JP2018047424A - Exhaust gas abatement system - Google Patents

Abstract

An exhaust gas abatement / discharge system which can avoid blockage of an exhaust gas passage between a vacuum pump and an abatement apparatus and requires a small installation area. An exhaust gas abatement and discharge system 1 includes an abatement device 12 with a built-in vacuum pump. A vacuum pump 16 is disposed in the apparatus housing 14 of the abatement apparatus 12 in addition to the plasma reactor 18, and the vacuum pump 16 and the plasma reactor 18 are connected by an internal exhaust gas pipe 17. The length of the exhaust gas pipe can be significantly reduced as compared with the case where an external vacuum pump is used. The pipe is prevented from being clogged by the adhesion and deposition of the reaction product, and the required installation area of the exhaust gas abatement / discharge system 1 can be reduced. [Selection diagram] FIG.

Description

  The present invention relates to an exhaust gas abatement / exhaust system including an abatement device that detoxifies and exhausts exhaust gas discharged from a semiconductor manufacturing process or the like.

  In the reaction chamber of manufacturing equipment such as semiconductor devices and liquid crystal display devices, various types of harmful or flammable / explosive gases with high risk and gases that harm the global environment such as ozone holes are used. ing. Exhaust gas from the reaction chamber is sucked by a vacuum pump, passed through an exhaust gas abatement device (hereinafter simply referred to as abatement device), rendered harmless, and then discharged into the atmosphere.

  As described in FIG. 1 of Patent Document 1, in general, in a manufacturing factory for semiconductor products and the like, a manufacturing apparatus is generally installed on an upper floor, and a vacuum pump and an abatement apparatus are configured on a lower floor. An exhaust gas abatement system will be installed. A piping connection is made between the reaction chamber of the manufacturing equipment on the upper floor and the suction port of the vacuum pump on the lower floor. On the lower floor, a piping connection is made between the exhaust port of the vacuum pump and the suction port of the abatement device. Is done.

  As a detoxification device, wet processing is performed using a liquid such as water according to the characteristics of the exhaust gas to be processed, dry processing for adsorbing harmful substances to the adsorbent, fuel and oxygen are mixed into the exhaust gas, and decomposition is performed through a combustion flame. A combustion type is known. A plasma type is also known in which an exhaust gas is passed through a plasma space to perform plasma decomposition treatment. Patent Document 2 proposes a plasma exhaust gas abatement apparatus.

  As the vacuum pump, a turbo pump, a mechanical booster pump, a screw pump, or the like is used. In some cases, a plurality of vacuum pumps having different characteristics are connected in series. For example, by combining a mechanical booster pump with a roughing pump such as a screw-type vacuum pump, the exhaust speed can be increased in a pressure region where the exhaust speed of the roughing pump drops.

JP 2016-33364 A Japanese Patent No. 5307556

  In the exhaust gas abatement system, foreign substances contained in the exhaust gas and reaction products of the exhaust gas are deposited and deposited in the exhaust gas passage. If left unattended, the pipeline will be blocked, so regular cleaning is required.

  In particular, the reaction product of the exhaust gas tends to adhere and accumulate on the inner surface of the pipe connecting the exhaust side of the vacuum pump and the intake side of the abatement apparatus. It is desired to be able to avoid or suppress product adhesion in the piping.

  In addition, it is desirable that pump cleaning and removing device cleaning for removing foreign substances and reaction products in the vacuum pump, which is an exhaust gas passage, and the inside of the removing device can be performed easily and efficiently.

  Furthermore, in manufacturing factories for products such as semiconductor products, there is always a demand for reduction in the installation space of vacuum pumps and abatement devices installed downstairs from the viewpoint of effective use of the installation space.

  In view of the above, an object of the present invention is to provide an exhaust gas abatement / exhaust system capable of avoiding or suppressing an exhaust gas passage between a vacuum pump and an abatement device due to foreign matter adhesion.

  Another object of the present invention is to provide an exhaust gas abatement / discharge system that can avoid or suppress blockage of the exhaust gas passage between the vacuum pump and the abatement apparatus and that requires a small installation area.

  Furthermore, the problem of the present invention is that it is possible to avoid or suppress clogging of the exhaust gas passage between the vacuum pump and the abatement device, and to clean the inside of the vacuum pump and the abatement device easily and efficiently. It is to provide an exhaust gas abatement system.

