Cleaning device and substrate processing system

Abstract

This cleaning device 100 for separating an inflow gas Go and particles that are contained in the gas Go includes a housing 1, a plate-shaped baffle 2, and a plurality of plasma units 5. The housing 1 has a cylindrical shape extending in the axial direction Da, and has an inflow port 121 and an outflow port 131 for the gas Go. The baffle 2 is disposed within the housing 1. The plasma units 5 generate plasma within the housing 1. The inside of the housing 1 has a plurality of internal spaces 14, and is configured so that the gas Go flowing thereinto from the inflow port 121 can flow out from the outflow port 131. Some internal spaces 14 adjacent to each other are connected so that the gas Go can flow therethrough. At least some adjacent internal spaces 14 are adjacent to each other by the intermediary of the baffle 2. The plasma units 5 are disposed with respect to at least two internal spaces 14.

Description

Cleaning device, substrate processing system

[0001] The present invention relates to a cleaning apparatus and a substrate processing system.

[0002] In semiconductor manufacturing equipment such as CVD equipment, many by-products are generated. When exhaust gas containing these by-products is discharged from the chamber, the exhaust line may become clogged, potentially damaging the vacuum pump. Therefore, in conventional semiconductor manufacturing equipment, a plasma unit and a collection trap device are installed in the exhaust line to remove the by-products. For example, in Patent Document 1, a plasma source is installed downstream of the processing chamber and upstream of an exhaust cooling device, and the generated plasma is introduced into the exhaust cooling device. This causes particles trapped in the exhaust cooling device to react with the plasma.

[0003] Special Publication No. 2021-524162

[0004] In recent years, there has been a trend toward thicker films being formed in semiconductor manufacturing equipment such as CVD equipment. This trend has also led to an increase in the amount of by-products emitted from the semiconductor manufacturing equipment. Therefore, it is necessary to improve the cleaning performance of the exhaust line to remove by-products.

[0005] SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to improve the decomposition power of gases and particles flowing into a cleaning device.

[0006] In order to achieve the above object, a cleaning apparatus according to one aspect of the present invention is an apparatus for decomposing an inflowing gas and particles contained in the gas. The cleaning apparatus includes a housing, a plate-shaped baffle, and multiple plasma units. The housing is cylindrical and extends axially, and has an inlet and an outlet for the gas. The baffle is disposed inside the housing. The plasma unit generates plasma inside the housing. The inside of the housing has multiple internal spaces, and is configured so that the gas flowing in from the inlet can flow out from the outlet. Some of the adjacent internal spaces are connected to allow the gas to flow through. At least some of the adjacent internal spaces are adjacent to each other via the baffle. The plasma unit is disposed for at least two of the internal spaces.

[0007] In order to achieve the above object, a substrate processing system according to one aspect of the present invention includes the above cleaning apparatus, a chamber, and a vacuum pump. A substrate to be processed using a process gas is placed in the chamber. The vacuum pump exhausts gas from the chamber. The cleaning apparatus is connected between the chamber and the vacuum pump and decomposes the gas and particles contained in the gas exhausted from the chamber.

[0008] Further features and advantages of the present invention will become more apparent from the following embodiments.

[0009] According to the present invention, the decomposition power of gases and particles flowing into the cleaning device can be improved.

[0010] Fig. 1 is a cross-sectional view showing a configuration example of a cleaning apparatus according to an embodiment; Fig. 2 is an external view of the cleaning apparatus according to an embodiment; Fig. 3 is a block diagram showing a configuration example of a substrate processing system equipped with the cleaning apparatus; Fig. 4 is a block diagram showing another configuration example of a substrate processing system equipped with the cleaning apparatus; Fig. 5 is an external view of a first modified example of the cleaning apparatus; Fig. 6 is an external view of a second modified example of the cleaning apparatus; Fig. 7 is a cross-sectional view showing a configuration example of a plasma unit;

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] 1. Embodiments A cleaning apparatus 100 according to an embodiment is disposed in an exhaust system of a substrate processing system 800 such as a CVD (chemical vapor deposition) apparatus or a dry etching apparatus. FIG. 1 is a cross-sectional view showing an example of the configuration of the cleaning apparatus 100 according to an embodiment. FIG. 2 is an external view of the cleaning apparatus 100 according to an embodiment. FIG. 3A is a block diagram showing an example of the configuration of a substrate processing system 800 equipped with the cleaning apparatus 100. FIG. 3B is a block diagram showing another example of the configuration of a substrate processing system 800 equipped with the cleaning apparatus 100. Note that FIG. 1 shows a cross-sectional structure of the cleaning apparatus 100 taken along the two-dot chain line II in FIG. 2. Also, FIG. 3A ..., for example, in a CVD apparatus, where the pressure is reduced from atmospheric pressure to 100. －１ 3B shows an example of the configuration of a substrate processing system 800 for performing processes such as film formation and surface processing on a substrate S under a vacuum of about [Pa]. －１ 8 shows an example of the configuration of a substrate processing system 800 that processes the surface of a substrate S under a vacuum higher than [Pa].

[0013] 3A and 3B, a configuration example of the substrate processing system 800 will be described. The substrate processing system 800 includes a cleaning apparatus 100, a chamber 200, a mass flow controller 300, an auto pressure controller 400, and a dry vacuum pump 500. In the following description, the mass flow controller 300 will be referred to as "MFC 300," and the auto pressure controller 400 will be referred to as "APC 400."

[0014] The chamber 200 is a processing chamber for the substrate S, controlled under a predetermined vacuum environment. A process gas Gi is supplied to the chamber 200 through a supply port 201, and a substrate S to be processed using the process gas Gi is placed therein. The substrate processing system 800 performs processes such as film formation and surface processing on the substrate S using the process gas Gi. During this process, by-product gases are generated within the chamber 200 through decomposition of the process gas Gi, and solid particles of the by-products are dispersed. These are exhausted from the exhaust port 202 along with the excess process gas Gi that has not been decomposed. In other words, the gas Go exhausted from the exhaust port 202 is a gas containing, for example, the remaining process gas Gi and by-product gases generated during the processing of the substrate S in the chamber 200. The solid particles are by-products generated during the processing of the substrate S in the chamber 200, and are included in the gas Go. The particles are mixed in with the gas flow and exhausted to the exhaust system.

