JP2006314864A - Trapping apparatus for exhaust gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain an exhaust route of a trapping apparatus for exhaust gas from being clogged locally. <P>SOLUTION: A diffusion plate 13 having the cross-sectional area larger than that of an opening of an exhaust gas introduction port 10 is arranged in a cylindrical housing 5 so that the diffusion plate is opposed to the introduction port 10. Cooling coils 17-22 are arranged between the diffusion plate 13 and a flange 7. The exhaust gas 23 introduced from the introduction port 10 is dispersed conically, made to flow in an upstream zone D along an inner wall of the housing 5 and then flow dispersedly in downstream zones E1-E4 and discharged through a discharge pipe 9 and a discharge port 8. Since the exhaust gas 23 flows dispersedly in the trapping apparatus for exhaust gas, the unreacted gas contained in the exhaust gas 23 is accumulated dispersedly in the trapping apparatus for exhaust gas. As a result, the exhaust route can be restrained from being clogged locally and the service life of the trapping apparatus for exhaust gas can be prolonged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an exhaust trap apparatus, and more particularly to an exhaust trap apparatus that removes unreacted gas discharged from a semiconductor manufacturing apparatus.

  In the manufacture of semiconductor devices, films such as InP (indium phosphide) and AlGaInP (aluminum gallium indium phosphide) are formed by a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus. When forming the above film, exhaust gas is discharged from the reactor of the CVD apparatus. This exhaust gas contains unreacted gas such as phosphine. This unreacted gas is collected by an exhaust trap device.

FIG. 5 shows a cross-sectional view of a conventional exhaust trap apparatus.
The exhaust trap device has a housing 31. The housing 31 includes an exhaust gas inlet 32 and an exhaust gas outlet 33. A cooling coil 34 for cooling the exhaust gas is provided inside the housing 31.
Exhaust gas discharged from a CVD apparatus (not shown) is introduced from the introduction port 32, and is discharged from the outlet port 33 via the region 35 immediately below the introduction port, the upstream region 36, and the downstream region 37. During this time, the exhaust gas is cooled inside the exhaust trap device. When the temperature of the exhaust gas is lowered to a predetermined temperature, a part of the unreacted gas is solidified and accumulated as a deposit in the exhaust trap apparatus. And exhaust gas is discharged | emitted from an exhaust trap apparatus in the state which made the density | concentration of unreacted gas low enough (for example, refer patent document 1).

JP-A-8-290050

  In the conventional exhaust trap device, the path through which the exhaust gas passes has a serial structure. For this reason, when the exhaust gas passes through the route, the route is likely to be locally blocked by deposits. As a result, the exhaust trap device had to be replaced even though the non-blocked portion of the path had the ability to collect unreacted gas.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to suppress the local blockage of a path through which exhaust gas passes in an exhaust trap apparatus and to extend the life of the exhaust trap apparatus. .

An exhaust trap apparatus according to the present invention is provided with a cylindrical housing, an exhaust gas inlet provided in the housing, and opposed to the exhaust gas inlet inside the housing, and a gap between the inner wall of the housing and the gap A plate larger than the opening cross section of the exhaust gas inlet, a cooling means provided around the central axis of the housing inside the housing, and a refrigerant supply means connected to the cooling means, And a conduit extending from the inside of the cooling means to the outside of the housing.
Other features of the present invention are described in detail below.

