COLLECTION ASSEMBLY AND SEMICONDUCTOR PRE-CLEANING CHAMBER

Abstract

The invention provides a collection assembly and a semiconductor pre-cleaning chamber, which relate to the semiconductor processing apparatus field. The collection assembly is configured to collect particle impurities in the semiconductor pre-cleaning chamber, and includes a protection plate and a collection plate arranged at an interval in the semiconductor pre-cleaning chamber. The protection plate is annular. A plurality of first through-holes are arranged at the protection plate and configured for the process gas in the semiconductor pre-cleaning chamber to pass through. The collection plate is located on a side of an air outlet end of the first through-holes and configured to capture at least a part of the particle impurities in the semiconductor pre-cleaning chamber passing through the first through-holes.

Claims

1-13. (canceled)

14. A collection assembly configured to collect particle impurities in a semiconductor pre-cleaning chamber comprising: a protection plate being annular and including a plurality of first through-holes configured for a process gas of the semiconductor pre-cleaning chamber to pass through; and a collection plate arranged at an interval with the protection plate in the semiconductor pre-cleaning chamber, located on a side of a gas outlet end of the first through-holes, and configured to capture at least a part of the particle impurities in the semiconductor pre-cleaning chamber passing through the first through-holes.

15. The collection assembly according to claim 14, wherein: the collection plate is annular and arranged opposite to the protection plate; and orthogonal projections of the first through-holes of the protection plate on a horizontal plane are within an orthogonal projection of the collection plate on the horizontal plane.

16. The collection assembly according to claim 15, wherein: a surface of the collection plate opposite to the protection plate is a plane; and the plane is parallel to the protection plate or is inclined relative to the protection plate.

17. The collection assembly according to claim 15, wherein a surface of the collection plate opposite to the protection plate has a concave structure.

18. The collection assembly according to claim 17, wherein the concave structure includes an annular concave groove arranged around a circumference of the collection plate.

19. The collection assembly according to claim 18, wherein a shape of a longitudinal cross section of the annular groove includes a rectangle, an arc, or a triangle.

20. The collection assembly according to claim 14, wherein: an outer peripheral edge of the collection plate includes an annular protrusion extending toward a direction close to the protection plate; and a gap is provided between an end of the annular protrusion close to the protection plate and the protection plate.

21. The collection assembly according to claim 14, wherein a surface of the collection plate opposite to the protection plate is a roughened surface.

22. The collection assembly according to claim 14, further comprising a distance adjustment structure configured to adjust a distance between the collection plate and the protection plate.

23. The collection assembly according to claim 22, wherein the distance adjustment structure includes: at least one distance adjustment piece arranged between the collection plate and the protection plate and located at an inner or outer peripheral edge of the protection plate, the distance between the collection plate and the protection plate being adjusted by setting a number and/or thickness of the distance adjustment piece.

24. The collection assembly according to claim 14, wherein the collection plate includes a connection member arranged at an inner or outer peripheral edge of the collection plate, and a plurality of threaded holes are correspondingly arranged at the connection member and the protection plate and distributed at intervals along a circumference of the protection plate; the collection assembly further comprising a plurality of fastening screws being threadedly connected to the threaded holes in a one-to-one correspondence and configured to fixedly connect the connection member to the protection plate.

25. The collection assembly according to claim 14, wherein: at least two collection plates are arranged at intervals along a direction away from the protection plate; except a collection plate of the at least two collection plates farthest to the protection plate, a plurality of second through-holes are arranged at the other collection plates; axes of the plurality of second through-holes of two neighboring collection plates do not coincide; and axes of second through-holes of the collection plate closest to the protection plate do not coincide axes of the first through-holes of the protection plate.

26. A semiconductor pre-cleaning chamber comprising: a chamber, a Faraday cup arranged in the chamber, a base configured to carry a wafer, and a collection assembly, including: a protection plate being annular and including a plurality of first through-holes configured for a process gas of the semiconductor pre-cleaning chamber to pass through; and a collection plate arranged at an interval with the protection plate in the semiconductor pre-cleaning chamber, located on a side of a gas outlet end of the first through-holes, and configured to capture at least a part of the particle impurities in the semiconductor pre-cleaning chamber passing through the first through-holes; wherein: the protection plate of the collection assembly being sleeved on the base; and when the base is in a process position, the protection plate cooperates with the Faraday cup to divide space inside the chamber body into an upper sub-chamber, and a lower sub-chamber.

