KR20210018491A - Exhaust gas control unit - Google Patents

Abstract

It greatly eliminates the clogging of the exhaust gas path from the foreline piping to the pyrolysis tower.
The exhaust gas removing unit U includes a vacuum pump 1, an exhaust gas introduction nozzle unit 20, and an exhaust gas cleaning unit 40. The exhaust gas introduction nozzle unit 20 includes an exhaust gas nozzle 21, a protective gas nozzle 25 forming a protective gas curtain Gk surrounding the exhaust gas H from the exhaust gas nozzle 21, It includes a water jet nozzle 27 surrounding the protective gas curtain Gk. The exhaust gas cleaning unit 40 includes the water tank 41 and the stirring unit 46. The water tank 41 is connected to an exhaust gas introduction nozzle part 20 to a hollow container for storing the cleaning water M therein. The space between the water M of the water tank 41 and the ceiling part 41a is a flow space 45 through which the exhaust gas H flows. The stirring part 46 is suspended from the ceiling part 41a of the water tank 41, and the lower part thereof is immersed in water M in the water tank 41, and the first bank 47 and the first bank 47 It is provided downstream of and includes a second embankment 48 whose upper portion is exposed above the water M.

Description

Exhaust gas control unit

The present invention relates to an exhaust gas detoxification unit for detoxifying exhaust gas discharged from the manufacturing process of electronic devices such as semiconductors and liquid crystals and discharging them to the atmosphere, and more particularly, to the exhaust gas. The present invention relates to an exhaust gas removal unit capable of remarkably alleviating clogging inside a pipe or equipment in an exhaust gas passage caused by contained dust or reaction products.

In the manufacturing process of electronic devices such as semiconductors or liquid crystals, many kinds of harmful or inflammable/explosive gases with high risk, or gases that destroy the global environment, such as causing ozone holes, are used. As the global environment destructive gas, for example, perfluoro compounds such as hydrogen perfluoride such as CF ₄ and C ₂ F ₆ used as cleaning gases of a CVD chamber or fluorine compounds that do not contain carbon such as NF ₃ (hereinafter, Gas of various compounds including "PFC") is mentioned.

In an electronic device manufacturing plant, in general, a manufacturing device such as CVD and a mechanical boster pump are installed in the clean room of the upper floor, and for example, a screw type vacuum pump, inlet scrubber, pyrolysis tower, A series of exhaust gas removing devices composed of an outlet scrubber or the like are individually provided, and these are connected by pipes (Patent Documents 1 and 2, etc.).

Then, through a mechanical booster pump, the process chamber of the upper layer manufacturing apparatus and the screw type vacuum pump of the lower layer are connected to each other by piping, and exhaust gas in the process chamber is sucked by the vacuum pump. The exhaust gas from the process chamber contains a reaction-producing component (for example, a water-soluble component or a hydrolyzable gas that reacts with moisture to produce a large amount of dust) generated in the device manufacturing process.

In the lower floor, the inlet scrubber is installed following the vacuum pump, and is used to remove the water-soluble component or hydrolyzable component by washing the exhaust gas discharged from the vacuum pump with water by a shower and collect dust generated by the reaction. , A water tank for accommodating the cleaning water discharged from the inlet scrubber, a pyrolysis tower installed on the water tank and pyrolyzing the water-washed exhaust gas, a reaction generating component generated in the pyrolysis tower and included in the detoxification exhaust gas ( An outlet scrubber to remove acidic components, dust, etc.) is connected by piping in this order.

As a pyrolysis tower for exhaust gas decomposition, a thermal decomposition type that decomposes exhaust gas into heat of an electric heater (Patent Document 2), and a plasma type that performs plasma decomposition treatment by passing exhaust gas through a plasma space are known. Yes (Patent Document 3).

Patent Document 1: JP Patent Publication No. 2016-33364 Patent Document 2: Japanese Laid-Open Patent Publication No. Hei 11-333247 Patent Document 3: Japanese Patent Publication No. 5307556

As described above, the exhaust gas may contain a hydrolyzable component, and the reaction product reacts with moisture in the piping of the exhaust gas control facility or in the equipment while it is discharged from the process chamber and flowing to the downstream exhaust gas control facility. And, it is attached to the inside of the pipe or the inner surface of the equipment and grows, eventually causing a blockage accident that causes the flow path to be blocked in any part of the exhaust gas flow path.

In the conventional exhaust gas control facility, a user separately purchases equipment such as a vacuum pump or an inlet scrubber, a pyrolysis tower, an outlet scrubber, a water tank for washing water recovery, and connection pipes for these, and the company's electronic device manufacturing plant Had been assembled within. In this case, there were the following problems.

(1) Since the individual devices constituting the exhaust gas control facility are separately arranged and connected to the pipe, the installation area of the exhaust gas control unit is liable to be widened.

(2) The user purchased the above equipment or connection pipes individually while checking the performance, but if they are purchased separately, it is difficult to achieve unification in terms of maintenance as a whole facility, and if there are weaknesses, the maintenance of that part is intensively required. It becomes difficult to manage the maintenance. For example, a pipe called a foreline that connects the inlet scrubber to the process chamber of the electronic device manufacturing apparatus through a vacuum pump reacts with the hydrolyzable component contained in the exhaust gas and the shower water of the inlet scrubber, and the shower outlet In the foreline pipe, the reaction product is deposited, clogging the shower outlet in a short time, or the moisture of the shower water reacts in the foreline pipe by reverse penetration of the exhaust gas flowing in the foreline pipe, and the reaction product There is a problem that the foreline piping is clogged in a short time due to adhesion and growth.

(3) In addition, when the exhaust gas from the process chamber is washed with water, a large amount of dust is generated, which is carried into the pyrolysis tower together with the cleaning exhaust gas, thereby causing clogging in the pyrolysis tower.

The present invention has been made in view of the problems of such a conventional system, and the first problem is to significantly eliminate clogging of the exhaust gas path from the foreline piping to the pyrolysis tower, thereby enabling a long-term continuous operation. The problem is to realize the space saving of the installation area by constructing the exhaust gas control unit as an exhaust gas control unit under the unified design concept of all the constituent elements and putting them in one housing.

In order to solve the above problems, the exhaust gas removing unit U of the present invention (claim 1) is a vacuum pump 1 that sucks exhaust gas H from the process chamber 201 of the semiconductor manufacturing apparatus 200. And, an exhaust gas introduction nozzle part 20 for washing the exhaust gas H discharged from the vacuum pump 1 with water, and a cleaning exhaust gas H discharged after water washing from the exhaust gas introduction nozzle part 20. ), and an exhaust gas cleaning unit 40 for collecting the contaminants contained in) and sending the cleaning exhaust gas H to the next exhaust gas decomposition process,

The exhaust gas introduction nozzle unit 20 includes an exhaust gas nozzle 21 for introducing an exhaust gas H into the exhaust gas cleaning unit 40, and an exhaust gas H ejected from the exhaust gas nozzle 21. A protective gas nozzle 25 for forming a protective gas curtain Gk by ejecting a protective gas G surrounding the protective gas nozzle 25, and a moisture jet nozzle 27 surrounding the protective gas curtain Gk ejected from the protective gas nozzle 25 ), and

The exhaust gas cleaning unit 40 includes the water tank 41 and the stirring unit 46,

The water tank 41 is a hollow container that extends in a horizontal direction and stores washing water M therein, and is an introduction opening 41c of the exhaust gas H to which the outlet of the exhaust gas introduction nozzle 20 is connected. ), and a through-flow space 45 through which the exhaust gas H flows in the space between the water M and the ceiling part 41a and is sent to the exhaust gas decomposition process,

The stirring part 46 is suspended from the ceiling part 41a of the water tank 41, the lower part is immersed in water M in the water tank 41, and an exhaust gas passageway 47a is provided in the immersion part. A stirring region in which the exhaust gas H that has passed through the exhaust gas passageway 47a agitates the water M in the first bank 47 and downstream of the first bank 47 ( 49), and characterized in that it includes a second embankment 48 that is exposed above the water M.

