JP6992527B2 - Gas processing equipment - Google Patents

Description

The present invention relates to a gas processing apparatus.

A method using a load cell is known as a method for detecting performance deterioration of a gas processing device such as exhaust gas for dry etching. In Patent Document 1, the gas treatment device is arranged on the load cell, and the weight of the gas treatment device is measured by using the load cell. It is stated to make a judgment. A method for detecting performance deterioration of a gas processing device using a load cell is widely used because it is a simple management method that does not require a gas detector or the like.

Japanese Unexamined Patent Publication No. 2008-68175

However, as a result of diligent research, the present inventors have found that it may not be possible to reliably detect deterioration in the performance of the gas treatment device depending on the type of gas to be treated, the type of treatment agent contained in the gas treatment device, and the like. rice field. Specifically, the present inventors when the gas to be treated contains chlorine as a main component and a zinc-based treatment agent containing a sulfur-based reducing agent and zinc oxide is used as the treatment agent. , It was found that the load cell may not be able to reliably detect the deterioration of the performance of the gas treatment device.

A main object of the present invention is to provide a gas processing apparatus containing chlorine as a main component and capable of detecting performance deterioration by a load cell.

The gas treatment apparatus according to the present invention is a gas treatment apparatus that treats a gas to be treated containing chlorine as a main component.

The gas processing apparatus according to the present invention includes a container. The container has an introduction port, a discharge port, and a processing chamber. The gas to be treated is introduced into the introduction port. The treated gas is discharged from the discharge port. The processing chamber is connected to the inlet and the outlet. The treatment chamber has a first treatment layer, a second treatment layer, and a third treatment layer. The second treatment layer is located closer to the discharge port than the first treatment layer. The third treatment layer is located on the discharge port side with respect to the second treatment layer. Iron oxide is arranged in the first treated layer. A zinc-based treatment agent containing a sulfur-based reducing agent and zinc oxide is arranged in the second treatment layer. Zeolites are arranged in the third treatment layer. The initial water content of the zinc-based treatment agent is 5% by mass or more and less than 15% by mass.

According to the present invention, it is possible to provide a gas processing apparatus containing chlorine as a main component and capable of detecting performance deterioration by a load cell.

It is a schematic sectional drawing of the gas processing apparatus which concerns on one Embodiment of this invention.

Hereinafter, an example of a preferred embodiment of the present invention will be described. However, the following embodiments are merely examples. The present invention is not limited to the following embodiments.

FIG. 1 is a schematic cross-sectional view of the gas processing apparatus 1 according to the embodiment of the present invention. The gas treatment device 1 is a device that treats a gas containing an undesired component (for example, a harmful substance) whose concentration is to be reduced (hereinafter referred to as “gas to be treated”). Specifically, the gas treatment device 1 is a device that reduces the concentration of an undesired component such as chlorine contained in the gas to be treated. Specifically, the gas treatment device 1 according to the present embodiment may be, for example, a device that reduces the concentration of harmful substances contained in the exhaust gas generated during dry etching. In addition to chlorine, the exhaust gas generated during dry etching includes, for example, chlorine compounds such as hydrogen chloride, boron trichloride, titanium chloride and silicon tetrachloride, and fluorine compounds such as silicon tetrafluoride and hydrogen fluoride. , Bromine, hydrogen bromide, silicon bromide and other bromine compounds may be contained. In this embodiment, an example in which the gas to be treated contains chlorine as a main component and further contains boron trichloride and hydrogen chloride will be described.

(Structure of gas treatment device 1)
The gas processing device 1 includes a container 10. The container 10 has a processing chamber 11, an introduction port 12, and a discharge port 13. The introduction port 12 and the discharge port 13 are each connected to the processing chamber 11. The gas to be processed is introduced into the processing chamber 11 from the introduction port 12. The treated gas treated in the treatment chamber 11 is discharged from the discharge port 13. In the present embodiment, the introduction port 12 is provided at the lower part of the container 10. The discharge port 13 is provided in the upper part of the container 10. However, the present invention is not limited to this configuration. For example, an introduction port may be provided at the upper part of the container, and a discharge port may be provided at the lower part.

