JP2010058118A - Apparatus for treating halogen-containing gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for treating a halogen-containing gas that enables highly efficient treatment and has a structure meeting users' needs. <P>SOLUTION: The apparatus for treating the halogen-containing gas includes: a cleaning unit 31 for removing byproducts generated in decomposition of the halogen-containing gas; a gas separation unit 321 for separating gases other than halogen-series gases from the halogen-containing gas to enrich the halogen-series gases; a gas-decomposing unit 36 for decomposing the enriched halogen-series gases; and an exhaust gas circulation unit 352 for returning the discharged gas, that has been treated in the gas-decomposing unit 36 and discharged, to the cleaning unit 31. These units are arranged orderly in series in the direction of flow of the halogen-containing gas containing the halogen-series gases supplied from a halogen-containing gas supply unit. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a halogen-containing gas processing apparatus, and more particularly, to a processing apparatus for fluorocarbons such as carbon tetrafluoride gas contained in exhaust gas of a semiconductor process or the like.

Microfabrication technology is indispensable for manufacturing processes of semiconductor devices, liquid crystal devices, and the like, and processing using gas plasma is becoming mainstream as a means of microfabrication technology. In this gas plasma processing, in addition to fluorocarbons such as carbon tetrafluoride gas (CF ₄ ), various halogen-based gases are introduced into a vacuum apparatus to be converted into plasma and reacted with the workpiece, and the reaction product is converted into a reaction product. This is a technique for discharging a gas and forming a desired pattern on a workpiece.

The gas discharged after reacting with the workpiece contains not only a causative substance that destroys the ozone layer, such as CF ₄ , but also a halogen-based gas that causes global warming. . For this reason, research on removing halogen-based gas contained in exhaust gas is underway.

  For example, in Patent Document 1, an exhausted halogen-based gas is mixed with hydrogen gas or a gas other than a halide containing a hydrogen atom, and the mixed gas is allowed to pass through a discharge portion to decompose the halogen-based gas and simultaneously with halogen. Methods and apparatus for producing hydrogen halide and collecting the hydrogen halide are described.

Japanese Patent Laid-Open No. 11-156156 (pages 5 to 6, FIG. 1)

  However, the method and apparatus using the discharge described in the above publication realizes a device structure that meets the user's needs such as efficient operation and running cost, and downsizing of the device by operating the discharge part stably and with high efficiency. There were many issues to do.

  In view of the above situation, the present invention provides a halogen-containing gas processing apparatus that enables high-efficiency processing and an apparatus structure that meets user needs in a halogen-containing gas processing apparatus. .

  The halogen-containing gas processing apparatus according to the present invention decomposes a halogen-containing gas sequentially connected in series to a gas flow supplied from a halogen-containing gas supply means for supplying a halogen-containing gas containing a halogen-based gas. Cleaning means for removing by-products generated at the time, gas other than the halogen-based gas from the halogen-containing gas, gas separation equipment for concentrating the halogen-based gas, and the halogen-based gas A gas decomposer that decomposes the concentrated gas, and an exhaust gas circulation means that returns the processed gas that has been processed and exhausted by the gas decomposer to the cleaning means.

  According to the halogen-containing gas processing apparatus of the present invention, the halogen-containing gas sequentially connected in series to the gas flow supplied from the halogen-containing gas supply means for supplying the halogen-containing gas containing the halogen-based gas. Cleaning means for removing by-products generated when the gas is decomposed, gas separation equipment for separating a gas other than the halogen-based gas from the halogen-containing gas, and concentrating the halogen-based gas, the halogen-based gas Since there is provided a gas decomposing unit for decomposing a gas enriched with gas, and an exhaust gas circulating unit for returning the processing gas that has been processed and discharged by the gas decomposing unit to the cleaning unit, there is no acid exhaust facility. An apparatus for treating a halogen-containing gas that can be used at a place can be provided.

It is a block diagram which shows Embodiment 1 which concerns on this invention. FIG. 3 is a cross-sectional view showing a discharge part in the first embodiment. It is a figure which shows the relationship between the purge gas flow volume in Embodiment 1, and a detoxification rate. It is a figure which shows the relationship between the discharge space | gap length of a discharge part, and a detoxification rate. It is a figure which shows the relationship between the discharge gap length of a discharge part, and average gas temperature. It is a block diagram which shows Embodiment 2 which concerns on this invention. It is a block diagram which shows Embodiment 5 which concerns on this invention. It is a block diagram which shows an example of Embodiment 6 which concerns on this invention. It is a block diagram which shows the other example of Embodiment 6 which concerns on this invention. It is sectional drawing which shows Embodiment 12 which concerns on this invention. It is sectional drawing which shows Embodiment 13 which concerns on this invention. It is a block diagram which shows Embodiment 15 which concerns on this invention. It is a block diagram which shows Embodiment 16 which concerns on this invention. It is a block diagram which shows Embodiment 17 which concerns on this invention. It is a block diagram which shows Embodiment 18 which concerns on this invention. It is sectional drawing which shows Embodiment 20 which concerns on this invention. It is sectional drawing which shows Embodiment 21 which concerns on this invention. It is a block diagram which shows Embodiment 23 which concerns on this invention.

Hereinafter, an embodiment of a halogen-containing gas processing apparatus according to the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing the first embodiment, and shows a configuration in a semiconductor process (etching step). In the figure, reference numeral 1 denotes a semiconductor process apparatus which is a halogen-containing gas discharge source, 2 denotes a halogen-containing gas supply means (system pump), and the system pump 2 includes a turbo molecular pump 21 and a dry pump 22. 5 is a purge gas supply means (purge gas supply equipment), 3 is a halogen-containing gas processing device, 31 is a cleaning means (wet scrubber), 32 is a gas concentrating means (gas concentrator), and the gas concentrator 32 is a gas separation membrane 321. , A deoxidizer 324 and a dehumidifier 325 are provided. 322 is a concentrated halogen component rich gas enriched with a halogen component, and 323 is a non-halogen component rich gas rich in a purge gas component. Reference numeral 33 denotes a discharge unit, 34 denotes a high-frequency power source for applying a high voltage to the discharge unit 33, 35 denotes an additional gas supply means (addition gas supply device), and 4 denotes an acid exhaust facility. In the figure, the solid line indicates the gas flow, and the two-dot chain line indicates the high-pressure line.

  As can be understood from FIG. 1, the present invention is different from a halogen-containing gas processing apparatus using a normal low-pressure plasma in that it can be processed out, that is, the processing can be performed at the subsequent stage of the existing system pump 2 in the semiconductor processing apparatus 1. It is a big feature.

  A gas (halogen-containing gas) containing PFC (Perfluorocarbon) gas discharged from the semiconductor process apparatus 1 is supplied from the purge gas supply facility 5 and diluted with a purge gas (generally nitrogen gas) introduced into the system pump 2. The dilution gas has a PFC concentration of about 0.1%. Since this dilution gas contains a large amount of solid matter and acid components generated by the semiconductor process, the wet gas scrubber 31 is cleaned so that impurities are not mixed into the discharge part 33.

  In the present embodiment, the wet scrubber 31 is used to obtain a sufficient impurity removal rate, but it is generally said that the scrubber has a low dust removal efficiency, and the types of impurities discharged by the manufacturing process are also different. Preferably, a dry scrubber and a wet scrubber are used in combination.

