JPH11233498A - Exhaust device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust device of a compact structure which can maintain trap effect for a long period. SOLUTION: A trap shell 12 into which exhaust gas from a silicon dioxide film forming processor flows is provided with a double pipe member 22 having an inner wall 24 forming a flow out pipe part 30 whose one end is opened and the other end, makes gas flow out to the outer part of the trap shell and an outer wall 26 where a circular space 28 in which a cooling medium circulates to the outer side of the inner wall 24 is formed and a fin 36 provided for the outer side of the double pipe member 22. In an exhaust device, powder in exhaust gas is cooled by the double pipe member 22 and therefore at least one of powder, mist and condensed gas contained in gas is acquired in the trap shell.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust device used in, for example, a semiconductor manufacturing apparatus, and more particularly, to a film forming process in a reactive gas, an etching process in a reactive gas, and an ionizing process in an ionic gas. Exhaust gas that is exhausted from a processing apparatus that performs at least one of the injection processing and a processing target member formed on at least one of a semiconductor and a metal, directly or via at least one of a vacuum pump and a gas exclusion device. The present invention relates to an exhaust device that captures powder, mist or condensable gas therein.

[0002]

2. Description of the Related Art For example, a wafer processing step in semiconductor manufacturing includes the following processing steps. 1) As one of the methods for forming a silicon dioxide (SiO ₂ ) film, there is a step of using TEOS (tetra-ethyl-oxide-silicon) and oxygen. Exhaust gas from a film forming apparatus for performing this film forming process contains fine powder of silicon dioxide. In this fine powder, when water vapor generated when TEOS is oxidized is condensed into a liquid, the condensed matter becomes a binding cause substance, and silicon dioxide grows into powder having larger powder particles. As a result, when the exhaust gas cools, the silicon dioxide contained in the gas tends to stay in the exhaust pipe as a powder having a large particle diameter. In some cases, TEOS (liquid) itself is included in the exhaust gas as a mist. When the mist is cooled, it adheres to the pipe wall of the exhaust pipe, and finally adheres as silicon dioxide.

[0005] 2) One of the methods for forming a silicon nitride film includes a step of using dichlorosilane and ammonia gas. Ammonium chloride is contained in exhaust gas of a film forming apparatus for performing such a film forming process. At about 140 ° C., ammonium chloride rapidly condenses and changes from a gas to a solid. For this reason, ammonium chloride adheres to the pipe wall of the exhaust pipe as a solid layer.

[0004] One of the methods for etching aluminum is a treatment step using hydrogen chloride gas. Aluminum chloride is contained in the exhaust gas of the etching apparatus that performs etching in the reactive gas. At about 100 ° C., aluminum chloride condenses and changes from a gas to a powdery solid. For this reason, aluminum chloride tends to stay in the exhaust pipe.

[0005] 4) There is an ion implantation step using a high concentration of phosphine or solid phosphorus as an ion source. The exhaust gas of this ion implanter contains ionized phosphorus. This ionic gas is condensed when cooled, and phosphorus is precipitated as fine powder. This fine powder of phosphorus adheres to the gap of a movable mechanism such as a vacuum pump, increases the friction of the movable mechanism, and eventually stops the vacuum pump.

[0006] 5) As a method of forming a metal tungsten film, there is a method using hexafunger tungsten and hydrogen gas. In this case, by setting the temperature of these gases to 120 ° C. or higher, metal tungsten is deposited, and a film is formed.
However, when metallic tungsten is precipitated in the pump, the hardness of the tungsten is higher than that of cast iron, which is a main material of the pump, and the pump is quickly worn and damaged.

[0007] If the powders produced in such various processing steps are left as they are, they block the exhaust pipe, and the solid layer that has adhered gradually grows, eventually causing the exhaust pipe to be blocked. Further, the ionic gas stops the vacuum pump, and the tungsten film forming gas wears and damages the vacuum pump. In order to prevent such solid matter from adhering in the exhaust system, a trap using a cooling medium or a heating medium is widely used as an exhaust device.

FIG. 11 shows a prior art trap used as such an exhaust system. Such a trap can use either a cooling medium or a heating medium, but in the following description, the trap will be mainly described as a water-cooled trap using water as a cooling medium.

This water-cooled trap has a closed structure in which a cooling pipe 4 is arranged in a cylindrical casing 2 having one end closed by a bottom wall, and the other end of the cylindrical casing 2 is closed by a sealing plate 6. Exhaust gas flows in through an intake port 2a provided in the cylindrical casing 2 and an exhaust port 2b provided in the sealing plate 6.
Is discharged from Cooling water is supplied into the cooling pipe 4 from a water supply port 4a, flows through this internal passage, and is discharged from a drain port 4b. Fins 8 are spirally attached to the outer peripheral portion of the cooling pipe 4.

