Trap device and exhaust device

Abstract

To provide a trap device that can suppress blockage of the exhaust path. [Solution] The trap device 10 is positioned in the middle of the exhaust path through which exhaust gas from the process chamber flows and comprises a container 11 having a gas inlet IN through which exhaust gas is supplied and a gas outlet OUT through which exhaust gas is discharged, a plurality of cooling fins 12 provided inside the container 11 having a pair of opposing trap surfaces 12a and forming a flow path 15 through which exhaust gas flows between the pair of trap surfaces 12a, and a cooling pipe 13 extending through the pair of trap surfaces 12a and through which a refrigerant that cools the plurality of cooling fins 12 flows.

Description

Technical Field

[0005] ,

[0001] Embodiments of the present invention relate to a trap device and an exhaust device.

Background Art

[0002] In recent years, an exhaust device having a trap device provided in the middle of an exhaust path to capture products in exhaust gas has been known for exhaust gas from a process chamber of a semiconductor manufacturing device such as an etching device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] [Figure 1] This is a schematic diagram showing an example of the structure of a trap device and exhaust device according to the embodiment. [Figure 2] This is a schematic diagram showing an example of the structure of a trap device. [Figure 3] This is a schematic diagram showing an example of the structure of a trap device. [Figure 4] This is a schematic diagram showing an example of the structure of a trap device. [Figure 5] This is a schematic diagram illustrating an example of capturing exhaust gas products using a trapping device. [Modes for carrying out the invention]

[0007] The embodiments will be described below with reference to the drawings. The relationship between the thickness and planar dimensions of each component shown in the drawings, the ratio of the thicknesses of each component, etc., may differ from the actual product. Also, in the embodiments, substantially identical components are denoted by the same reference numerals and their descriptions are omitted as appropriate.

[0008] Figure 1 is a schematic diagram showing an example of the structure of a trap device and exhaust device according to an embodiment. Figure 1 shows the exhaust device 1.

[0009] The exhaust system 1 can discharge exhaust gas from the process chamber of a semiconductor manufacturing apparatus. The exhaust system 1 includes a trap device 10 and an exhaust pump 20.

[0010] An example of semiconductor manufacturing equipment includes an etching apparatus. An etching apparatus can, for example, supply a predetermined etching gas into a process chamber and use the plasma generated from the etching gas to etch films such as silicon oxide films and silicon nitride films. However, unwanted products are generated during this etching process and discharged from the process chamber as exhaust gas. These unwanted products include, for example, carbon compounds such as fluorinated hydrocarbon compounds. To prevent these products from becoming a load on the exhaust pump 20 and the pollution control equipment, it is preferable to capture the products in the exhaust gas by liquefying or solidifying them using a trapping device 10.

[0011] The trap device 10 is installed in the middle of an exhaust path, for example, including pipes P1, P2, and P3. The exhaust path is through which exhaust gas can flow. The trap device 10 can capture products in the exhaust gas by liquefying or solidifying them. The trap device 10 is installed in the exhaust device 1 so as to form an exhaust path along the longitudinal (vertical) direction of the exhaust device 1.

[0012] The exhaust pump 20 is installed in the middle of the exhaust path. Figure 1 shows an example in which the exhaust pump 20 is installed before the trap device 10 in the exhaust path and connected to the trap device 10 via piping P2, but is not limited to this, and the exhaust pump 20 may be installed after the trap device 10 in the exhaust path. The exhaust pump 20 is connected to the process chamber via piping P1 and to the trap device 10 via piping P2. Examples of the exhaust pump 20 include vacuum pumps such as dry pumps. The exhaust pump 20 can discharge exhaust gas from the process chamber.

[0013] Next, we will describe an example of the structure of the trap device 10. Figures 2, 3, and 4 are schematic diagrams showing an example of the structure of the trap device 10. Figure 2 schematically shows an example of the internal structure of the trap device 10 when viewed from the Y-axis direction. Figure 3 schematically shows an example of the internal structure of the trap device 10 when viewed from the X-axis direction. Figure 4 schematically shows an example of the internal structure of the trap device 10 when viewed from the Z-axis direction. The X, Y, and Z axes intersect perpendicularly to each other. The Z axis corresponds, for example, to the vertical direction of the exhaust device 1. Note that the following description regarding the general direction of the trap device 10 may include some directional variations due to differences between devices when the trap device 10 is installed in the exhaust device 1.