  After removing solids and the like with the wet scrubber 31, a halogen-containing gas containing PFC is introduced into the discharge unit 33, and treatment / detoxification is performed by plasma. The halogen-containing gas containing PFC is discharged into the discharge unit 33. Before introducing into the discharge section 33, the concentration of the PFC gas is concentrated to at least 1% or more, preferably 10% or more in the gas concentrator 32, and the concentrated halogen component rich gas 322 is introduced into the discharge section 33, thereby further efficient processing. Can do.

  In the present embodiment, the gas separation membrane 321 is used for the gas concentrator 32. However, the same effect can be obtained by using an adsorbent and a cold trap. As the gas separation membrane 321, a carbon membrane, a polyimide membrane, or the like can be used, and a halogen gas component and a non-halogen component gas (purge gas component) can be easily separated by generating a pressure difference between the inside and outside of the membrane. . Therefore, a compressor is provided before the separation membrane 321, or a vacuum pump is provided after the separation membrane 321.

  Since the gas introduced into the gas separation membrane 321 passes through the wet scrubber 31, it is highly likely that the moisture in the gas is completely saturated. In the gas separation membrane 321, if a large amount of the water is present in the gas, the separation efficiency of the halogen component and the non-halogen component is lowered. Therefore, the gas dew point should be kept at + 10 ° C. or lower using a dryer. Leads to a better separation effect.

  In addition to the method using the gas separation membrane 321, there is a method of separating by selectively adsorbing a necessary or unnecessary gas component using an adsorbent, and activated carbon, zeolite, or the like can be used as the adsorbent. . A cold trap can also be used. In the cold trap, the PFC component is liquefied and recovered with liquid nitrogen and then vaporized.

  The concentrated halogen component rich gas 322 separated and generated by the gas concentrator 32 is introduced into the discharge unit 33, and the non-halogen component rich gas 323 is circulated to the system pump 2 via the deoxidation unit 324 and the dehumidification unit 325, as a purge gas Can be reused.

  The non-halogen component rich gas 323 separated by the gas separation membrane 321 may contain acid components and solid components such as hydrogen fluoride gas that could not be completely removed by the wet scrubber 31, so these hydrogen fluorides are mixed. It is necessary to remove acid components such as gas and solid components before circulating them to the system pump 2 using a deoxidation unit 324 configured by a wet scrubber, a dry scrubber, a filter, an electrostatic chuck using Coulomb force, or the like. is there.

  Further, when the wet deoxidation unit 324 is used, the gas dew point of the non-halogen component rich gas 323 is high. Therefore, the dehumidification unit 325 including a dehumidifier, a dryer, a cold trap, and the like is provided in the front stage of the system pump 2. It is preferable to provide a gas dew point of at least −20 ° C. or lower.

  Thus, by separating and reusing the non-halogen component rich gas 323 using the gas concentrator 32, the amount of purge gas newly supplied from the purge gas supply facility 5 can be greatly reduced.

  FIG. 2 is a cross-sectional view showing the structure of the discharge unit 33, which is a case where one processing unit having a pair of electrodes is provided, and only one of the electrodes (installation side electrode 331) is cooled by a cooling water circulator or the like. An example of cooling by means is shown. In FIG. 2, reference numeral 331 denotes a ground-side electrode made of a conductor, and 332 denotes a high-voltage side electrode, which is formed by forming a conductive layer such as a metal film on the dielectric 332A. 333 is a discharge space, 334 is a spacer provided via a dielectric 332A, 335 is a cooling water flow path of water supplied from cooling means such as a cooling water circulator, 336 is a gas inlet, 337 is a gas outlet, 338 Indicates a discharge part case, 339 indicates a high-voltage terminal, and an arrow in the figure indicates a gas flow direction.

  The discharge part 33 is a parallel plate type plasma generation part, and is generated by silent discharge plasma generated through a dielectric 332A provided on the surface of the ground side electrode 331 and the ground side electrode 331 of the high voltage side electrode 332 facing each other. The halogen-containing gas is treated under atmospheric pressure or a pressure in the vicinity thereof. The gap length d of the discharge space 333 can be determined by the thickness of the spacer 334. The dielectric 332A may be provided on the opposing surface of the ground-side electrode 331, or may be provided on both opposing surfaces of the ground-side electrode 331 and the high-voltage side electrode 332.

For example, CF ₄ gas, which is known to be hardly decomposable, collides with electrons and dissociates as shown in the following formula (1) by the plasma generated in the discharge unit 33.
CF ₄ + e → C + 4F + e ----- (1)
In the above formula (1), e represents an electron.

The inventors can generate a very stable high-energy plasma at or near atmospheric pressure using the discharge part 33 having a discharge gap length of 1.0 mm and 0.5 mm, and are inexpensive and difficult to decompose. It has been found that sufficient energy can be supplied to directly dissociate the bonds of halogen-based gas molecules contained in a halogen-containing gas. For example, it can be decomposed almost 100% 99.9999% of the CF ₄ gas 100SCCM in power application of about 300 W.

FIG. 3 is a diagram showing the detoxification rate of CF ₄ when a mixed gas obtained by diluting 99.9999% CF ₄ gas with a purge gas is processed by applying 1 kW of power (4 to 5 kW in a conventional catalytic type). . In the figure, the vertical axis represents the CF ₄ gas abatement rate (%), the horizontal axis represents the purge gas flow rate (SLM), and shows the case where the purge gas is nitrogen gas (N ₂ ) and argon gas (Ar). Yes. Note that the flow rate of CF ₄ gas is constant. As shown in FIG. 3, with the increase of the flow rate of nitrogen gas (with decreasing CF ₄ concentration) abatement rate of CF ₄ is rapidly decreased. However, when argon gas is used, there is almost no change in the detoxification rate of CF ₄ gas with an increase in the flow rate. This result is thought to be due to the large ineffective consumption of energy resulting from vibration excitation of nitrogen gas.

In the present embodiment, by using the gas concentrator 32, the CF ₄ gas can be concentrated even if the CF ₄ gas is diluted with the purge gas and has a low concentration, for example, 0.1 vol% CF _4. 3 is concentrated to 1 vol%, the operating point of the discharge part 33 can be moved from the point A to the point B shown in FIG. 3, so that efficient processing is always possible even when nitrogen gas is used as the purge gas. Become. In addition, it can be seen from the figure that a detoxification rate of 90% or more can be guaranteed even in a nitrogen gas purge by operating at a point concentrated to 1 vol% or more. When the CF ₄ gas concentration is concentrated to 10 vol%, the treatment efficiency is further improved, and a detoxification rate close to 100% can be achieved.

  In addition, even in the case of processing a low concentration process target gas of about 0.1 vol%, it can be concentrated 10 times or more by the gas concentrator 32, so that it is processed with high efficiency plasma without supplying excessive energy. It becomes possible to do.

  As described above, according to the present embodiment, a high field discharge is performed at atmospheric pressure by the discharge unit 33 by using the discharge unit 33 to convert a hardly decomposable gas such as PFC or chlorofluorocarbon, which is normally difficult to decompose efficiently with plasma. Can generate high-energy electrons, decompose with low power consumption (low cost) of about 1 kW, and maintain a high detoxification rate with the gas concentrator 32 for any low-concentration halogen-containing gas it can.

Figure 4 shows the change in the abatement rate of CF ₄ gas by discharge gap length d. In FIG. 4, the CF ₄ gas flow rate and the purge gas flow rate are constant (CF ₄ gas concentration is constant). As shown in this result, the smaller the discharge gap length d, the higher the detoxification rate of CF ₄ gas at the same input power. In particular, when the discharge gap length d is 1.0 mm or less, the discharge gap length The difference in the removal rate of CF ₄ gas due to d is small, the removal rate exceeds 80% for the first time when d is 1.0 mm, and by further reducing d, a removal rate of 90% or more can be obtained. it can. On the other hand, when d exceeds 1.0 mm, the reduction of the detoxification rate due to d is extremely large, and it becomes difficult to achieve even the detoxification rate of 70%. Therefore, as described above, if the discharge gap length d is 1.0 mm or less, it is possible to effectively input energy sufficient to directly dissociate the molecular bond of the halogen-containing gas.