[0015] The MFC 300 controls the flow rate of the process gas Gi supplied into the chamber 200 .

[0016] The APC 400 is, for example, an electric butterfly valve and is disposed at the exhaust port 202 of the chamber 200. The APC 400 controls the degree of vacuum (i.e., air pressure) within the chamber 200 by controlling the flow rate of the gas Go exhausted from the chamber 200. For example, a pressure sensor 401 is disposed within the chamber 200. The pressure sensor 401 detects the degree of vacuum within the chamber 200 and outputs the detected value to the APC 400. The APC 400 controls the flow rate of the exhausted gas Go based on the detection result of the pressure sensor 401. For example, if the degree of vacuum within the chamber 200 tends to be lower than the target value (i.e., the air pressure is increasing), the APC 400 increases the amount of exhaust of the gas Go. On the other hand, if the degree of vacuum within the chamber 200 tends to be higher than the target value (i.e., the air pressure is decreasing), the APC 400 reduces the amount of exhaust of the gas Go. This maintains the degree of vacuum within the chamber 200 at the target value.

[0017] The dry vacuum pump 500 exhausts the gas Go inside the chamber 200. For example, the dry vacuum pump 500 is disposed at the final stage of an exhaust system of the substrate processing system 800, and removes gas from inside the chamber 200 and transports it to the outside. For example, the dry vacuum pump 500 generates a negative pressure environment in the exhaust system where the air pressure is lower than that inside the chamber 200. This causes the gas inside the chamber 200 to flow out into the exhaust system from the exhaust port 202.

[0018] The cleaning apparatus 100 is an apparatus for decomposing the inflowing gas Go and particles contained in the gas Go, and is connected between the chamber 200 and the dry vacuum pump 500. For example, the cleaning apparatus 100 is disposed upstream of the dry vacuum pump 500 in the exhaust system of the substrate processing system 800, and decomposes the gas Go exhausted from the chamber 200 and exhausts it to the dry vacuum pump 500. In detail, the cleaning apparatus 100 collects particles such as by-products generated within the chamber 200 and contained in the gas Go flowing from the inlet 121 to the outlet 131, as well as gas solidified due to a temperature drop (e.g., by-product gas), and decomposes the particles and solidified gas into the gas Go containing excess process gas and by-product gas.

[0019] When film formation and processing of the substrate S is performed under high vacuum, the substrate processing system 800 further includes a turbomolecular pump 600 as shown in Fig. 3B. The turbomolecular pump 600 is disposed between the APC 400 and the cleaning device 100 in the exhaust system. When film formation and processing of the substrate S is performed under low vacuum, the turbomolecular pump 600 is not disposed as shown in Fig. 3A.

[0020] <1-2. Cleaning Device 100> Next, a configuration example of the cleaning device 100 will be described with reference to Figures 1 and 2 and 4 and 5. Figure 4 is an external view of a first modified example of the cleaning device. Figure 5 is an external view of a second modified example of the cleaning device.

[0021] The cleaning device 100 includes a housing 1 , a baffle 2 , an internal cooling mechanism 3 , an external cooling mechanism 4 , and a plurality of plasma units 5 .

[0022] The housing 1 is cylindrical and extends in an axial direction Da parallel to the central axis J, and has an inlet 121 and an outlet 131 for the gas Go. A first lid portion 12 and a second lid portion 13 are disposed at both axial ends of the housing 1. The inlet 121 for the gas Go is disposed at one axial end of the housing 1. The outlet 131 for the gas Go is disposed at the other axial end of the housing 1.

[0023] The housing 1 has a cylindrical portion 11 , a first lid portion 12 , and a second lid portion 13 .

[0024] The cylindrical portion 11 extends in the axial direction Da and surrounds the baffle 2. The cylindrical portion 11 has side holes 111a to 111d arranged therein, which penetrate the cylindrical portion 11 in the radial direction. In this embodiment, the number of side holes 111 is four. However, this is not limiting, and the number of side holes 111 may be any number other than four. In the following, at least one of the side holes 111a to 111d may be simply referred to as the "side hole 111."

[0025] The first lid portion 12 covers one axial end portion of the tubular portion 11. The second lid portion 13 covers the other axial end portion of the tubular portion 11. In this embodiment, when viewed from the axial direction Da, the inlet 121 is located in the center of the first lid portion 12, and the outlet 131 is located in the center of the second lid portion 13.

[0026] However, this is not intended to be limiting, and for example, as shown in Fig. 4, at least one of the inlet 121 and the outlet 131 may be disposed on the radially outer surface of the tubular portion 11. In this case, the axial positions of the inlet 121 and the outlet 131 are not limited to the example shown in Fig. 4. For example, the axial position of the inlet 121 may be the same as the axial position of the outlet 131.

[0027] The baffle 2 is a plate-shaped member that obstructs the flow of gas Go inside the housing 1 and is disposed inside the housing 1. In this embodiment, the baffle 2 extends in a direction intersecting the axial direction Da. The outer edge of the baffle 2 faces the inner circumferential surface of the housing 1 in the radial direction, with a gap therebetween. However, this is not limited to this example, and at least a portion of the outer edge of the baffle 2 may abut against the inner circumferential surface of the housing 1. The means for fixing the baffle 2 to the housing 1 is not particularly limited. For example, the baffle 2 may be fixed to the inner circumferential surface of the housing 1 via a rib (not shown). Alternatively, at least a portion of the outer edge of the baffle 2 may be fixed to the inner circumferential surface of the housing 1 by welding, brazing using silver solder, or the like.