27. The semiconductor pre-cleaning chamber according to claim 26, wherein: the collection plate is annular and arranged opposite to the protection plate; and orthogonal projections of the first through-holes of the protection plate on a horizontal plane are within an orthogonal projection of the collection plate on the horizontal plane.

28. The semiconductor pre-cleaning chamber according to claim 27, wherein: a surface of the collection plate opposite to the protection plate is a plane; and the plane is parallel to the protection plate or is inclined relative to the protection plate.

29. The semiconductor pre-cleaning chamber according to claim 28, wherein a surface of the collection plate opposite to the protection plate has a concave structure.

30. The semiconductor pre-cleaning chamber according to claim 29, wherein the concave structure includes an annular concave groove arranged around a circumference of the collection plate.

31. The semiconductor pre-cleaning chamber according to claim 30, wherein a shape of a longitudinal cross section of the annular groove includes a rectangle, an arc, or a triangle.

32. The semiconductor pre-cleaning chamber according to claim 26, wherein: an outer peripheral edge of the collection plate includes an annular protrusion extending toward a direction close to the protection plate; and a gap is provided between an end of the annular protrusion close to the protection plate and the protection plate.

33. The semiconductor pre-cleaning chamber according to claim 26, wherein a surface of the collection plate opposite to the protection plate is a roughened surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the technical solutions of embodiments of the present disclosure or the existing technology, the accompanying drawings used in the embodiments or the existing technology are briefly introduced below. Obviously, the accompanying drawings in the following description are merely embodiments of the present disclosure. For those skilled in the art, without creative effort, other drawings can be obtained according to the accompanying drawings.

[0024] FIG. 1 illustrates a schematic structural diagram of a semiconductor pre-cleaning chamber according to some embodiments of the present disclosure.

[0025] FIG. 2 illustrates a schematic structural diagram of a collection assembly of a second form according to some embodiments of the present disclosure.

[0026] FIG. 3 illustrates a schematic structural diagram of a collection assembly of a third form according to some embodiments of the present disclosure.

[0027] FIG. 4 illustrates a schematic structural diagram of a collection assembly of a fourth form according to some embodiments of the present disclosure.

[0028] FIG. 5 illustrates a schematic structural diagram of a collection assembly of a fifth form according to some embodiments of the present disclosure.

[0029] FIG. 6 illustrates a schematic structural diagram of a collection assembly of a sixth form according to some embodiments of the present disclosure.

[0030] FIG. 7 illustrates a schematic cross-sectional diagram showing a collection plate of the collection assembly of the second form according to some embodiments of the present disclosure.

[0031] FIG. 8 illustrates a schematic cross-sectional diagram showing a collection plate of the collection assembly of the third form according to some embodiments of the present disclosure.

[0032] FIG. 9 illustrates a schematic cross-sectional diagram showing a collection plate of the collection assembly of the fourth form according to some embodiments of the present disclosure.

[0033] FIG. 10 illustrates a schematic cross-sectional diagram showing a protection plate of a collection assembly of a first form according to some embodiments of the present disclosure.

[0034] FIG. 11 illustrates a schematic cross-sectional diagram showing a protection plate of the collection assembly of the second form according to some embodiments of the present disclosure.

[0035] FIG. 12 illustrates a schematic cross-sectional diagram showing a protection plate of the collection assembly of the third form according to some embodiments of the present disclosure.

[0036] FIG. 13 illustrates a schematic cross-sectional diagram showing a protection plate of the collection assembly of the fourth form according to some embodiments of the present disclosure.

