JPH07256002A - Exhaust gas treatment apparatus - Google Patents

Abstract

PURPOSE:To adjust the position of a fin to be attached by fixing a fin position- adjusting fixture on the fin, and attaching the fin on a radiator pipe with the fixture detachably. CONSTITUTION:An exhaust gas inflow pipe 7 is inserted into a trap main body 2 from the outside of an upper support lid 4, and a radiator pipe 8 is extended to the bottom of the trap main body 2 by inserting it from the outside of the lid 4 through the middle of the main body 2. More than one fin 9 with protrusions is installed on the outer wall of the radiator pipe 8. The intervals of the fins 9 are adjusted to become narrower from the gas inflow side of the upper part of the main body 2 to the lower part. The fins 9 are attached on the radiator pipe 8 detachably. In this way, the contact area of exhaust gas is enlarged to increase efficiently the fixing amount of unreacted gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas treatment device used in semiconductor manufacturing equipment and the like.

[0002]

2. Description of the Related Art Conventionally, in semiconductor manufacturing equipment,
A harmful reaction gas is often used for manufacturing semiconductor wafers and the like. For example, in a polycincon CVD (chemical vapor phase) method in which silane exhaust gas flows out, it is necessary for safety to keep the silane concentration in the exhaust gas at 1% or less.

From this point of view, in this type of semiconductor manufacturing apparatus, exhaust gas is often introduced into a cold trap to remove harmful unreacted components.

FIG. 4 is a sectional view showing the structure of a conventional cold trap.

Inside the body 101 of this cold trap, a trap body 102 is provided with a predetermined space 1 from the body 101.
It is fixed to the upper support lid 104 with 03 interposed therebetween. A cooling gas such as nitrogen gas for cooling the trap body 102 flows into the gap 103 from the inlet 105 of the upper support lid 104, and the cooling gas is supplied to the upper support lid 1
It is discharged to the outside from the outflow port 106 of 04.

An exhaust gas inflow pipe 107 is connected to the inside of the trap body 102 from the outside of the upper support cover 104, and an exhaust gas outflow pipe 108 is connected to the upper support cover 10.
4 extends from the outside of the trap body 102 through the center of the trap body 102 to the bottom surface thereof. The exhaust gas outflow pipe 1
A plurality of fins 109 are welded to the outer wall of 08 at regular intervals.

According to the above cold trap, the fin 109 is also cooled as a result of cooling the outer wall surface of the trap body 102 by the cooling gas. When the exhaust gas flowing from the exhaust gas inflow pipe 107 toward the exhaust gas outflow pipe 108 comes into contact with the surface of the fin 109 cooled to such a low temperature, unreacted components in the exhaust gas are condensed and fixed on the surface of the fin 109 as a solid. In this way, the cold trap can collect and remove unreacted components in the exhaust gas.

[0008]

However, in the above-mentioned conventional cold trap, since the fins 109 are provided on the outer wall of the exhaust gas outflow pipe 108 at regular intervals, the untreated exhaust gas first flows near the gas inlet. Fin 1
In the process in which unreacted components are gradually removed and discharged while contacting 09, the ratio of unreacted components fixed to each fin 109 is higher than that in the vicinity of the gas outlet of the exhaust gas outlet pipe 108. It gets higher near the entrance. Therefore, there is a risk that the flow of exhaust gas may be hindered.

Further, in the cold trap, the fins 109 are simply welded to the exhaust gas outflow pipe 108 at regular intervals, which is still insufficient from the viewpoint of efficiently promoting the removal of unreacted components in the exhaust gas. It was not satisfactory.

From such a point, the conventional cold trap has a problem that the deterioration progresses rapidly and the life is short.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an exhaust gas treatment apparatus capable of ensuring good circulation of exhaust gas. Another object is to provide an exhaust gas treatment device that can promote removal of unreacted components in exhaust gas.

[0012]

In order to achieve the above object, a feature of the present invention is that a heat radiation pipe through which exhaust gas flows,
Exhaust gas treatment comprising: a gas treatment body having a plurality of fins fixed to the outer wall of the heat dissipation pipe; cooling the gas treatment body to fix a predetermined component in the exhaust gas introduced into the gas treatment body to the fins. In the device, mounting fins for fixing the fin position are fixed to the respective fins,
The fins are detachably attached to the heat radiating pipe by the attachment fittings.

Further, preferably, the fins attached to the heat radiation pipe have a wide space on the gas inflow side,
Make the gas outlet side narrow.

Preferably, a plurality of protrusions are installed on each fin.

[0015]

According to the above construction, when each fin is attached to the heat radiating pipe by the attachment fitting, its attachment position can be freely adjusted. For example, the space between the fins attached to the heat dissipation pipe is wide on the gas inflow side,
By narrowing the gas outflow side, a wider exhaust gas flow path is secured on the gas inflow side, and it is possible to prevent the above-mentioned obstruction of exhaust gas flow due to fixation of unreacted components.

By installing a plurality of protrusions on each fin, the exhaust gas contact area is increased, and the amount of unreacted gas fixed can be efficiently increased.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the structure of a cold trap which is an exhaust gas treating apparatus embodying the present invention.

This cold trap has a cylindrical body 1. Inside the body 1, a cylindrical trap body (gas treatment body) 2 separates a predetermined gap 3 from the inner wall surface and bottom surface of the body 1. And is fixed to the upper support lid 4. Body 1
A cooling gas, such as nitrogen gas, for cooling the trap body 2 flows into the gap 3 formed between the trap body 2 and the trap body 2 through the inflow port 5 opened at the end of the upper support lid 4. Then, the cooling gas is discharged to the outside through the outlet 6 formed in the upper support lid 4.