[0028] The baffle 2 (particularly the plate portion 21 described below) divides the internal space 14 of the housing 1. In other words, the interior of the housing 1 has multiple internal spaces 14a to 14d, and is configured so that the gas Go flowing in from the inlet 121 can flow out from the outlet 131. Each of the internal spaces 14a to 14d is a space obtained by dividing the interior of the housing 1 with the baffle 2 (the plate portion 21) or the like. Some of the adjacent internal spaces 14 are connected to each other so that the gas Go can flow through them. Furthermore, at least some of the adjacent internal spaces 14 are adjacent to each other via the baffle 2.

[0029] In this embodiment, there are multiple baffles 2 arranged in the axial direction Da. For example, as shown in FIG. 2, there are three baffles 2, and the housing 1 is divided into four internal spaces 14a to 14d. However, this is not limiting, and the number of baffles 2 may be one or a number other than three. In the following, at least one of the multiple partitioned internal spaces 14a to 14d may be simply referred to as the "internal space 14."

[0030] The internal cooling mechanism 3 is an example of a "first cooling mechanism" in the present invention, and cools the baffles 2. The internal cooling mechanism 3 has cooling pipes 31 through which the refrigerant F2 flows. The cooling pipes 31 are arranged on the axial end faces of the respective baffles 2 and are in contact with the baffles 2. The cooling pipes 31 are an example of a "first cooling pipe" in the present invention. The refrigerant F1 is an example of a "first refrigerant" in the present invention, and is water in this embodiment. However, the refrigerant F1 is not limited to the example in this embodiment, and may be a liquid other than water, or may be a gas.

[0031] In this embodiment, the cooling pipes 31 are arranged on the other axial end surfaces of all the baffles 2 and are in contact with the other axial end surfaces of the baffles 2. However, without being limited to this example, the cooling pipes 31 may be arranged on one axial end surface of the baffles 2 and in contact with them, or may be arranged on both axial end surfaces of the baffles 2 and in contact with them.

[0032] The internal cooling mechanism 3 further includes a supply pipe 32 and a discharge pipe 33. The supply pipe 32 supplies the refrigerant F1 to the cooling pipe 31. The discharge pipe 33 discharges the refrigerant F1 discharged from the cooling pipe 31 to the outside of the housing 1.

[0033] By cooling the baffle 2 with the cooling pipe 31 of the internal cooling mechanism 3, particles are more likely to adhere to the axial end surface of the baffle 2. This improves the efficiency of capturing particles contained in the gas Go. However, the example of this embodiment does not exclude a configuration in which the cooling pipe 31 is not provided on at least one of the baffles 2.

[0034] The external cooling mechanism 4 is an example of a "second cooling mechanism" in the present invention, and cools the housing 1. In the present embodiment, the external cooling mechanism 4 has a cooling pipe 41 through which the refrigerant F2 flows. The cooling pipe 41 is an example of a "second cooling pipe" in the present invention. The refrigerant F2 is also an example of a "second refrigerant" in the present invention, and is water in the present embodiment. However, the refrigerant F2 is not limited to the example in the present embodiment, and may be a liquid other than water, or may be a gas.

[0035] The cooling pipe 41 is disposed on the outer surface of the housing 1 and is in contact with the housing 1, extending along the outer surface of the housing 1 in at least one of the axial direction Da and the circumferential direction. An inlet 411 through which the refrigerant F2 is supplied is disposed at one end of the cooling pipe 41. An outlet 412 through which the refrigerant F2 is discharged is disposed at the other end of the cooling pipe 41. Cooling the housing 1 with the above-described cooling pipe 41 makes it easier for particles to adhere to the inner surface (particularly the inner circumferential surface) of the housing 1. Therefore, the efficiency of collecting particles contained in the gas Go can be improved.

[0036] Each plasma unit 5 generates plasma inside the housing 1. Furthermore, the plasma units 5 are arranged for at least two internal spaces 14, and in this embodiment, the plasma units 5 are arranged individually for all internal spaces 14. In the examples shown in Figures 1 and 2 and 4 and 5, the plasma units 5 are attached to the cylindrical portion 11 of the housing 1. However, this is not limiting, and at least one plasma unit 5 may be attached to at least one of the first cover portion 12 and the second cover portion 13 of the housing 1.

[0037] According to the cleaning device 100 of this embodiment, by disposing the plate-shaped baffle 2 intersecting the axial direction Da inside the housing 1, the interior of the housing 1 can be divided by the baffle 2. Therefore, compared to a configuration in which the baffle 2 is not disposed, the residence time of the gas Go in each internal space 14 inside the housing 1 is longer. Therefore, particles contained in the resident gas Go (so-called contamination, for example, by-products generated in the chamber 200) can be more easily collected in each internal space 14. This improves the efficiency of particle removal.

[0038] Furthermore, the plasma generated by the plasma unit 5 can decompose the gas Go remaining in each internal space 14, and particles captured in or contained in the gas Go. Furthermore, by arranging the plasma unit 5 for at least two internal spaces 14, the plasma generation area within the housing 1 can be increased. Therefore, the ability to decompose the gas Go and particles flowing into the cleaning device 100 can be improved.

[0039] Furthermore, by adjusting the plasma units 5 disposed for each internal space 14 differently, the decomposition performance in each internal space 14 can be changed. For example, the amount of gas Go and particles in the internal space 14 closer to the inlet 121 (e.g., internal space 14a) is greater than the amount of gas Go and particles in the internal space 14 closer to the outlet 131 (e.g., internal space 14d). Therefore, for example, by changing the power applied to the plasma units 5, the processing capacity of the plasma unit 5 disposed for the internal space 14 closer to the inlet 121 can be made greater than the processing capacity of the plasma unit 5 disposed for the internal space 14 closer to the outlet 131. In other words, the decomposition power, such as the decomposition rate of gas Go and particles, of the plasma units 5 disposed for each internal space 14 can be adjusted. Therefore, the cleaning device 100 can decompose gas Go and particles in each internal space 14 at a processing capacity appropriate for that internal space 14. Therefore, the cleaning device 100 can efficiently decompose gas and particles while reducing power consumption, etc.