The exhaust gas flowing through the cylindrical casing 2 contacts the surfaces of the cooling pipes 4 and the fins 8 and is efficiently cooled, and the powder in the exhaust gas is cooled on the surfaces of the cooling pipes 4 and the fins 8. The powder, the condensable gas, the mist, and the like can be removed from the exhaust gas by adhering or condensing the substance causing the adhesion.

Therefore, by using such a water-cooled trap, the powder in the exhaust gas is forcibly removed in the trap, or the condensable gas in the gas is forcibly fixed in the trap. The substance causing fixation therein can be removed. The effect of removing such a powder or a substance causing sticking from the exhaust gas is called a scrubbing effect. Due to this scrubbing effect, the exhaust gas from which the powder or condensable gas has been forcibly removed hardly causes solid matter to adhere or generate inside the exhaust pipe or the vacuum pump. Exhaust stop trouble accompanying pump stop can be prevented beforehand. It is desirable that such an exhaust stop trouble can be prevented for a long period of time.

[0012]

However, if powder or solid matter adheres to the surfaces of the cooling pipes and fins to some extent, the cooling capacity of the cooling pipes and fins is reduced, so that scrubbing in a water-cooled trap forming an exhaust system is performed. The effect is also reduced, and eventually the powder or condensable gas cannot be removed. In such a state, the exhaust system causes the above-described problem, and causes the exhaust system to stop. In other words, when the powder or condensable gas cannot be removed in this way, the trapping effect of the water-cooled trap is lost, and the service life of the water-cooled trap is extended. Of course, it is desirable that the trap effect be maintained over a long period of time. However, in order to extend the service life of the conventional water-cooled trap, it is necessary to increase the internal surface area of the trap. Was extended. In this case, there is a problem that the water-cooled trap becomes extremely large.
The present invention has been made in view of the above, and an object of the present invention is to provide an exhaust device having a compact structure capable of maintaining a trapping effect for a long period of time.

[0013]

The exhaust system according to the present invention comprises at least one of a film forming process in a reactive gas, an etching process in a reactive gas, and an ion implantation process in an ionic gas. An exhaust device that exhausts gas from a processing device that performs processing on a member to be processed formed at least one of a semiconductor and a metal, directly or through at least one of a vacuum pump and a gas abatement device, A trap shell having an inlet into which gas flows, and an outlet formed at one end with an opening opening into the trap shell and an outlet at the other end through which gas flows out of the trap shell through an internal flow path to the outside of the trap shell. A double pipe member having an inner wall formed and an outer wall forming an annular space of a closed structure between the inner wall, and a double shell member projecting from the outer wall of the double pipe member toward the trap shell, At least one fin that contacts the trapping shell, and a medium supply port and a medium discharge port for circulating a cooling or heating medium in the annular space. At least one of the powder contained in the gas, the mist, and the condensable gas is trapped in the trap shell by the temperature difference with the circulating medium.

In this exhaust device, the gas flowing into the trap shell from the inflow port flows outside the outer wall of the double pipe member while coming into contact with the outer wall and the fins, and further flows into one end of the double pipe member. It flows into the internal flow path from the formed opening, flows along the internal flow path while being in contact with the internal wall, and flows out of the trap shell from an outlet formed at the other end of the internal wall. In the annular space between the inner wall and the outer wall of the double pipe member, a cooling or heating medium circulates through a medium supply port and a medium discharge port. , Forming a very large cooling or heating contact surface for the gas.

The fin includes an elongated fin plate spirally wound with one of a pair of long edges fixed to an outer wall of the double pipe member by, for example, welding, and one long edge of the fin plate is provided. It is preferable that the portion has a wavy shape composed of a plurality of small curved portions that alternately protrude from one end side and the other end side in the axial direction of the double pipe member.

Further, the fin is fixed to an outer wall of the double pipe member at an inner peripheral portion thereof, and a plurality of the fins are helically arranged along the axial direction of the double pipe member while standing upright from the outer wall. A fin plate may be provided, and a slit may be formed between adjacent side edges of these fin plates. As a result, even if the powder stays at the bottom in the trap shell, a flow path of the exhaust gas is formed other than between the spiral fin plates,
Further, there is an effect of extending the service life.

On the other hand, a jacket portion can be arranged on the outer peripheral surface of the trap shell, and the medium can be circulated inside the jacket portion. Thereby, the cooling effect or the heating effect can be further enhanced.

The trap shell has a cylindrical side wall, a gas inflow pipe protruding from the side wall to form the gas inlet, and a side portion at a portion axially adjacent to the gas inflow portion. A gas outlet pipe protruding from the wall, and the inner wall of the double pipe member may have the other end formed with the outlet communicating with the gas outlet pipe. Thus, the exhaust device according to the present invention can be attached later to an existing place where the exhaust pipe is installed.