  According to the present invention, in the exhaust trap apparatus, it is possible to suppress the local passage of the path through which the exhaust gas passes and to extend the life of the exhaust trap apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an entire exhaust trap apparatus according to the present embodiment and a semiconductor manufacturing apparatus including the exhaust trap apparatus.
The semiconductor manufacturing apparatus shown in FIG. 1 is a MOCVD (Metal Organic Chemical Vapor Deposition) apparatus for forming a film such as InP (indium phosphide) or AlGaInP (aluminum gallium indium phosphide). This CVD apparatus has a reaction furnace 1. An exhaust trap device 2 is connected to the reaction furnace 1. A throttle valve 3 is connected to the exhaust trap device 2. A pressure reducing pump 4 is connected to the throttle valve 3.
The above-described films such as InP and AlGaInP are formed in the reaction furnace 1. Then, exhaust gas is discharged from the reaction furnace 1 to the exhaust trap device 2. This exhaust gas includes reaction products generated in the reaction furnace 1, unreacted gases that did not contribute to film formation in the reaction furnace 1, and the like. These reaction products and unreacted gas (hereinafter simply referred to as “unreacted gas”) are collected by the exhaust trap device 2. Further, the exhaust gas is discharged to the outside of the CVD apparatus via the throttle valve 3 and the decompression pump 4.

  A method for collecting the above-mentioned unreacted gas will be described. The exhaust gas discharged from the reaction furnace 1 shown in FIG. 1 is introduced into the exhaust trap device 2. The exhaust gas is cooled inside the exhaust trap device 2. When the temperature of the exhaust gas becomes equal to or lower than a predetermined temperature, a part of the unreacted gas becomes a deposit and accumulates inside the apparatus. In this way, the exhaust gas passes through the exhaust trap device 2 while reducing the concentration of the unreacted gas. And it is discharged | emitted outside the CVD apparatus in the state which made the density | concentration of unreacted gas small enough.

FIG. 2A is a cross-sectional view of the exhaust trap device 2 shown in FIG. First, the configuration of this apparatus will be described.
The exhaust trap device has a housing 5. The housing 5 has a cylindrical shape with AA ′ as the central axis. At both ends of the housing 5, flanges 6 and 7 are provided, respectively. On the side surface of the central portion of the housing 5, an outlet 8 is provided with BB ′ as the central axis. A lead-out pipe 9 is connected to the lead-out port 8 with AA ′ as the central axis inside the housing 5. One open end 9 a of the outlet pipe 9 is disposed so as to face the flange 6. The other open end 9 b of the outlet pipe is disposed so as to face the flange 7. The flange 6 is provided with an introduction port 10 having AA ′ as a central axis. The flange 6 is provided with a cooling water inlet 11 and a cooling water outlet 12. A diffusion plate 13 is connected to the cooling water inlet 11 and the cooling water outlet 12 inside the housing 5. The end of the diffusion plate 13 is bent in the direction of the flange 7. The diffusion plate 13 faces the introduction port 10. The portion of the diffusion plate 13 that faces the inlet 10 is larger than the opening cross section of the inlet 10 and smaller than the opening cross section of the housing 5. A cooling water inlet 14 and a cooling water outlet 15 are provided in the flange 7. Inside the housing 5, a rectifying plate 16 is provided on the flange 7.
A cooling coil 17 is fixed so as to contact the end of the diffusion plate 13. The cooling coil 17 is arranged in a cylindrical shape so as to surround the central axis AA ′. Inside the cooling coil 17, the cooling coil 18 is arranged in a cylindrical shape so as to surround the central axis AA ′. Inside the cooling coil 18, a cooling coil 19 is arranged in a cylindrical shape so as to surround the central axis AA ′. The cooling coils 17, 18, and 19 are connected to each other. Cooling coils 20, 21, and 22 are arranged in a cylindrical shape at positions symmetrical to the cooling coils 17, 18, and 19 with the central axis BB ′ in between. The cooling coil 20 is fixed so as to be in contact with the end of the rectifying plate 16. The cooling coils 20, 21, and 22 are connected to each other.

The arrangement of the cooling coils 17, 18, and 19 will be described in detail.
FIG. 2B is an enlarged view of a part of the cooling coils 17, 18 and 19 shown in FIG. The interval between the housing 5 and the cooling coil 17 is d1, the interval between the cooling coils 17-18 is d2, the interval between the cooling coils 18-19 is d3, and the interval between the cooling coil 19 and the outlet tube 9 is d4. For example, it arrange | positions so that it may become d1> d2 = d3> d4.
Thus, the space | interval d1 of the housing 5 and the cooling coil 17 is arrange | positioned so that it may become relatively larger than said d2, d3, d4.