[0040] 1 and 2 and 4 and 5, an example of the configuration of the baffle 2 will be described. The baffle 2 has a plate portion 21, a vent hole 22, and a porous portion 23.

[0041] The plate portion 21 is a plate-like member accommodated inside the housing 1. In this embodiment, the plate portion 21 extends in a direction intersecting the axial direction Da, and in FIGS. 2 and 4, the plate portion 21 extends in a radial direction. However, the direction in which the plate portion 21 extends is not limited to the above example. For example, as shown in FIG. 5, the plate portion 21 may be a plate-like member extending in a direction perpendicular to the axial direction Da as a normal direction. Note that in FIG. 5, as in FIGS. 1 and 2, the inlet 121 is disposed in the first cover portion 12, and the outlet 131 is disposed in the first cover portion 12. However, this is not limited to this example. In the configuration illustrated in FIG. 5, at least one of the inlet 121 and the outlet 131 may be disposed on the radially outer surface of the tubular portion 11, as in FIG. 4, for example. Furthermore, in this embodiment, the normal direction of the plate portion 21 is parallel to the opening direction of the inlet 121 and the outlet 131, as shown in FIG. 2, etc. However, this example is not limiting, and the normal direction of the plate portion 21 may intersect (particularly perpendicular to) at least one of the directions in which the inlet 121 opens and the outlet 131 opens, as shown in Figure 5, for example.

[0042] The vent 22 is an opening disposed in the plate portion 21 of the baffle 2 and connects the internal spaces 14 via the baffle 2. For example, the internal space 14a connected to the inlet 121 is connected to the internal space 14b via the vent 22 (and the porous portion 23) disposed in the baffle 2a. Therefore, the gas Go flowing in from the inlet 121 can flow between the adjacent internal spaces 14a and 14b via the baffle 2a. Furthermore, the internal space 14b is connected to the internal space 14c via the vent 22 (and the porous portion 23) disposed in the baffle 2b. Therefore, the gas Go can flow between the adjacent internal spaces 14b and 14c via the baffle 2b. Furthermore, the internal space 14c is connected to the internal space 14d connected to the outlet 131 via the vent 22 (and the porous portion 23) disposed in the baffle 2c. Therefore, the gas Go can flow between the adjacent internal spaces 14c and 14d via the baffle 2c, and can flow from the internal space 14d to the outside of the housing 1 through the outlet 131. In this way, the adjacent internal spaces 14 are connected to enable the flow of the gas Go, so that inside the housing 1, the gas Go flowing in from the inlet 121 can flow out from the outlet 131 to the outside.

[0043] Preferably, in the baffle 2 disposed closest to the inlet 121, the position of the vent 22 is offset from the position of the inlet 121 as viewed in the axial direction Da. The baffle 2 is adjacent in the axial direction Da to the cover portion (i.e., the first cover portion 12) on one axial side Da1. That is, in the above-described baffle 2, the vent 22 is disposed at a different position from the inlet 121 without overlapping with it as viewed in the axial direction Da. This prevents the gas Go flowing in from the inlet 121 from flowing to the vent 22 via the shortest path. This prevents a decrease in the residence time of the gas Go in the internal space 14 connected to the inlet 121. However, this example does not exclude a configuration in which at least some of the vents 22 overlap with the inlet 121 as viewed in the axial direction Da in the above-described baffle 2.

[0044] Preferably, in adjacent baffles 2 in the axial direction Da, the positions of the vent holes 22 in one baffle 2 are offset from the positions of the vent holes 22 in the other baffle 2 as viewed from the axial direction Da. That is, the vent holes 22 in one baffle 2 are positioned at different positions from the vent holes 22 in the other baffle 2 without overlapping as viewed from the axial direction Da. This prevents the gas Go flowing in from the vent holes 22 on the one axial side Da1 from flowing via the shortest path to the vent holes 22 on the other axial side Da2. This prevents a decrease in the residence time of the gas Go in the internal space 14. However, this example does not exclude a configuration in which at least some of the vent holes 22 in one baffle 2 overlap with the vent holes 22 in the other baffle 2 as viewed from the axial direction Da.

[0045] Preferably, a portion of the plasma unit 5 is disposed on at least one of the axial sides Da1 and Da2 of the vent 22. By disposing the plasma unit 5 relative to the vent 22 as described above, the plasma unit 5 can generate plasma in the flow path of the gas Go that flows through the vent 22 to the next internal space 14. This further improves the decomposition capability of the gas Go and particles. However, this example does not exclude a configuration in which a portion of the plasma unit 5 is not disposed on either the axial side Da1 or the axial side Da2 of the vent 22. For example, a portion of the plasma unit 5 may be disposed offset from the vent 22 in the circumferential direction relative to the central axis J.

[0046] The porous portion 23 is composed of a plurality of holes 231 having a smaller diameter than the vent port 22, and connects adjacent internal spaces 14 in the axial direction Da via the baffle 2. However, the flow path resistance of the porous portion 23 is larger than that of the vent port 22. Therefore, the flow rate of the gas Go flowing through the porous portion 23 to the next internal space 14 is smaller than the flow rate at the vent port 22.

[0047] In this embodiment, the perforated portions 23 are arranged in the entire area of ​​the axial end face of the plate portion 21, except for the area where the vent holes 22 are arranged. In other words, the baffle 2 is a perforated board in which the vent holes 22 are formed. However, without being limited to this example, the perforated portions 23 may be arranged in some areas other than the area where the vent holes 22 are arranged, and not in other areas.

[0048] Preferably, both the vent hole 22 and the porous portion 23 are disposed in the plate portion 21 of the baffle 2. In this way, the arrangement of the vent hole 22 suppresses pressure loss of the gas Go and suppresses an increase in flow path resistance within the housing 1, while the arrangement of the porous portion 23 increases the contact area between the baffle 2 (particularly the plate portion 21) and the gas Go, thereby improving the efficiency of capturing particles contained in the gas Go. However, this example does not exclude a configuration in which at least one of the vent hole 22 and the porous portion 23 is not disposed in the plate portion 21 in at least one baffle 2. In other words, it is possible that one of the vent hole 22 and the porous portion 23 is disposed in the plate portion 21, and the other is not disposed.