According to this, the exhaust gas H ejected from the exhaust gas nozzle 21 is blocked from contact with the moisture M from the moisture ejection nozzle 27 within the range protected by the protective gas curtain Gk. Therefore, reaction products such as dust generated by the reaction of the hydrolyzable component of the exhaust gas (H) and moisture (M) are attached to the exhaust gas nozzle 21 to close the exhaust gas nozzle 21. In no case, there is no case where the exhaust gas path on the upstream side of the exhaust gas nozzle 21 is blocked by reverse permeation of the exhaust gas H flowing through the exhaust gas nozzle 21.

And the cleaning exhaust gas H exiting the exhaust gas introduction nozzle part 20 is introduced into the water tank 41 of the exhaust gas cleaning part 40, and together with the water M in the water tank 41, the stirring part ( By stirring at 46), contaminants such as dust contained in the exhaust gas are effectively collected in the water M and sent to the next step as the cleaning exhaust gas H that does not contain contaminants.

In addition, in the present invention, water includes water, mist, steam, sprinkling water, and the like, and all are indicated by the symbol M.

In claim 2, in the exhaust gas removing unit (U) of claim 1,

The exhaust gas introduction nozzle unit 20 crosses the protective gas curtain Gk at a position away from the exhaust gas nozzle 21, and the exhaust gas H and the moisture ejection nozzle 27 ejected from the exhaust gas nozzle 21 ) Is installed at a location where moisture (M) from the collision collides, and the exhaust gas (H), protective gas (G), and moisture (M) collide and further includes a scattering member 30 to spread these around Characterized in that.

As a result, gas-liquid contact between the exhaust gas H and the moisture M is efficiently performed, and most of the hydrolyzable components in the exhaust gas H are decomposed there, thereby generating a large amount of dust.

In claim 3, in the exhaust gas removing unit (U) according to claim 1 or 2,

The vacuum pump 1 includes a mechanical booster pump 2 connected to a first foreline pipe P1 taken out from a process chamber 201 of a semiconductor manufacturing apparatus 200, and a lower side of the mechanical booster pump 2 It is installed in and is composed of a rough vacuum pump 4 connected to the second foreline pipe P2 drawn out from the mechanical booster pump 2,

The exhaust gas introduction nozzle part 20 is connected to the third foreline pipe P3 drawn out from the rough vacuum pump 4,

It is connected to the first foreline pipe P1, and when cleaning the semiconductor manufacturing apparatus 200, fluorine radicals (F·) are supplied into the first foreline pipe P1, and the first foreline pipe P1 ), as well as the inner surface cleaning unit 10 for removing the inner surface attachment (S) of the constituent member including the exhaust gas introduction nozzle unit 20,

It is connected to the second foreline pipe (P2) and supplies cleaning water (M) after the inner surface cleaning by fluorine radical (F·) to supply not only the second foreline pipe (P2) but also the exhaust gas. The inner surface attachment (S) of the constituent member including the introduction nozzle part 20 is washed with water, and then, a drying gas (G) is supplied to the exhaust gas introduction nozzle as well as the second foreline pipe (P2). It is characterized by consisting of an inner surface cleaning unit 16 for drying the inner surface of the constituent member including the unit 20.

In this way, not only the first foreline pipe P1, but also the inner surface cleaning of the constituent members including the exhaust gas introduction nozzle unit 20 is simultaneously performed at the time of cleaning of the semiconductor manufacturing apparatus 200, thereby reducing maintenance time. It can be shortened.

In claim 4, in the exhaust gas removing unit (U) according to claim 1,

A pyrolysis tower 60 for pyrolyzing the cleaning exhaust gas H from the vacuum pump 1, the exhaust gas introduction nozzle part 20, the exhaust gas cleaning part 40, and the exhaust gas cleaning part 40, and the pyrolysis The decomposition exhaust gas (H) from the tower 60 is washed with water to remove contaminants in the decomposition exhaust gas (H) generated by the pyrolysis, and the decomposition exhaust gas (H) is taken out of the apparatus as a clean exhaust gas (H). It is characterized by comprising an outlet scrubber 80 to discharge, a piping system for connecting the components, and a housing 90 for accommodating them.

According to this, since the constituent devices for exhaust gas control and their piping systems are integrated and housed in one housing 90, the installation area can be made compact compared to the conventional one. In addition, since a series of exhaust gas control components are prepared by the same manufacturer, the performance of the entire exhaust gas control unit (U) is harmonized, and dust clogging in the foreline piping system, which was originally considered a weakness, was able to be eliminated. .

As described above, in the present invention, the exhaust gas H is dusted by cooperation with the water jet nozzle 27 of the exhaust gas introduction nozzle unit 20 and the stirring unit 46 of the exhaust gas cleaning unit 40. It can be sent to the next step as it does not contain contaminants such as the back.

In addition, since the decontamination equipment and piping systems are integrated in a unified design idea, and these are housed in one housing 90, the installation area of the exhaust gas decontamination unit U can be saved, and for the user, the exhaust gas It is now possible to comprehensively manage the demolition unit (U) from the entrance to the exit.

1 is a front view showing the internal structure of an exhaust gas removing unit to which the present invention is applied.
Fig. 2 is an explanatory view of the functions of the constituent elements of Fig. 1 and an enlarged view of a stirring unit (bank).
3A is a schematic cross-sectional view of a first embodiment of an inner surface cleaning unit of the present invention, and FIG. 3B is a schematic cross-sectional view of a second embodiment of the present invention.
4 is a cross-sectional view of an exhaust gas introduction nozzle part of the present invention.
5 is a cross-sectional view of the pyrolysis tower of the present invention.
6 is a cross-sectional view of the exit scrubber of the present invention.

Hereinafter, the present invention will be described according to the illustrated embodiment. This exhaust gas removing unit U is configured to reduce the exhaust gas H discharged from a manufacturing apparatus 200 used in a semiconductor device manufacturing process, for example, a CVD film forming apparatus, to the housing 90 of the exhaust gas removing unit U. ) Installed in the vacuum pump (1) (mechanical booster pump (2) and rough vacuum pump (4)), this exhaust gas (H) is sequentially transferred to equipment stored in the same housing (90), and this It is a facility that is detoxified by pyrolysis and released into the atmosphere.

Further, in the description of the background art, the decomposition of PFC exhaust gas has been described as a representative example, but since the non-decomposable exhaust gas is not limited to the PFC exhaust gas, the treatment target gas of the present invention is simply referred to as exhaust gas (H). .

Hereinafter, an example of an embodiment of the exhaust gas removing unit U of the present invention will be described with reference to the drawings. The exhaust gas control unit U is, for example, in a manufacturing plant such as a semiconductor product or a liquid crystal panel, a layer below it with respect to any upper floor of the clean room 210 in which the semiconductor manufacturing apparatus 200 is installed. And constitutes an exhaust system of the semiconductor manufacturing apparatus 200.