The treatment chamber 11 has a first treatment layer 11a, a second treatment layer 11b, and a third treatment layer 11c. Of the first to third treatment layers 11a to 11c, the first treatment layer 11a is located closest to the introduction port 12. The second treatment layer 11b is located closer to the discharge port 13 than the first treatment layer 11a. The third treatment layer 11c is located closer to the discharge port 13 than the second treatment layer 11b. Therefore, the gas to be treated introduced from the introduction port 12 passes through the first treatment layer 11a, the second treatment layer 11b, and the third treatment layer 11c in this order, and is discharged from the discharge port 13.

(First processing layer 11a)
Iron oxide (Fe ₂ O ₃ ) is arranged in the first treated layer 11a as a treating agent for the gas to be treated. Therefore, as shown in the following formula, the first treated layer 11a is treated with boron trichloride and hydrogen chloride contained in the gas to be treated.

2BCl ₃ + Fe ₂ O ₃ = 2FeCl ₃ + B ₂ O ₃
6HCl + Fe ₂ O ₃ = 2FeCl ₃ + 3H ₂ O

The first treated layer 11a preferably contains water. When the first treatment layer 11a contains water, the treatment with boron trichloride is promoted as shown in the following formula. The water may be contained as, for example, a hydrate such as iron oxide, or may be contained, for example, as steam or liquid water.

2BCl ₃ + 6H ₂ O = 6HCl + 2H ₃ BO ₃
6HCl + Fe ₂ O ₃ = 2FeCl ₃ + 3H ₂ O

As described above, the first treated layer 11a is treated with boron trichloride and hydrogen chloride, but the first treated layer 11a is treated with all of the boron trichloride and hydrogen chloride contained in the gas to be treated. It is not always necessary. All of boron trichloride and hydrogen chloride contained in the gas to be treated may be treated by the first treatment layer 11a. Even if a part of boron trichloride and hydrogen chloride contained in the gas to be treated is treated by the first treated layer 11a and the gas to be treated containing boron trichloride and hydrogen chloride flows into the second treated layer 11b. good.

(Second processing layer 11b)
The second treatment layer 11b is provided on the discharge port 13 side of the first treatment layer 11a. Therefore, the gas to be treated by the first treated layer 11a flows into the second treated layer 11b.

A zinc-based treatment agent is arranged on the second treatment layer 11b. The zinc-based treatment agent contains zinc oxide (ZnO) and a sulfur-based reducing agent. The zinc-based treatment agent preferably contains zinc oxide as a main component.

Since the zinc-based treatment agent arranged in the second treatment layer 11b contains zinc oxide, hydrogen chloride contained in the gas to be treated is treated in the second treatment layer 11b as shown in the following formula. ..

2HCl + ZnO = ZnCl ₂ + H ₂ O

The content of zinc oxide in the zinc-based treatment agent is preferably 5% by mass to 25% by mass, and more preferably 10% by mass to 20% by mass. By setting the content of zinc oxide in the zinc-based treatment agent within this range, hydrogen chloride can be sufficiently decomposed.

Further, since the zinc-based treating agent contains, for example, a sulfur-based reducing agent such as Na ₂ S ₂ O _{3.5H 2} O, it is contained in the gas to be treated in the second treated layer 11b as shown in the following formula. The chlorine is treated.

4Cl ₂ + Na ₂ S ₂ O _{3.5H 2} O = 2 NaCl + H ₂ SO ₄ + 6HCl
6HCl + 3ZnO = 3ZnCl ₂ + 3H ₂ O
H ₂ SO ₄ + Z ₂ O = ZnSO ₄ + H ₂ O

Other specific examples of the sulfur-based reducing agent preferably used include, for example, sulfites, sulfites, tetrathionates, thiosulfates and the like. Specific examples of the sulfite salt preferably used include sodium sulfite, potassium sulfite, ammonium sulfite and the like. Specific examples of the nitionate phosphite preferably used include sodium phosphite, potassium phosphite and the like. Specific examples of the tetrathionate acid salt preferably used include sodium tetrathionate, potassium tetrathionate and the like. Specific examples of the thiosulfate preferably used include sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate and the like. Only one of these reducing agents may be used, or a plurality of types may be mixed and used.