[0019]

FIG. 1 shows an exhaust device according to a preferred embodiment of the present invention. This exhaust device is suitably used in a semiconductor manufacturing apparatus, and is, for example, TEOS as described above.
Silicon dioxide film formation processing device using oxygen and oxygen, silicon nitride film formation processing device using dichlorosilane and ammonia gas, aluminum etching processing device using hydrogen chloride gas, or high concentration Captures powder, mist or condensable gas in exhaust gas exhausted directly from a processing device such as an ion implantation processing device that uses phosphine or solid phosphorus as an ion source, or via a vacuum pump or gas exclusion device Is what you do.

The exhaust device 10 has a cylindrical trap shell 12. The trap shell 12 has one end closed by a bottom wall 14 and a flange 16 provided at the other open end. At the other end of the opening, the sealing plate 18
Is attached to this flange 16 via an O-ring,
For example, it is fixed with bolts or the like. Further, at a portion close to the flange 16, a gas inflow pipe portion 20 which is a gas inflow port protrudes from a side wall portion of the trap shell 12, and the above-described film forming processing apparatus, etching processing apparatus, or ion implantation processing is performed. Reactive gas or ionic gas exhausted from a processing apparatus such as an
From the trap shell 12.

Further, the exhaust device 10 includes a double pipe member 22 disposed in the trap shell 12. The double pipe member 22 has a cylindrical inner wall 24 and an outer wall 26, and an annular space 28 is formed between the inner wall 24 and the outer wall 26 in a closed structure. One end of the inner wall 24 close to the bottom wall 14 of the trap shell 12 opens into the trap shell 12, and the other end penetrates through the sealing plate 18 and projects outside the trap shell 12. The other end of the inner wall 24 projecting from the trap shell 12 forms a gas outlet pipe portion 30 which is an outlet from the exhaust device 10,
The gas outlet pipe portion 30 is connected to the trap shell 1 via an internal flow path formed in the internal wall 24 and an open end.
2 inside.

At the outer periphery of the double pipe member 22, an inflow pipe 2
The fins 36 are helically arranged from the portion facing the zero to the portion adjacent to the open one end. The fins 36 in the present embodiment are formed from a plurality of fin plates 38 in the shape of an annular plate penetrating the center as shown in FIG. These fin plates 38
Is placed upright against the outer wall 26,
2 and is formed in a continuous spiral along the axial direction, and the inner peripheral edge thereof and the outer wall of the double pipe member 22 are integrally formed by welding. The edges are also welded together by welding to form a continuous band.

An annular space 28 formed in a closed structure between the inner wall 24 and the outer wall 26 of the double pipe member 22.
Is connected to a medium supply pipe 32 and a medium discharge pipe 34 for circulating a cooling medium such as cooling water in the annular space 28. Medium supply pipe 32 in the present embodiment
Extends through the sealing plate 18 in the annular space 28 in the axial direction, and opens into the annular space 28 near one open end of the double pipe member 22. On the other hand, the medium discharge pipe 34 penetrates the sealing plate 18 and
8 and opens into the annular space 28 near the sealing plate 18. Therefore, the medium such as cooling water
It flows through the annular space 28 from one open end to the other end.

In the annular space 28, water or the like can be circulated as a cooling medium when exhaust gas is cooled, and water is used when cooling the double pipe member 22 to 0 ° C. or lower. Instead, it is preferable to circulate a cooling medium such as glycerin. On the other hand, for example, tungsten fluoride (W
When used in a film forming apparatus for forming a tungsten film using F6), tungsten fluoride is decomposed at 120 ° C. or more under atmospheric pressure to precipitate tungsten, and therefore, instead of a cooling medium such as cooling water, A heating medium such as a heated liquid is circulated. When heating is performed in this manner, a heater can be arranged in the annular space 28.

The operation of the exhaust device 10 according to this embodiment is as follows. Exhaust gas discharged from the above-described various processing devices flows into the trap shell 12 from the gas inflow pipe portion 20, and flows along the spiral flow path formed by the fins 36 and the outer wall. It flows in the direction of the bottom wall 14 while contacting 26. Further, the double pipe member 22
Flows through the internal flow path in the internal wall 24 from the opened one end while contacting the internal wall 24, and is discharged from the gas outflow pipe portion 30. When a cooling medium such as water is circulated in the annular space 28 of the double pipe member 22, the gas inflow pipe section 2
The exhaust gas that has flowed into the trap shell 12 from the outside is cooled on the surfaces of the outer wall 26 and the fins 36 of the double pipe member 22, and further, while flowing through the internal flow path of the inner wall 24, It is also cooled by the inner walls, and therefore
The fine powder in the exhaust gas grows into a large powder, and the condensable gas becomes solid and adheres to the surfaces of the fins 36, the outer wall 26, and the inner wall 24. Further, mist in the exhaust gas also adheres to the outer wall 26, the fins 36, and the inner wall 24.