The exhaust gas removing unit U of the present invention includes a vacuum pump 1, an inner surface cleaning unit 10, an inner surface cleaning unit 16, an exhaust gas introduction nozzle unit 20, an exhaust gas cleaning unit 40, and pyrolysis. It consists of a tower 60, an outlet scrubber 80, a piping system connecting them, and a housing 90 accommodating them.

The semiconductor manufacturing apparatus 200 is provided with a process chamber 201 for performing a liquid crystal panel, a semiconductor wafer film formation, etching and other processes. The exhaust gas removing unit U is provided in the lower layer as described above.

The vacuum pump 1 includes a mechanical booster pump 2 used as an upper pump for evacuating the process chamber 201, and a rough vacuum pump 4 (for example, a dry pump or a screw pump) as a lower pump. Equipped.

As can be seen from FIG. 1, the mechanical booster pump 2 is placed on the shelf 91 of the housing 90, and the rough vacuum pump 4 is immediately below it, an exhaust gas cleaning unit 40 to be described later. ) Is placed on the tank 41.

In this embodiment, the first foreline pipe P1 drawn out from the process chamber 201 penetrates the floor 220 and is connected to the mechanical booster pump 2 below the floor.

In addition, the mechanical booster pump 2 and the rough vacuum pump 4 are connected by a second foreline pipe P2, and additionally, to the third foreline pipe P3 drawn out from the rough vacuum pump 4 An exhaust gas introduction nozzle part 20 is provided.

In the present invention, in the housing 90, the mechanical booster pump 2 and the rough vacuum pump 4 are arranged up and down, and the exhaust gas introduction nozzle part 20 is arranged right next to the rough vacuum pump 4 Therefore, the pipe length of the second foreline pipe P2 and the third foreline pipe P3 connecting them is very short.

And, the second foreline pipe (P2) is formed in a J-shaped as can be seen from Figure 1, the upper end is connected to the mechanical booster pump (2), the bottom of the second foreline pipe (P2) is rough The inner surface cleaning unit 16 described later is connected to the vacuum pump 4 and to the connector P2c at the end of the second foreline pipe P2 facing in the transverse direction.

The inner surface cleaning unit 16 is detachable from the connector P2c provided at the end of the second foreline pipe P2. When the inner surface cleaning unit 16 is not connected, the connector P2c of the second foreline pipe P2 is closed, and the inner surface cleaning unit 16 is connected during internal cleaning.

The first foreline pipe (P1) is provided with an inner surface cleaning unit (10) that gasifies not only the first foreline pipe (P1) by generating fluorine radicals, but also the inner surface attachment (S) of pipes or equipment, and removes it. In the second foreline pipe (P2), an inner surface cleaning unit (16) that supplies cleaning water (M) or heating inert gas (G) for drying to pipes or equipment as well as the second foreline pipe (P2). Is installed.

The inner surface cleaning unit 10 includes a radical generation chamber 12, a high-frequency coil 13, and a high-frequency power supply 14.

The radical generation chamber 12 is a hollow cylindrical member provided with openings in both end faces in the longitudinal direction, and an opening provided in one end surface is an inlet opening 12a, and an opening provided in the other end surface is an outlet opening 12b. do.

Attachment of the radical generation chamber 12 to the first foreline pipe P1 is as shown in FIG. 3B and when connected in series to the first foreline pipe P1 as shown in FIG. 3A. In some cases, it is connected to the first foreline pipe P1 through the outlet opening 12b.

In the radical generation chamber 12 of FIG. 3A, the first foreline pipe P1 is connected to the inlet opening 12a of the upper end in the longitudinal direction, and the first foreline is connected to the outlet opening 12b at the lower end. The second half of the pipe P1 is connected. Then, a decomposition gas supply pipe 12c for supplying an in-pipe attachment decomposition gas (for example, NF ₃ ) is connected to the front part of the first foreline pipe P1.

In the case of FIG. 3B, the decomposition gas supply pipe 12c is connected to the inlet opening 12a of the radical generation chamber 12.

Incidentally, an arrow generated in the roof portion 13a of the radical generation chamber 12 and emerging from the outlet opening 12b represents a fluorine radical (F·).

The radical generation chamber 12 is a material excellent in airtightness, heat resistance, corrosion resistance and mechanical strength, such as metals such as stainless steel (SUS) or Hastelloy (registered trademark), or ceramics such as SiO ₂ or Al ₂ O ₃ It is a common member composed of.

A high-frequency coil 13 is disposed inside the radical generation chamber 12. The high frequency coil 13 is a cylindrical loop coil formed by winding a wire made of a conductive metal such as copper or stainless steel in a spiral shape. The high frequency coil 13 is wound in a spiral shape so that the central axis of the loop portion 13a provided with a cylindrical space therein and the central axis of the radical generation chamber 12 are the same axis. It is mounted within 12. In addition, both ends of the loop portion 13a of the high frequency coil 13 extend from the inside of the radical generation chamber 12 to the outside, and are connected to the high frequency power supply 14.

In addition, in order to prevent overheating, the high-frequency coil 13 and the above-described radical generation chamber 12 are preferably cooled as necessary.

The points indicated in the first foreline pipe P1 and the radical generation chamber 12 indicate the inner surface attachment S. A reaction product accompanying the exhaust gas H from the process chamber 201 is attached to the inner surface of the first foreline pipe P1 connected to the process chamber 201.

The high frequency power supply 14 is a power source that applies a high frequency voltage to the high frequency coil 13.

The inner surface cleaning unit 16 connected as necessary to the connector P2c of the second foreline piping P2 is composed of a water supply piping 18 for cleaning and a dry gas supply piping 19, for cleaning. The common pipe 17 between the water supply pipe 18 and the dry gas supply pipe 19 is connected to a connector (P2c) provided at the lower end of the J-type second foreline pipe (P2) to a fluorine radical (F·). It is connected according to the internal cleaning by means of. On/off valves 18v·19v are attached to the water supply pipe 18, the dry gas supply pipe 19, and the common pipe 17, respectively.

Clean tap water (M) (or water (M) in the water tank 41) is supplied from the water supply pipe 18, and from the drying gas supply pipe 19, in this embodiment, heating inert gas (nitrogen) (G ) Is supplied.

The exhaust gas introduction nozzle unit 20 is a device connected to the outlet of the third foreline pipe P3 extending from the outlet of the rough vacuum pump 4. In the exhaust gas introduction nozzle unit 20, first, the exhaust gas H delivered from the rough vacuum pump 4 is reversely permeated, and the third foreline pipe P3, a pipe upstream from this, or the interior of the equipment. A function of preventing the reaction product (S) from adhering to is required, and secondly, a function of hydrolyzing the hydrolyzable component contained in the exhaust gas (H) by spraying moisture (M) is required. It is explained next.

Next, the exhaust gas introduction nozzle unit 20 includes a casing 35, a triple pipe 20a mounted on the ceiling portion of the casing 35, and a scattering member provided immediately below the triple pipe 20a ( 30).

The nozzle structure of the triple tube 20a is an exhaust gas nozzle 21 as an inner tube, an intermediate tube surrounding the exhaust gas nozzle 21, and ejects an inert gas G to surround the exhaust gas H. A protective gas nozzle 25 forming a protective gas curtain GK, and an external appearance surrounding the protective gas nozzle 25, and a moisture jet nozzle 27 for ejecting moisture from the outside of the protective gas curtain Gk. ).

