JP2001280240A - Trapping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a trapping device for constructing a reliable exhaust system line by improving the sealing property during trapping or recovering. SOLUTION: The trapping device comprises a trapping chamber 24 arranged in an exhaust passage 14 for exhaustion from an air sealed chamber 10 via a vacuum pump 12, a recovering chamber 32 arranged adjacent to the trapping chamber 24, a tapping portion 36 for trapping and recovering products in an exhaust gas while being moved between the trapping chamber 24 and the recovering chamber 32, valve elements 46a, 46b moved integrally with the trapping portion 36 and sealing the trapping chamber 24 and the recovering chamber 32 alternately via a sealing member 50. Sealing members 46a, 46b are pressed against sealed faces 54a, 54b, 58a, 58b formed to be tapered to perform sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trap device used in a vacuum exhaust system used to evacuate a vacuum chamber of a semiconductor manufacturing apparatus, for example.

[0002]

2. Description of the Related Art A conventional vacuum pumping system will be described with reference to FIG. Here, the hermetic chamber 10 is a process chamber used in a semiconductor manufacturing process such as an etching apparatus or a chemical vapor deposition apparatus (CVD).
2 are connected. The vacuum pump 12 is for raising the pressure of the process exhaust gas from the hermetic chamber 10 to the atmospheric pressure. Conventionally, an oil rotary pump is used, and at present, a dry pump is mainly used. When the degree of vacuum required by the hermetic chamber 10 is higher than the ultimate degree of vacuum of the vacuum pump 12, an ultra-high vacuum pump such as a turbo molecular pump is further arranged upstream of the vacuum pump 12.

[0003] Exhaust gas from a process has toxicity and explosive properties depending on the type of process, and therefore cannot be released to the atmosphere as it is. Therefore, an exhaust gas treatment device 16 is arranged downstream of the vacuum pump 12. Among the exhaust gas of the process whose pressure has been increased to the atmospheric pressure, those which cannot be released to the atmosphere as described above are subjected to treatments such as adsorption, decomposition, and absorption, and only harmless gases are released to the atmosphere. The exhaust pipe 14 is provided with a valve at an appropriate position as needed.

[0004]

In the conventional vacuum evacuation system as described above, when a substance having a high sublimation temperature is present in the reaction by-products, the gas is exhausted by the vacuum pump 12, so that the pressure increases during the evacuation. Accordingly, there is a disadvantage that the gas is solidified and precipitates in the vacuum pump 12 to cause a failure of the vacuum pump 12. For example, in order to perform the etching of aluminum, the use of _BCl 3, Cl ₂ which is a typical process gas from the airtight chamber 10, _BCl 3, Cl
The residual gas of the process gas of No. ₂ and a reaction by-product of AlCl ₃ are exhausted by the vacuum pump 12.

This AlCl ₃ does not precipitate on the suction side of the vacuum pump 12 because the partial pressure is low, but the partial pressure rises during pressurization and exhaust, and precipitates and solidifies in the vacuum pump 12 and forms on the inner wall of the pump. They adhere and cause a failure of the vacuum pump 12. This means, for example, CVD for forming a film of SiN.
The same applies to reaction by-products such as (NH ₄ ) ₂ SiF ₆ and NH ₄ CI generated from the apparatus.

Conventionally, measures against this problem have been taken such as heating the entire vacuum pump to prevent solidified substances from depositing inside the vacuum pump and passing the gas through the vacuum pump in a gaseous state. Was. However, this measure is effective for the deposition in the vacuum pump, but as a result, solidified substances are deposited in the exhaust gas treatment device located downstream of the vacuum pump, and the clogging of the packed bed is prevented. There was a problem that caused it.

For this reason, it is conceivable to provide an appropriate trap device, such as a low-temperature trap, upstream of the vacuum pump to trap components that easily solidify in the exhaust gas. In this case, since the trapped solids accumulate in the trap portion of the trap device, it is necessary to replace the trap portion after a suitable time has elapsed, or to remove and regenerate the solids by a predetermined method. Become. In the former case, many trap units must be prepared, and automation is also difficult.