Therefore, in the exhaust device 10 of the present embodiment, due to the temperature difference between the exhaust gas flowing into the trap shell 12 and the medium circulating in the annular space 28 in the double pipe member 26, the exhaust gas The powder, mist, or condensable gas contained in this trap shell 12
After being trapped and removed in the exhaust gas, the exhaust gas is discharged from the gas outlet pipe section 30.

FIG. 2 shows an exhaust device 1 according to this embodiment.
The scrubbing effect of 0 is explained in comparison with a conventional water-cooled trap as shown in FIG. FIG. 2A schematically shows the relationship between the distance from the cooling pipe 4 of the conventional water-cooled trap or the outer surface of the double pipe member 22 of the exhaust device 10 in the present embodiment and the temperature. (B) schematically shows the relationship between the distance from the inner surface of the double pipe member of the exhaust device 10 and the temperature in the present embodiment.

Here, the vertical axis of the graphs shown in FIGS. 2A and 2B is the difference between the temperature of the heat transfer surface, that is, the surface of the cooling pipe 4 and the double pipe member 22, and the specific temperature of the exhaust gas. ΔT
(Absolute value) is expressed as a relative value as a temperature difference between the gas intrinsic temperature and the surface temperature. Therefore, a small ΔT means that the exhaust gas is sufficiently cooled by the cooling pipe or the like, and a large ΔT means that the exhaust gas is not cooled by the cooling pipe or the like. The horizontal axis represents the distance d from the surfaces of the cooling pipe 4 and the double pipe member 22. r is the radius of the heat transfer surface of the cooling pipe 4 and the double pipe member 22, that is, the radius of the surface. The specific heat of the gas is sufficiently smaller than the specific heat of the cooling pipe 4 or the double pipe member 22, the exhaust gas flows smoothly, and the heat is propagated by the diffusion based on the temperature gradient. , Have evaluated. The flow rate of the exhaust gas was the same both in the case of the outside (FIG. 2A) of the cooling pipe 4 or the double tube member 22 and in the case of the inside part (FIG. 2B). The result of this ideal condition is in good agreement with the actual effect.

As apparent from FIG. 2A, in the conventional water-cooled trap, the lowest temperature point is the cooling pipe 4.
Is the outer peripheral surface, that is, the surface. When the cooling effect is calculated from the structure of the cooling pipe 4, the temperature of the exhaust gas in the direction outside the cooling pipe 4 sharply differs from the surface temperature of the cooling pipe 4 as the distance from the cooling pipe 4 increases. Becomes larger and returns to the gas-specific temperature, so that the further away from the surface, the less the exhaust gas is cooled. That is, the cooling effect is reduced. On the other hand, as shown in FIG. 2B, inside the double pipe member 22, the temperature of the exhaust gas is different from the outward direction shown in FIG. Even at the separated central position, the difference ΔT from the surface temperature is not so large, and therefore the temperature of the surface of the double pipe member 22 is maintained considerably. That is, the exhaust gas is considerably cooled by the cooling medium, the cooling effect is less reduced, and a sufficient scrubbing effect is obtained.

As is clear from FIG. 2A, FIG.
In the case where the conventional water-cooled trap 4 shown in FIG. 1 is used, although the powder or the adhered matter adheres to the cooling fins 8, the place where the amount of the most adhered is the cooling pipe 4, that is, the outer peripheral surface. When a certain amount of powder or solid matter adheres to the surface of the cooling pipe 4, the surface thermal conductivity of the cooling pipe 4 is reduced, and the cooling capacity of the cooling pipe 4 is reduced. In this case, the scrubbing effect is also reduced, so that powder or condensable gas cannot be finally removed. Therefore, in order to extend the life of the trap effect in the conventional water-cooled trap, it is necessary to increase the surface area inside the trap, and therefore, it is necessary to increase the axial length of the cooling pipe 4. The size itself increases.

On the other hand, the exhaust device 10 according to the present embodiment employs a double tube member 22 as shown in FIG.
A medium for cooling or the like is circulated in the internal space 28 of the double pipe member 22, so that not only the outer peripheral surface but also the inner peripheral surface can act as a heat transfer surface. Double pipe member 22
In the internal flow path formed by the internal wall 24, the temperature difference ΔT from the surface, that is, the inner peripheral surface does not increase even in the central portion most distant from the inner peripheral surface, and the exhaust gas is considerably cooled. A scrubbing effect can be obtained throughout the internal flow path.

Further, since the specific heat of the gas of the cooling medium is much smaller than that of the refrigerant, the temperature of the cooling medium hardly increases during the circulation in the internal space 28 of the double pipe member 22. In other words, since the scrubbing effect can be obtained with a small volume of the cooling medium, it is not necessary to increase the volume of the annular space 28 of the double pipe member 22, and therefore, the outer diameter of the double pipe member 22 is reduced. Need not be formed large.