[0049] Furthermore, without being limited to the example of this embodiment, the porous portion 23 does not have to be configured with a plurality of holes 231. For example, the porous portion 23 may be configured such that a plurality of flow paths that have a higher flow path resistance than the vent hole 22 and that penetrate the plate portion 21 in the axial direction Da are arranged in the plate portion 21, and may be configured with, for example, a mesh, a plurality of slits, or the like.

[0050] <1-4. Plasma Unit 5> Next, a configuration example of the plasma unit 5 will be described with reference to FIGS. 1 to 2 and 6. FIG. 6 is a cross-sectional view showing the configuration example of the plasma unit 5. Note that, hereinafter, a direction intersecting the axial direction Da and the radial direction will be referred to as the "first direction D1," and a direction intersecting the axial direction Da and the first direction D1 will be referred to as the "second direction D2." In FIG. 6, the first direction D1 is perpendicular to the axial direction Da and the radial direction. Furthermore, the second direction D2 is perpendicular to the axial direction Da and the first direction D1. However, the second direction D2 may or may not be a radial direction based on the central axis J.

[0051] The plasma unit 5 includes a waveguide 51 , an antenna 52 , and a cooling mechanism 53 .

[0052] The waveguide 51 has a cylindrical shape extending in the first direction D1 and is disposed radially outward from the housing 1. For example, the waveguide 51 has a waveguide 511, a joint 512, and flanges 5131 and 5132. The waveguide 511 has a cylindrical shape extending in the first direction D1. Two side holes 5111 and 5112 that face each other in the second direction D2 are disposed in the center of the waveguide 511 in the first direction D1. The side holes 5111 and 5112 penetrate the waveguide 511 in the thickness direction. The side hole 5111 opens toward the side hole 111 of the cylindrical portion 11 and is connected to the side hole 111.

[0053] For example, a connecting pipe 5113 is disposed on the side surface of the waveguide 511 facing the cylindrical portion 11 in the second direction D2. The connecting pipe 5113 is cylindrical and surrounds the side hole 5111, and extends from the waveguide 511 toward the cylindrical portion 11 in the second direction D2. Meanwhile, a connecting pipe 112 is disposed on the side surface of the cylindrical portion 11 facing the waveguide 511 in the second direction D2. The connecting pipe 112 is cylindrical and surrounds the side hole 111, and extends from the cylindrical portion 11 toward the waveguide 511 in the second direction D2. The end of the connecting pipe 112 facing the waveguide 511 is butted against the end of the connecting pipe 5113 facing the cylindrical portion 11 via a sealing member such as an O-ring or a gasket, and the two are connected using a clamp (not shown). As a result, the side hole 5111 of the waveguide 511 is connected to the side hole 111 of the cylindrical portion 11 through the insides of the connecting pipe 5113 and the connecting pipe 112. Furthermore, airtightness between the connecting pipe 5113 and the connecting pipe 112 is maintained.

[0054] The flange portion 5131 is disposed at one end of the waveguide 511 in the first direction D1 and extends in a direction perpendicular to the first direction D1. A high-frequency generator 514 is disposed at one end of the waveguide 511 (i.e., the flange portion 5131). The high-frequency generator 514 radiates high-frequency waves into the inside of the waveguide 51.

[0055] The flange portion 5132 is disposed at the other end of the waveguide 511 in the first direction D1, and extends in a direction perpendicular to the first direction D1.

[0056] The antenna unit 52 extends in the second direction D2, penetrates the waveguide unit 51 in the second direction D2, and is inserted into the side hole 111 of the tubular unit 11. For example, the antenna unit 52 is inserted from the side hole 5112 on the opposite side of the tubular unit 11 in the second direction D2 to the side hole 5111 on the tubular unit 11 side, and then inserted into the side hole 111 of the tubular unit 11 through the inside of the connecting tube 5113 and the connecting tube 112. Preferably, the antenna unit 52 is inserted into the side hole 111 of the tubular unit 11 so as to be movable in the second direction D2. In other words, the amount of protrusion in the second direction D2 of the tip of the antenna unit 52 (i.e., the tip of a dielectric 522, described later) relative to the internal space 14 of the tubular unit 11 is adjustable. However, this example does not exclude a configuration in which the antenna unit 52 is inserted into the side hole 111 so as not to be movable in the second direction D2.

[0057] The antenna unit 52 has a pillar portion 521 and a dielectric 522. The pillar portion 521 is made of metal and extends in the second direction D2. The dielectric 522 covers the tip of the pillar portion 521. The pillar portion 521 also has a covered cylindrical outer cylinder portion 5211 and an inner cylinder portion 5212. The outer cylinder portion 5211 extends in the second direction D2. The tip of the outer cylinder portion 5211 is covered with the dielectric 522. The inner cylinder portion 5212 extends in the second direction D2 and is housed inside the outer cylinder portion 5211.

[0058] A part of the column portion 521 and a radially outer portion of the dielectric 522 are exposed inside the waveguide 51. Furthermore, the tip portion (radially inner portion) of the dielectric 522 is inserted into the side hole 111 and exposed to the internal space 14 of the housing 1. The outer surface of the dielectric 522 slidably abuts against the inner circumferential surface of the side hole 5111 via a sealing member such as an O-ring or a gasket. This maintains the airtightness of the internal space 14 facing the side hole 111.

[0059] The plasma unit 5 of this embodiment generates surface waves on the antenna 52 (e.g., a portion of the column 521 and a radially outer portion of the dielectric 522) by applying high-frequency waves radiated from the high-frequency generator 514 into the waveguide 51 to the antenna 52. Furthermore, the plasma unit 5 can propagate the surface waves to the radially inner portion of the dielectric 522 exposed to the internal space 14 (i.e., the tip). This generates heat at the tip of the dielectric 522, and the potential at the tip increases due to friction with the gas Go and particles. As a result, the gas Go near the tip of the dielectric 522 is ionized. The plasma unit 5 of this embodiment can generate plasma with a higher ionization density than other plasma units, such as inductively coupled plasma (ICP). Furthermore, the plasma unit 5 of this embodiment can be configured more compactly than other plasma units, thereby preventing the cleaning device 100 from becoming larger even when multiple units are installed.