Therefore, for example, a regeneration chamber is provided adjacent to the trap chamber, and a regeneration liquid or gas such as hot water or a chemical solution heated to a predetermined temperature is circulated in the regeneration chamber with the trap portion positioned in the regeneration chamber. It is conceivable that automatic operation can be performed by regenerating (washing) the trap section.

However, in such a trap device, the sealing property between the trap chamber and the regeneration chamber poses a problem when switching between trapping and regeneration. For example, the general O
When the trap chamber and the regeneration chamber are separated from each other by the ring and the continuous operation of the trap and the regeneration is performed, the effect on the seal is as follows.
Leakage amount 1 × ^{E 5} are reported as proven 0RUN.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a trap device in which the sealing property at the time of trapping or regeneration is improved to form a reliable exhaust system line. Aim.

[0011]

According to a first aspect of the present invention, there is provided a trap chamber disposed in an exhaust path for evacuating from a hermetic chamber by a vacuum pump, a regeneration chamber disposed adjacent to the trap chamber, A trap section that moves between the trap chamber and the regeneration chamber to trap and regenerate products in exhaust gas, and a sealing member that moves integrally with the trap section to seal the trap chamber and the regeneration chamber. And a valve element that alternately seals the seal member through the seal member, and the seal member is configured to be pressed against and seal the seal surface formed by the tapered surface.

Thus, when the valve body is moved to alternately seal the trap chamber and the regeneration chamber via the seal member, the seal member is crushed by the seal surface formed by the tapered surface, thereby improving the sealing performance. . In addition, since it can fit into the tapered surface, it is close to the shaft seal and can absorb the deviation of the parallelism of the plurality of valves.

According to a second aspect of the present invention, there is provided a trap chamber disposed in an exhaust passage for evacuating a hermetic chamber by a vacuum pump, a regeneration chamber disposed adjacent to the trap chamber, the trap chamber and the regeneration chamber. A trap section that moves between the chamber and traps and regenerates the product in the exhaust gas, and moves integrally with the trap section to alternately seal the trap chamber and the regeneration chamber via a sealing member. A sealing body subjected to a water-repellent treatment is formed on at least one of the valve body or the trap chamber and the container constituting the regeneration chamber which are close to each other when sealing the regeneration chamber. A trap device.

Thus, when the regeneration section such as warm water or a chemical solution is circulated in the regeneration chamber while the regeneration section is sealed to regenerate (wash) the trap section, the liquid is repelled by the seal face subjected to the water-repellent treatment. This prevents the liquid in the regeneration chamber from flowing out of the regeneration chamber to the outside.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 show a first embodiment of a trap device according to the present invention, in which an airtight chamber 10 constituting a part of a semiconductor manufacturing apparatus is shown.
Is provided by a vacuum pump 12, and a trap device 18 is provided upstream of the vacuum pump 12. The trap device 18 includes a trap chamber 2 having an intake port 20 and an exhaust port 22 communicating with the exhaust pipe 14.
4, and a regeneration container 34 that forms a regeneration chamber 32 having an inlet 28 and an outlet 30 for a regeneration liquid or gas adjacent to the trap chamber 24.

A shaft 38 to which a trap portion 36 is attached is penetrated through both the containers 26 and 34, and the shaft 38 is reciprocated in the axial direction by an air cylinder 40 as a driving means.
The trap section 36 moves between the trap chamber 24 and the regeneration chamber 32 alternately. The trap unit 36
A baffle plate 42 is attached around the shaft body 38 via an end plate 44, and a flow path (not shown) for flowing a low-temperature fluid is formed inside the shaft body 38. 4
4, the baffle plate 42 is cooled.