  As shown in FIG. 2, the halogen-containing gas to be processed is introduced from the entire periphery of the flat discharge space 333 toward the central portion, and is processed by silent discharge plasma, and is installed in the central portion. 337. Thus, by providing a treated gas discharge port in the center of the electrode 331 and supplying a halogen-containing gas to be treated from the periphery of the electrode 331, a uniform gas flow path can be formed in the discharge space 333, And the compact discharge part 33 can be implement | achieved easily. Furthermore, in order to form a plurality of discharge spaces, it is only necessary to stack electrodes, and a compact device can be formed even if the capacity is increased.

In this embodiment, a stainless steel to the ground electrode 331, and coating the discharge space side of the stainless steel in Al ₂ O _3. Further, an Al ₂ O ₃ plate having a conductive layer is used for the high voltage side electrode 332.

  The spacer 334 is made of stainless steel and is formed in a plate shape with a predetermined thickness. The spacer 334 is installed so as not to disturb the gas flow, and the discharge gap length is kept constant. The discharge space 333 is cooled by cooling means using low-temperature cooling water circulated through the cooling water flow path 335 in the ground side electrode 331.

Further, both the ground side electrode 331 and the high voltage side electrode 332 are made of metal, each discharge space side surface is coated with Al ₂ O ₃ , and cooling water is allowed to flow inside the electrodes 331 and 332. It is effective. By flowing cooling water through both electrodes 331 and 332, the cooling efficiency of the discharge space 333 is improved by a factor of four or more compared to when cooling water is flowed through only one of the electrodes. It can be made more compact. However, in this case, it is necessary to use ion exchange water or pure water as cooling water.

  Since the silent discharge plasma in the present invention has a relatively low temperature, an acid-resistant and inexpensive resin pipe such as PVC can be used for the exhaust pipe after the discharge section 33.

  FIG. 5 is a diagram showing the relationship between the discharge gap length and the average gas temperature in the discharge space. According to the figure, as described above, when the discharge gap length is 1.0 mm or less, the average gas temperature in the discharge space 333 is about 100 to 200 ° C. The halogen-containing gas plasma-treated at an average gas temperature of about 100 to 200 ° C. is naturally cooled to 50 ° C. or lower when discharged from the halogen-containing gas processing apparatus 3 and can be used with piping such as PVC. Is. If the temperature exceeds 200 ° C., the thermal load on the pipe becomes a problem, and it is necessary to use stainless steel instead of PVC.

In addition, the Al ₂ O ₃ plate is brittle, and may be damaged when a high voltage is applied (a temperature rise of several hundred degrees Celsius) while a slight mechanical stress is applied. By setting the length to 1.0 mm or less, the average gas temperature becomes 200 ° C. or less, which is effective for preventing damage to the Al ₂ O ₃ plate. Furthermore, considering the improvement of the detoxification rate of the halogen-containing gas, the discharge field is preferably formed with a discharge gap length of 0.5 mm or less.

  As described above, by setting the discharge gap length to 1.0 mm or less, preferably 0.5 mm or less, the input energy for dissociating the bonds of the halogen-containing gas molecules can be lowered, and a higher electric field discharge field can be formed. Thermally, the treatment can be performed at a low temperature.

  In the description of the present embodiment, the case where the ground side electrode 331 is cooled is shown. However, when all of the ground side electrode 331 and the high voltage side electrode 332 of the discharge unit 33 are cooled, as described above, the discharge space Since the cooling effect of 333 can be improved four times, by setting the discharge gap length to 4.0 mm or less, preferably 2.0 mm or less, sufficient energy to directly dissociate the molecular bond of the halogen-containing gas is obtained. It can be input effectively.

  In addition, when the halogen-containing gas is treated with plasma, an additional gas is added from the additional gas supply means (additional gas supply device) 35 shown in FIG. Can be regenerated into molecules that are easy to process. When molecular bonds are broken by plasma in the main halogen gas, carbon atoms and fluorine atoms are liberated. To regenerate as a gas that can be released into the atmosphere with these atoms or that is extremely easy to process, water (water vapor) is added to the halogen-containing gas, and plasma treatment is performed in the presence of water, so that carbon dioxide, hydrogen fluoride, etc. To gas molecules.

  The amount of water added can be uniquely determined by the halogen-based gas concentration in the halogen-containing gas. When the halogen-based gas concentration is Cp and the concentration of added water (water vapor) is Ch, Ch / Cp = 0.5 to 3, preferably Ch / Cp = 1-2.

  In addition, since the regenerated carbon dioxide is a gas that has an extremely small effect on global warming compared to a halogen-containing gas, the effect on the global warming is very small compared to PFC gas and the like even if released to the atmosphere.

  In addition, since the regenerated hydrogen fluoride can be exhausted to the acid exhaust equipment 4 generally held in the semiconductor manufacturing equipment and processed, it can be easily rendered harmless without providing an acid exhaust equipment. Large capital investment is not required.

  As described above, in the present embodiment, the discharge gap length is set to 1.0 mm or less, preferably 0.5 mm or less (4.0 mm or less, preferably 2.0 mm or less if all electrodes are cooled). As a result, the halogen gas-containing gas can be efficiently processed by plasma at a low cost at the process-out installation location.

  Even when the halogen-containing gas concentration of the halogen-containing gas discharged from the semiconductor process apparatus 1 is low, a high detoxification rate can be maintained by using the gas concentrator 32.

  Further, by separating and reusing the non-halogen component rich gas 323 using the gas concentrator 32, the new purge gas supplied to the system pump 2 can be greatly reduced, and energy can be saved.

Embodiment 2. FIG.
Examples of the halogen-containing gas used in the semiconductor / liquid crystal manufacturing process include CF ₄ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , CHF ₃ , NF ₃ , and SF ₆ as fluorine compound gases. Hereinafter, these are collectively referred to as PFC gas.

  In addition, halogen-containing gases recovered from home appliances include CFC (Chlorofluorocarbon) gas, HCFC (Hydrofluorocarbon) gas, and HFC (Hydrofluorocarbon) gas.

  The PFC gas, CFC gas, HCFC gas, and HFC gas cannot be released into the atmosphere, and are particularly stable and difficult to decompose.

  The halogen-containing gas treatment apparatus described in Embodiment 1 can easily treat the CFC gas, HCFC gas, and HFC gas.

  FIG. 6 is a block diagram showing the second embodiment, and is a diagram for explaining a method for treating CFC gas, HCFC gas, and HFC gas-containing gas. FIG. 6B shows a process for treating CFC gas and HFC gas-containing gas in the storage container 1A for home appliances, and FIG. 6A shows a process for treating PFC gas discharged from the semiconductor process. It is shown in contrast with. In the figure, the pretreatment indicates a cleaning process using a scrubber 31 or the like.