[0014] The trap device 10 includes a container 11, cooling fins 12, cooling pipes 13, and a cover 14.

[0015] The container 11 has a gas inlet IN and a gas outlet OUT. The interior of the container 11 forms a space S through which exhaust gas flows from the gas inlet IN to the gas outlet OUT. Examples of the shape of the container 11 include a cylindrical shape. The container 11 extends, for example, in a direction substantially parallel to the vertical direction of the exhaust device 1 (e.g., the Z-axis direction). The container 11 can be formed using, for example, a metallic material. The metallic material may be, for example, stainless steel (SUS). The inner surface of the container 11 facing the space S may be surface-treated to enhance resistance to exhaust gas.

[0016] The gas inlet IN is connected to piping P2. The gas inlet IN is provided, for example, on the lower vertical end surface (bottom) of the container 11 and connected to space S.

[0017] The gas outlet OUT is connected to a pollution control device via piping P3. The exhaust gas that passes through the trap device 10 and is discharged from the gas outlet OUT is treated by the pollution control device and released, for example, into the atmosphere. The gas outlet OUT is provided, for example, on the upper vertical surface (ceiling) of the container 11 and connected to the space S.

[0018] The cooling fins 12 are fixed to the inner wall surface of the space S of the container 11. The cooling fins 12 have a trapping surface 12a. The trapping surface 12a extends in a direction substantially parallel to the vertical direction of the exhaust device 1. The cooling fins 12 are preferably cooled so that the temperature of the exhaust gas contacting the trapping surface 12a is not higher than the liquefaction temperature of the product in the exhaust gas. The trapping surface 12a cooled to a temperature not higher than the liquefaction temperature of the product can liquefy or solidify the product in the exhaust gas by contacting the exhaust gas from the gas inlet IN. The planar shape of the trapping surface 12a is not particularly limited, but for example, it is rectangular. In FIGS. 2 to 4, an example of the flow direction of the exhaust gas is indicated by an arrow. By providing a plurality of cooling fins 12 having a trapping surface 12a that extends along a direction substantially parallel to the vertical direction of the exhaust device 1, which is the direction in which the exhaust gas flows, the exhaust gas can be cooled to a temperature not higher than the liquefaction temperature of the product on the trapping surface 12a. FIGS. 2 to 4 show a plurality of cooling fins 12, but the number of the plurality of cooling fins 12 is not limited to the number of the cooling fins 12 shown in FIGS. 2 to 4.

[0019] The cooling fins 12 can be formed, for example, using a metallic material. The metallic material may be, for example, stainless steel (SUS). The cooling fins 12 may be formed using a metal plate that has been surface-treated to enhance resistance to the exhaust gas. The cooling fins 12 may be integrally formed using the same material as the container 11.

[0020] Adjacent cooling fins 12 have a pair of opposing trapping surfaces 12a. The pair of trapping surfaces 12a are spaced apart so as to face each other, for example, in a direction (for example, the X-axis direction) substantially perpendicular to the vertical direction of the exhaust device 1. The plurality of cooling fins 12 form a flow path 15 between the pair of trapping surfaces 12a. The flow path 15 extends, for example, along a direction substantially parallel to the vertical direction of the exhaust device 1. In the flow path 15, the exhaust gas from the gas inlet IN can flow toward the upper end surface of the container 11, for example. The length of the pair of trapping surfaces 12a in the Z-axis direction may be greater than the lengths of the pair of trapping surfaces 12a in the X-axis and Y-axis directions.

[0021] The cooling pipe 13 allows a refrigerant for cooling the cooling fins 12 to flow through it. The refrigerant may be a liquid or a gas. The refrigerant can cool the cooling fins 12 so that the temperature of the exhaust gas contacting the pair of trap surfaces 12a is below the liquefaction temperature of the product in the exhaust gas. Examples of the refrigerant include cooling water. The cooling pipe 13 extends through the pair of trap surfaces 12a in a direction (e.g., the X-axis direction) intersecting the pair of trap surfaces 12a. In FIG. 3, a part of the cooling pipe 13 is shown by a dotted line for the sake of convenience.