The inlet portion of the exhaust gas nozzle 21 is connected to a third foreline pipe P3 drawn out from the rough vacuum pump 4. The longitudinal cross-sectional shape of the inner surface of the exhaust gas nozzle 21 is formed in a thick circular straight tubular shape from the inlet portion to the middle portion, and is narrowed so that the inner diameter gradually decreases from the middle portion toward the exhaust gas outlet 21f which is its outlet. . It is preferable to form a knife edge shape so that reaction products and dust do not adhere to this exhaust gas outlet 21f and deposit. An inverted conical trapezoidal portion gradually decreasing toward the exhaust gas ejection port 21f on the outer surface of the exhaust gas nozzle 21 becomes the inner surface of the gap constituting the protection gas ejection path T1 through which the protection gas G is injected. .

The protective gas nozzle 25 has a cylindrical storage concave portion 25b that opens to the center of the upper surface, and is a nozzle hole of a thinner (lot shape) from the center of the storage concave portion 25b toward the bottom. (25a) is perforated. The portion where the nozzle hole 25a is provided is referred to as the nozzle portion 25c. This nozzle portion 25c is hollow and has an inverted conical trapezoidal shape.

The front end opening of this protective gas blowing path T1 surrounds the entire circumference of the exhaust gas blowing port 21f at the protective gas blowing port 25f. Further, a protective gas supply pipe 26 is connected to the upper side of the protective gas nozzle 25, and a gas reservoir 26a formed between the inner surface of the storage concave portion 25b and the outer surface of the exhaust gas nozzle 21 Communicate with In other words, the gas storage 26a is in communication with the protective gas blowing path T1 leading to the protective gas blowing port 25f*. And the protective gas ejection port 25f protrudes from the exhaust gas ejection port 21f in the exhaust gas ejection direction.

The water jet nozzle 27 is provided to surround the entire circumference of the protective gas nozzle 25.

The nozzle portion 27c of the moisture jet nozzle 27 is formed in a conical shape with a thin front formed with the same taper as the nozzle portion 25c of the protective gas nozzle 25, and the outer peripheral surface of the protective gas nozzle 25 and the moisture jet A gap constituting the water jet passage T2 between the inner circumferential surface of the nozzle 27 is formed over the entire circumference of the outer circumferential surface of the protective gas nozzle 25.

This water jet passage T2 is connected to a water supply pipe 28 via a water puddle 28a. The water supply pipe 28 is connected to the first pumping pipe 42, and water M of the water tank 41 is supplied to the first pumping pump YP1 installed in the first pumping pipe 42.

In FIG. 4, the water supply pipe 28 is connected to the side surface of the water jet nozzle 27 and is connected to the water puddle 28a.

This triple pipe 20a is provided in the casing 35, and a scattering member 30 is provided below the nozzle inlet of the triple pipe 20a. The scattering member 30 is a plate-shaped portion 31, a support member 34 attached to the casing 35, and a plate-shaped portion 31 constituted as a leg portion 32 is a circular and shallow plate-shaped member. As a result, the periphery of the upper surface is raised, and the inside of the raised frame 31b is recessed. This recessed part is referred to as the collision part 31a. The distance between the collision part 31a and the nozzle inlet tip of the protective gas nozzle 25 is a point at which the moisture (heated steam or fine water droplets) ejected from the water jet nozzle 27 breaks through the protective gas curtain Gk. , Or a lower position beyond this point is preferred. If the collision portion 31a is too close to the nozzle inlet of the protective gas nozzle 25, the moisture shielding effect of the protective gas curtain Gk is impaired.

The support member 34 is a disc-shaped member and is fixed to the inner surface of the casing 35. An exhaust gas flow hole 33 is perforated in the proper place of the support member 34. In addition, the upper end of the columnar leg portion 32 is attached to the center of the bottom portion of the plate-shaped portion 31. The lower end of the leg portion 32 is attached to the center of the support member 34.

The casing 35 is composed of a cylindrical body having an opening in the lower surface, and a triple pipe 20a is attached downwardly to the ceiling portion as described above. The lower surface opening is attached to the introduction opening 41c of the exhaust gas H of the water tank 41 to be described later.

The exhaust gas cleaning unit 40 is a hollow container that is elongated in a horizontal direction, and a water tank 41 in which cleaning water (M) is stored at a constant height, and one or more provided in the water tank 41 It includes a stirring unit 46 and one to a plurality of spray nozzles 50. As for the stirring unit 46, a bank having a high gas-liquid contact effect by stirring of water M is used (an enlarged view of Fig. 2).

A flow space 45 through which the exhaust gas H flows is provided between the ceiling portion 41a of the water tank 41 and the washing water M. In the water tank 41 of this embodiment, in order to increase the gas-liquid contact between the exhaust gas H flowing through the flow space 45 and the cleaning water M, in this embodiment, the embankment structure is formed by the stirring unit 46 (Hereinafter, the stirring portion 46 may be referred to simply as the embankment 46). The stirring unit 46 is composed of a first bank 47 and a second bank 48, and a stirring region 49 is provided between the first bank 47 and the second bank 48 (Fig. 2 Enlarged view).

The first embankment 47 is suspended from the ceiling 41a of the water tank 41 on the upstream side of the exhaust gas H, and its lower end is submerged in the washing water M. Then, a passage hole serving as the exhaust gas passage 47a is formed in the submerged portion (the exhaust gas passage 47a is not limited to a hole, and may be an embankment through which the exhaust gas H can escape. Here, a passage hole is used as the exhaust gas passage passage 47a). The exhaust gas passageway 47a is formed of a slit-shaped gap extending horizontally in accordance with the water surface immediately below the water surface, or one to a plurality of through holes arranged horizontally. A guide nozzle 47b extending in a downstream direction is provided at an edge of the hole of the exhaust gas passageway 47a.

The second embankment 48 is provided on the downstream side of the first embankment 47 via the stirring region 49. Its installation is provided so that the whole of the first embankment 47 is inclined downward toward the downstream side in a direction in which the lower part gradually falls with respect to the upper part of the second embankment 48 with respect to the first embankment 47.

The upper part of the second embankment 48 protrudes from the water surface, and the remaining lower part is submerged in the water. And, the upper part of the protruding part is bent or curved in the direction of the first embankment 47, and the lower part of the submerged part is obliquely downward from the bottom part (4lb) direction of the water tank 41 to the first embankment 47 side. It is formed to be bent or curved. The upper curved portion is referred to as the upper curved piece 48b, and the lower curved portion is referred to as the lower curved piece 48a. As a whole, the second embankment 48 has an inverted C shape.

The curved line 48l of the lower curved piece 48a submerged in water is located below the exhaust gas passageway 47a of the first embankment 47.

As described above, the stirring region 49 is the space between the first embankment 47 and the second embankment 48, and the gap therebetween is the widest in the vicinity of the outlet portion of the exhaust gas passageway 47a, and upwards. It gradually narrows as it goes. Then, the gap between the front end of the upper curved piece 48b and the first embankment 47 is the narrowest, and is connected to the flow space 45 therefrom.

The embankment 46 is provided in the entire width of the water tank 41 in a direction perpendicular to the longitudinal direction of the water tank 41. One stirrer 46 may be provided, but two or more may be provided side by side.

In the flow space 45 of the water tank 41, the spray nozzle 50 is provided so as to eject water M toward the horizontal direction. In the embodiment of the drawing, three spray nozzles 50 are installed, connected to the branch pipe of the first pumping pipe 42, and washing water of the water tank 41 with the injection pump FP provided in the branch pipe ( M) will be supplied.

In the exhaust gas introduction nozzle unit 20, the hydrolyzable component in the exhaust gas H reacts with the water M by water spray of the triple pipe 20a to generate a large amount of dust.