A pair of valve bodies 46 which move integrally with the trap portion 36 are provided on both sides of the shaft body 38 with the trap portion 36 interposed therebetween.
a and 46b are provided in the trap chamber 24 and the regeneration chamber 32, respectively. Tapered chamfers 48 are formed on both sides of the outer peripheral edges of the valve bodies 46a and 46b, and O-rings 50 as seal members are mounted in grooves provided in the chamfers 48.

At both ends of the trap container 26, partition walls 52a and 52b projecting inward are provided.
a, a sealing surface 5 formed of a tapered surface on the inner wall surface of 52b
4a and 54b are provided. Similarly, the regeneration container 34 is provided with partition walls 56a and 56b protruding inward at both ends, and sealing surfaces 58a and 58b formed of tapered surfaces on the inner wall surfaces of the partition walls 56a and 56b.

As a result, in FIG. 2, the O-ring 50 attached to the left side of the valve body 46a is attached to the left sealing surface 54a of the trap container 26,
The O-ring 50 mounted on the left side of the valve body 46b is pressed against the 8a to seal the trap chamber 24, and the O-ring 50 mounted on the right side of the valve body 46a is regenerated on the sealing surface 54b on the right side of the trap container 26. The O-ring 50 mounted on the right side of the valve body 46b is pressed against the sealing surface 58b on the right side of the container 34 so as to seal the regeneration chamber 32. At this time, the O-ring 50 is crushed by the sealing surfaces 54a, 54b, 56a, 56b formed of tapered surfaces,
As the crushed area increases, the sealing property is improved, and the trap chamber 24 and the regeneration chamber 32 are sealed with high accuracy. In addition, the sealing area can be reduced, and the outer diameter of the trap portion 36 can be correspondingly increased, thereby increasing the trap area and improving the trap efficiency.

Next, the trap device 1 having the above-described configuration will be described.
8 will be described. At the time of manufacturing the semiconductor device, the trap unit 36 is switched so as to be located in the trap chamber 24, and the baffle plate 42 is cooled by the refrigerant.
Accordingly, when a specific component contained in the exhaust gas flowing into the trap chamber 24 along the exhaust pipe 14, for example, when forming a film of aluminum, a component such as aluminum chloride is trapped in the trap portion 36 as a solid content. And is removed from the exhaust gas.

The trap section 3 is provided by a temperature sensor, a pressure sensor, or the like.
When it is detected that the trap amount of No. 6 has reached a certain amount, the processing is temporarily stopped, or the path is switched to another exhaust trap path, and then the trap section 36 is moved to the regeneration chamber 32. Then, a regenerating solution or gas is injected into the regenerating chamber 32 from the inlet 28 and discharged from the outlet 30 to regenerate the trap portion 36. In these processes, since the O-ring 50 and the sealing surfaces 54a, 54b, 56a, 56b are in close contact with each other, the trap chamber 24 and the regeneration chamber 32 are sealed with high precision, and the exhaust gas, the regeneration liquid or the gas is discharged. It does not leak outside.

FIG. 3 shows a second embodiment of the present invention, in which regeneration vessels 34a and 34b which define regeneration chambers 32a and 32b on both sides of a trap vessel 26 which defines a trap chamber 24. Has been arranged. The shaft body 38 to which the two trap portions 36a and 36b are attached.
Is provided so as to be slidable through the trap chamber 24 and the regeneration chambers 32a and 32b, and one trap portion 36a is provided between the one regeneration chamber 32a and the trap chamber 24, and the other trap portion 36b is disposed in the other regeneration chamber. It is configured to be movable between the chamber 32b and the trap chamber 24.

According to this embodiment, one trap portion 36 is always provided in the trap chamber 24 communicating with the exhaust pipe 14.
The processing can be performed continuously while the other trap portion 36a or 36b is being regenerated in the regenerating chamber 32a or 32b such that the position a or 36b is located.