Next, a cooling unit for cooling the inside of the exhaust trap device will be described. The cooling unit includes the above-described plurality of cooling coils and a circulation system for cooling them. The circulation system includes a cooling water inlet 11, a cooling water outlet 12, and a diffusion plate 13. When cooling water is introduced from the cooling water inlet 11, it is discharged through the inside of the diffusion plate 13 and the cooling water outlet 12. As described above, the diffusion plate 13 contacts the cooling coil 17, and the cooling coils 17, 18, and 19 are connected to each other. For this reason, when the cooling water passes through the inside of the diffusion plate 13, the cooling coils 17, 18, and 19 can be cooled. Thus, the cooling coils 17, 18, 19, the cooling water inlet 11, the cooling water outlet 12, and the diffusion plate 13 are configured by one system cooling unit. Similarly, the cooling coils 20, 21, 22, the cooling water inlet 14, the cooling water outlet 15, and the rectifying plate 16 are constituted by a single cooling unit.
With these cooling units, the temperature inside the exhaust trap device can be lowered.

Next, a process of collecting unreacted gas contained in the exhaust gas using the exhaust trap device shown in FIG. 2A will be described.
First, exhaust gas is discharged from the reaction furnace 1 shown in FIG. Next, as shown in FIG. 2A, the exhaust gas 23 is introduced from the introduction port 10 into the region C immediately below the introduction port. This gas flows in a conical manner toward the outer side of the diffusion plate 13 so as to be away from the central axis AA ′. During this time, a part of the exhaust gas 23 is cooled in the region C immediately below the inlet and becomes a deposit.
At this time, the exhaust gas 23 is cooled while being dispersed in a wide area from the area C immediately below the inlet. Thereby, it is possible to prevent the deposits from being concentrated and generated in the region C immediately below the inlet. Therefore, it is possible to prevent the inlet 10 from being locally blocked by deposits accumulated in this region.

Next, the exhaust gas 23 flows toward the flange 7 between the cooling coil 17 and the housing 5 and between the cooling coil 20 and the housing 5 (hereinafter referred to as “upstream region D”).
The exhaust gas 23 is cooled by the cooling coils 17 and 20 while flowing through the upstream region D. A part of the unreacted gas becomes a deposit and accumulates on the inner wall of the housing 5 and the surfaces of the cooling coils 17 and 20. At this time, since the exhaust gas 23 flows in a distributed manner along the inner wall of the housing 5, it is possible to prevent the upstream region D from being locally blocked.
Further, as shown in FIG. 2B, the interval d1 between the housing 5 and the cooling coil 17 is disposed to be relatively larger than d2, d3, and d4. For this reason, the amount of deposits that can be accumulated in the upstream region D can be increased. Thereby, it can suppress more effectively that upstream field D obstruct | occludes locally.