In the exhaust gas cleaning unit 40, the dust is collected before the exhaust gas H is sent to the next pyrolysis process, and a large amount of dust in the exhaust gas H is attached to the inner surface of the water tank 41. It imposes a role of not clogging the flow space 45 in the water tank 41 by depositing.

In the embodiment of the drawing, since the embankment 46 is provided in a plurality of positions (three positions), the first injection nozzle 50a is at the top of the passage space 45 and at the side wall of the water tank 41, the passage space ( Water M is sprayed toward the downstream of 45), and the inner surface of this periphery (introduction opening 41c) of the water tank 41 is sprayed.

Since the periphery of the introduction opening 41c is a place with the largest amount of dust, the second injection nozzle 50b is also provided on the downstream side of the introduction opening 41c in the flow space 45. It is arranged so as to be ejected from the second injection nozzle 50b in two directions, an upstream side and a downstream side of the flow space 45, and in the downstream side of the introduction opening 41c, the water tank 41 around this Spray inside.

The 3rd injection nozzle 50c is arrange|positioned so that it may eject in two directions upstream and downstream from the downstream side of the stirring part 46 of the most downstream, and sprays the inner surface of the water tank 41 around this.

In the above case, the injection nozzle 50 may be provided at a plurality of positions as shown in the drawing, but may be provided only in the introduction opening 41c of the exhaust gas H.

Separation by dividing the pyrolysis tower 60 side and the outlet scrubber 80 side between the pyrolysis tower 60 and the outlet scrubber 80 to be described later in the water tank 41 in the downstream portion of the flow space 45 The embankment plate 55 is provided over the entire width of the water tank 41. This separation embankment plate 55 is suspended from the ceiling part 41a of the water tank 41, and its lower end is submerged in the washing water M. As a result, the exhaust gas H flowing out of the passage space 45 is blocked by the separation bank 55 and is guided to the pyrolysis tower 60. The configuration downstream from the separation embankment plate 55 will be described on the page of the outlet scrubber 80.

The pyrolysis tower 60 of this embodiment shown in FIG. 5 is a pyrolysis treatment apparatus for exhaust gas H using atmospheric pressure plasma, and is installed at the top of a thick cylindrical tower body 62 and the tower body 62. , A non-transfer-type plasma jet torch 61 for generating a high-temperature plasma jet J toward the inside of the tower main body 62, a thin cylindrical combustion cylinder 64 installed upright under the tower body 62, and the A water introduction part that is a ring-shaped space installed to surround the upper outer periphery of the tower main body 62, where water (M) is always supplied and flows water to the inner wall of the tower main body 62 by overflow to form a water film It consists of (63). The water M of the water tank 41 is supplied to the water introduction part 63 by a second pump YP2 installed in the second pumping pipe 43.

The pyrolysis tower 60 is installed upright on the upstream side of the separating levee plate 55 in the downstream portion of the flow space 45 of the water tank 41, and is opened to the flow space 45, and the water tank 41 It is connected to the flow space 45 through the communication opening 41d provided in the ceiling part 41a of the.

The combustion cylinder portion 64 is disposed in accordance with the central axis of the tower main body 62, and its lower end is immersed in the water M of the water tank 41. Then, the exhaust pipe 66 from the lower portion of the combustion cylinder 64 directly above the water surface branches in the horizontal direction, passes through the separation levee plate 55 and opens to the outlet scrubber 80 side. The space on the side of the outlet scrubber 80 in which the exhaust pipe 66 is opened is a decomposed exhaust gas inflow space 45a.

The plasma jet torch 61 provided at the top of the pyrolysis tower 60 has a plasma generating chamber (not shown) therein, and a plasma jet generated in the plasma generating chamber at the center of the lower surface of the plasma jet torch 61 ( A plasma jet ejection hole (not shown) for ejecting J) is provided. The upper side of the plasma jet torch 61 is provided with a working gas supply pipe (not shown) such as nitrogen gas as necessary.

The plasma jet J ejected from the plasma jet ejection hole is blown into the combustion cylinder 64 provided in the center of the tower main body 62.

On the side of the decomposition exhaust gas inflow space (45a) of the water tank (41) beyond the separating embankment plate (55), rises from the bottom (4lb) of the water tank (41), the upper end coincides with the water surface of the washing water (M) One overflow embankment 56 is provided, and a portion beyond the overflow embankment 56 is a drainage region 57, and is discharged as factory drainage.

The water tank 41 is supplied with the same amount of new water M as the water M discharged due to overflow, so that the water M in the water tank 41 maintains a constant water level.

The outlet scrubber 80 is a so-called wet scrubber, and its structure will be described next (Fig. 6). The outlet scrubber 80 is installed substantially upright in the pyrolysis tower 60 in the ceiling part 41a of the water tank 41.

The outlet scrubber 80 includes an exterior casing 81, a cyclone cylinder 82, an exhaust fan 89, and auxiliary facilities thereof. Examples of auxiliary facilities include a third pumping pipe 44, a third pumping pump YP3 provided in the middle thereof, a first outlet washing spray 88a, and a second outlet washing spray 88b.

The outer casing 81 is a hollow pipe shape with a lower surface opening, and its bottom portion is immersed in water M stored in the side of the decomposition exhaust gas inflow space 45a. In the bottom portion immersed in water M, a decomposition exhaust gas passage hole 81a is provided in a plurality of positions at a position immediately below the water surface. A transverse funnel-shaped guide nozzle 8lb is provided inward on the periphery of the decomposition exhaust gas passage hole 81a. Then, the cleaning exhaust gas discharge cylinder 86 is suspended downward through the ceiling portion of the exterior casing 81. This cleaning exhaust gas discharge cylinder 86 is connected to an exhaust fan 89 described later.

In the exterior casing 81, a cyclone cylinder portion 82 is suspended from the ceiling portion of the exterior casing 81 at its center. The upper portion of the cyclone cylinder portion 82 is formed in a cylindrical shape, and the cleaning exhaust gas discharge cylinder portion 86 is positioned at the center of the cylindrical portion 82c. In addition, a decomposition exhaust gas introduction port 82b through which decomposition exhaust gas H flows into the cyclone cylinder portion 82 is formed in the cylindrical portion 82c. At the lower end of the cylindrical portion 82c, a funnel-shaped portion 82a narrowed in a funnel shape is provided downward, and a thin tube portion 82d from the lower end of the funnel-shaped portion 82a is provided downward. The lower end portion of the thin pipe portion 82d is immersed in the cleaning water M in the decomposition exhaust gas inflow space 45a.

In the space between the exterior casing 81 and the thin tube portion 82d of the cyclone tube portion 82, an obstruction tube member 83 is provided upright so as to surround the entire lower portion of the thin tube portion 82d. The upper part of the obstruction tube member 83 protrudes upward from the water M, and the lower part is immersed in the water M. The lower end (83a) of the lower part immersed in water (M) is bent obliquely downward toward the guide nozzle (8lb) side, and the upper upper end (83b) protruding upward from the water (M) is a thin tube part (82d) It is bent horizontally toward the direction of In addition, the submerged portion of the obstruction tube member 83 faces the guide nozzle 8lb of the exterior casing 81 in front, and the entire thereof is disposed so as to be inclined with respect to the exterior casing 81 as described above, and the water tank It plays the same role as the second embankment 48 of 41. Further, the curved line 83l of the submerged portion is provided below the decomposition exhaust gas passage hole 81a.

