JP3979458B2 - Trap device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a trap device used in, for example, an evacuation system used for evacuating a vacuum chamber of a semiconductor manufacturing apparatus.
[0002]
[Prior art]
A conventional evacuation 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), and this hermetic chamber 10 is connected to a vacuum pump 12 through an exhaust pipe 14. . The vacuum pump 12 is for boosting the exhaust gas of the process from the hermetic chamber 10 to atmospheric pressure. Conventionally, an oil rotary pump and a dry pump are 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 ultrahigh vacuum pump such as a turbo molecular pump is further arranged upstream of the vacuum pump 12.
[0003]
The exhaust gas from a process is toxic or explosive depending on the type of the process and cannot be released into the atmosphere as it is. Therefore, an exhaust gas treatment device 16 is disposed downstream of the vacuum pump 12. Among the exhaust gases of the process whose pressure has been increased to atmospheric pressure, those that cannot be released into the atmosphere as described above are subjected to treatments such as adsorption, decomposition and absorption, and only harmless gases are released into the atmosphere. The exhaust pipe 14 is provided with a valve at an appropriate position as necessary.
[0004]
[Problems to be solved by the invention]
In the conventional vacuum evacuation system as described above, when a substance having a high sublimation temperature is present in the reaction by-product, the gas is exhausted by the vacuum pump 12, so that the gas is solidified in the middle of the pressure increase, and the vacuum pump 12 There is a drawback in that it is deposited inside and causes the vacuum pump 12 to fail. For example, when BCl ₃ and Cl ₂ , which are typical process gases, are used to etch aluminum, the residual gas of the BCl ₃ and Cl ₂ process gases and a reaction by-product of AlCl ₃ are generated from the hermetic chamber 10. Things are evacuated by the vacuum pump 12.
[0005]
This AlCl ₃ does not precipitate because the partial pressure is low on the intake side of the vacuum pump 12, but the partial pressure rises during pressure exhaust, precipitates and solidifies in the vacuum pump 12, and adheres to the inner wall of the pump. This causes a failure of the vacuum pump 12. The same applies to reaction by-products such as (NH ₄ ) ₂ SiF ₆ and NH ₄ CI produced from a CVD apparatus for forming a SiN film, for example.
[0006]
Conventionally, countermeasures have been taken against this problem, such as heating the entire vacuum pump to prevent the solidified material from depositing inside the vacuum pump and allowing the gas to pass through the vacuum pump. However, this measure has an effect on the precipitation in the vacuum pump, but as a result, the solidified material is deposited in the exhaust gas treatment device arranged downstream of the vacuum pump, and the packed bed is clogged. There was a problem to cause.
[0007]
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 are easily solidified in the exhaust gas. In this case, since the trapped solid matter accumulates in the trap part of the trap device, it is necessary to replace the trap part after an appropriate period of time or to regenerate by removing the solid substance by a predetermined method. Become. In the former case, many trap sections must be prepared, and automation is difficult.
[0008]
Therefore, for example, a regeneration chamber is provided adjacent to the trap chamber, and a regeneration solution or gas such as warm 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 is possible by regenerating (cleaning).
[0009]
However, in such a trap device, sealing between the trap chamber and the regeneration chamber becomes a problem when switching between trapping and regeneration. For example, when the trap chamber and the regeneration chamber are separated from each other by a general O-ring and the trap and the regeneration are continuously operated, the influence on the seal is as follows. × E ⁵ has been reported as a track record.
[0010]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a trap apparatus that can improve the sealing performance at the time of trapping or regeneration, and can configure a reliable exhaust system line. .
[0011]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a trap chamber disposed in an exhaust path for exhausting from an airtight chamber by a vacuum pump, a regeneration chamber disposed adjacent to the trap chamber, and the trap chamber and the regeneration chamber. A trap portion that moves between and traps the product in the exhaust gas and regenerates, and a valve body that moves integrally with the trap portion and seals the trap chamber and the regeneration chamber alternately via a seal member; The seal member is mounted in a groove provided in a tapered chamfered portion formed on both sides of the outer peripheral edge of the valve body , and the seal member is pressed against the seal surface constituted by a tapered surface. The trap device is configured to be sealed.
[0012]
Thereby, when the valve body is moved and the trap chamber and the regeneration chamber are alternately sealed via the seal member, the seal member is crushed by the seal surface constituted by the tapered surface, thereby improving the sealing performance. Further, since it can be inserted into the tapered surface, it becomes close to the shaft seal and can absorb the deviation in parallelism of the plurality of valves.