In order to solve the above problems, the exhaust gas abatement / discharge system of the present invention is:
A detoxification device having an exhaust gas treatment unit for detoxifying the exhaust gas to be treated;
A vacuum pump that sucks the exhaust gas and supplies it to the exhaust gas treatment section of the abatement device,
The vacuum pump is built in the exhaust gas abatement apparatus.

  The exhaust gas abatement / exhaust system of the present invention includes a vacuum pump built in the abatement apparatus. That is, in addition to the exhaust gas treatment unit such as a plasma reactor, a vacuum pump is disposed in the apparatus housing of the abatement apparatus. The vacuum pump and the exhaust gas treatment unit are connected by an internal pipe disposed in the apparatus housing.

  Compared with the case of using an externally attached vacuum pump, the pipe length of the pipe connecting between the vacuum pump and the exhaust gas treatment unit of the abatement apparatus can be significantly shortened. Therefore, the possibility that the reaction product adheres and accumulates in the pipe and the pipe is blocked is greatly reduced. Moreover, compared with the case where a detoxification apparatus and a vacuum pump are installed separately, the installation area required in order to install both can be reduced by the installation area of a vacuum pump. Furthermore, since it is not necessary to secure a piping space around the abatement device for routing the piping connected to the vacuum pump, the installation area and the installation space can be greatly reduced.

  A plasma-type abatement device can be used as the abatement device, and the exhaust gas treatment unit includes a plasma reactor and a waste liquid recovery / circulation tank disposed below the plasma reactor. Further, as the built-in vacuum pump, a screw-type vacuum pump installed in a vertical state so that the inlet port is located at the upper end can be used. In this case, it is desirable to arrange the exhaust port of the screw type vacuum pump at the same position as or higher than the intake port of the plasma reactor.

  When the cleaning liquid is caused to flow from the intake port of the screw type vacuum pump, the cleaning liquid flows down along the exhaust gas passage route inside the screw type vacuum pump and inside the abatement apparatus. Therefore, foreign substances such as reaction products adhering to the inside can be easily and efficiently cleaned.

In the present invention, the abatement apparatus is not limited to the plasma type. As described above, various types of abatement devices such as a wet type, a dry type, a combustion type, and a plasma type are known. Of course, these can be used.

  The exhaust gas abatement / exhaust system of the present invention includes a reaction chamber of an apparatus such as a semiconductor manufacturing apparatus that is a source of exhaust gas to be processed via an external pipe connected to an intake side of the internal vacuum pump. Used by connecting to the exhaust port. If necessary, a front-stage vacuum pump is connected between the exhaust gas generation source and the built-in vacuum pump in the exhaust gas abatement / exhaust system. The front-stage vacuum pump can be an external vacuum pump that is externally attached to the abatement apparatus.

  For example, a high vacuum pump such as a mechanical booster pump or a turbo molecular pump can be used as an external vacuum pump that is a higher-order pump connected to the upstream side. As a built-in vacuum pump that is a roughing pump connected to the rear stage side, for example, a rotary vacuum pump such as a two-leaf type, a roots type, a screw type, a vane type, or a water seal type can be used.

  As an example, a screw-type vacuum pump can be used as a built-in vacuum pump that is a roughing pump, and a mechanical booster pump can be used as an external vacuum pump that is an upper pump.

  Moreover, the external vacuum pump which is a high-order pump can be a combination of different types of vacuum pumps connected in series. For example, a mechanical booster pump and a screw type vacuum pump can be used. Moreover, it can also be set as the combination of the vacuum pump of the same type connected in series. For example, two mechanical booster pumps can be used.

  Furthermore, in a conventional general exhaust gas abatement / exhaust system in which a plurality of vacuum pumps connected in series, that is, a host pump and a roughing pump are separated from the abatement apparatus, the abatement apparatus Instead of this, it is possible to connect and use an exhaust gas abatement system comprising an abatement apparatus equipped with a built-in vacuum pump according to the present invention. The system of the present invention can be easily constructed for an existing exhaust gas abatement system.

  Thus, in the conventional general exhaust gas abatement / exhaust system, instead of the abatement device, the system of the present invention, that is, the abatement device equipped with the built-in vacuum pump (vacuum pump built-in abatement device). When used, the inside of the pipe connecting the external vacuum pump and the built-in vacuum pump in the detoxifying apparatus of the present invention is decompressed by the built-in vacuum pump. Therefore, reaction product adhesion in the piping can be reduced, and power consumption of the external vacuum pump can be reduced.