On the upper side of the obstruction tube member 83, a ring-shaped baffle plate 84 is provided horizontally from the inner peripheral surface of the outer casing 81 toward the inner side. A cylindrical portion 84a extending downward is provided at the periphery of the hole of the ring-shaped baffle plate 84. A thin tube portion 82d of the cyclone cylinder portion 82 passes through the center of the cylindrical portion 84a. And, this cylindrical portion 84a enters between the water surface protruding portion of the upper half of the obstruction cylinder member 83 and the thin pipe portion 82d of the cyclone cylinder portion 82, and a complicated passage path of the decomposition exhaust gas H Configure.

On the upper side of the ring-shaped baffle plate 84, a plurality of first outlet cleaning sprays 88a are installed around the thin pipe portion 82d to spray water up and down in the vertical direction. A third pumping pipe 44 for pumping up water M stored in the decomposition exhaust gas inlet space 45a is connected to the first outlet cleaning spray 88a, and a third pumping pipe 44 is connected to the third pumping pipe 44. A positive water pump YP3 is provided on the way. The water spray M from the first outlet cleaning spray 88a covers the space between the cyclone tube portion 82 and the exterior casing 81, and makes both inner surfaces wet with water (M) at all times. The water M sprayed with the first outlet cleaning spray 88a flows along the inner surfaces of both and returns to the water tank 41.

A second outlet cleaning spray 88b is provided in the cleaning exhaust gas discharge cylinder 86, and water is sprayed from the cleaning exhaust gas discharge cylinder 86 toward the funnel-shaped portion 82a. The sprinkling (M) of the second outlet cleaning spray (88b) is the final stage of water washing, and since the clean exhaust gas (H) is released to the atmosphere, fresh water is used.

An exhaust fan 89 is provided at the top of the exterior casing 81, and is connected to the cleaning exhaust gas discharge cylinder 86 of the exterior casing 81. Then, an exhaust pipe 89a for exhausting the atmosphere provided in the exhaust fan 89 is drawn out from the housing 90 and is connected to the factory pipe 150.

The control panel C of the exhaust gas removal unit U is mainly composed of a control system of the pyrolysis tower 60 and a pump centralized control system that centrally controls the mechanical booster pump 2 and the rough vacuum pump 4. . The control panel C is assembled in the housing 90.

Next, the operation of the exhaust gas removing unit U of the present invention will be described. In the semiconductor manufacturing process, various source gases are supplied to the process chamber 201 of the semiconductor manufacturing apparatus 200, and an electronic device including a plurality of semiconductor substrates accommodated in the process chamber 201 (not shown) Various treatments are performed on the. The raw material gas used in the reaction process becomes exhaust gas H and is discharged to the exhaust gas removing unit U through the first foreline pipe P1. When the exhaust fan 89 is operated, the exhaust gas path of the exhaust gas removing unit U is maintained at a negative pressure, and the exhaust gas H is sucked into the exhaust fan 89.

In the exhaust gas (H) discharged, contaminant components such as reaction-generated components and unreacted components including dust generated in the above process are mixed. While passing through the first foreline pipe (P1) as well as pipes or equipment, such contaminants are adhered and deposited therein. This is called the inner surface attachment (S). The deposition of such inner surface attachment S becomes remarkable as it goes downstream of the first foreline pipe P1 or less.

Then, the exhaust gas H sucked from the process chamber 201 by the vacuum pump 1 reaches the exhaust gas introduction nozzle unit 20, and the exhaust gas H of the water tank 41 from the exhaust gas nozzle 21 ) Is injected toward the introduction opening 41c. Then, a protective gas curtain Gk injected from the protective gas nozzle 25 surrounds the entire circumference of the injected exhaust gas H.

Hydrolyzed from the tip opening of the water jet passage T2 of the moisture jet nozzle 27 of the outermost layer to surround the inner protective gas curtain Gk and parallel to the protective gas curtain Gk. The dragon's moisture (hot water vapor) (M) erupts. Since the protection gas blowing path T1 for forming the moisture blowing path T2 and the protective gas curtain Gk is parallel, the moisture blowing path T2 is ejected from the protection gas nozzle 25 by a specific distance. The moisture M for hydrolysis is ejected in parallel with the protective gas curtain Gk, and within the distance range, there is no need to break through the protective gas curtain Gk and contact the exhaust gas H inside.

And, when the moisture (M) is ejected in parallel to the protective gas curtain (Gk) from the moisture ejection path (T2) as described above, it spreads at a certain distance with a decrease in flow rate, and the moisture (M), protection The gas curtain Gk and the exhaust gas H are mixed with each other. The dish-shaped part 31 of the scattering member 30 is provided at this point, and the exhaust gas H, the protective gas curtain Gk, and the moisture M collide. And, by this collision, these things are scattered around the plate-shaped part 31 and fly up inside the casing 35 at the same time. In the meantime, gas-liquid contact between the exhaust gas H and the moisture M is effectively performed, and the hydrolyzable component in the exhaust gas H comes into contact with the moisture M to generate a large amount of dust.

This dust is about to adhere to the inner surface of the casing 35 or the triple pipe 20a, but is always washed away by the moisture M floating in the casing 35, and the inner surface of the casing 35 or the triple pipe 20a The adhesion to the body is alleviated.

On the other hand, from the upper part of the casing 35 flying into the casing 35, the protective gas curtain Gk is strongly ejected from the protective gas nozzle 25, so that the moisture M that has taken off is the protective gas curtain Gk It cannot break through, and there is no contact with the ejected exhaust gas H within the protection range of the protective gas curtain Gk. Therefore, there is no reverse permeation of the moisture M going up through the third foreline pipe P3.

The exhaust gas H blown into the flow space 45 of the water tank 41 together with a large amount of dust is the first and second injection nozzles 50a and 50b covering the entire surface of the introduction opening 41c of the exhaust gas H. In contact with the spray water M from ), a part thereof is collected and recovered in the water M of the water tank 41. At the same time, the spray water M wets the inner wall of the water tank 41 and washs off the inner surface deposits S that are about to be attached to the inner wall, thereby slowing the deposition.

The exhaust gas H flows in the direction of the agitator 46 together with the dust avoided from being collected by the airflow in the direction of the pyrolysis tower 60 by suction of the exhaust fan 89. It is necessary to avoid taking this dust into the pyrolysis step of the next step as much as possible.

In the stirring unit 46, the exhaust gas H collides with the first embankment 47, suppresses the water surface near the first embankment 47 with the momentum, and passes the exhaust gas passageway 47a just below the water surface. And enters the stirring area 49. As it is stirred in the stirring area 49, it becomes a bubble and floats, while water (M) and exhaust gas (H) are in gas-liquid contact, and contaminants such as dust in the exhaust gas (H) are effectively transferred to the water (M). Is captured. In the second embankment 48, since the lower curved piece 48a is curved downward in the direction of the first embankment 47, the water M sprayed along the second embankment 48 protrudes due to the rise of the bubbles. It bumps against the upper curved piece 48b of the part and returns downward, and the stirring area 49 is sufficiently stirred. This increases the dust collection effect.

The foamy exhaust gas (H) floats as it is, bursts from the water surface, and enters the flow space (45).

If the stirring unit 46 is provided in a plurality of steps, the above-described collection operation is repeated, and by the time it reaches the pyrolysis tower 60, it becomes the cleaning exhaust gas H that hardly contains contaminants such as dust.