Further, an exhaust gas inflow pipe 7 is communicated with the inside of the trap body 2 from the outside of the upper support lid 4, and an exhaust gas outflow pipe (heat dissipation pipe) 8 is further provided from the outside of the upper support lid 4 in the center of the trap body 2. It further penetrates and extends to the bottom surface. In addition, a plurality of fins 9 provided with protrusions 9a are attached to the outer wall of the exhaust gas outflow pipe 8 penetrating the trap body 2. The space between the fins 9 attached to the exhaust gas outflow pipe 8 is wide on the gas inflow side of the upper part of the trap body 2 (the tip side of the exhaust gas inflow pipe 7) and on the gas outflow side of the lower part of the trap body 2 (of the exhaust gas outflow pipe 8). The tip side) becomes narrower.

FIG. 2 is a plan view of the fins 9. As shown in FIG. 2, each fin 9 has a circular shape with a cutout 9b serving as a flow path for exhaust gas. This diameter corresponds to the cylindrical shape of the trap body 2, and each fin 9
An insertion hole 9c into which the exhaust gas outflow pipe 8 is inserted is bored in the center of the trap main body 2 and the peripheral end of each fin 9 is formed in
It is designed to be closely attached to the inner wall surface of the.

Further, four protrusions 9a are provided at predetermined intervals at the end of the upper surface of the fin 9, and have an inner diameter equal to the diameter of the insertion hole 9c at the center of the fin 9. A fitting 9d for adjusting the fin position is provided upright in the center of the fin 9 in alignment with the insertion hole 9c. A bolt hole is provided in the projecting piece of the mounting member 9d, and each fin 9 is fixed to the exhaust gas outflow pipe 8 by tightening a bolt 9e inserted into the bolt hole.

As described above, according to this embodiment, the fins 9 can be detachably attached to the exhaust gas outflow pipe 8 by the attachment fittings 9d, and the distance between the fins is wide on the gas inflow side and the gas outflow side is large. Since the side is made narrower, a wider exhaust gas flow path is secured on the gas inflow side, and it is possible to prevent the exhaust gas flow obstruction due to the sticking of unreacted components as in the conventional device.

Further, since a plurality of protrusions 9a are provided on each fin 9, the contact area of the exhaust gas is increased, and the amount of unreacted gas fixed can be efficiently increased.

FIG. 3 is a diagram showing an example of application of the exhaust gas treating apparatus of the present invention, showing the structure of an exhaust system in a low pressure CVD apparatus.

In the CVD reactor 21, the controller 22
The gas supply amount control, the temperature control, the sequence control, and the like are performed by the above, and the CVD process is performed on the silicon wafer. Then, the exhaust gas flows into the cold trap 24 having the same structure as the cold trap of the above-described embodiment via the exhaust gas inflow pipe 23, and the cold trap 2
At 4, the unreacted gas is removed and discharged to the exhaust gas outflow pipe.

After that, it passes through a main valve 25 provided in the exhaust gas outflow pipe or a sub valve 27 provided in the bypass pipe 26, and a mechanical booster 28 and a rotary pump 29 for reducing the pressure of the CVD reactor 21 side. Is discharged. An oil filter 30 for preventing deterioration of the rotary pump 29 is attached to the rotary pump 29.

[0027]

As described above in detail, according to the present invention, the fin-position adjusting fittings are fixed to the respective fins, and the fins are detachably attached to the heat radiating pipe by the fittings. The mounting position of each fin can be freely adjusted.

For example, the fins attached to the radiating pipe are arranged such that the gas inflow side is wide and the gas outflow side is narrow, whereby the obstruction of the exhaust gas flow due to the fixation of unreacted components in the exhaust gas can be alleviated. .

By providing a plurality of protrusions on each fin, the exhaust gas contact area is increased, and the amount of unreacted gas fixed can be efficiently increased.

This makes it possible to extend the replacement life of the cold trap.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a cold trap which is an exhaust gas treating apparatus embodying the present invention.

FIG. 2 is a plan view of the fin 9 shown in FIG.

FIG. 3 is a diagram showing an application example of the exhaust gas treatment apparatus of the present invention.

FIG. 4 is a sectional view showing a structure of a conventional cold trap.

[Explanation of reference numerals] 1 body 2 trap body 3 void 4 upper support lid 7 exhaust gas inflow pipe 8 exhaust gas outflow pipe 9 fins 9a protrusions

Claims (3)

[Claims] 1. A gas treatment main body having a heat radiation pipe through which exhaust gas flows and a plurality of fins fixed to an outer wall of the heat radiation pipe, the gas treatment main body being cooled and introduced into the gas treatment main body. In an exhaust gas treatment device for adhering a predetermined component in exhaust gas to the fins, mounting fins for adjusting the fin position are fixed to the fins, and the fins are detachably attached to the radiating pipe by the mounting brackets. An exhaust gas treatment device characterized by: 2. The exhaust gas treating apparatus according to claim 1, wherein the fins attached to the heat radiating pipe are widened on the gas inflow side and narrowed on the gas outflow side. 3. The exhaust gas treating apparatus according to claim 1, wherein a plurality of protrusions are provided on each of the fins.