It is explanatory drawing which shows the exhaust gas abatement discharge system to which this invention is applied. It is explanatory drawing which shows an example of a built-in vacuum pump. It is explanatory drawing which shows the system structural example of the exhaust gas abatement discharge system of this invention. It is explanatory drawing which shows the example which applied this invention to the general exhaust gas abatement discharge system.

  Embodiments of an exhaust gas abatement / discharge system to which the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is an explanatory view showing an exhaust gas abatement system according to the present embodiment. The exhaust gas abatement / exhaust system 1 is installed in an upper floor 4 and a lower floor 5 where a clean room 3 in which a semiconductor manufacturing apparatus 2 is installed, for example, in a semiconductor product manufacturing factory. Configure the system.

  The semiconductor manufacturing apparatus 2 is provided with a process chamber 6 for performing film formation, etching, and other processes of a semiconductor wafer. The exhaust gas abatement / exhaust system 1 includes a mechanical booster pump 11 (external vacuum pump) used as an upper pump that exhausts the process chamber 6. The exhaust gas abatement / exhaust system 1 includes a plasma abatement apparatus 12 installed on the lower floor 5. The exhaust port 11a of the mechanical booster pump 11 and the suction port 12a of the plasma type detoxifying device 12 are connected by an exhaust gas pipe 13 drawn from the upper floor 4 to the lower floor 5.

  The plasma-type abatement apparatus 12 installed on the lower floor 5 includes, for example, a rectangular parallelepiped apparatus housing 14. In the apparatus housing 14, a plasma type exhaust gas treatment unit 15 is incorporated, and a vacuum pump 16 (built-in vacuum pump) used as a roughing pump is incorporated. The exhaust port 15 a of the exhaust gas treatment unit 15 and the exhaust port 16 b of the vacuum pump 16 are connected by an internal exhaust gas pipe 17. The plasma-type exhaust gas treatment unit 15 includes a plasma reactor 18, an outlet scrubber 19, a waste liquid recovery / circulation tank 20 disposed below these, and the like.

  The control system of the exhaust gas abatement / exhaust system 1 is mainly configured by a control panel 21 of the abatement apparatus 12 and a pump centralized control panel 22 that centrally controls the mechanical booster pump 11 and the vacuum pump 16. The control panel 21 of the abatement apparatus 12 is assembled to the apparatus housing 14, and the pump central control panel 22 is mounted on a pump rack 23 on which the mechanical booster pump 11 is mounted.

  As described above, the exhaust gas abatement / exhaust system 1 includes the abatement apparatus 12, the vacuum pump 16 built in the abatement apparatus 12, and the external mechanical booster pump 11. Exhaust gas vacuumed by the mechanical booster pump 11 from the process chamber 6 of the semiconductor manufacturing apparatus 2 passes through the exhaust gas pipe 13 and is sucked by the vacuum pump 16 built in the abatement apparatus 12, and through this, the exhaust gas treatment unit Fifteen plasma reactors 18 are fed.

  In the plasma reactor 18, the exhaust gas is oxidized and decomposed by plasma to be rendered harmless. Next, the exhaust gas is showered at the outlet scrubber 19, and by-products decomposed and generated by the plasma reactor 18 contained therein are removed and cooled. Next, the exhaust gas is released into the atmosphere via an unillustrated exhaust fan. The inner wall of the plasma reactor 18 is a water wall, and the exhaust gas passing through and its reaction product do not directly contact the plasma reactor 18, so that the exhaust gas passage portion is prevented from being blocked and corroded.

  In the exhaust gas abatement / exhaust system 1, the exhaust gas treatment of the abatement apparatus 12 is performed by vacuum suction of the exhaust gas using a vacuum pump 16 built in the abatement apparatus 12 and an external mechanical booster pump 11 in the abatement apparatus 12. It supplies to the part 15. The length of the internal exhaust gas pipe 17 on the atmospheric pressure side between the built-in vacuum pump 16 and the plasma reactor 18 is extremely short. It can be avoided or suppressed that the reaction product of the exhaust gas adheres and accumulates and the internal exhaust gas pipe 17 is blocked.