Next, the exhaust gas 23 flows through a region (hereinafter referred to as “downstream region E1”) between the rectifying plate 16 and the central axis AA ′ via a hole 16 a provided in the rectifying plate 16. The exhaust gas 23 is discharged from the opening end 9b via the outlet pipe 9 and the outlet port 8. A part of the exhaust gas 23 flowing in the upstream region D branches near the central axis BB ′. Furthermore, a part thereof flows in a distributed manner between the cooling coils 20-21, between the cooling coils 21-22, and between the cooling coil 22 and the outlet pipe 9 (hereinafter referred to as “downstream region E2”). These exhaust gases are discharged via the downstream end E1 via the open end 9b, the lead-out pipe 9, and the lead-out port 8. Further, of the exhaust gas 23 branched near the central axis BB ′, the remaining portions not branched to the downstream region E2 side are between the cooling coils 17-18, between the cooling coils 18-19, and between the cooling coil 19 and the outlet pipe. It flows in a region between 9 (hereinafter referred to as “downstream region E3”). These exhaust gases pass through a region between the both ends of the diffusion plate 13 and the central axis AA ′ (hereinafter referred to as “downstream region E4”) through the opening end 9a, the outlet pipe 9, and the outlet port 8. It is discharged via.
The exhaust gas 23 is cooled by the cooling coils 18, 19, 21, and 22 while flowing through the downstream areas E1 to E4. A part of the unreacted gas becomes a deposit and accumulates on the surfaces of the cooling coil and the outlet tube 9. At this time, the exhaust gas 23 flows in a distributed manner in each region E1 to E4. Further, these exhaust gases flow in a distributed manner between the cooling coils in each region and between the cooling coils and the outlet pipe 9. Thereby, the deposit accumulated in the downstream areas E1 to E4 can be dispersed. Therefore, it can suppress that the downstream area | regions E1-E4 obstruct | occlude locally.

  According to the configuration of the exhaust trap apparatus described above, it is possible to disperse the path through which the exhaust gas passes through the inside of the apparatus, and to suppress the local blockage of the path. Thereby, the lifetime of the exhaust trap device can be extended.

  The exhaust trap device shown in FIG. 2A can easily take out the cooling coils 17 to 22 by detaching the flanges 6 and 7 from the housing 5. Thereby, cleaning and maintenance of the deposit generated in the cooling coil of the exhaust trap device can be easily performed.

Next, a modification of the present embodiment will be described.
The cooling coils 17, 18, and 19 of the exhaust trap apparatus shown in FIG. 2 (a) are connected to each other, and the cooling unit including these is constituted by one system. Moreover, the cooling coils 20, 21, and 22 are connected to each other, and the cooling unit including these is configured as one system. On the other hand, the cooling coils 17, 18, and 19 may be made independent from each other so that each cooling coil is included in an independent cooling unit. Similarly, the cooling coils 20, 21, and 22 may be made independent from each other, and each cooling coil may be included in an independent cooling unit.
By setting it as the said structure, the temperature of the upstream area | region D and downstream area | region E1-E4 shown to Fig.2 (a) can each be controlled independently. Thereby, the conductance (ease of flow) of the exhaust gas 23 inside the exhaust trap device can be controlled for each region. Therefore, the optimum temperature can be given to each cooling unit according to the type of exhaust gas and the concentration of unreacted gas, and the life of the exhaust trap device can be extended.

Embodiment 2. FIG.
FIG. 3 is a cross-sectional view of the exhaust trap apparatus according to the present embodiment. Here, the configuration different from that of the first embodiment will be mainly described.
As shown in FIG. 3, the cooling coil 17 is arranged in a tapered shape so that the diameter increases as the distance from the flange 6 increases. Inside the cooling coil 17, the cooling coil 18 is tapered with AA ′ as the central axis. Inside the cooling coil 18, a cooling coil 19 is tapered with AA ′ as the central axis. Each cooling coil becomes narrower as the distance from the housing 5 is closer to the central axis BB ′.
Cooling coils 20, 21, and 22 are arranged at positions symmetrical to the cooling coils 17, 18, and 19 with the central axis BB 'in between. Each cooling coil becomes narrower as the distance from the housing 5 is closer to the central axis BB ′.
Since other configurations are the same as those in the first embodiment, description thereof is omitted.

  According to the exhaust trap device having the above configuration, the conductance of the exhaust gas 23 in the upstream region D is reduced. For this reason, in the upstream area | region D, the time made to contact a cooling coil can be lengthened. Thereby, when the freezing point of the unreacted gas contained in the exhaust gas 23 is low or when the concentration of the unreacted gas is low, it is possible to prevent the deposit from being concentrated in the downstream regions E1 to E4. . Therefore, the life of the exhaust trap device can be extended.

