water in the water storage tank 40 reaches CL, the valve is closed. As shown in FIG. 7, the fluorine concentration of water in the water storage tank 40 gradually increases with time by closing the valve.

As described above, the fluorine concentration of water in the water storage tank 40 is varied between UCL and CL by repeatedly opening and closing the valve. As a result, it is possible to reduce the fluorine concentration of water discharged outside the abatement device 100 at the time of total replacement or partial replacement to less than the national emission standards, which is even stricter than that. It can be below the set emission standard.
Here, as shown in FIG. 7, the fluorine concentration of the water in the water storage tank 40 is always kept lower than the emission standard set by the country. Therefore, the total replacement of the water in the water storage tank 40 is shown in FIG. It may be executed at an arbitrary timing on the horizontal (time) axis shown. Total replacement of the water in the water storage tank 40 is performed by stopping the abatement process by the abatement apparatus 100, and then closing the water supply valve SV1 and opening the drain valve SV2.

In FIG. 7, when “valve closed”, normally, no new water is supplied into the water storage tank 40 and no water is discharged from the water storage tank 40 to the outside. Therefore, for example, water can be saved as compared with a detoxification device that constantly supplies a constant amount of water to a water storage tank.
Next, a method for removing exhaust gas discharged from the semiconductor processing apparatus 90 using the above-described removal apparatus 100 will be described. First, exhaust gas containing PFC gas discharged from the semiconductor processing apparatus 90 enters the exhaust pipe 10 from the gas inlet and is sent to the first scrubber 21. The exhaust gas that has reached the first scrubber 21 is washed by the water circulating between the first scrubber 21 and the water storage tank 40 by the operation of the pump P, and mainly the powder contained in the exhaust gas is removed. Is done.

Next, the exhaust gas from which the powder and the like have been removed exits the first scrubber 21 and reaches the reaction cylinder 30. In the reaction cylinder 30, the PFC gas in the exhaust gas is thermally decomposed mainly into CO ₂ and HF. Next, the exhaust gas containing CO ₂ and HF is sent to the second scrubber 22. The exhaust gas that has reached the second scrubber 22 is washed by the water circulating between the second scrubber 22 and the water storage tank 40 by the operation of the pump P, and HF contained in the exhaust gas is dissolved in water. By the cleaning process in the second scrubber 21, HF is almost completely removed from the exhaust gas. Thereafter, the exhaust gas from which HF has been almost completely removed is sent from the second scrubber 22 to the gas outlet of the exhaust pipe.

  Further, the water concentration in the water storage tank used as the cleaning liquid by the first scrubber 21 and the second scrubber 22 is measured periodically (for example, at intervals of several seconds) according to the flowchart shown in FIG. And when the measured value exceeds the upper control value (UCL) of the fluorine concentration, the opening degree of the water supply valve SV1 and the drainage valve SV2 is adjusted under the control of the control unit 50, respectively. Some water is replaced. That is, the fluorine concentration meter 60, the control unit 50, the water supply valve SV1, and the drain valve SV2 adjust the fluorine concentration of water stored in the water storage tank 40 so as not to exceed the upper control value (UCL). The

As described above, according to the abatement apparatus 100 according to the embodiment of the present invention, the fluorine concentration of water used for the exhaust gas cleaning process can be accurately grasped, and the cleaning liquid discharged to the outside of the abatement apparatus. It is possible to prevent the fluorine concentration of the gas from exceeding a predetermined emission standard.
For example, when the fluorine concentration of water after being used for exhaust gas cleaning treatment exceeds the upper control value (UCL), the water after use is used until the fluorine concentration falls below the upper control value (UCL). Can be diluted. As a result, corrosion inside the abatement apparatus 100 can be suppressed, and fluorine removal treatment can be easily performed with the emission standard of fluorine concentration set by the company, which is stricter than the emission standard established by the country, or the wastewater treatment equipment installed at the subsequent stage. Strict adherence to possible values.