From the above, in the exhaust gas path from the first foreline pipe P1 to the exhaust gas nozzle 21 of the exhaust gas introduction nozzle unit 20, the protective gas curtain Gk of the exhaust gas introduction nozzle unit 20 , The contact between the moisture M in the exhaust gas introduction nozzle unit 20 and the exhaust gas H containing a hydrolyzable component is blocked, so that clogging of the path is suppressed. And, by the gas-liquid contact of the exhaust gas H and the moisture (hot steam) M scattered by the presence of the scattering member 30 in the casing 35 of the exhaust gas introduction nozzle part 20, Most of the hydrolyzable components in the exhaust gas H are decomposed, and a large amount of dust is accompanied.

In addition, the exhaust gas H accompanying such dust is washed in a number of steps in the stirring unit 46 of the water tank 41 and supplied to the pyrolysis tower 60 in a state not accompanied by dust.

The exhaust gas H cleaned in the water tank 41 is introduced into the pyrolysis tower 60 from the communication opening 41d of the water tank 41, and is a pyrolysis area at the top of the tower body 62 and the combustion cylinder 64 At 65, it contacts the plasma jet J of the plasma jet torch 61 and thermally decomposes in the presence of moisture. As a result, contaminants such as dust and reaction products are generated in the decomposition exhaust gas H.

The pyrolyzed exhaust gas H passes through the combustion cylinder 64 together with the contaminants. Since the bottom of the combustion cylinder 64 is open, most of the contaminants such as dust or reaction products contained in the decomposition exhaust gas H fall as it is and fall into the water M of the water tank 41 and are collected and decomposed. The exhaust gas H passes through the exhaust pipe 66 together with the remaining light contaminants, and flows into the decomposition exhaust gas inflow space 45a.

The decomposition exhaust gas H flowing into the decomposition exhaust gas inflow space 45a presses the water surface near the decomposition exhaust gas passage hole 81a of the outer casing 81 by the suction force of the exhaust fan 89 to decompose exhaust gas. It flows into the through hole 81a, and rises as a bubble in the stirring area 87 between the exterior casing 81 and the obstruction tube member 83. By this foaming, the water M in the stirring region 87 is greatly agitated. In this way, most of the contaminants including dust contained in the decomposition exhaust gas H are collected by the water M in the stirring region 87.

The cleaned decomposition exhaust gas H passes through the serpentine flow path in the obstruction tube member 83 and the ring-shaped baffle plate 84, and additionally, the cylindrical portion 84a of the ring-shaped baffle plate 84 It emerges from the space between the and the thin tube portion 82d into the space above the ring-shaped baffle plate 84. In the meandering flow path, the cleaned decomposition exhaust gas H becomes turbulent and comes into contact with the obstruction tube member 83, the ring-shaped baffle plate 84, and the thin tube portion 82d. A first outlet cleaning spray 88a is provided on the upper side of the ring-shaped baffle plate 84, and dirt adhered by the sprinkling M from there flows down.

The first outlet cleaning spray 88a sprays M in two directions, so that the inner surface of the exterior casing 81 is covered with a downward flowing water film, so that the dirt is washed away and does not adhere.

The decomposed exhaust gas H is not collected even by the shower ring and rises together with a small amount of dirt or mist that has not fallen, passes through the decomposition exhaust gas inlet 82b, and enters the cyclone cylinder portion 82. The decomposition exhaust gas (H) that has entered into the cyclone cylinder portion (82) turns around the cleaning exhaust gas discharge cylinder portion (86), and is a contaminant that is heavier than the decomposition exhaust gas (H) by the formation of vortex in the cyclone cylinder portion (82) Ina mist falls while turning by its centrifugal force and gravity, and is recovered as water (M) in the water tank 41.

The clean exhaust gas H that does not contain contaminants through water washing and cyclone is sucked into the exhaust fan 89 and discharged to the exhaust pipe 89a, and flows out to the factory pipe 150.

When the reaction process and the decontamination operation are completed, the process changes to a cleaning process of the process chamber 201. In the cleaning process, the common pipe 17 of the inner surface cleaning portion 16 is connected to the connector P2c of the second foreline pipe P2. At this stage, the on-off valves 18v·19v are closed.

Thereafter, a fluorine-based cleaning gas (for example, C ₂ F ₆ , NF _3, etc.) flows into the process chamber 201, and the reaction product attached to the inner surface of the process chamber 201 is exhausted with a volatile gas such as NF ₄ It flows toward the gas removal unit (U) side. In this way, cleaning in the process chamber 201 is performed.

On the side of the exhaust gas removing unit U, dust or reaction products adhere to the exhaust gas path from the first foreline pipe P1 to the exhaust gas introduction nozzle unit 20. In the cleaning process, cleaning gas is supplied to the process chamber 201, but most of this cleaning gas is consumed in the cleaning process of the process chamber 201, and the exhaust gas after cleaning sucked into the first foreline piping P1 is removed. 1 There is little cleaning capability in the exhaust gas path as well as the foreline piping (P1).

Therefore, the opening/closing valve 10a is opened, a separate cleaning gas (for example, NF ₃ ) is supplied to the inner surface cleaning unit 10, and the inner surface of the exhaust gas path as well as the first foreline pipe P1 is cleaned. .

That is, the high frequency power supply 14 is operated while separately supplying a cleaning gas to the radical generation chamber 12 of the inner surface cleaning unit 10 to apply a high frequency voltage to the high frequency coil 13. In this case, a capacitively coupled plasma (CCP) is generated inside the loop portion 13a of the high frequency coil 13, and an inductively coupled plasma (ICP) is generated by the flow of an induced current by an induced magnetic field to the CCP.

The cleaning gas is decomposed by high heat or electron impact of the ICP in the radical generation chamber 12. As a result of this, fluorine radicals (F·) are generated in large quantities, and are attached to the inner surfaces of the first foreline piping (P1) or mechanical booster pump (2), and also while passing through the downstream equipment or piping. The reaction product (S) is gasified. That is, the cleaning by the F radicals (F and) was generated by decomposition of NF _3, by gasification of the reaction product (S) to the reaction of Si + 4F → SiF _4. In this way, the inner surface of the first foreline pipe P1 or the mechanical booster pump 2, and the downstream equipment or pipes are simultaneously cleaned during the cleaning process of the process chamber 201.

When the inner surface cleaning by the fluorine radical (F·) is finished, the on-off valve 10a of the inner surface cleaning unit 10 is closed.

The common pipe 17 of the inner surface cleaning unit 16 is connected to the connector P2c at the lower end of the second foreline pipe P2 prior to the inner surface cleaning. After closing the on-off valve 10a of the inner surface cleaning unit 10, the on-off valve 18v of the water supply pipe 18 of the inner surface cleaning unit 16 is opened.

The cleaning water M from the water supply pipe 18 passes through the common pipe 17, flows into the rough vacuum pump 4, passes through the rough vacuum pump 4, and passes through the third foreline pipe P3. And flows into the water tank 41 after passing through the exhaust gas nozzle 21. This cleans not only the rough vacuum pump 4 but also the equipment and the inside of the third foreline pipe P3. Further, since water cannot be passed through the mechanical booster pump 2, water washing is performed in the rough vacuum pump 4 or lower.

When the water washing is completed, the open/close valve 18v of the water supply pipe 18 is closed, and the open/close valve 19v of the dry gas supply pipe 19 is opened. In this way, a heating inert gas (for example, heating nitrogen gas) G is supplied from the drying gas supply pipe 19, flows into the water tank 41 through the water washing path, and the inner surface of this path is dried. . By this drying, cleaning of the exhaust system is ended, and the process moves to the next manufacturing process.