[0013]
According to a second aspect of the present invention, there is provided a trap chamber disposed in an exhaust path for exhausting from an airtight chamber by a vacuum pump, a regeneration chamber disposed adjacent to the trap chamber, and the trap chamber and the regeneration chamber. a trap unit for reproducing the trap of the product in the exhaust gas to move between a valve body for sealing alternately through the sealing member and the reproduction chamber and the trap chamber and moves together with the trap portion And 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, is formed with a water-repellent sealing surface. It is a characteristic trap device.
[0014]
Thereby, when circulating the regenerating liquid such as warm water or chemical liquid in the regenerating chamber in a state where the regenerating chamber is sealed, and regenerating (cleaning) the trap part, by repelling the liquid on the sealing surface subjected to the water repellent treatment, The liquid in the regeneration chamber is prevented from flowing out of the regeneration chamber.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of the trap apparatus of the present invention. An exhaust pipe 14 for exhausting an airtight chamber 10 constituting a part of a semiconductor manufacturing apparatus by a vacuum pump 12 is shown. A trap device 18 is provided on the upstream side of the vacuum pump 12. The trap device 18 traps a trap container 26 forming a trap chamber 24 having an intake port 20 and an exhaust port 22 communicating with the exhaust pipe 14, and a regeneration chamber 32 having an inlet 28 and a discharge port 30 for a regenerated liquid or gas. And a regeneration container 34 formed adjacent to the chamber 24.
[0016]
A shaft body 38 to which the trap portion 36 is attached is disposed so as to penetrate both the containers 26 and 34. The shaft body 38 is reciprocated in the axial direction by an air cylinder 40 as a driving means, and the trap portion 36 is moved to the trap chamber. 24 and the regeneration chamber 32 are moved alternately. The trap portion 36 is configured by attaching a baffle plate 42 around an axial body 38 via an end plate 44, and a flow path (not shown) for circulating a low-temperature fluid is formed inside the axial body 38. Thus, the baffle plate 42 is cooled via the end plate 44.
[0017]
A pair of valve bodies 46 a and 46 b that move integrally with the trap portion 36 are provided in the trap chamber 24 and the regeneration chamber 32 on both sides of the trap portion 36 of the shaft body 38. Tapered chamfered portions 48 are formed on both sides of the outer peripheral edge portions of the valve bodies 46a and 46b, and O-rings 50 as seal members are mounted in grooves provided in the respective chamfered portions 48.
[0018]
At both ends of the trap container 26, partition walls 52 a and 52 b projecting inward are provided, and seal surfaces 54 a and 54 b each having a tapered surface are provided on the inner wall surfaces of the partition walls 52 a and 52 b. Similarly, the regeneration container 34 is provided with partition walls 56a and 56b projecting inward at both ends, and seal surfaces 58a and 58b each having a tapered surface are provided on the inner wall surfaces of the partition walls 56a and 56b.
[0019]
2, the O-ring 50 attached to the left seal surface 54a of the trap container 26 on the left side of the valve body 46a is replaced with the O-ring 50 attached to the left seal surface 58a of the regeneration container 34 on the left side of the valve body 46b. 50 is in pressure contact with each other to seal the trap chamber 24, and the O-ring 50 attached to the right seal surface 54 b of the trap container 26 on the right side of the valve body 46 a is connected to the right seal surface 58 b of the regeneration container 34 on the valve body 46 b. The regeneration chamber 32 is sealed by the O-rings 50 mounted on the right side of each of which are pressed against each other. At this time, the O-ring 50 is crushed by the sealing surfaces 54a, 54b, 58a, and 58b formed by taper surfaces, and the crushed area increases to improve the sealing performance, and the trap chamber 24 and the regeneration chamber 32 have high accuracy. Sealed with. In addition, the seal area can be reduced and the outer diameter of the trap portion 36 can be increased correspondingly to increase the trap area and improve the trap efficiency.
[0020]
Next, the operation of the trap device 18 configured as described above will be described. At the time of manufacturing the semiconductor device, the trap portion 36 is switched so as to be located in the trap chamber 24, and the baffle plate 42 is cooled by the refrigerant. As a result, when a specific component contained in the exhaust gas flowing into the trap chamber 24 along the exhaust pipe 14, for example, aluminum is formed, a component such as aluminum chloride is trapped in the trap unit 36 as a solid content. And removed from the exhaust gas.
[0021]
When it is detected by a temperature sensor, a pressure sensor, or the like that the trap amount of the trap unit 36 has reached a certain amount, the processing is temporarily stopped or switched to another exhaust trap path before the trap unit 36 is moved to the regeneration chamber 32. Move to. Then, a regeneration solution or gas is injected into the regeneration 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, 58a, 58b are in close contact with each other, the trap chamber 24 and the regeneration chamber 32 are sealed with high accuracy. There is no leakage outside.