  Further, since the vacuum pump 16 is built in the apparatus housing 14, the required installation area of the exhaust gas abatement / exhaust system 1 can be reduced as compared with the case where both pumps are arranged separately from the abatement apparatus 12. In addition to this, when the exhaust gas pipe connecting the abatement apparatus 12 and the vacuum pump 16 is routed outside the abatement apparatus 12, an installation space for the exhaust gas pipe is necessary. In this example, it is only necessary to arrange the internal exhaust gas pipe 17 in the apparatus housing 14, so that it is not necessary to secure a space for the exhaust gas pipe outside the abatement apparatus 12. Also by this, the installation space of the exhaust gas abatement / exhaust system 1 can be reduced as compared with the conventional case.

  Here, a dry pump can be used as the vacuum pump 16 used as a roughing pump built in the abatement apparatus 12. For example, as shown in FIG. 2, a twin screw vacuum pump having a pair of screw rotors meshing with each other can be used. In this case, it is desirable to install the screw type vacuum pump 16 </ b> A in a vertically placed state at a position above the plasma reactor 18 in the apparatus housing 14. Specifically, the screw type vacuum pump 16A is installed in a vertical state so that the intake port 16a is located at the upper end. Further, the exhaust port 16b is set at the same position as or higher than the intake port 15a of the plasma type exhaust gas treatment unit 15.

  The biaxial screw type vacuum pump 16 </ b> A includes a pair of screw rotors 33 and 34 that mesh with each other in a pump chamber 32 formed in a pump casing 31. An intake port 16 a is opened at the upper end of the pump casing 31, and an exhaust port 16 b that opens laterally is opened at the lower end portion of the pump casing 31. An internal exhaust pipe 17 is connected to the exhaust port 16b substantially horizontally or slightly downward. The other end of the internal exhaust gas pipe 17 is connected to an intake port 15 a formed at the upper end of the plasma reactor 18. The plasma reactor 18 is a cylindrical reactor arranged vertically, and the exhaust gas flowing from the intake port 15a flows from the top to the bottom of the plasma reactor 18.

  In the case where the vertically installed screw type vacuum pump 16A is used, cleaning of the inside thereof is performed by flowing a cleaning liquid from the upper inlet 16a. The cleaning liquid flows down from the top to the bottom of the pump chamber 32 from the upper intake port 16a to wash away the deposits and the like, and flows out from the lower exhaust port 16b to the internal exhaust gas pipe 17. Then, it flows into the plasma reactor 18 from the intake port 15a at the upper end of the plasma reactor 18 from the internal exhaust gas pipe 17 and flows down there to wash away foreign substances adhering to the inner peripheral surface of the internal exhaust gas pipe 17 and the like. The cleaning liquid that has flowed down the plasma reactor 18 is recovered in the waste liquid recovery / circulation tank 20 disposed below, so that it can be discharged to the outside. As described above, the inside of the screw type vacuum pump 16A, the internal exhaust gas pipe 17 and the inside of the plasma reactor 18 can be easily cleaned by flowing the cleaning liquid from the intake port 16a.

  FIG. 3 is an explanatory diagram showing a system configuration example of the exhaust gas abatement / discharge system of the present invention. A system configuration example 1A shown in FIG. 3A shows the case of the exhaust gas abatement / exhaust system 1 shown in FIG. 1, and an external mechanical booster pump 11 used as an upper pump as a vacuum pump constituting the vacuum exhaust system, A detoxifying device 12 used as a roughing pump is provided with a built-in vacuum pump 16.

  In the system configuration example 1B shown in FIG. 3B, as a vacuum pump, two mechanical booster pumps 11A and 11B connected in series used as a high-order pump and a vacuum pump built in the abatement apparatus 12 used as a roughing pump are used. 16. As an external vacuum pump, a plurality of vacuum pumps other than the mechanical booster pump can be arranged.

  In the system configuration example 1C shown in FIG. 3C, a vacuum built in the mechanical booster pump 11C and the screw type vacuum pump 11D connected in series used as the upper pump and the abatement apparatus 12 used as the roughing pump as the vacuum pump. And a pump 16. As an external vacuum pump, a combination of different types of vacuum pumps other than the combination of a mechanical booster pump and a screw type vacuum pump can be used.

  In addition, as shown in the system configuration example 1D shown in FIG. 3D, in some cases, without using an external vacuum pump, the abatement apparatus 12 with the built-in vacuum pump 16 is directly connected to the exhaust gas. It is also possible to connect to the process chamber 6 of an apparatus such as a semiconductor manufacturing apparatus that is a generation source. Note that a turbo molecular pump (TMP) is disposed in an apparatus such as a semiconductor manufacturing apparatus, and the process chamber 6 may be evacuated via the turbo molecular pump and the vacuum pump 16.