As described above, in the present invention, by cooperation between the exhaust gas introduction nozzle unit 20 and the exhaust gas cleaning unit 40, decomposition of the hydrolyzable component contained in the exhaust gas H, and dust due to this decomposition. Not only is it possible to remove contaminants, but also by cooperation of the inner surface cleaning unit 10 and the inner surface cleaning unit 16, from the first foreline pipe P1 to the exhaust gas introduction nozzle unit 20 according to the cleaning process. It is possible to clean the exhaust gas path of the car, and it is possible to significantly suppress clogging in this part where clogging accidents are most likely to occur.

C: control panel, F·: fluorine radical, FP: injection pump, G: protective gas (dry gas, heating gas, inert gas), Gk: protective gas curtain, H: exhaust gas, J: plasma jet, M: moisture (Water, water droplets, mist, steam, spray water, water spray), P1: first foreline pipe, P2: second foreline pipe, P2c: connector, P3: third foreline pipe, S: inner surface attachment (reaction product ), T1: protective gas jet furnace, T2: moisture jet furnace, U: exhaust gas removal unit, YP1: first pumping pump, YP2: second pumping pump, YP3: third pumping pump, 1: vacuum pump, 2: Mechanical booster pump, 4: rough vacuum pump, 10: inner cleaning part, 10a: on-off valve, 12: radical generation chamber, 12a: inlet opening, 12b: outlet opening, 12c: decomposition gas supply pipe, 13: high frequency coil, 13a : Loop part, 14: high frequency power supply, 16: inner cleaning part, 17: common pipe, 18: water supply pipe, 18v: on/off valve, 19: drying gas supply pipe, 19v: on/off valve, 20: exhaust gas introduction nozzle portion, 20a: triple pipe, 21: exhaust gas nozzle, 21f: exhaust gas outlet, 25: protective gas nozzle, 25a: nozzle hole, 25b: storage recess, 25c: nozzle portion, 25f: protective gas outlet, 26: protective gas supply Piping, 26a: gas reservoir, 27: water jet nozzle, 27c: nozzle portion, 28: water supply pipe, 28a: water puddle, 30: scattering member, 31: plate shape, 31a: impact portion, 3lb: raised rim , 32: leg, 33: exhaust gas flow hole, 34: support member, 35: casing, 40: exhaust gas cleaning portion, 41: water tank, 41a: ceiling, 4lb: bottom, 41c: introduction opening, 41d: communication opening , 42: first pumping pipe, 43: second pumping pipe, 44: third pumping pipe, 45: flow space, 45a: decomposition exhaust gas inlet space, 46: stirring part (bank), 47: first agent Room, 47a: exhaust gas passage, 47b: guide nozzle, 48: second embankment, 48a: lower curved piece, 48b: upper curved piece, 48I: curved line, 49: stirring area, 50 (50a to 50c): injection Nozzle, 55: separation dike plate, 56: overflow bank, 57: drainage area, 60: pyrolysis tower, 61: plasma jet torch, 62: tower body, 63: water inlet, 64: combustion cylinder, 65: pyrolysis zone, 66: exhaust pipe, 80: outlet scrubber, 81: outer casing, 81a: decomposition exhaust gas flow hole, 8lb: guide nozzle, 82: cyclone cylinder portion, 82a: funnel-shaped portion, 82b: decomposition exhaust gas inlet, 82c: cylinder Shape portion, 82d: thin tube portion, 83: obstruction tube member, 83a: lower portion, 83b: upper portion, 83I: bending line, 84: ring-shaped baffle plate, 84a: cylindrical portion, 86: cleaning exhaust gas discharge cylinder portion, 87 : Stirring area, 88a: first outlet cleaning spray, 88b: second outlet cleaning spray, 89: exhaust fan, 89a: exhaust pipe, 90: housing, 91: shelf, 150: factory pipe, 200: semiconductor manufacturing apparatus, 201: process chamber, 210: clean room, 220: floor.

Claims (4)

A vacuum pump that sucks exhaust gas from a process chamber of a semiconductor manufacturing apparatus, an exhaust gas introduction nozzle part that water-washs the exhaust gas discharged from the vacuum pump, and a cleaning exhaust gas that is water-washed and discharged from the exhaust gas introduction nozzle part. An exhaust gas cleaning unit that collects the contaminants contained in and sends the cleaning exhaust gas to the next exhaust gas decomposition process,
The exhaust gas introduction nozzle unit includes an exhaust gas nozzle for introducing exhaust gas to the exhaust gas cleaning unit, a protection gas nozzle for forming a protective gas curtain by blowing a protective gas surrounding the exhaust gas ejected from the exhaust gas nozzle, and the It includes a moisture jet nozzle surrounding the protective gas curtain jetted from the protective gas nozzle,
The exhaust gas cleaning unit includes the water tank and the stirring unit,
The water tank is a hollow container that extends in a horizontal direction and stores water for washing therein, and is exhausted in a space between the water and the ceiling portion and the exhaust gas introduction opening to which the outlet of the exhaust gas introduction nozzle part is connected. It includes a flow space through which gas is passed and sent to the exhaust gas decomposition process,
The stirring portion is suspended from the ceiling portion of the water tank, the lower portion thereof is immersed in water in the water tank, the first embankment provided with an exhaust gas passage path in the immersion portion, and the exhaust gas passage passage downstream of the first embankment. Exhaust gas removal unit, characterized in that it comprises a second embankment in which the passed exhaust gas is provided with a stirring region for stirring the water therebetween, and the upper part thereof is exposed above the water. The exhaust gas introduction nozzle part according to claim 1, wherein the exhaust gas introduction nozzle part is provided at a position where the exhaust gas ejected from the exhaust gas nozzle and water from the moisture ejection nozzle collide with the protective gas curtain at a position away from the exhaust gas nozzle. An exhaust gas removing unit, characterized in that it further comprises a scattering member through which the exhaust gas, the protective gas and the moisture collide and spread them around. The mechanical booster pump according to claim 1 or 2, wherein the vacuum pump is installed below the mechanical booster pump and connected to the first foreline pipe drawn from the process chamber of the semiconductor manufacturing apparatus, and from the mechanical booster pump. It is composed of a rough vacuum pump connected to the drawn second foreline pipe,
An exhaust gas introduction nozzle part is connected to the third foreline pipe drawn from the rough vacuum pump,
An inner surface attachment of a constituent member connected to the first foreline pipe and including the exhaust gas introduction nozzle part below the first foreline pipe by supplying fluorine radicals into the first foreline pipe during cleaning of the semiconductor manufacturing apparatus An inner cleaning unit that removes
It is connected to the second foreline pipe, and after the inner surface cleaning by fluorine radicals, cleaning water is supplied to wash the inner surface attachment of the constituent member including the exhaust gas introduction nozzle part below the second foreline pipe with water. And then, an inner surface cleaning unit (16) configured to supply a drying gas to dry the inner surface of the constituent member including the exhaust gas introduction nozzle unit below the second foreline pipe. The pyrolysis tower according to claim 1, wherein the vacuum pump, the exhaust gas introduction nozzle part, the exhaust gas cleaning part, and the pyrolysis tower for pyrolyzing the cleaning exhaust gas from the exhaust gas cleaning part, and the decomposition exhaust gas from the pyrolysis tower are washed with water. Exhaust, characterized by comprising an outlet scrubber for removing contaminants in the decomposed exhaust gas generated by the decomposition exhaust gas and discharging the decomposed exhaust gas to the outside of the apparatus as clean exhaust gas, a piping system connecting the components, and a housing for accommodating these Gas decontamination unit.

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