The content of the sulfur-based reducing agent in the zinc-based treating agent is preferably 10% by mass to 30% by mass, and more preferably 15% by mass to 25% by mass. By setting the content of the sulfur-based reducing agent in the zinc-based treatment agent within this range, chlorine can be sufficiently decomposed.

(Third processing layer 11c)
The third treatment layer 11c is provided on the discharge port 13 side with respect to the second treatment layer 11b. Therefore, the gas treated by the first and second treatment layers 11a and 11b flows into the third treatment layer 11c.

Zeolites are arranged in the third treatment layer 11c. Therefore, in the third treatment layer 11c, the water contained in the gas is adsorbed on the zeolite. Further, chlorine, boron trichloride, hydrogen chloride and the like that were not treated in the first and second treated layers 11b and 11c and remained in the gas are also adsorbed on the zeolite.

The mass ratio of zeolite to the zinc-based treatment agent is preferably 1/2 or less, 1/20 or more. If the mass ratio of zeolite to the zinc-based treatment agent is too high, the treatment capacity of the gas treatment apparatus 1 may be too low. If the mass ratio of zeolite to the zinc-based treatment agent is too low, it is possible to suitably detect the performance deterioration of the gas treatment device by the load cell.

(Detection of performance deterioration of gas processing device 1)
In the present embodiment, the performance deterioration of the gas processing device 1 is detected by using the load cell 20. Specifically, the gas processing device 1 is arranged on the load cell 20, and the weight of the gas processing device 1 can be measured by the load cell 20.

When the treatment of the exhaust gas proceeds by the gas treatment device 1, for example, iron chloride, zinc chloride, zinc sulfate and the like are generated, so that the treatment of the gas to be treated proceeds and the weight of the gas treatment device 1 increases. When the weight of the gas treatment device 1 increases to a predetermined weight, it is considered that the performance of the gas treatment device 1 has deteriorated, and the first to third treatment layers 11a to 11c in the gas treatment device 1 are replaced. do.

By the way, when the gas to be treated contains chlorine as a main component and a zinc-based treatment agent is used as the treatment agent, water is generated.

4Cl ₂ + Na ₂ S ₂ O _{3.5H 2} O = 2 NaCl + H ₂ SO ₄ + 6HCl
6HCl + 3ZnO = 3ZnCl ₂ + 3H ₂ O
H ₂ SO ₄ + Z ₂ O = ZnSO ₄ + H ₂ O

Therefore, the amount of water flowing into the third treatment layer 11c increases. Therefore, the zeolite arranged in the third treatment layer 11c may be broken by water, and the water generated in the treatment chamber 11 may be discharged from the discharge port 13. When the water generated in the treatment chamber 11 is discharged from the discharge port 13, the weight increase of the gas treatment device 1 is reduced by the amount of the discharged water. Therefore, it becomes difficult to detect the performance deterioration of the gas processing device 1 by the load cell 20.

As a result of diligent research, the present inventors set the initial water content of the zinc-based treatment agent within a predetermined range, so that water is discharged from the discharge port 13 regardless of the water content during treatment. Therefore, it has been found that it is possible to detect the performance deterioration of the gas treatment device 1 by the load cell 20. Specifically, as a result of diligent research by the present inventors, by setting the initial water content of the zinc-based treatment agent to 5% by mass or more and less than 15% by mass, it is eliminated regardless of the water content during treatment. It has been found that the performance deterioration of the gas treatment device 1 can be detected by the load cell 20 without discharging water from the outlet 13, and the present invention has been made.