In addition to cooling the exhaust gas, as described above, when the film is used in a film forming apparatus for forming a tungsten film using tungsten fluoride (WF6), the cooling medium such as cooling water may be used. Alternatively, even in the case of circulating a heating medium such as a heated liquid, the temperature difference between the exhaust gas and the outer and inner peripheral surfaces of the double pipe member 22 is effectively reduced in the same manner as in the case of circulating the cooling medium. It is clear that the scrubbing effect can be obtained with a small amount of heating medium. Also in this case, the tungsten adheres to the surfaces of the fins 36, the outer wall 26, and the inner wall 24.

Therefore, the exhaust device 10 according to the present embodiment can maintain the trapping effect for a long period of time while having a very compact structure in the axial direction and the radial direction.

Actually, the exhaust device 10 according to the present embodiment shown in FIG. 1 and the conventional water-cooled trap shown in FIG. 11 were connected to the exhaust side of the above-mentioned processing apparatus, and the trap life was compared. In this case, as the life of the trap, a period until the exhaust pressure of the vacuum pump becomes high due to clogging of the exhaust system including the trap and the exhaust pipe downstream of the trap and the pump is stopped due to abnormal exhaust pressure is adopted. The results are as follows. However, the exhaust gas from the tungsten film forming apparatus is a comparison between the trap according to the related art shown in FIG. 11 and the exhaust apparatus shown in FIG. 10 described later. In order to do so, a description will be given here together with a comparison result of the exhaust device 10 of FIG.

A comparison of the trap life of the exhaust gas from the SiO ₂ film forming apparatus with silicon dioxide as the object of scrubbing shows that the conventional water-cooled trap shown in FIG. The exhaust device 10 according to the present embodiment shown in FIG. Si ₃ N ₄
In the comparison of the trap life of the exhaust gas from the film forming apparatus with ammonium chloride as the object of scrubbing, the conventional water-cooled trap shown in FIG. 11 was 3 months whereas the conventional water-cooled trap shown in FIG. Exhaust device 10 by form
Was six months. A comparison of the trap life of the exhaust gas from the Al etching apparatus with aluminum chloride as the object of scrubbing showed that the conventional water-cooled trap shown in FIG. The exhaust device 10 according to the configuration has been 1.5 years. A comparison of the trap life of the exhaust gas from the phosphorus ion implantation apparatus with the object of scrubbing being phosphorus shows that the conventional water-cooled trap shown in FIG. 11 was one year, whereas the conventional water-cooled trap shown in FIG. Exhaust system by configuration was 2 years.

With respect to the exhaust gas from the tungsten film forming apparatus, the object of scrubbing is metal tungsten, and the trap life when the heater is heated instead of the cooling medium is determined by the wear life of the vacuum pump located downstream of the trap. Then, in the conventional trap (using a heating medium) shown in FIG. 11, the trap life was 4 months, whereas the exhaust device 1 according to the embodiment shown in FIG.
At 0, it was 11 months.

Thus, the exhaust device 1 according to the present embodiment will be described.
It was confirmed that the trap life of 0 was extremely long. Further, when comparing the amount of powder or solid matter remaining inside, in the exhaust device 10 of the present embodiment,
The amount was about twice that of the conventional water-cooled trap shown in FIG. From this point as well, the exhaust device 10 according to the present embodiment
Was confirmed to be about twice as long as the conventional water-cooled trap.

FIGS. 3 to 10 show an exhaust device 10 according to another embodiment of the present invention. The following embodiment is basically the same as the embodiment shown in FIG. 1, and therefore, the same parts as those in the embodiment shown in FIG. Detailed description is omitted.

The exhaust device 10 shown in FIG.
In addition, a plurality of slits 40 are formed, and a flow path that bypasses the spiral flow path is formed between the gas inflow pipe section 20 and the opening of one end of the double pipe member 22. The slit 40 in the present embodiment is formed on one side of the double pipe member 22 adjacent to the gas inflow pipe section 20 and between the opposing side edges of the adjacent fin plate 38.

The exhaust device 10 according to this embodiment is particularly suitable for exhaust gas containing a large amount of powder. That is, when the exhaust device 10 is arranged with its axis line substantially in the horizontal direction, the powder in the exhaust gas tends to stay below the double pipe member 22, and the powder staying below this causes the powder inside the trap shell 12 to stay inside the trap shell 12. The exhaust gas passage may be blocked. When the flow path of the exhaust gas is blocked in this way, the exhaust device 10 itself causes the exhaust system of the processing device to be blocked.