  When recovering CFC gas, HCFC gas, and HFC gas-containing gas from the home appliance storage container 1A, etc., when the recovery location does not have the acid exhaust facility 4 shown in FIG. There are many. Therefore, as shown in FIG. 6B, after the gas to be processed is drawn into the discharge processing unit 33 by the pump 20 and subjected to the plasma processing, it can be sprayed in the post-processing equipment 4A such as wet processing using an alkaline solution or the like. Necessary, for example, neutralizing with a calcium hydroxide solution, detoxifying calcium fluoride and calcium chloride, and adding a step of recovery. In this case, pretreatment such as washing is generally unnecessary, but it is preferable to carry out the pretreatment.

Embodiment 3 FIG.
In FIG. 1, the gas added to the discharge part 33 from the additional gas supplier 35 together with the PFC-containing gas is hydrogen, oxygen, ozone, methane, ethane, propane, ammonia, or a mixture thereof in addition to water vapor.

  These gases may be introduced into the discharge unit 33 by controlling the flow rate with a mass flow controller or a flow meter. Further, a PFC-containing gas is introduced into a solution tank containing a solution in which the additive gas is dissolved in water, for example, hydrogen water, ozone water, or a solution in which an organic solvent such as ethanol or methanol is dissolved. Even if it is made to coexist with the PFC-containing gas by bubbling or the like, the same effect as when water (water vapor) or the like is added to the discharge part can be obtained.

  By adding the above gas species or solution from the additional gas supply device 35, the gas molecules to be treated decomposed by the plasma can be easily treated with existing facilities in the factory, or the gas has less influence on global warming. Can be converted to a molecule.

Embodiment 4 FIG.
In the semiconductor / liquid crystal process, since the purge gas of the system pump 2 shown in FIG. 1 is often nitrogen gas, the PFC gas to be processed in the apparatus of the present invention is preferably diluted with nitrogen. However, even if diluted with air or oxygen in addition to nitrogen, the purge gas can be treated directly.

  Further, as shown in FIG. 1, when the gas concentrator 32 is used, the non-halogen component rich gas 323 can be separated and reused in the system pump 2, so that helium and argon which are more expensive than nitrogen, air and oxygen are used. Even if diluted with neon or xenon, there is no problem in running cost. In addition, since the halogen-based gas in the gas to be processed can be concentrated with high efficiency, it is possible to always perform high-efficiency processing regardless of the halogen-based gas concentration of the gas to be processed.

  In particular, helium, argon, neon, and xenon consume very little energy in the discharge field, so that more efficient processing can be performed even in plasma processing.

Embodiment 5 FIG.
FIG. 7 is a block diagram showing the fifth embodiment, and shows a purge gas supply system in which the non-halogen component rich gas 323 is reused as a purge gas for the system pump 2. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. 326 is a flow meter such as a mass flow meter, 327 is a moisture drain, 36 is an arithmetic unit, 37 is a flow rate adjusting means such as a mass flow controller, the solid line is a gas flow, the one-dot chain line is a signal line, and the two-dot chain line is a high-pressure line. Show.

  When the gas concentrator 32 is used, the concentrated halogen component rich gas 322 is introduced into the discharge unit 33, but the non-halogen component rich gas 323 in the PFC-containing gas introduced into the gas concentrator 32 is supplied from another port. Discharged.

  After the non-halogen component rich gas 323 from the gas concentrator 32 is deoxidized and dehumidified, the flow rate 326 is detected by the flow meter 326. The flow rate signal is converted into a detection signal such as a current or voltage signal and introduced into the arithmetic unit 36 in which the purge gas flow rate Q0 required for the system pump 2 is stored. The arithmetic unit 36 may be a commercially available instrumentation arithmetic converter or linearizer. Therefore, the newly introduced purge gas flow rate Q2 is calculated by (Q0-Q1), and the signal is transmitted to the flow rate adjusting means 37 to automatically supply the insufficient flow rate.

  With this purge gas supply system, a constant flow rate of purge gas can always be supplied to the system pump 2 even if the concentration efficiency of the gas concentrator 32 varies, and the semiconductor process and the interlock operation of the system pump 2 are not affected.

Embodiment 6 FIG.
FIG. 8 is a block diagram showing the sixth embodiment, in which the same reference numerals as those in FIG. 1 denote the same or corresponding parts. This embodiment is a purge gas supply system that reuses the non-halogen component rich gas 323 as the purge gas of the system pump 2 and the purge gas of the exhaust gas generated by the discharge unit 33.

  By concentrating the PFC component with the gas concentrator 32, the gas after being processed in the discharge part 33 contains a very high concentration of hydrogen fluoride gas. Although depending on the equipment of the semiconductor factory, the pipe from the discharge part 33 to the acid exhaust equipment 4 may not be able to withstand the high concentration hydrogen fluoride gas, but a part of the non-halogen component rich gas 323 is used as the system pump 2. At the same time as being reused as a purge gas, the feed part 33 is also fed to the subsequent stage of the discharge part 33 to dilute the discharge generated gas, thereby suppressing damage caused by the high concentration hydrogen fluoride gas to the pipe from the discharge part 33 to the acid exhaust system 4 be able to.

  In FIG. 8, 328 is a purge component of the system pump 2, and 329 is an exhaust gas purge component. The separated non-halogen component rich gas 323 is branched into two directions, one of which is used as a purge gas for the system pump 2 and the other is used as a dilution of a discharge product gas. Preferably, the pump purge component 328 uses a dehumidifying part 325 such as a cold trap or a dryer to set the gas dew point to −20 ° C. or lower in order to prevent moisture condensation in the pump. Further, it is preferable to remove impurities such as hydrogen fluoride in the non-halogen component rich gas 323 by the deoxidizer 324 before the dehumidification. As for the purge component 329 of the exhaust gas, means such as deoxidation and dehumidification are unnecessary and can be used as they are.

  FIG. 9 shows a gas concentrator 32 in which a gas separation membrane 321 and a water concentration unit 320 using a polymer hollow fiber separation membrane are installed.

  In FIG. 8, when the purge gas component is reused for the system pump 2, it is necessary to remove the almost saturated water amount from the purge gas rich component 323 by the deoxidizer 324, so that a dryer, a cold trap, etc. It was necessary to install several types of equipment such as a dehumidifying unit 325 and a moisture drain 327 (the pH of this moisture may be low, so care should be taken in handling and disposal).

On the other hand, in FIG. 9, the installation of only the gas concentrator 32, the deoxidizer 324, and the moisture concentrator 320 eliminates the need for a device that consumes power, such as a dryer, and is advantageous in terms of cost and footprint. Become. Both the gas separation membrane 321 and the water concentrating unit 320 are constituted by hollow fiber separation membranes, but the gas concentrator 32 can perform the separation of the halogen component and the non-halogen component as described above. The moisture concentrating unit 320 is used for separation of moisture in the non-halogen component and other components. Moisture has a very high permeation rate compared to the permeation rate of other components through the hollow fiber membrane, so that both can be easily separated.
Since the amount of moisture to the exhaust gas purge component 329 is not limited, all the moisture to be discharged from the water drain can be discharged together with the exhaust gas purge component 329 in FIG.

  The water concentration unit 320 can be easily realized simply by using a commercially available hollow fiber membrane made of polyimide resin or the like. The water concentration unit 320 automatically causes the purge component 328 of the system pump 2 to at least have a gas dew point of −20 ° C. or less. Therefore, facilities such as a cold trap and a dryer and a drain for draining water are not required, and the cost can be reduced sufficiently.

  With the configuration as described above, by using the gas concentrator 32, it is possible to reduce the amount of new purge gas introduced from the purge gas supply facility 5 of the system pump 2 and avoid the danger due to the high concentration of the discharge generated gas. .