[0022] The cooling pipe 13 extends in a meandering manner while passing through a plurality of cooling fins 12, thereby penetrating through a plurality of locations on one trap surface 12a. Thus, as shown in FIG. 2, the cooling pipe 13 may extend so as to intersect in the Y-axis direction. The refrigerant inlet 13a and the refrigerant outlet 13b of the cooling pipe 13 are provided, for example, on the upper end surface of the container 11 and connected to a refrigerant supply source. Thereby, the refrigerant can be circulated from the refrigerant inlet 13a to the refrigerant outlet 13b of the cooling pipe 13 through a plurality of cooling fins 12. Note that the refrigerant supply source and the cooling pipe 13 may be connected via a pump for flowing the refrigerant.

[0023] The cover 14 is provided between the gas inlet IN and the plurality of cooling fins 12 in the Z-axis direction and covers the gas inlet IN. The cover 14 is provided, for example, above the gas inlet IN so as to overlap the gas inlet IN in the Z-axis direction. The cover 14 has an opening O. The opening O connects the gas inlet IN and the space S. Thereby, the exhaust gas can flow from the gas inlet IN to the space S through the opening O. FIG. 2 shows an example in which the opening O is provided in the X-axis direction of the cover 14, but the opening O may be provided in the Y-axis direction of the cover 14.

[0024] The cover 14 can be formed using, for example, a metal material. The metal material may be, for example, stainless steel (SUS). The surface of the cover 14 may be surface-treated to enhance its resistance to exhaust gases. The shape of the cover 14 is not particularly limited, as long as it is a shape that can cover the gas inlet IN. Examples of the shape of the cover 14 include prismatic, pyramidal, cylindrical, conical, dome-shaped, hemispherical, and partially spherical shapes.

[0025] Next, an example of capturing exhaust gas products by the trap device 10 will be described. Figure 5 is a schematic diagram illustrating an example of capturing exhaust gas products by the trap device 10. Figure 5 schematically shows a pair of trap surfaces 12a, a cooling pipe 13, and a cover 14.

[0026] In this embodiment, the trap device 10 is equipped with a plurality of cooling fins 12, each having a pair of trap surfaces 12a that form a flow path 15 through which exhaust gas flows in a direction substantially parallel to the vertical direction of the exhaust device 1. Compared to, for example, the case where the plurality of cooling fins 12 are arranged so that the pair of trap surfaces 12a form a flow path 15 in a direction substantially perpendicular to the vertical direction of the exhaust device 1, the cooling area provided by the plurality of cooling fins 12 can be increased without significantly reducing the conductance of the exhaust gas inside the container 11 of the trap device 10, thereby enabling efficient cooling of the exhaust gas.

[0027] The exhaust gas supplied to the space S from the gas inlet IN located below the cooling fins 12 passes through the flow path 15 along a direction approximately parallel to the vertical direction of the exhaust device 1 and is discharged from the gas outlet OUT located above the cooling fins 12. At this time, if the exhaust gas supplied from the gas inlet IN is at a temperature higher than, for example, the liquefaction temperature of product X, product X in the exhaust gas will not liquefy or solidify and will be discharged from the trap device 10 in gaseous form. This can cause product X to adhere to the piping P3 downstream of the trap device 10, blocking the exhaust path. If piping P3 becomes blocked, for example, a pressure sensor located downstream of the trap device 10 in the exhaust path may be activated, causing the exhaust pump 20 to stop.