In the exhaust device 10 of the embodiment shown in FIG. 3, a considerable amount of powder stays between the trap shell 12 and the lower side of the double pipe member 22, that is, on the opposite side of the gas inflow pipe portion 20. Also, a plurality of slits 4 formed in the fin 36 on one side of the double pipe member 22 close to the gas inflow pipe section 20.
By forming a bypass flow path between the gas inflow pipe portion 20 and the opening at one end of the double pipe member 22, the flow path of the exhaust gas can be secured. Also in this case, it is apparent that the scrubbing effect can be obtained by the double pipe member 22.

FIG. 4 shows an exhaust device 10 according to still another embodiment of the present invention. The exhaust device 10 uses the property that the powder in the exhaust gas is separated from the exhaust gas, which is a gas, by gravity and stays below the trap shell 12 when the powder becomes almost stationary, so that the powder in the trap shell 12 This makes it easier for the powder to be retained.

In the exhaust device 10 according to the present embodiment, similarly to the above-described embodiment, the axis is disposed in a substantially horizontal direction, and the space between the fin plates 38 is lower than the upper side below the double pipe member 22. Are also roughly arranged. As a result, the flow rate of the exhaust gas flowing along the spiral flow path outside the double pipe member 22 decreases below the double pipe member 22. Due to the decrease in the flow rate of the exhaust gas, the powder is easily separated from the exhaust gas below the double pipe member 22, and the exhaust device 1
Powder is prevented from flowing into the exhaust system downstream of zero. That is, in the exhaust device 10 of the present embodiment, the effect of trapping the powder is higher.

FIG. 5 shows an embodiment in which the scrubbing effect on condensable gas is further enhanced. The exhaust device 10 according to the present embodiment includes a trap shell 12 as shown in FIG.
And a jacket 42 arranged on the outer peripheral surface of the main body. The annular space 44 of the jacket 42 is provided with a medium communication pipe 46.
Thereby, it communicates with the annular space 28 of the double pipe member 22.

In the exhaust device 10 according to the present embodiment, a medium such as a cooling medium is supplied into the annular space 28 of the double pipe member 22 near the gas inlet pipe section 20 by the medium supply pipe 32, It flows toward one open end of the tube member 22, and is then fed into the annular space 44 of the jacket 42 by the medium communication tube 46. In the annular space 44 of the jacket 42, the gas flows from a portion close to the gas inflow pipe portion 20 toward the bottom wall 14, and is discharged from the medium discharge pipe 34 to the outside.

Therefore, the exhaust device 10 according to the embodiment of FIG. 5 can further enhance the scrubbing effect by, for example, cooling the exhaust gas from the outside of the trap shell 12. Of course, in the case of exhaust gas containing WF 6 as a condensable gas, scrubbing of the exhaust gas is performed by supplying a heating medium to both annular spaces 44 and 28 of the jacket 42 and the double pipe member 22.

FIG. 6 shows an embodiment in which the scrubbing effect is enhanced for exhaust gas containing a large amount of condensable gas to extend the trap life, that is, the life of the exhaust system.

That is, in the exhaust device 10 according to the embodiment shown in FIG. 6, a fin plate 48 is added immediately below the gas inflow pipe portion 20 so that a scrubbing effect can be obtained also in this portion. . The additional fin plate 48 is provided below the double pipe member 22, that is, on the side opposite to the gas inflow pipe section 20, and is not located in the flow path of the exhaust gas. Therefore, even if a large amount of adhered matter adheres to the added fin plate 48, the flow of the exhaust gas is not hindered. Therefore, even if the scrubbing effect increases,
Trap life is not shortened.

FIGS. 7 to 9 show an embodiment in which the area of the fin 36 is enlarged so that powder and the like can be more efficiently captured. FIG. 7A shows one such embodiment, in which the inner peripheral side of the fin 36 near the double tube member 22 is formed in a wavy shape. FIG. 7B
7A shows a fin plate 38 forming the fin 36 in each of the above embodiments other than the embodiment of FIG. 7A, and FIG. 7C shows the fin plate 38 of the embodiment shown in FIG. Fin plate 50 for forming fins 36 in form
Is shown. The symbol r is the radius of the outer wall 26 of the double tube member 22, and the symbol R is the radius of the outer edge of the fin 36.

The disk-shaped fin plate 38 shown in FIG. 7B has a central portion penetrating therethrough. By extending the opposed side edges in the axial direction of the double pipe member 22, the fin plate 38 is formed. With the surface standing upright from the outer wall 26, the double tube member 22 is spirally arranged along the axial direction of the double tube member 22. The fin 36 shown in FIG. 1 can be formed by welding and fixing the inner peripheral edge to the outer wall 26 and welding and fixing the opposite side extending portions of the similar fin plate 38 to each other.