Embodiment 7 FIG.
In FIG. 2, as the material for the ground side electrode 331 or the high voltage side electrode 332 and both the ground side electrode 331 and the high voltage side electrode 332, aluminum alloy, titanium alloy, Inconel, or Hastelloy may be used in addition to stainless steel.

  In the present invention, when hydrogen fluoride is generated in the discharge part 33 and water (water vapor) is allowed to coexist as an additional gas, it is placed in an extremely severe corrosive environment. Therefore, Inconel and Hastelloy are materials having excellent corrosion resistance and can be used as they are. However, when an aluminum alloy and a titanium alloy are used, a surface treatment is required to improve the corrosion resistance.

  When using aluminum alloy and titanium alloy, corrosion resistance is improved by forming an oxide film on the surface by anodic oxidation, etc., forming a corrosion-resistant oxide film by spraying, etc., or coating with fluorine resin. Can be improved.

  In the case of using an aluminum alloy, it is better to perform the same treatment on the cooling water contact portion on the inner surface of the electrode so that the cooling water system in the semiconductor factory is not contaminated with aluminum.

Embodiment 8 FIG.
In FIG. 2, the dielectric 332A installed in the discharge part 33 contains Al ₂ O ₃ , TiO ₂ , ZrO ₂ , MgO, La ₂ O ₃ , CaO, SiO ₂ , fluorine-based resin, and acrylic resin. Can be used. It is preferable to select a material that is excellent in electrical insulation and corrosion resistance, has a small tan δ and generates little heat.

  By interposing the above dielectric having sufficient insulation, corrosion resistance and good secondary electron emission characteristics in the discharge part, it is possible to realize stability of the device, longer life, and high-efficiency energy input.

  In addition, the diameter of the dielectric 332A is larger than the diameters of the high-voltage side electrode 332 and the ground-side electrode 331 made of a conductive layer, and the diameter of the high-voltage side electrode 332 is preferably larger than the diameter of the ground-side electrode 331. . By having such a magnitude relationship between the diameter of the dielectric 332A and the diameters of the electrodes 331 and 332, creeping discharge and abnormal discharge can be avoided, ideal energy input can be performed, and the stability and long life of the apparatus can be achieved. Can be realized.

Embodiment 9 FIG.
In FIG. 2, a material formed from stainless steel, aluminum alloy, titanium alloy, Inconel, Hastelloy, ceramics, fluorine-based resin, and heat-resistant plastic is used for the spacer 334 installed in the discharge portion 33.

  Since the corrosive fluid is generated by the plasma treatment in the discharge portion 33, the corrosion resistance of the apparatus can be improved by using the material as it is or after the surface treatment, and the maintenance period can be sufficiently long.

  When aluminum alloy and titanium alloy are used, corrosive fluid is generated by plasma treatment in the discharge part, so that the corrosion resistance of the device is further improved by applying a fluorination treatment or forming an oxide film on the surface, The maintenance period can be made sufficiently long.

  Further, when the discharge gap length is increased, the cooling effect of the discharge space 333 is reduced. Therefore, when using a resin / plastic, it is necessary to consider its heat resistance.

  Further, a spacer portion is formed on the electrode surface by cutting or the like when the electrode is manufactured, or the spacer 334 made of the above material is fixed to the electrode surface by adhesion or the like, and the electrode surface together with the spacer 334 is coated as shown in Embodiment 10 below. It is better to coat with material.

Embodiment 10 FIG.
In FIG. 2, the gas contact part where the electrode in the discharge part 33 is in contact with the plasma-treated gas is Al ₂ O ₃ , TiO ₂ , ZrO ₂ , MgO, La ₂ O ₃ , CaO, fluorine-based resin, heat-resistant plastic. It coat | covers with either coating material of these.

  Since the corrosive fluid is generated by the plasma treatment in the discharge part, the corrosion resistance of the apparatus is improved by covering the member in contact with the corrosive fluid, and the maintenance period can be sufficiently long.

Embodiment 11 FIG.
In FIG. 2, when the electrodes 331 and 332 and the spacer 334 are formed of an aluminum alloy or a titanium alloy, the surface layer is subjected to a fluorination treatment. By the fluoride treatment, the dense fluoride layer having a film thickness of about several tens of μm formed on the surface layer has corrosion resistance in a corrosive environment. Furthermore, after the fluorination treatment, by coating with the coating material shown in the embodiment 10 from above, even better corrosion resistance can be obtained.

Embodiment 12 FIG.
FIG. 10 is a cross-sectional view showing the twelfth embodiment, and the same reference numerals as those in FIG. 2 denote the same or corresponding parts. This embodiment shows a case where the number of discharge spaces 333 is two. When the number of discharge spaces 333 is two (only the ground-side electrode 331 is cooled), the number of ground-side electrodes 331 is two. By making the ground side electrode 331 also serve as a part of the case 338 of the discharge part 33, the structure of the discharge part 33 becomes simple and the number of constituent members can be reduced, so that a compact processing apparatus can be formed, Easy maintenance and a reduction in initial cost can be realized.

  Reference numeral 330 denotes a power supply member, which simultaneously applies a high voltage to the two high voltage side electrodes 332. The arrows in the figure indicate the gas flow.

  The number of discharge spaces 333 is not limited to two and can be three or more. When the number of discharge spaces 333 is N (N is an even number equal to or greater than 2), the first and (N / 2) + 1th ground-side electrodes 331 can also serve as part of the case 338, and the discharge space As the number of 333 increases, the cost can be sufficiently reduced even when the number of processing units is increased and the processing capacity is increased. Similarly, when all the electrodes are cooled, when the number of discharge spaces is N, the first and (N / 2) + 1th ground side electrodes also serve as a part of the case 338.

Embodiment 13 FIG.
In the discharge part 33 shown in FIG. 2 and FIG. 10, there is a case where a member such as ceramics such as Al ₂ O ₃ that may break may be used. Ceramics break when subjected to sudden temperature rise, fall, thermal stress, or mechanical stress. Therefore, a member that functions to absorb a rise in temperature or an external impact in the discharge space is required.

  FIG. 11 is a cross-sectional view showing the thirteenth embodiment, and the same reference numerals as those in FIG. 2 denote the same or corresponding parts. This embodiment shows a case where an elastic body is included when there are two discharge spaces, that is, two discharge portions. In the figure, 6 is a power feeding body, 7 is an elastic body, and 8 is a power feeding plate. The power feeding body 6, the elastic body 7, and the power feeding plate 8 are each made of metal so as to maintain the same potential, and the power feeding body 6 and the high voltage side electrode 332 of the discharge portion are in close contact with each other. Therefore, the high voltage side electrode contact portion of the power supply body 6 has a highly accurate finishing process.

  The elastic body 7 supports the high voltage side electrode 332 of the discharge part via the power supply body 6 and the power supply plate 8, absorbs thermal and mechanical stress of the discharge part, and protects a member that may be damaged. To do. By absorbing thermal and mechanical stresses by the elastic body 7, a stable discharge state can always be obtained, and damage to the discharge space 333 due to temperature rise can be suppressed.

  Further, in the present embodiment, the elastic body 7 serves as both a function as a power supply member and a protection function of the electrode member of the discharge part due to elasticity, so that an increase in the device volume can be avoided.

Embodiment 14 FIG.
In order to suppress the rise in the temperature of the discharge space 333 and the increase in the dew point of the halogen-containing gas as shown in FIGS. 2 and 10, the discharge gap length is increased by providing a structure that can cool the case 338 of the discharge portion 33. Even when the temperature of the discharge space rises, stable operation can be realized.