[0028] Therefore, in this embodiment, the cooling pipe 13 is extended so as to penetrate a pair of trap surfaces 12a, and the multiple cooling fins 12 are cooled so that the pair of trap surfaces 12a are below the liquefaction temperature of the product X. This allows the exhaust gas to be cooled to below the liquefaction temperature of the product X at the trap surfaces 12a, and furthermore, variations in the cooling temperature within the trap surfaces 12a can be suppressed, thereby suppressing a decrease in the cooling efficiency of the cooling fins 12. If the cooling pipe 13 is extended around a region containing the multiple cooling fins 12 without penetrating the pair of trap surfaces 12a, for example, variations in the cooling temperature may occur between the center and the periphery of the trap surfaces 12a, which may reduce the cooling efficiency of the cooling fins 12. In contrast, with multiple cooling fins 12 provided with the cooling pipe 13 penetrating a pair of trap surfaces 12a, the product X in the exhaust gas can be stably cooled to below its liquefaction temperature, thereby liquefying or solidifying the product X at the trap surfaces 12a and capturing it. Thus, blockage of the exhaust path can be suppressed.

[0029] The temperature of the exhaust gas in contact with the trap surface 12a is cooled to below the liquefaction temperature of the product X in the exhaust gas. As a result, the captured product X, which has liquefied or solidified, then falls below the multiple cooling fins 12 along a direction parallel to the vertical direction of the exhaust device 1.

[0030] In contrast, by covering the gas inlet IN with the cover 14 in the vertical direction of the container 11, it is possible to suppress the backflow of liquefied or solidified product X from the gas inlet IN into the exhaust path. This prevents the exhaust path from being blocked by product X. Furthermore, since the liquefied or solidified product X accumulates on the inner bottom surface of the container 11, the product X can be efficiently recovered, for example, by removing the piping P2 from the container 11. In addition, since the product X can be dropped downward from the trap surfaces 12a of the multiple cooling fins 12 that extend in a direction substantially parallel to the vertical direction and collected in one place in the container 11, cleaning of the container 11 is simplified and maintenance of the trap device 10 is made easier.

[0031] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0032] 1... Exhaust device, 10... Trap device, 11... Container, 12... Cooling fins, 12a... Trap surface, 13... Cooling piping, 13a... Refrigerant inlet, 13b... Refrigerant outlet, 14... Cover, 15... Flow path, 20... Exhaust pump, IN... Gas inlet, O... Opening, OUT... Gas outlet, P1... Piping, P2... Piping, P3... Piping, S... Space, X... Product.

Claims

1. A container positioned in the exhaust path through which exhaust gas from a process chamber flows, having a gas inlet into which the exhaust gas is supplied and a gas outlet from which the exhaust gas is discharged, A plurality of cooling fins provided inside the container, each having a pair of opposing trap surfaces, and forming a passage between the pair of trap surfaces through which the exhaust gas flows; A cooling pipe extends through the pair of trap surfaces and through which a refrigerant that cools the plurality of cooling fins flows, A trap device equipped with the following.

2. A container positioned in the exhaust path through which exhaust gas from a process chamber flows, having a gas inlet into which the exhaust gas is supplied and a gas outlet from which the exhaust gas is discharged, A plurality of cooling fins provided inside the container, each having a pair of opposing trap surfaces, and forming a passage between the pair of trap surfaces through which the exhaust gas flows; A cooling pipe through which a refrigerant cools the plurality of cooling fins flows, A cover is provided between the gas inlet and the plurality of cooling fins, and covers the gas inlet. A trap device equipped with the following.

3. The system further comprises a cover provided between the gas inlet and the plurality of cooling fins, and covering the gas inlet. The trap device according to claim 1.

4. A trap device according to claim 1 or claim 2, An exhaust pump provided either before or after the trap device in the exhaust path, An exhaust system equipped with the following:

5. A container is positioned in the middle of the exhaust path through which exhaust gas from the process chamber flows, extending in a direction substantially parallel to the vertical direction, and having a gas inlet into which the exhaust gas is supplied, and a gas outlet into which the exhaust gas is discharged. A plurality of cooling fins provided within the container, having a pair of trap surfaces extending in a direction substantially parallel to the vertical direction and facing a direction substantially perpendicular to the vertical direction, and forming a passage for the exhaust gas to flow between the pair of trap surfaces, A cover is provided between the gas inlet and the plurality of cooling fins in the vertical direction, and covers the gas inlet. A trap device having, An exhaust pump provided either before or after the trap device in the exhaust path, An exhaust system equipped with the following:

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