[0060] Preferably, a reflecting portion 515 is disposed at the other end of the waveguide portion 51 (i.e., the flange portion 5132) and covers the other end of the waveguide portion 51. The reflecting portion 515 reflects the high frequency wave output from the high frequency generator 514.

[0061] More preferably, the position of the reflecting portion 515 in the first direction D1 is adjustable. For example, the reflecting portion 515 is attached to the flange portion 5132 via a position-adjusting frame or a cylindrical body that is extendable and contractible in the first direction D1.

[0062] In this way, a standing wave can be formed inside the waveguide 51 by combining the high frequency wave output from the high frequency generator 514 and the reflected wave output from the reflector 515 toward the high frequency generator 514. Therefore, for example, by arranging the antenna 52 at a position where the strength of the standing wave is strongest, a high-intensity surface wave can be efficiently generated in the antenna 52. Therefore, the plasma unit 5 can efficiently generate plasma with a high ionization density at the tip of the dielectric 522.

[0063] However, this example does not exclude a configuration in which the position of the reflecting portion 515 in the first direction D1 is not adjustable. For example, the reflecting portion 515 may be directly fixed to the flange portion 5132. Furthermore, the above example does not exclude a configuration in which the reflecting portion 515 is not disposed at the other end of the waveguide 51 (i.e., the flange portion 5132). For example, nothing may be attached to the flange portion 5132, and the other end of the waveguide 51 may be open.

[0064] The cooling mechanism 53 uses the refrigerant F3 to cool the antenna unit 52. The cooling mechanism 53 is an example of a "third cooling mechanism" in the present invention. The refrigerant F3 is also an example of a "third refrigerant" in the present invention, and is water in this embodiment. However, the refrigerant F3 is not limited to the example in this embodiment, and may be a liquid other than water, or may be a gas.

[0065] The cooling mechanism 53 has a supply flow path Pi and a discharge flow path Po.

[0066] The supply flow path Pi supplies the refrigerant F3 to the interior of the inner cylindrical portion 5212. For example, as shown in FIG. 6 , the supply flow path Pi is composed of an elbow joint 531, a union tee 532, and a connecting pipe 533. One end of the elbow joint 531 is an inlet for the refrigerant F3. The other end of the elbow joint 531 is connected to one end of the connecting pipe 533. The other end of the connecting pipe 533 is inserted into a first opening 5321 of the union tee 532 and further connected, inside the union tee 532, to an end of the inner cylindrical portion 5212 that is inserted from the second opening 5322 to the first opening 5321 on the opposite side from the cylindrical portion 11 in the second direction D2. With this configuration, the refrigerant F3 is supplied from one end of the elbow joint 531 into the interior of the inner cylindrical portion 5212 and sent to the interior of the tip portion of the outer cylindrical portion 5211 (the end portion on the cylindrical portion side in the second direction D2).

[0067] The discharge flow path Po discharges the refrigerant F3 flowing out from between the outer cylindrical portion 5211 and the inner cylindrical portion 5212 to the outside. For example, as shown in FIG. 6 , the discharge flow path Po is composed of a union tee 532 and a reducer 534. An end of the outer cylindrical portion 5211 opposite the cylindrical portion 11 in the second direction D2 is connected to a second opening 5322 of the union tee 532. One end of the reducer 534 is connected to a third opening 5323 of the union tee 532. The other end of the reducer 534 is an outlet for the refrigerant F3. With this configuration, the refrigerant F3 is sent from between the outer cylindrical portion 5211 and the inner cylindrical portion 5212 to the third opening 5323 of the union tee 532 and is discharged to the outside from the other end of the reducer 534.

[0068] By flowing the refrigerant F3 supplied from the supply flow path Pi through the interior of the inner cylinder 5212 to the tip of the outer cylinder 5211, the tip of the antenna unit 52 (particularly the outer cylinder 5211), which is prone to a significant temperature rise, can be immediately cooled, effectively suppressing the temperature rise. Furthermore, by flowing the refrigerant F3 flowing to the tip between the outer cylinder 5211 and the inner cylinder 5212, the portion of the antenna unit 52 that is exposed to high frequencies can be cooled. This portion includes the part of the outer cylinder 5211 exposed inside the waveguide 511 and the radially outer portion of the dielectric 522. This prevents damage to the antenna unit 52 due to a temperature rise, and can prevent, for example, the outer cylinder 5211 from melting due to heat generation.

[0069] The plasma unit 5 generates plasma by ionizing the gas Go. At this time, an auxiliary gas Ga may be supplied to the dielectric 522 that generates the plasma. The auxiliary gas Ga promotes ionization and assists in the generation of the plasma. Ar (argon) gas or the like is used as the auxiliary gas Ga. For example, as shown in FIG. 6 , a supply port 5115 is preferably provided in the cylindrical portion 11. The supply port 5115 is a member that supplies the auxiliary gas Ga to the radially inner portion of the dielectric 522 that is exposed to the internal space 14. The supply port 5115 may be provided in the connecting pipe 5113 on the waveguide 51 side. A backflow prevention member such as a check valve is also provided in the supply port 5115. This maintains the airtightness of the internal space 14 even when the auxiliary gas Ga is not supplied.

[0070] The provision of the supply port 5115 allows the supply of an auxiliary gas Ga, which improves the plasma generation efficiency, to the tip of the dielectric 522. Therefore, the plasma unit 5 can generate a higher density plasma over a wider range near the tip of the dielectric 522. However, this example does not exclude a configuration in which the auxiliary gas Ga is not supplied to the dielectric 522 when plasma is generated. For example, the provision of the supply port 5115 may be omitted in at least one of the side holes 111.

[0071] 2. Remarks The above describes the embodiments of the present invention. Note that the above embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each process, and that such modifications are within the scope of the present invention.