Embodiment 3 FIG.
FIG. 4A is a cross-sectional view of the exhaust trap apparatus according to the present embodiment. FIG. 4B is a side view from the direction of the central axis AA ′ in FIG. Here, the configuration different from that of the first embodiment will be mainly described.
As shown in FIG. 4A, the exhaust trap apparatus according to the present embodiment is provided with introduction ports 10a and 10b on the side surface of the housing 5 at symmetrical positions with respect to BB ′. As shown in FIG. 4B, the introduction ports 10 a and 10 b are provided so that the central axis of each opening does not intersect with the central axis AA ′ of the housing 5. Note that the exhaust trap apparatus according to the present embodiment is not provided with the introduction port 10 shown in FIG. Since other configurations are the same as those in the first embodiment, description thereof is omitted.

Next, a method for collecting exhaust gas using the exhaust trap device will be described.
First, exhaust gas is introduced from the inlets 10a and 10b of the exhaust trap device. Then, as shown in FIG. 4A, a vortex convection 24 of the exhaust gas is generated. The vortex convection 24 circulates in the upstream region D in a spiral shape. A part of the exhaust gas circulating in the upstream region D is discharged via the downstream regions E1 to E4, the outlet pipe 9, and the outlet port 8.
By passing the exhaust gas as described above, it is possible to lengthen the time for the exhaust gas to contact the cooling coil in the upstream region D as compared with the case shown in FIG. Thereby, when the freezing point of the unreacted gas contained in the exhaust gas is low, or when the concentration of the unreacted gas is low, it is possible to prevent the deposit from being concentrated in the downstream regions E1 to E4. . Therefore, the life of the exhaust trap device can be extended.

1 is an overall view of a CVD apparatus including an exhaust trap apparatus according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view of the exhaust trap device according to the first embodiment. Sectional drawing of the exhaust trap apparatus which concerns on Embodiment 2. FIG. FIG. 6 is a cross-sectional view of an exhaust trap device according to a third embodiment. Sectional drawing of the conventional exhaust trap apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Reactor, 2 Exhaust trap device, 3 Throttle valve, 4 Pressure reduction pump, 5 Housing, 6,7 Flange, 8 Outlet, 9 Outlet, 10 Inlet, 11,14 Cooling water introduction, 13 Diffusion plate, 12 , 15 Cooling water outlet, 16 Current plate, 17-22 Cooling coil, 23 Exhaust gas, 24 Vortex convection (exhaust gas).

Claims (6)

A cylindrical housing;
An exhaust gas inlet provided in the housing;
A plate provided inside the housing so as to face the exhaust gas inlet, having a gap with the inner wall of the housing, and having a larger opening cross section than the exhaust gas inlet;
Cooling means provided around the central axis of the housing within the housing;
Refrigerant supply means connected to the cooling means;
A conduit from the inside of the cooling means to the outside of the housing;
An exhaust trap device comprising: A cylindrical housing;
An exhaust gas inlet provided on a side surface of the housing so that the central axis of the opening does not intersect the central axis of the housing;
A cooling means provided around a central axis of the housing between one bottom surface and the other bottom surface of the housing;
Refrigerant supply means connected to the cooling means;
A conduit from the inside of the cooling means to the outside of the housing;
An exhaust trap device comprising:   The exhaust trap apparatus according to claim 1 or 2, wherein the cooling means includes a plurality of cylindrical coils having different diameters arranged on a concentric shaft of the housing.   The exhaust trap apparatus according to claim 3, wherein the cooling means is connected to an independent refrigerant supply means for each coil having a different diameter.   The exhaust trap apparatus according to claim 3 or 4, wherein the coil is provided on one bottom surface side and the other bottom surface side of the housing.   6. The exhaust trap according to claim 5, wherein a diameter of each of the coils provided on the one bottom surface side and the other bottom surface side increases as the distance from the bottom surface on each side increases. apparatus.

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