FIG. 4 shows a third embodiment of the present invention. In this embodiment, a regenerating solution is introduced into the regenerating chamber 32 and, when the regenerating chamber 32 is sealed in FIG. Inside the O-ring mounting portion of the right chamfer 48 of the valve body 46a adjacent to the right seal surface 54b of the trap container 26, and the right chamfer of the valve body 46b adjacent to the right seal surface 58b of the regeneration container 34. The inside of the O-ring mounting part of the part 48 is coated with, for example, a tetrafluoroethylene polymer or the like, and is subjected to a water-repellent treatment on the sealing surface 60.
a and 60b are formed. Other configurations are the same as those shown in FIG.

According to this embodiment, when the trap portion is located in the regeneration chamber 32 and a regeneration solution such as warm water or a chemical solution is injected and regenerated, the sealing surfaces 60a, 60 subjected to the water-repellent treatment are used.
By flipping the regeneration liquid at 0b, the regeneration liquid in the regeneration chamber 32 is prevented from flowing out of the regeneration chamber 32 to the outside. Thus, cleaning with a chemical such as hydrofluoric acid can be performed safely. Moreover, even in a process in which a product having a sublimation temperature lower than 180 ° C. is produced, for example, the sealing surfaces 60a,
This can be handled by heating 60b with a heater or the like.

In this example, the seal surfaces 60a and 60b subjected to the water repellent treatment are formed on the valve bodies 46a and 46b side. However, the partition walls 52b of the trap container 26 and the partition walls of the regeneration container 34 are shown. You may make it form the sealing surface which performed the water-repellent treatment on 56b side.

[0027]

As described above, according to the present invention, when the valve body is moved to alternately seal the trap chamber and the regeneration chamber via the seal member, the sealing property of the seal member is improved. The trap chamber and the regeneration chamber can be sealed with high precision. Thus, there is no need to stop the apparatus for regeneration of the trap portion or prepare a replacement trap, and it is possible to perform stable processing in the airtight chamber. It is also easy to achieve safe automation by using appropriate switching timing determination means. Therefore, it is possible to extend the life of the vacuum pump, protect the abatement apparatus, improve the reliability of operation by reducing loss time, and further reduce equipment and operation costs.

[Brief description of the drawings]

FIG. 1 is a system diagram illustrating an evacuation system including a trap device according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional front view of the trap device of FIG. 1;

FIG. 3 is a system diagram showing an evacuation system including a trap device according to a second embodiment of the present invention.

FIG. 4 is a vertical sectional front view showing a trap device according to a third embodiment of the present invention.

FIG. 5 is a system diagram of a conventional evacuation system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Airtight chamber 12 Vacuum pump 14 Exhaust pipe 18 Trap device 24 Trap chamber 26 Trap container 32, 32a, 32b Regeneration chamber 34, 34a, 34b Regeneration container 36, 36a, 36b Trap portion 46a, 46b Valve body 50 O-ring (seal member) ) 52a, 52b Partition wall 54a, 54b Seal surface 56a, 56b Partition wall 58a, 58b Seal surface 60a, 60b Seal surface

Claims (2)

[Claims] A trap chamber disposed in an exhaust path for evacuating the airtight chamber by a vacuum pump, a regeneration chamber disposed adjacent to the trap chamber, and moving between the trap chamber and the regeneration chamber. A trap portion for trapping and regenerating the product in the exhaust gas, and a valve body that moves integrally with the trap portion to alternately seal the trap chamber and the regeneration chamber via a sealing member, A trap device, wherein a sealing member is configured to be pressed against a sealing surface formed by a tapered surface to seal the sealing member. 2. A trap chamber arranged in an exhaust path for evacuating the airtight chamber by a vacuum pump, a regeneration chamber arranged adjacent to the trap chamber, and moving between the trap chamber and the regeneration chamber. A trap portion for trapping and regenerating the product in the exhaust gas, and a valve body that moves integrally with the trap portion to alternately seal the trap chamber and the regeneration chamber via a sealing member, A trap having a water-repellent sealing surface formed on at least one of the valve body or the trap chamber and the container constituting the regeneration chamber which are close to each other when the regeneration chamber is sealed. apparatus.