  Cooling water may be circulated as necessary by wrapping the cooling water piping around the case 338 or casting the cooling water piping in the wall of the case 338. If the cooling water used here is branched from the cooling water system of the electrode and connected, it is not necessary to provide a new cooling water system.

Embodiment 15 FIG.
FIG. 12 is a block diagram showing the fifteenth embodiment, and the same reference numerals as those in FIG. 1 denote the same or corresponding parts. This embodiment shows a case where a plurality of discharge portions are provided. FIG. 12A shows a case where a plurality of discharge parts 33A, 33B,... 33N are installed and connected in series with respect to the flow of the processing gas, and when processing a higher concentration and hardly decomposable gas. effective. In particular, when the discharge parts are connected in series in this way, the gas that could not be processed by the first-stage discharge part 33A and the gaseous discharge products newly generated by the first-stage discharge are classified into N stages (N = 2, 3,...

  In addition, it is possible to perform high-efficiency processing by driving a required number of discharge units among a plurality of discharge units in accordance with the flow rate or concentration of the halogen-containing gas to be processed.

  Further, when a disturbing gas that disturbs discharge, such as hydrogen fluoride, is generated in the middle Nth stage discharge section, the disturbing substance remover 32A shown in the figure is connected to each discharge section other than the last stage. By providing it in the subsequent stage, it is possible to prevent the interference gas from flowing into the discharge part of each stage, and the total processing efficiency is improved.

  The interfering substance removing device 32A can remove the interfering gas from the gas to be treated by employing, for example, a wet process using water or a chemical solution or a dry process using an adsorbent. In the wet processing method, the interfering gas is dissolved in water or a chemical solution and removed by wet scrubber or bubbling. In the method using the dry adsorption treatment, an adsorbent such as activated carbon, alumina, or zeolite is filled in a container or pipe, and the adsorbent is adsorbed to remove the interfering gas.

Further, fluorine storage alloys such as K ₃ NiF ₇ and solid alkali metals such as LiF, NaF, and KF can be reacted with the interfering fluorine component to be absorbed.

  In addition, an adsorbent or a fluorine storage alloy is installed in the discharge space of the discharge part, and a discharge is generated in the presence of the adsorbent or the fluorine storage alloy. Thus, the interfering gas can be removed to prevent the processing efficiency from being lowered. Furthermore, only hydrogen fluoride may be removed using a cold trap.

  Also, as shown in FIG. 12 (b), a discharge unit is installed and connected in parallel to the flow of the processing gas, and a required number of discharge units are operated in accordance with the processing flow rate or concentration to discharge the discharge. What is necessary is just to increase / decrease the area of space. Further, when the treatment flow rate or concentration increases, a method of increasing the electrode diameter may be used.

Embodiment 16 FIG.
FIG. 13 is a block diagram showing the sixteenth embodiment, and the same reference numerals as those in FIG. 1 denote the same or corresponding parts. As shown in the figure, a halogen gas type detection means 9 is provided in the front stage of the discharge section 33, the detection signal is converted into a current or voltage signal, and the current or voltage signal is converted into an electric valve 10 via an arithmetic unit 12. And transmitted to the high frequency power supply 34. The gas type to be processed is stored in advance in the arithmetic unit 12 so that electric power can be applied to the discharge unit 33 only when a gas containing the stored gas type passes. In the figure, a solid line indicates a gas flow, a dashed line indicates a signal line, and a two-dot chain line indicates a high voltage line.

  The gas type detection means (gas type detector) 9 may be the same as the gas alarm that issues an alarm when the stored gas type is detected. The halogen-containing gas processing apparatus of the present invention is normally operated continuously for 24 hours. However, regarding the driving of the discharge unit 33, the halogen-containing gas that needs to be processed only when the semiconductor process apparatus is actually performing the processing. In order to flow in, the discharge part 33 is driven only when the halogen-containing gas flows. When the process is not processing and only the purge gas flows, the electric valve 10 causes the gas to flow into the bypass pipe 11. The same applies to the case where a plurality of discharge units 33 are connected in series or in parallel.

  According to the present embodiment, the gas type detection means 9 is provided in the front stage of the discharge unit, the detected gas type detection signal is converted into a current or voltage signal, and the current or voltage signal sent via the arithmetic unit 12 is used. The high-frequency power source 34 drives the discharge unit 33 only when a gas that requires processing is introduced, so that the running cost can be significantly reduced.

Embodiment 17. FIG.
FIG. 14 is a block diagram showing the seventeenth embodiment, and the same reference numerals as those in FIG. 1 denote the same or corresponding parts. As shown in the figure, a gas flow rate detector 13 is provided in the front stage of the discharge unit 33, the detected signal is converted into a current or voltage signal, and the converted signal is sent to the high frequency power source 34 via the arithmetic unit 12. Send. In the figure, the solid line indicates the gas flow, the one-dot broken line indicates the signal line, and the two-dot broken line indicates the high-pressure line.

  The arithmetic unit 12 receives a correlation between the flow rate and the power in advance, and transmits a signal to the high-frequency power supply 34 to apply power corresponding to the transmitted current or voltage signal to the discharge unit 33. At the same time, the rated power of the discharge unit 33 is also input to the arithmetic unit 12, and when the rating of one discharge unit 33 is exceeded, a plurality of discharge units connected in parallel are driven.

  According to the present embodiment, the detected gas flow rate is converted into a current or voltage signal, and only the number of discharge parts required for the gas flow rate is determined by the current or voltage signal sent to the arithmetic unit 12. Since it is operated, it can be processed efficiently without wasting unnecessary energy.

Embodiment 18 FIG.
FIG. 15 is a block diagram showing the eighteenth embodiment, and the same reference numerals as those in FIG. 1 denote the same or corresponding parts. As shown in the figure, a gas concentration detector 14 is provided in the front stage of the discharge unit 33, the detected concentration signal is converted into a current or voltage, and the converted signal is added to the additional gas supplier via the arithmetic unit 12. 35. In the figure, a solid line indicates a gas flow, a one-dot chain line indicates a signal line, and a two-dot chain line indicates a high-pressure line.

  The arithmetic unit 12 receives a correlation between the halogen gas concentration and the required additional gas amount with respect to the concentration, and determines the required additional gas amount according to the halogen gas concentration. A signal transmitted from the arithmetic unit 12 is transmitted to a flow rate adjusting means such as an automatic adjustment valve, a proportional control valve or a mass flow controller in the additional gas supply device 35, and this flow rate adjustment means is appropriately driven.

  According to the present embodiment, the flow rate adjusting means of the additional gas supply device 35 can be operated by the current or voltage signal sent to the arithmetic unit 12 to supply the appropriate amount of additional gas required. Excessive additional gas is not introduced into the discharge part, and stable discharge can be maintained.

Embodiment 19. FIG.
When the halogen-containing gas is cleaned by the wet scrubber (water scrubber) 31 shown in FIG. 1, the amount of water contained in the cleaned gas is extremely large and may be completely saturated. If a halogen-containing gas is introduced into the discharge part while the water is saturated, a stable discharge state may not be obtained due to an excessive amount of water, and steady processing efficiency may not be maintained, and a failure of the discharge part may occur. However, by providing moisture removal means that properly removes moisture in the halogen-containing gas before flowing into the discharge part, a stable discharge state can be obtained and steady processing efficiency can be maintained. Become.

  In this embodiment, the dew point of the halogen-containing gas is lowered before the halogen-containing gas is introduced into the discharge part. For example, a gas cooler is inserted before or after the wet scrubber 31 so that the gas temperature of the halogen-containing gas is at least lower than the atmospheric temperature, and from the wet scrubber 31 to the discharge portion 33. The amount of moisture in the halogen-containing gas is reduced by maintaining the temperature of the constituent members, that is, the gas piping and the discharge electrodes 331 and 332, at 5 ° C. or lower than the temperature of the scrubber solution.