In the gas treatment apparatus 1 of the present embodiment, the initial water content of the zinc-based treatment agent is 5% by mass or more and less than 15% by mass. Therefore, it is possible to detect the performance deterioration of the gas treatment device 1 by the load cell 20 without discharging the water from the discharge port 13. When the initial water content of the zinc-based treatment agent is 15% by mass or more, the amount of water generated increases and the water escapes from the discharge port 13, so that the performance of the gas treatment device 1 deteriorates due to the load cell 20. It becomes difficult to detect. On the other hand, when the initial water content of the zinc-based treatment agent is less than 5% by mass, the generation of water can be suppressed, but the treatment capacity of the gas treatment device 1 for chlorine is low. From the above viewpoint, the initial water content of the zinc-based treatment agent is more preferably 5% by mass to 13% by mass, further preferably 5% by mass to 11% by mass.

From the viewpoint of increasing the treatment capacity of the gas treatment apparatus 1 for chlorine, it is preferable that the second treatment layer 11b contains a large amount of a zinc-based treatment agent. However, if the amount of the zinc-based treatment agent is too large, a large amount of water is generated, and the water is easily discharged from the discharge port 13. Therefore, the mass ratio of zeolite to the zinc-based treatment agent is preferably 1/20 or more, preferably 1/15 or more, and more preferably 1/10 or more. However, if the amount of the zinc-based treatment agent is too small, the treatment capacity of the gas treatment device 1 for chlorine may become too low. Therefore, the mass ratio of zeolite to the zinc-based treatment agent is preferably 1/2 or less.

Hereinafter, the present invention will be described in more detail based on specific experimental examples, but the present invention is not limited to the following experimental examples, and the present invention is appropriately modified without changing the gist thereof. It is possible to do.

(Experimental Example 1)
A container with a capacity of 500 cc equipped with a gas inlet, a gas outlet, a dew point meter, and a gas detector contains 50 g of iron oxide, a zinc-based treatment agent (10% by mass of zinc oxide and 20% by mass of sodium thiosulfate, water content). : 10% by mass) 350 g and 50 g of zeolite were sequentially packed in layers from the bottom. At this time, the mass ratio of zeolite to the zinc-based treatment agent was 1/7.

Next, nitrogen gas containing 5000 mass ppm of chlorine was supplied at a flow rate of 6 L / h. As a result, it broke down 303 minutes after the start of supply. During that time, the water content from the discharge port was below the detection limit, and the control in the load cell was good.

(Comparative Example 1)
A container with a capacity of 500 cc equipped with a gas inlet, a gas outlet, a dew point meter, and a gas detector contains 50 g of iron oxide, a zinc-based treatment agent (10% by mass of zinc oxide and 20% by mass of sodium thiosulfate, water content). : 3% by mass) 350 g and 50 g of zeolite were sequentially packed in layers from the bottom. At this time, the mass ratio of zeolite to the zinc-based treatment agent was 1/7.

Next, nitrogen gas containing 5000 mass ppm of chlorine was supplied at a flow rate of 6 L / h. As a result, although the water content from the discharge port was below the detection limit, it broke down only 197 minutes after the start of supply.

(Comparative Example 2)
A container with a capacity of 500 cc equipped with a gas inlet, a gas outlet, a dew point meter, and a gas detector contains 50 g of iron oxide, a zinc-based treatment agent (10% by mass of zinc oxide and 20% by mass of sodium thiosulfate, water content). : 15% by mass) 350 g and 50 g of zeolite were sequentially packed in layers from the bottom. At this time, the mass ratio of zeolite to the zinc-based treatment agent was 1/7.

Next, nitrogen gas containing 5000 mass ppm of chlorine was supplied at a flow rate of 6 L / h. As a result, it broke down 320 minutes after the start of supply, but during that time, about 20 g of water was distilled out from the discharge port, and it was difficult to manage with the load cell.