[0072] 3. Summary The following provides a summary of the embodiments described above.

[0073] For example, the cleaning device 100 disclosed in this specification is a cleaning device 100 for decomposing an inflowing gas Go and particles contained in the gas Go, and comprises: a cylindrical housing 1 extending in the axial direction Da and having an inlet 121 and an outlet 131 for the gas Go; a plate-shaped baffle 2 arranged inside the housing 1; and a plurality of plasma units 5 that generate plasma inside the housing 1, wherein the interior of the housing 1 has a plurality of internal spaces 14 and is configured so that the gas Go flowing in from the inlet 121 can flow out from the outlet 131, some adjacent internal spaces 14 are connected to allow the gas Go to flow, at least some adjacent internal spaces 14 are adjacent to each other via the baffle 2, and the plasma unit 5 is configured to be arranged relative to at least two of the internal spaces 14 (first configuration).

[0074] Moreover, in the cleaning device 100 of the first configuration, the housing 1 has a cylindrical portion 11 extending in the axial direction Da and surrounding the baffle 2, the cylindrical portion 11 has a side hole 111 arranged in the cylindrical portion 11 and penetrating the cylindrical portion 11 in the radial direction, the plasma unit 5 has a cylindrical waveguide portion 51 arranged radially outward of the housing 1 and extending in a first direction D1 intersecting the radial direction, with a high-frequency generator 514 arranged at one end, and an antenna portion 52 that penetrates the waveguide portion 51 in a second direction D2 intersecting the axial direction Da and the first direction D1 and is inserted into the side hole 111, the antenna portion 52 has a metallic pillar portion 521 extending in the second direction D2, and a dielectric 522 covering the tip end of the pillar portion 521, a part of the pillar portion 521 and a radially outer part of the dielectric 522 are exposed inside the waveguide portion 51, A radially inner portion of the dielectric 522 may be configured to be inserted into the side hole 111 and exposed to the internal space 14 of the housing 1 (second configuration).

[0075] Furthermore, the cleaning device 100 of the second configuration may be configured (third configuration) such that a reflecting section 515 that reflects the high frequency wave output from the high frequency generator 514 is disposed at the other end of the waveguide section 51, and the position of the reflecting section 515 in the first direction D1 is adjustable.

[0076] Furthermore, the cleaning device 100 of the second or third configuration may be configured (fourth configuration) in which the column portion 521 has: an outer tube portion 5211 having a capped cylindrical shape that extends in the second direction D2 and has a tip covered by the dielectric 522; and an inner tube portion 5212 that extends in the second direction D2 and is housed inside the outer tube portion 5211; the plasma unit 5 further has a third cooling mechanism 53 that cools the antenna portion 52 using a third refrigerant F3; and the third cooling mechanism 53 has: a supply flow path Pi that supplies the third refrigerant F3 to the inside of the inner tube portion 5212; and a discharge flow path Po that discharges the third refrigerant F3 flowing out from between the outer tube portion 5211 and the inner tube portion 5212 to the outside.

[0077] Furthermore, the cleaning device 100 of any of the second to fourth configurations may be configured (fifth configuration) in which a supply port 5115 is arranged in the cylindrical portion 11 for supplying an auxiliary gas Ga that assists in generating plasma to the radially inner portion of the dielectric 522 exposed to the internal space 14.

[0078] In the cleaning device 100 of any of the first to fifth configurations, the baffle 2 is provided with an air vent 22 that connects adjacent internal spaces 14 via the baffle 2, and in the baffle 2 that is provided closest to the inlet 121, the position of the air vent 22 is offset from the position of the inlet 121 when viewed from the axial direction Da (sixth configuration).

[0079] Furthermore, the cleaning device 100 of the sixth configuration may be configured (seventh configuration) such that the baffles 2 are multiple and aligned in the axial direction Da, and in the baffles 2 adjacent to each other in the axial direction Da, the position of the ventilation hole 22 in one baffle 2 is shifted from the position of the ventilation hole 22 in the other baffle 2 as viewed from the axial direction Da.

[0080] Furthermore, the cleaning device 100 of the sixth or seventh configuration may be configured (eighth configuration) such that the baffle 2 is provided with the ventilation hole 22 and a porous portion 23 consisting of a plurality of holes 231 having a smaller diameter than the ventilation hole 22, and the ventilation hole 22 and the porous portion 23 connect the internal spaces 14 adjacent to each other in the axial direction Da via the baffle 2.

[0081] Furthermore, the cleaning device 100 having any of the sixth to eighth configurations may be configured (ninth configuration) in which a part of the plasma unit 5 is arranged on at least one of the axial side Da1 and the axial side Da2 of the ventilation port 22.

[0082] Furthermore, the cleaning device 100 of any of the first to ninth configurations may further include a first cooling mechanism 3 that cools the baffle 2, and the first cooling mechanism 3 may have a configuration (tenth configuration) that includes: a first cooling pipe 31 that is arranged on the axial end face of the baffle 2 and is in contact with the baffle 2; a supply pipe 32 that supplies a first refrigerant F1 to the first cooling pipe 31; and a discharge pipe 33 that discharges the first refrigerant F1 discharged from the first cooling pipe 31 to the outside of the housing 1.

[0083] Furthermore, the cleaning device 100 of any of the first to tenth configurations may further include a second cooling mechanism 4 that cools the housing 1, the second cooling mechanism 4 having a second cooling pipe 41 through which a second refrigerant F2 flows, and the second cooling pipe 41 being arranged on the outer surface of the housing 1 and in contact with the housing 1, and extending along the outer surface of the housing 1 in at least one of the axial direction Da and the circumferential direction (eleventh configuration).

[0084] Furthermore, the substrate processing system 800 disclosed in this specification comprises a cleaning device 100 of any one of the first to eleventh configurations described above, a chamber 200 in which a substrate S to be processed using a process gas Gi is placed, and a vacuum pump 500 that exhausts gas Go from the chamber 200, wherein the cleaning device 100 is connected between the chamber 200 and the vacuum pump 500 and is configured to decompose the gas Go exhausted from the chamber 200 and particles contained in the gas Go (twelfth configuration).