  As a gas cooling means in the gas cooler, a halogen-containing gas pipe is formed in a serpentine tube so as to have a large contact surface area, and immersed in a tank capable of storing and circulating cooling water, The simplest method is to flow a halogen-containing gas.

  A desired cooling effect can be obtained by changing the temperature of the cooling water and the contact surface area, and the dew point of the gas can be lowered to a desired value. The gas pipe is preferably a metal pipe having a small diameter and a small thickness.

  Further, even if a dehumidifying dryer, a moisture adsorbent and a polymer hollow fiber separation membrane are installed after the wet scrubber, the dew point of the halogen-containing gas can be similarly lowered. When using these dehumidifying dryers, moisture adsorbents, and polymer hollow fiber separation membranes, it is preferable to install a compressor in the front stage or a vacuum pump in the rear stage to create a pressure difference, which leads to effective water removal. .

  The dehumidifying dryer may be for producing dry air such as a dehumidifier or an air dryer which is generally on the market.

  As the adsorbent, zeolite, silica gel, activated alumina or the like may be used.

  The polymer hollow fiber separation membrane is most easily made of polyimide. The hollow fiber separation membrane can be separated by the difference in permeation speed of the substance to be introduced with respect to the membrane. In particular, since there is a large difference between the permeation rate of water and the permeation rate of the halogen-containing gas, both can be easily separated and removed.

  Further, when the wet scrubber 31 also serves as the additional gas (water) supply facility 35 and the halogen-containing gas has a high concentration, the amount of water supplied to the halogen-containing gas from the wet scrubber 31 alone is a hydrogen to the discharge part. When the supply amount of atoms and oxygen atoms is insufficient, conversely, the temperature of the scrubber solution is set at least higher than the temperature, and the constituent members from the wet scrubber 31 to the discharge part 33 are at least 5 ° C. or more than the scrubber solution. By keeping it high, the required additional gas can be supplied.

  As described above, moisture in the halogen-containing gas is removed using a dryer, a moisture adsorbent or a hollow fiber separation membrane having an appropriate processing capacity, or the halogen-containing gas is cooled directly or indirectly. As a result, excessive water is not introduced into the discharge part 33, and stable discharge can be maintained.

  Further, by keeping the scrubber solution temperature below the air temperature, and keeping the temperature of the gas contact part from the wet scrubber 31 to the discharge part 33 at least 5 ° C. lower than the scrubber solution temperature, the halogen-containing gas has more water content than necessary. Therefore, stable discharge can be maintained in the discharge part 33.

Embodiment 20. FIG.
As shown in the nineteenth embodiment, when the halogen-containing gas is washed with the wet scrubber 31 as a pretreatment for the plasma treatment, excessive moisture may be introduced into the discharge portion.

  FIG. 16 is a cross-sectional view showing the twentieth embodiment, in which the wet scrubber 31 serves as a gas cleaning means and an appropriate moisture supply means. When water (steam) is selected as an additional gas to the discharge unit, the use of this wet scrubber 31 eliminates the need for the additional gas supply device 35 installed in FIG. 1 and the like, and an economical system can be constructed. .

  In FIG. 16, 311 is a gas inlet, 312 is a scrubber tank, 313 is a scrubber tower, 314 is spray, 315 is a gas outlet, 316 is a water supply (or drainage) port, 317 is a drainage (or water supply) port, 318 is A throw-in cooler, 319 is a thermocouple, 310 is a circulation pump, a solid line arrow in the figure indicates the flow of the halogen-containing gas, and a broken line arrow indicates the direction in which the circulating water flows.

  The halogen-containing gas is introduced from the lower part of the scrubber tower 313, moves in the upper direction, is supplied to the upper part by the circulation pump 310 from the scrubber tank 312 and is washed by the scrubber water discharged from the spray 314, and water is added. Is called.

  Thereafter, the halogen-containing gas is discharged from the upper part of the scrubber tower 313 and introduced into the discharge part. In addition, a filler is installed in the scrubber tower 313 in order to improve the efficiency of gas-liquid contact.

  In order to prevent excessive moisture addition and dew condensation in the discharge part, and to compensate for stable operation in the discharge part, the temperature of water stored in the scrubber tank 312 (water to be brought into contact with the halogen-containing gas) is at least below atmospheric temperature. There is a need. Therefore, the water in the scrubber tank 312 is maintained at an appropriate low temperature by circulating water whose temperature is controlled by a cooler or the like through the water supply port 316 and the drainage port 317.

  In addition, the water in the scrubber tank 312 may be directly cooled using a throw-in cooler 318 and a thermocouple 319. Thus, by controlling the temperature of the scrubber water to at least the temperature or less, preferably 10 ° C. or less, the halogen-containing gas can be sufficiently washed and have an appropriate amount of added water for the discharge part.

  In addition, scrubber water is washed with a halogen-containing gas to lower its pH value and become acidic.

  When the halogen-containing gas to which the acidic scrubber water is added is introduced into the discharge portion, the constituent members of the discharge portion may cause corrosion or destruction.

  Therefore, preferably, the pH value of the scrubber water is set to an alkalinity of 8 or more, and when the pH value falls below a predetermined pH value (preferably pH 6), the pH value is increased by automatically performing water supply and drainage from each port. By preventing the acidic component from being introduced into the discharge part, corrosion and destruction of the discharge part can be prevented.

Embodiment 21. FIG.
FIG. 17 is a cross-sectional view showing the twenty-first embodiment. Like the twentieth embodiment, the wet scrubber 31 serves as a gas cleaning means and an appropriate moisture supply means. Unlike the nineteenth embodiment, the present embodiment does not introduce a halogen-containing gas from the lower part of the scrubber tower 313, but bubbling the gas from the gas passage inlet 311 into the scrubber water of the scrubber tank 312 and bubbling the halogen-containing gas. Wash with spray 314.

  By cleaning both the bubbling and the spray 314, an extremely high cleaning effect and a halogen-containing gas cooling effect are exhibited, and the halogen-containing gas in an appropriate state can be introduced into the discharge portion 33, thereby improving the processing efficiency. it can. This effect is due to a significant improvement in the contact area and contact time between the halogen-containing gas and the scrubber water.

  More preferably, in this wet scrubber, the scrubber water temperature is controlled to 10 ° C. or lower by controlling the scrubber water temperature using a cooler as in the nineteenth embodiment or by directly cooling the scrubber water with a throw-in cooler. Good to keep.

Embodiment 22. FIG.
As shown in FIG. 8, the discharge section 33, the gas cleaning means 31 such as a scrubber, and the gas concentrator such as a gas separation membrane, which operate at high efficiency under the atmospheric pressure with a discharge gap length of 1.0 mm or less or in the vicinity thereof. 32. Halogen-containing gas processing system provided with a recycling facility and an additional gas control facility for reusing the non-halogen component gas generated by the gas concentrator 32 as a purge gas for the system pump 2 and a purge gas after discharge (after detoxification) Build up.

  The halogen-containing gas processing system constructed as described above is inserted between the existing system pump and the acid exhaust equipment in the manufacturing plant, and the existing piping equipment is diverted.

  According to the present embodiment, it is only necessary to supply power (electricity, water, gas) from the user side, and there is no need for preparation of incidental facilities. Existing equipment can also be used as is for piping, etc., greatly reducing the costs associated with connection work.