  Further, when the fluorine concentration of the water after being used for the exhaust gas cleaning process is equal to or lower than the upper control value (UCL), the water supply valve SV1 and the drain valve SV2 are closed, and the water in the water storage tank 40 is used as it is. Can be reused in the cleaning process. Since it is possible to prevent wasteful discharge of water whose fluorine concentration does not reach the upper control value to the outside world, it is possible to reduce the amount of tap water, industrial water, or the like, for example.

In the first embodiment, the reaction cylinder 30 corresponds to the exhaust gas heat treatment means of the present invention, and the second scrubber 22 corresponds to the exhaust gas cleaning means of the present invention. The fluorine concentration meter 60 corresponds to the fluorine concentration measuring means of the present invention, and the water storage tank 40 corresponds to the cleaning liquid tank of the present invention. Further, the control unit 50, the water supply valve SV1, and the drain valve SV2 correspond to the fluorine concentration adjusting means of the present invention.
(2) Second Embodiment FIG. 4 is a block diagram showing a configuration example of a control system of an abatement apparatus 200 according to a second embodiment of the present invention. 4, parts having the same functions as those of the abatement apparatus 100 shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The abatement apparatus 200 shown in FIG. 4 has a configuration in which a pH meter 70 that measures the pH of water in the water storage tank 40 is added to the abatement apparatus 100 shown in FIGS. 1 and 2. The pH meter 70 is connected to the control unit 50 via a signal line. And in this abatement apparatus 200, the control part 50 adjusts the opening degree of the water supply valve SV1 and the drainage valve SV2 based on the concentration measurement value of the fluorine concentration meter 60 and the pH measurement value of the pH meter 70, respectively. It has become.

With such a configuration, even when the fluorine concentration of the water in the water storage tank 40 is equal to or lower than the upper control value (UCL), the pH of the water deviates from the pH control value (that is, the pH value is abnormal). ), It is possible to dilute the water in the water storage tank 40 until the pH of the water in the water storage tank 40 falls within the pH control value (that is, the pH value becomes normal). Thereby, corrosion inside the abatement apparatus 100 by acids other than hydrofluoric acid or alkali can be suppressed. In addition, for example, it is possible to strictly observe the emission standards for acids and alkalis set by the company, which are stricter than the emission standards set by the government. In the second embodiment, the pH meter 70 corresponds to the pH measuring means of the present invention.
(3) Third Embodiment FIG. 5 is a block diagram illustrating a configuration example of a control system of an abatement apparatus 300 according to a third embodiment of the present invention. 5, parts having the same functions as those of the abatement apparatus 100 shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The abatement device 300 shown in FIG. 5 is configured by adding a water level meter 80 for measuring the amount of water stored in the water storage tank 40 (ie, water level) to the abatement device 100 shown in FIGS. 1 and 2. It has become. The water level gauge 80 is connected to the control unit 50 through a signal line. And in this abatement apparatus 300, the control part 50 adjusts the opening degree of the water supply valve SV1 and the drainage valve SV2 based on the concentration measurement value of the fluorine concentration meter 60 and the water level measurement value of the water level meter 80, respectively. It has become.

With such a configuration, when the water stored in the water storage tank 40 evaporates and the amount thereof is reduced, the amount of evaporation can be known, so that the water corresponding to the evaporated amount is stored in the water. It is possible to replenish the tank 40 anew. In the third embodiment, the water level meter 80 corresponds to the liquid amount measuring means of the present invention.
(4) Fourth Embodiment FIG. 6 is a block diagram illustrating a configuration example of a control system of an abatement apparatus 400 according to a fourth embodiment of the present invention. 6, parts having the same functions as those of the abatement apparatus 100 shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The abatement device 400 shown in FIG. 6 has a configuration in which both the pH meter 70 and the water level meter 80 described above are added to the abatement device 100 shown in FIGS. 1 and 2. As shown in FIG. 6, the pH meter 70 is connected to the control unit 50 through a signal line. The water level gauge 80 is also connected to the control unit 50 through a signal line. And in this abatement apparatus 400, the control part 50 is based on the measured concentration value of the fluorine concentration meter 60, the measured pH value of the pH meter 70, and the measured water level value of the water level meter 80, and the water supply valve SV1 and the drainage valve. The opening degree of SV2 is adjusted.