  Next, FIG. 4 is an explanatory view showing an exhaust gas abatement / exhaust system constructed by applying the present invention to a general exhaust gas abatement / discharge system. The exhaust gas abatement / exhaust system 1E includes an abatement apparatus 12 installed on a floor 5 below a floor 4 where a manufacturing apparatus such as a semiconductor manufacturing apparatus that generates exhaust gas is installed, and a separate vacuum pump 11E. Yes. The abatement device 12 has a built-in vacuum pump 16. The vacuum pump 11E includes a mechanical booster pump 41 and a vacuum pump 42 connected in series. In some cases, a turbo molecular pump is disposed in an apparatus such as a semiconductor manufacturing apparatus, and a process chamber in the apparatus and a separate vacuum pump 11E are connected via the turbo molecular pump.

  The exhaust gas abatement / exhaust system 1E having this configuration can be constructed by using the vacuum pump built-in abatement apparatus 12 according to the present invention instead of the existing abatement apparatus. Further, the inside of the exhaust gas pipe 13 </ b> E connecting the vacuum pump 42 and the abatement apparatus 12 is decompressed by the vacuum pump 16 built in the abatement apparatus 12. Therefore, the production | generation in the piping of a reaction product can be decreased, and the maintenance inspection work of the exhaust gas piping 13E is reduced. Moreover, the power consumption of the vacuum pump 11E can be reduced.

DESCRIPTION OF SYMBOLS 1 Exhaust gas elimination system 1A, 1B, 1C, 1D System configuration 1E Exhaust gas elimination system 2 Semiconductor manufacturing device 3 Clean room 4 Upper floor 5 Lower floor 6 Process chamber 11, 11A, 11B, 11C, 41 Mechanical booster pump 11E, 42 Vacuum pump 11a Exhaust port 12 Detoxifying device 12a Suction port 13, 13E Exhaust gas pipe 14 Device housing 15 Exhaust gas processing part 15a Inlet port 16 Vacuum pump 16A Screw type vacuum pump 16a Inlet port 16b Exhaust port 17 Internal exhaust gas tube 18 Plasma reactor 19 Outlet scrubber 20 Waste liquid recovery / circulation tank 21 Control panel 22 Centralized pump control panel 23 Pump rack 31 Pump casing 32 Pump chambers 33 and 34 Screw rotor

Claims (8)

A detoxification device having an exhaust gas treatment unit for detoxifying the exhaust gas to be treated;
A vacuum pump that vacuum sucks the exhaust gas and supplies the exhaust gas to the exhaust gas treatment unit,
The exhaust gas abatement / exhaust system, wherein the vacuum pump is a built-in vacuum pump built in the abatement apparatus. In claim 1,
The detoxification device is a plasma type detoxification device, and the exhaust gas treatment unit includes a plasma reactor, and a waste liquid recovery / circulation tank disposed below the plasma reactor,
The built-in vacuum pump is a screw-type vacuum pump installed in a vertically placed state so that the intake port is located at the upper end,
The exhaust port of the screw type vacuum pump is an exhaust gas abatement / exhaust system arranged at the same position as or higher than the intake port of the plasma reactor. The claim 1, further comprising:
Having a vacuum pump on the front side for vacuum suction of the exhaust gas and supplying it to the built-in vacuum pump;
The exhaust gas abatement / discharge system, wherein the front-stage vacuum pump is an external vacuum pump externally attached to the abatement apparatus. In claim 3,
The built-in vacuum pump is a screw type vacuum pump,
The external vacuum pump is an exhaust gas abatement system that is a mechanical booster pump. In claim 4,
The detoxification device is a plasma type detoxification device, and the exhaust gas treatment unit includes a plasma reactor, and a waste liquid recovery / circulation tank disposed below the plasma reactor,
The built-in vacuum pump is a screw-type vacuum pump installed in a vertically placed state so that the intake port is located at the upper end,
The exhaust port of the screw type vacuum pump is an exhaust gas abatement / exhaust system arranged at the same position as or higher than the intake port of the plasma reactor. In claim 3,
An exhaust gas abatement / discharge system comprising a plurality of vacuum pumps connected in series as the external vacuum pump. In claim 6,
An exhaust gas abatement / discharge system comprising a mechanical booster pump and a screw type vacuum pump as the external vacuum pump. In claim 6,
An exhaust gas abatement system comprising a plurality of mechanical booster pumps as the external vacuum pump.

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