(Example 2)
A container with a capacity of 500 cc equipped with a gas inlet, a gas outlet, a dew point meter, and a gas detector contains 50 g of iron oxide, a zinc-based treatment agent (10% by mass of zinc oxide and 20% by mass of sodium thiosulfate, water content). : 10% by mass) 381 g and 19 g of zeolite were sequentially packed in layers from the bottom. At this time, the mass ratio of zeolite to the zinc-based treatment agent was 1/20.

Next, nitrogen gas containing 5000 mass ppm of chlorine was supplied at a flow rate of 6 L / h. As a result, it broke 305 minutes after the start of supply, but during that time, a small amount of water was confirmed to be distilled from the outlet.

(Example 3)
A container with a capacity of 500 cc equipped with a gas inlet, a gas outlet, a dew point meter, and a gas detector contains 50 g of iron oxide, a zinc-based treatment agent (10% by mass of zinc oxide and 20% by mass of sodium thiosulfate, water content). : 10% by mass) 200 g and 200 g of zeolite were sequentially packed in layers from the bottom. At this time, the mass ratio of zeolite to the zinc-based treatment agent was 1/1.

Next, nitrogen gas containing 5000 mass ppm of chlorine was supplied at a flow rate of 6 L / h. As a result, it broke down 266 minutes after the start of supply. During that time, the water content from the discharge port was below the detection limit, and the control in the load cell was good.

(Experimental Example 4)
A container with a capacity of 500 cc equipped with a gas inlet, a gas outlet, a dew point meter, and a gas detector contains 50 g of iron oxide, a zinc-based treatment agent (10% by mass of zinc oxide and 20% by mass of sodium thiosulfate, water content). : 10% by mass) 350 g and 50 g of zeolite were sequentially packed in layers from the bottom. At this time, the mass ratio of zeolite to the zinc-based treatment agent was 1/7.

Next, nitrogen gas containing 2500 mass ppm of chlorine and 2500 mass ppm of boron trichloride was supplied at a flow rate of 6 L / h. As a result, it broke down 207 minutes after the start of supply. During that time, the water content from the discharge port was below the detection limit, and the control in the load cell was good.

From the above results, by setting the initial water content of the lead-based treatment agent to 5% by mass or more and less than 15% by mass, it is possible to prolong the time until breakthrough and suppress the distillation of water. As a result, load cell management was good.

Further, this tendency was remarkably observed when the mass ratio of zeolite to the zinc-based treatment agent was 1/20 or more and 1/2 or less.

1: Gas treatment device 10: Container 11: Treatment chamber 11a: First treatment layer 11b: Second treatment layer 11c: Third treatment layer 12: Introduction port 13: Discharge port 20: Load cell

Claims (5)

A gas treatment device that treats a gas to be treated containing chlorine.
A container having an introduction port into which the gas to be treated is introduced, an discharge port from which the treated gas is discharged, and a processing chamber connected to the introduction port and the discharge port is provided.
The processing room
The first processing layer and
A second treatment layer located closer to the discharge port than the first treatment layer,
A third treatment layer located closer to the discharge port than the second treatment layer,
Have,
Iron oxide is arranged in the first treated layer, and iron oxide is arranged.
A zinc-based treatment agent containing a sulfur-based reducing agent and zinc oxide is arranged in the second treatment layer.
Zeolites are arranged in the third treatment layer.
The initial water content of the zinc-based treatment agent is 5% by mass or more and less than 15% by mass.
A gas treatment device located above the load cell . The gas treatment apparatus according to claim 1, wherein the mass ratio of zeolite to the zinc-based treatment agent is 1/20 or more and 1/2 or less. The gas treatment apparatus according to claim 1 or 2, wherein the zinc oxide content in the zinc-based treatment agent is 5% by mass to 25% by mass. The gas treatment apparatus according to any one of claims 1 to 3, wherein the content of the sulfur-based reducing agent in the zinc-based treatment agent is 10% by mass to 30% by mass. The gas treatment apparatus according to any one of claims 1 to 4, wherein the gas to be treated contains at least one of boron trichloride and hydrogen chloride.

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