[0085] 100 Cleaning device 200 Chamber 201 Supply port 202 Exhaust port 300 MFC (Mass flow controller) 400 APC (Automatic pressure controller) 401 Pressure sensor 500 Dry vacuum pump 600 Turbo molecular pump 800 Substrate processing system 1 Housing 11 Cylindrical portion 111 Side hole 112 Connecting pipe 12 First cover portion 121 Inlet 13 Second cover portion 131 Outlet 14, 14a to 14d Internal space 2, 2a to 2c Baffle 21 Plate portion 22 Vent 23 Perforated portion 231 Hole 3 Internal cooling mechanism 31 Cooling pipe 32 Supply pipe 33 Exhaust pipe 4 External cooling mechanism 41 Cooling pipe 411 Inlet 412 Exhaust port 5 Plasma unit 51 Waveguide portion 511 Waveguide 5111, 5112 Side hole 5113 Connection pipe 5115 Supply port 512 Joint portion 5131,5132 Flange portion 514 High frequency generator 515 Reflector portion 52 Antenna portion 521 Pillar portion 5211 Outer cylinder portion 5212 Inner cylinder portion 522 Dielectric 53 Cooling mechanism 531 Elbow joint 532 Union tee 5321 to 5323 First to third openings 533 Connection pipe 534 Reducer Gi Process gas Go Exhaust gas Ga Auxiliary gas S Substrate Pi Supply flow path Po Exhaust flow path F1, F2, F3 Refrigerant J Central axis Da Axial direction Da1 One axial direction Da2 Other axial direction D1 First direction D2 Second direction

Claims

1. A cleaning device for decomposing an incoming gas and particles contained in the gas, comprising: a housing that is cylindrical and extends in the axial direction and has an inlet and an outlet for the gas; a plate-shaped baffle disposed inside the housing; and a plurality of plasma units that generate plasma inside the housing. The inside of the housing has a plurality of internal spaces and is configured such that the gas flowing in from the inlet can flow out from the outlet. Some adjacent internal spaces are connected so that the gas can flow through them, and at least some adjacent internal spaces are adjacent to each other via the baffle. The plasma units are disposed with respect to at least two of the internal spaces.

2. The housing has a cylindrical portion that extends in the axial direction and surrounds the baffle. Side holes that penetrate the cylindrical portion in the radial direction are disposed in the cylindrical portion. The plasma unit includes: a cylindrical waveguide portion that is disposed outside the housing in the radial direction, extends in a first direction that intersects the radial direction, and has a high-frequency generator disposed at one end; and an antenna portion that penetrates the waveguide portion in the axial direction and the second direction that intersects the first direction and is inserted into the side hole. The antenna portion includes: a metal column portion that extends in the second direction; and a dielectric that covers the tip of the column portion. A part of the column portion and a radially outer portion of the dielectric are exposed inside the waveguide portion, and a radially inner portion of the dielectric is inserted into the side hole and exposed to the internal space of the housing. The cleaning device according to claim 1.

3. A reflection portion that reflects the high-frequency output from the high-frequency generator is disposed at the other end of the waveguide portion, and the arrangement position of the reflection portion in the first direction is adjustable. The cleaning device according to claim 2.

4. The column portion has a covered cylindrical outer cylinder portion extending in the second direction and having a tip portion covered with the dielectric, and an inner cylinder portion extending in the second direction and accommodated inside the outer cylinder portion. The plasma unit further has a third cooling mechanism for cooling the antenna portion using a third refrigerant. The third cooling mechanism has a supply flow path for supplying the third refrigerant inside the inner cylinder portion, and a discharge flow path for discharging the third refrigerant flowing out between the outer cylinder portion and the inner cylinder portion to the outside. The cleaning device according to claim 2 or claim 3.

5. A supply port for supplying an auxiliary gas for assisting the generation of plasma is arranged in the cylindrical portion at a radially inner side portion of the dielectric exposed to the internal space. The cleaning device according to any one of claims 2 to 4.

6. An air vent for connecting the adjacent internal spaces through the baffle is arranged in the baffle. In the baffle arranged closest to the inlet, when viewed axially, the position of the air vent is shifted from the position of the inlet. The cleaning device according to any one of claims 1 to 5.

7. There are a plurality of the baffles arranged axially. In the baffles adjacent to each other axially, when viewed axially, the position of the air vent in one of the baffles is shifted from the position of the air vent in the other baffle. The cleaning device according to claim 6.

8. An air vent and a porous portion composed of a plurality of holes having a smaller diameter than the air vent are arranged in the baffle. The air vent and the porous portion connect the internal spaces adjacent to each other axially through the baffle. The cleaning device according to claim 6 or claim 7.

9. A part of the plasma unit is arranged on at least one of one axial side and the other axial side of the air vent. The cleaning device according to any one of claims 6 to 8.

10. The cleaning device further includes a first cooling mechanism for cooling the baffle. The first cooling mechanism has a first cooling pipe arranged on an axial end surface of the baffle and in contact with the baffle, a supply pipe for supplying a first refrigerant to the first cooling pipe, and a discharge pipe for discharging the first refrigerant discharged from the first cooling pipe to the outside of the housing. The cleaning device according to any one of claims 1 to 9.

11. The cleaning device according to any one of claims 1 to 10 further comprises a second cooling mechanism for cooling the housing, the second cooling mechanism having a second cooling pipe through which a second refrigerant flows, the second cooling pipe being disposed on an outer surface of the housing in contact with the housing and extending along the outer surface of the housing in at least one of an axial direction and a circumferential direction.

12. A substrate processing system comprising the cleaning device according to any one of claims 1 to 11, a chamber on which a substrate to be processed using a process gas is placed, and a vacuum pump for discharging gas in the chamber, the cleaning device being connected between the chamber and the vacuum pump and decomposing the gas discharged from the chamber and particles contained in the gas.

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