On the other hand, the fin 3 shown in FIG.
6 is formed from an elongated band-like fin plate 50 as shown in FIG. This fin plate 50
Has a pair of long edges 52 and 54 and is welded and fixed to the inner peripheral side, that is, to the outer wall 26 of the double pipe member 22.
Are formed along the small curved portion 56. These small curved portions 56 are bent so as to alternately protrude around the virtual spiral line 58 on the double pipe member 22 at one end and the other end in the axial direction of the double pipe member 22. Therefore, a wavy shape is formed at the inner peripheral long edge 52.
These small curved portions 56 gradually become smaller toward the other long edge portion 54, and the long edge portion 54 arranged on the outer peripheral side forms a smooth spiral shape along the virtual spiral line 58.

By doing so, the area of the fin 36 shown in FIG. 7A becomes larger than that of the fin 36 shown in FIG. Assuming that the radius of the outer wall of the double pipe member 22 is r and the radius of the fin 36 as viewed from the axial center of the double pipe member 22 is R, the outer circumference of the disc-shaped fin plate 38 shown in FIG. The length is 2πR, and the area (referred to as A1) of the fin plate 38 is π (R ² −r ² ) per pitch. On the other hand, in the fin 36 shown in FIG. 7A formed by bending the elongated band-shaped fin plate 50 shown in FIG. 7C, the area (A2) which can be formed by the outer circumference 2πR is also: It is 2πR (R−r) per pitch. Taking these ratios, A2 / A1 = {2 · (1-r / R)} / {1- (r /
R) ² ｝. This is illustrated in FIG. 7D. That is, the area of the fin 36 shown in FIG. 7A can be increased by about several tens of percent compared with the disk-shaped fin plate 38. This is the exhaust system 10
Contributes to extending the trap life.

FIGS. 8A and 8B show the fins 36.
Another embodiment in which the area of is increased. The fin 36 in this embodiment has a large number of small curved portions or bent portions 66 in which the fin plate 60 is bent from the inner peripheral edge 62 to the outer peripheral edge 64. The fin plate 60 has an inner peripheral side edge portion 62 spirally extending on the outer peripheral surface of the double pipe member 22. In this embodiment, the bending angle is about 38 degrees on the outer peripheral surface of the double pipe member 22, and the area is increased by about 18% as compared with the fin 36 in the embodiment of FIG.

FIG. 9 shows an exhaust device 10 suitable for a case where the flow rate of the exhaust gas is not large but sufficient cooling is required. The outer wall 70 of the double pipe member 22 is provided with a welding bellows pipe as shown,
To form An annular space 28 is formed between the bellows and the inner wall 24. As a result, the surface area of the outer wall 70 is formed to be at least twice as large.

The exhaust device 10 according to the present embodiment can be suitably used particularly for scrubbing ionic gas. In the exhaust gas containing the ionic gas, the amount of the deposit is not large, but the fine powder adheres to the gap of the pump mechanism in the exhaust system, and the pump is easily stopped. By attaching the exhaust device 10 according to the present embodiment to an upstream portion of a pump (not shown), fine powder can be effectively removed.

FIGS. 10A and 10B show an embodiment in which the gas outlet pipe portion 30 is projected from the cylindrical side wall of the trap shell 12. The gas outlet pipe portion 30 in this embodiment is projected from the cylindrical side wall of the trap shell 12 at a portion radially opposite to the gas inlet pipe portion 20, but is not limited thereto. It is also possible to protrude from an appropriate position close to the gas inflow pipe section 20 in the axial direction on the 12 cylindrical side walls. This is made possible by the double pipe member 22 forming an internal flow path. Thereby, the degree of freedom in attaching the processing device to the exhaust system can be increased.

[0058]

According to the exhaust system of the present invention, a trap shell having an inflow port into which gas flows, an opening formed in the trap shell at one end, and gas trapped from the opening through an internal flow path are provided. A double pipe member comprising: an inner wall formed at the other end with an outlet for flowing out of the shell; and an outer wall forming an annular space having a closed structure between the inner wall and the double pipe member. At least one fin projecting from the outer wall of the trap shell toward the trap shell and contacting the gas; and a medium supply port and a medium discharge port for circulating a cooling or heating medium in the annular space. Due to the temperature difference between the gas flowing into the shell and the medium circulating in the double pipe member, at least one of the powder, mist, and condensable gas contained in the gas is trapped in the trap shell. By 捉, while a compact structure, it is possible to maintain the trapping effect over a long period of time.

The fin includes an elongated fin plate which is spirally wound with one of the pair of long edges fixed to the outer wall of the double pipe member. In the case where the heavy pipe member has a wavy shape including a plurality of small curved portions that alternately protrude from one end side and the other end side in the axial direction, the area of the fin increases, and the life of the trap can be prolonged.

A plurality of fins are fixed in an inner peripheral portion to an outer wall of the double pipe member, and are helically arranged along the axial direction of the double pipe member in a state of standing upright from the outer wall. If the slits are formed between the adjacent side edges of these fin plates, these slits are doubled even if the powder in the exhaust gas stays below the double pipe member. By forming a bypass flow path outside the pipe member, the scrubbing effect can be maintained for a long period of time.