  In addition, by constructing a system that combines a discharge unit that operates at a discharge gap length of 1.0 mm or less under atmospheric pressure or a pressure near it, and a gas cleaning unit, a concentration unit, a reuse unit, and an additional gas supply unit in the preceding stage. , Stable operation of gas treatment by plasma, high efficiency can be created, and high cost performance can be realized.

Embodiment 23. FIG.
FIG. 18 is a block diagram showing Embodiment 23, which is a processing system effective when used in a factory having no acid exhaust equipment. In the figure, 31 is a cleaning means such as a wet scrubber for removing acid and impurities, 350 is a filter, 351 is a compressor, 325 is a dehumidifier, 321 is a gas separation facility using a gas separation membrane such as a polyimide membrane, and 36 is A gas decomposer of a halogen-based gas by discharge is shown, and each arrow indicates a gas flow.

  A processing gas is introduced into the cleaning means 31 to remove acid components and other impurities. Further, the filter 350 completely removes impurities. Thereafter, the pressure of the gas is increased to about 7 atm by the compressor 325, for example. The gas is separated by the gas separation equipment 321 using this pressure as a driving force. Since the gas separation performance is degraded when moisture is contained, it is desirable to dispose a dehumidifier 325 in front of the gas separation facility 321. The clean gas 323 separated by the gas separation facility 321 is opened to the atmosphere as it is. The halogen-containing gas 322 to be processed is introduced into the gas decomposer 36 and decomposed into HF or the like. The decomposed gas is returned to the cleaning means 31 again by the exhaust gas circulation means 352 such as a pump, and the processing is performed.

  In this system, the halogen-containing gas is decomposed while being circulated between the cleaning means 31 and the gas decomposer 36 in a closed loop by the exhaust gas circulation means 352, and only the purified gas 323 can be discharged out of the system. Therefore, even when the processing gas cannot be completely decomposed by the gas decomposer 36, the processing gas is returned to the system again, and the processing is performed again, so that harmful gases discharged outside the system can be minimized.

  Further, since harmful substances such as HF generated by decomposing the gas are processed by the cleaning means 31, there is a great feature that an acid exhaust facility is not required.

  In this embodiment, the case where gas separation is performed using a polyimide membrane module has been described. However, an adsorption system or other apparatus can be used as long as it is a facility capable of separating gas.

Further, although only the gas decomposition method using discharge plasma has been shown as the gas decomposer 36, a thermal decomposition method, a catalyst method, or other methods can also be used. Furthermore, in 31 parts of the cleaning means, an acid component or the like can be easily dissolved in water by bringing the treatment gas into contact with water, but the HF generated by adding calcium hydroxide (Ca (OH) ₂ ) or the like. the method is effective also to reduce environmental impact and recovering of fluorite (CaF _2).

1 semiconductor process equipment, 1A home appliance storage container, 2 system pump,
3 Halogen-containing gas treatment equipment, 4 acid exhaust equipment, 4A aftertreatment equipment,
5 Purge gas supply equipment, 6 Power supply body, 7 Elastic body, 8 Power supply plate, 9 Gas type detection means, 10 Conductive valve, 11 Bypass piping, 12, 36 arithmetic unit,
13 gas flow detector, 20 pump, 21 turbo molecular pump, 22 dry pump,
31 cleaning means (wet scrubber), 32 gas concentrator, 32A interfering substance remover,
33, 33A, 33B, 33N Discharge section, 34 high frequency power supply, 35 additional gas supply,
37 Flow control valve, 38 Gas decomposer, 310 Circulation pump, 311 Gas inlet,
312 scrubber tank, 313 scrubber tower, 314 spray,
315 gas outlet, 316 water supply (or drainage) port,
317 Drain (or water supply) port, 318 Throw cooler, 319 Thermocouple,
320 moisture concentrating section, 321 gas separation membrane, 322 concentrated halogen component rich gas,
323 non-halogen component rich gas, 324 deoxidation part, 325 dehumidification part,
326 flow meter, 327 moisture drain, 328 pump purge component,
329 Exhaust purge component, 330 Power supply member, 331 Ground side electrode,
332 High-voltage side electrode, 333 discharge space, 334 spacer, 335 cooling water channel,
336 gas inlet, 337 gas outlet, 338 discharge section case, 339 high voltage terminal,
350 Filter, 351 Compressor, 352 Exhaust gas circulation means.

Claims (9)

A by-product generated when the halogen-containing gas is decomposed is sequentially connected in series to the gas stream supplied from the halogen-containing gas supply means for supplying the halogen-containing gas containing the halogen-based gas. Cleaning means for separating a gas other than the halogen-based gas from the halogen-containing gas and concentrating the halogen-based gas, a gas decomposer for decomposing the gas enriched in the halogen-based gas, and An apparatus for treating a halogen-containing gas, comprising exhaust gas circulation means for returning the treated gas processed and exhausted by the gas decomposer to the cleaning means. The halogen-containing gas is diluted with any one of a dilution gas composed of air, nitrogen, oxygen, carbon dioxide, helium, argon, neon, or xenon, or a mixture of the dilution gases. The halogen-containing gas treatment apparatus according to 1. The halogen-containing gas processing apparatus according to claim 1, further comprising a gas separation facility for concentrating the halogen-based gas concentration in the halogen-containing gas to 1 vol% or more. The gas decomposer includes an additional gas supply means for adding an additional gas of water vapor, hydrogen, oxygen, ozone, methane, ethane, propane, or ammonia having a concentration corresponding to the halogen-based gas concentration to the halogen-containing gas. The halogen-containing gas processing apparatus according to claim 1, further comprising: At least one surface is provided with a dielectric, and includes at least one discharge part having a ground side electrode and a high-voltage side electrode arranged to face each other via the dielectric, and a cooling means for cooling the electrode. The gas decomposer for applying a high voltage to the discharge part to generate a discharge and decomposing the halogen-containing gas containing the halogen-based gas supplied between the two electrodes by the halogen-containing gas supply means The gas pressure in the discharge space between the two electrodes is atmospheric pressure or a pressure near atmospheric pressure, only one of the electrodes is cooled, and the discharge gap length of the discharge space is 1.0 mm or less. 2. The halogen-containing gas processing apparatus according to claim 1, wherein At least one surface is provided with a dielectric, and includes at least one discharge part having a ground side electrode and a high-voltage side electrode arranged to face each other via the dielectric, and a cooling means for cooling the electrode. The gas decomposer for applying a high voltage to the discharge part to generate a discharge and decomposing the halogen-containing gas containing the halogen-based gas supplied between the two electrodes by the halogen-containing gas supply means The gas pressure in the discharge space between the two electrodes is atmospheric pressure or a pressure near atmospheric pressure, both the electrodes are cooled, and the discharge gap length of the discharge space is less than 4.0 mm. 2. The halogen-containing gas processing apparatus according to claim 1, wherein: 6. A plurality of said discharge parts are connected in series with the flow of said halogen-containing gas, and an arbitrary number of said plurality of discharge parts are driven. Alternatively, the halogen-containing gas processing apparatus according to claim 6. 7. The halogen-containing gas according to claim 5, wherein the gas decomposing unit is provided between the discharge units connected in series with an interfering substance removing unit that removes an interfering gas for discharge. 8. Processing equipment. A plurality of the discharge units are connected in parallel to the flow of the halogen-containing gas, and the gas decomposer is configured to drive any required number of the plurality of discharge units. The apparatus for treating a halogen-containing gas according to claim 5 or 6, wherein:

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