[0022]
FIG. 3 shows a second embodiment of the present invention, in which regeneration containers 34a and 34b for partitioning and forming regeneration chambers 32a and 32b are arranged on both sides of a trap container 26 for partitioning and forming a trap chamber 24, respectively. ing. A shaft body 38 to which 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 connected to one regeneration chamber 32a. The other trap portion 36 b is configured to be movable between the other regeneration chamber 32 b and the trap chamber 24 between the trap chamber 24 and the trap chamber 24.
[0023]
According to this embodiment, one trap portion 36a or 36b is always located in the trap chamber 24 communicating with the exhaust pipe 14, and the other trap portion 36a or 36b is regenerated in the regeneration chamber 32a or 32b. However, the process can be performed continuously.
[0024]
FIG. 4 shows a third embodiment of the present invention, which is configured to introduce a regenerating liquid into the regenerating chamber 32, and in FIG. The right chamfered portion 48 of the right side chamfered portion 48 of the valve body 46a close to the inner side of the O-ring mounting portion of the chamfered portion 48 on the right side of the valve body 46a and the right side chamfered portion 58b of the regeneration container 34. Seal surfaces 60a and 60b are formed on the inner side of the O-ring mounting portion by, for example, coating with a tetrafluoroethylene polymer or the like and applying a water repellent treatment. Other configurations are the same as those shown in FIG.
[0025]
According to this embodiment, when the trap portion is positioned in the regeneration chamber 32 and a regeneration solution such as warm water or a chemical solution is injected and regenerated, the regeneration solution is repelled by the seal surfaces 60a and 60b subjected to the water repellent treatment. This prevents the regeneration liquid in the regeneration chamber 32 from flowing out of the regeneration chamber 32. As a result, cleaning with a chemical such as hydrofluoric acid can be performed safely. Moreover, for example, even in a process in which a product having a sublimation temperature lower than 180 ° C. is produced, it can be dealt with by heating the sealing surfaces 60a and 60b with a heater or the like as a countermeasure against adhesion.
[0026]
In this example, the sealing surfaces 60a and 60b subjected to the water repellency treatment are formed on the valve bodies 46a and 46b, but the partition wall 52b of the trap container 26 and the partition wall 56b side of the regeneration container 34 are illustrated. A seal surface that has been subjected to a water repellent treatment may be formed.
[0027]
【The invention's effect】
As described above, according to the present invention, when the valve body is moved and the trap chamber and the regeneration chamber are alternately sealed via the seal member, the sealing performance of the seal member is improved, and the trap chamber and the regeneration chamber are improved. Can be sealed with high accuracy. Thereby, it is not necessary to stop the apparatus for regeneration of the trap part or prepare a trap for replacement, and stable processing can be performed in the airtight chamber. It is also easy to achieve safe automation using appropriate switching timing determination means. Accordingly, it is possible to extend the life of the vacuum pump, protect the abatement device, improve the operation reliability by reducing the loss time, and further reduce the equipment and operation costs.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an evacuation system including a trap device according to a first embodiment of the present invention.
FIG. 2 is a longitudinal 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 longitudinal 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 piping 18 Trap apparatus 24 Trap chamber 26 Trap container 32, 32a, 32b Regeneration chamber 34, 34a, 34b Regeneration container 36, 36a, 36b Trap part 46a, 46b Valve body 50 O ring (seal member) )
52a, 52b Partition walls 54a, 54b Seal surfaces 56a, 56b Partition walls 58a, 58b Seal surfaces 60a, 60b Seal surfaces

Claims (2)

A trap chamber disposed in an exhaust path for exhausting from the airtight chamber by a vacuum pump;
A regeneration chamber disposed adjacent to the trap chamber;
A trap unit that moves between the trap chamber and the regeneration chamber to trap and regenerate the product in the exhaust gas;
A valve body that moves integrally with the trap portion and seals the trap chamber and the regeneration chamber alternately via a seal member;
The seal member is mounted in a groove provided in a tapered chamfered portion formed on both sides of the outer peripheral edge of the valve body , and is sealed by pressing the seal member against a seal surface constituted by a tapered surface. A trap device characterized by being configured to do. A trap chamber disposed in an exhaust path for exhausting from the airtight chamber by a vacuum pump;
A regeneration chamber disposed adjacent to the trap chamber;
A trap unit that moves between the trap chamber and the regeneration chamber to trap and regenerate the product in the exhaust gas;
A valve body that moves integrally with the trap portion and seals the trap chamber and the regeneration chamber alternately via a seal member;
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, is formed with a water-repellent sealing surface. Trap device.

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