When a jacket portion is arranged on the outer peripheral surface of the trap shell and the medium is circulated also inside the jacket portion, the trap shell also produces a scrubbing effect similarly to the double tube member, and therefore, the trap shell has a trapping effect. The effect increases.

A trap shell has a cylindrical side wall, a gas inflow pipe projecting from the side wall to form the gas inflow port, and a portion in axial proximity to the gas inflow section from the side wall. A protruding gas outlet pipe portion, and the inner wall of the double pipe member has an inner wall formed with an outlet for communicating with the gas outlet pipe portion when the processing device is attached to the exhaust system. Can be increased.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an internal structure of an exhaust device according to a preferred embodiment of the present invention.

FIG. 2 is a diagram for explaining the scrubbing effect of the exhaust device according to the present invention in comparison with a conventional water-cooled trap.

FIG. 3 is an explanatory view schematically showing an internal structure of an exhaust device according to another embodiment.

FIG. 4 is an explanatory view schematically showing an internal structure of an exhaust device according to still another embodiment.

FIG. 5 is a schematic explanatory view of an exhaust device according to still another embodiment in which a jacket is arranged outside a trap shell.

FIG. 6 is an explanatory view schematically showing an internal structure of an exhaust device according to still another embodiment.

FIG. 7 is a view for explaining another fin structure, and FIG.
Is an explanatory view of a state where the fin is attached to the double pipe member,
(B) is a diagram of a fin plate for forming a fin used in the exhaust device shown in FIG. 1; (C) is an explanatory diagram of a fin plate for forming the fin of (A);
The graph figure which compares the area of the fin plate of (B) and (C).

8A is a diagram showing a fin having a deformed structure of FIG. 7A, FIG. 8A is a schematic perspective view showing a state where the fin is attached to a double pipe member, and FIG. FIG.

FIG. 9 is an explanatory view of an exhaust device having fins of still another modified structure.

10A and 10B are diagrams illustrating a modified structure of the trap shell, in which FIG. 10A schematically illustrates an internal structure, and FIG. 10B is a schematic perspective view.

FIG. 11 is a view showing a conventional water-cooled trap.

[Explanation of symbols]

10 exhaust device, 12 trap shell, 14 bottom wall,
16: flange, 18: sealing plate, 20: gas inflow pipe,
22 ... double pipe member, 24 ... inner wall, 26, 70 ... outer wall, 28, 44 ... annular space, 30 ... gas outflow pipe part,
32: medium supply pipe, 34: medium discharge pipe, 36: fin,
38, 50, 60 ... fin plate, 40 ... slit,
42 ... jacket, 46 ... connecting pipe, 52, 54, 62,
64: long edge portion, 56, 66: small curved portion, 58: virtual spiral line.

Claims (5)

[Claims] At least one of a film forming process in a reactive gas, an etching process in a reactive gas, and an ion implantation process in an ionic gas is performed by at least one of a semiconductor and a metal. From the processing device applied to the formed workpiece,
An exhaust device for exhausting a gas directly or through at least one of a vacuum pump and a gas exclusion device, comprising a trap shell having an inflow port into which the gas flows, and an opening that opens into the trap shell at one end. An inner wall formed at the other end with an outlet formed at the other end to allow gas to flow out of the trap shell through the internal flow path from the opening, and an outer wall forming a closed annular space between the inner wall and the inner wall And a fin protruding from the outer wall of the double pipe member toward the trap shell side and in contact with gas; and circulating a cooling or heating medium in the annular space. A medium supply port and a medium discharge port, and are contained in the gas due to a temperature difference between the gas flowing into the trap shell and the medium circulating in the annular space. Exhaust system to trap in the trap shell at least one of the powder and mist and condensable gases. 2. The fin includes an elongated fin plate spirally wound with one of a pair of long edges fixed to an outer wall of a double tube member, and one long edge of the fin plate. 2. The exhaust device according to claim 1, wherein the exhaust device has a wavy shape including a plurality of small curved portions that alternately protrude from one end side and the other end side in the axial direction of the double pipe member. 3. A plurality of fins having an inner peripheral portion fixed to an outer wall of a double tube member and helically arranged along the axial direction of the double tube member in a state of standing upright from the outer wall. The exhaust device according to claim 1, further comprising a fin plate, wherein a slit is formed between adjacent side edges of the fin plate. 4. The exhaust device according to claim 1, further comprising a jacket disposed on an outer peripheral surface of the trap shell and through which the medium is circulated. 5. The trap shell includes a cylindrical side wall, a gas inflow pipe protruding from the side wall and forming the gas inflow port, and a side in a portion axially adjacent to the gas inflow section. The exhaust device according to any one of claims 1 to 4, further comprising a gas outlet pipe protruding from the outer wall, wherein the other end of the inner wall of the double pipe member communicates with the gas outlet pipe. .