  With such a configuration, even when the fluorine concentration of the water in the water storage tank 40 is equal to or lower than the upper control value (UCL), if the pH value is abnormal, the value in the water storage tank is not changed until the value becomes normal. It is possible to dilute the water. This makes it possible to suppress corrosion inside the detoxifying device due to acids other than hydrofluoric acid and alkali. For example, it is installed in the company's own acid or alkali emission standards that are more stringent than the national emission standards It is possible to strictly observe the values that can be easily removed with fluorine in the wastewater treatment facility.

Further, when the amount of water stored in the water storage tank 40 evaporates and the amount thereof decreases, the amount of evaporation can be known, so water corresponding to the amount of evaporation is newly supplied to the water storage tank 40. Is possible.
The electronic device manufacturing system according to the present invention includes, for example, any one of the above-described abatement apparatuses 100, 200, 300, or 400, and one or more semiconductor processing apparatuses. . If it is such a structure, the exhaust gas discharged | emitted from the semiconductor processing apparatus 90 can be detoxified using any one of the abatement apparatuses 100, 200, 300 or 400. Accordingly, it is possible to accurately grasp the fluorine concentration of the water after being used for the exhaust gas cleaning treatment, and to make the fluorine concentration of the water discharged out of the abatement apparatus close to a constant value.

The conceptual diagram which shows the structural example of the abatement apparatus 100 which concerns on 1st Embodiment. The block diagram which shows the structural example of the control system of the abatement apparatus 100. FIG. The flowchart which shows the adjustment method of the fluorine concentration of the water in the water storage tank. The block diagram which shows the structural example of the control system of the abatement apparatus 200 which concerns on 2nd Embodiment. The block diagram which shows the structural example of the control system of the abatement apparatus 300 which concerns on 3rd Embodiment. The block diagram which shows the structural example of the control system of the abatement apparatus 400 which concerns on 4th Embodiment. The figure which shows the timing of the opening / closing operation | movement of the water supply valve SV1 connected to the water storage tank 40, and the drain valve SV2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Exhaust pipe, 21 1st scrubber, 22 2nd scrubber, 30 Reaction cylinder, 40 Water storage tank, 50 Control part, 52 RAM, 60 Fluorine concentration meter, 70 pH meter, 80 Water level meter, 90 Semiconductor processing apparatus, 100, 200 , 300,400 Detoxifying device, SV1 water supply valve, SV2 drainage valve, P pump

Claims (7)

Exhaust gas cleaning means for cleaning the exhaust gas discharged from the predetermined manufacturing apparatus and thermally decomposed by the exhaust gas heat treatment means with a predetermined cleaning liquid;
An exhaust gas abatement apparatus, comprising: a fluorine concentration measuring unit that measures a fluorine concentration of the cleaning liquid used for the exhaust gas cleaning process by the exhaust gas cleaning unit.   The exhaust gas abatement apparatus according to claim 1, further comprising fluorine concentration adjusting means for adjusting the fluorine concentration of the cleaning liquid based on the fluorine concentration of the cleaning liquid measured by the fluorine concentration measuring means.   The exhaust gas abatement apparatus according to claim 1, further comprising a pH measuring unit that measures a pH of the cleaning liquid used for the exhaust gas cleaning process by the exhaust gas cleaning unit. A cleaning liquid tank for storing the cleaning liquid used in the exhaust gas cleaning process by the exhaust gas cleaning means;
The exhaust gas abatement apparatus according to any one of claims 1 to 3, further comprising a liquid amount measuring unit that measures the amount of the cleaning liquid stored in the cleaning liquid tank.   The exhaust gas abatement apparatus according to any one of claims 1 to 4, further comprising an exhaust gas heat treatment means for thermally decomposing the exhaust gas discharged from the manufacturing apparatus.   An exhaust gas abatement method characterized by using the exhaust gas abatement apparatus according to any one of claims 1 to 5 to detoxify the exhaust gas discharged from a predetermined manufacturing apparatus. . An exhaust gas abatement apparatus according to any one of claims 1 to 5,
An electronic device manufacturing system comprising: one or two or more electronic device manufacturing apparatuses.

Images