REFERENCE NUMERALS

[0037]

TABLE-US-00001 100 Protection plate 110 First through-hole 120 Center through-hole 210 Collection plate 211 Annular concave groove 212 Annular protrusion 213 Threaded hole 214 Fastening screw 215 Second through-hole 220 Connection member 300 Distance adjustment piece 510 Chamber body 521 First metal ring 522 Second metal ring 530 Coil 540 Coil shielding box 550 Coupling window 560 Faraday cup 570 Cover plate 580 Quartz ring 590 Base 610 Upper electrode radio 620 Upper electrode frequency power supply matching device 630 Lower electrode radio 640 Lower electrode frequency power supply matching device 700 Vacuum pump 800 Wafer

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] To make the above objects, features, and advantages of the present disclosure more comprehensible, specific embodiments of the present disclosure are described in detail below in connection with the accompanying drawings. It should be understood that the specific embodiments described here are only used to explain the present disclosure, not to limit the present disclosure.

[0039] Embodiments of the present disclosure provide a semiconductor pre-cleaning chamber. As shown in FIG. 1, the semiconductor pre-cleaning chamber includes a chamber body 510 and a Faraday cup 560 arranged in the chamber body 510, a base 590 configured to carry a wafer 800, and a collection assembly. The collection assembly is mounted to sleeve the base 590. When the base 590 is at a processing position, a protection plate 100 of the collection assembly can cooperate with the Faraday cup 560 to divide space inside the chamber body 510 into an upper sub-chamber and a lower sub-chamber.

[0040] In embodiments of the present disclosure, the semiconductor pre-cleaning chamber further includes a first metal ring 521, a second metal ring 522, a coil 530, a coil shielding box 540, a coupling window 550, a cover plate 570, a quartz ring 580, and an upper electrode radio frequency (RF) power supply 610, and an upper electrode matching device 620, a lower electrode RF power supply 630, a lower electrode matching device 640, and a vacuum pump 700. It should be noted that the above structure and corresponding working principle except for the collection assembly are mature existing technology, which is not improved in the present disclosure and are not repeated here.

[0041] In the semiconductor pre-cleaning chamber of the present disclosure, when the process is performed, the wafer 800 can be arranged on the base 590. The upper electrode RF power supply 610 can apply RF power to the coil 530 through the upper electrode matching device 620. The RF power can be coupled into the upper sub-chamber through the Faraday cup 560 to excite the process gas (e.g., argon) into a plasma. The RF power of the lower electrode RF power supply 630 can be applied to the base 590 through the lower electrode matching device 640 to cause the base 590 to generate an RF self-bias to attract the plasma to physically bombard the wafer 800 or a chemical reaction can be performed simultaneously to remove the impurities on the surface of the wafer. The particle impurities generated by the process can enter the lower sub-chamber through a first through-hole 110 of the protection plate 100. During this process, a large amount of particle impurities can be captured and collected by the collection plate 210, while the remaining particle impurities that are not captured by the collection plate 210 can be sucked and collected by the vacuum pump 700.

[0042] The collection assembly of embodiments of the present disclosure is described in detail below.

[0043] The collection assembly of embodiments of the present disclosure can be configured to collect the particle impurities in the semiconductor pre-cleaning chamber. As shown in FIG. 1, the collection assembly includes a protection plate 100 arranged at an interval in the semiconductor pre-cleaning chamber and a collection plate 210. The protection plate 100 can be annular. In some embodiments, a center through-hole 120 can be arranged at the protection plate 100. The protection plate can be sleeved on the base 590 through the center through-hole 120. A plurality of first through-holes 110 can be arranged at the protection plate 100 and configured to allow the process gas in the semiconductor pre-cleaning chamber to pass through. That is, the process gas can pass through the first through-holes 110 from the upper sub-chamber to enter the lower sub-chamber.

[0044] In embodiments of the present disclosure, as shown in FIG. 1, the first through-holes 110 are straight through-holes with a circular cross-sectional shape. However, in other embodiments of the present disclosure, the first through-holes 110 can also be in other forms. As shown in FIG. 11, the cross-sectional shape of the first through-holes 110 can also be rectangular. As shown in FIG. 12, the first through-holes 110 are also folded holes. As shown in FIG. 13, the first through-holes 110 are also oblique holes.

[0045] It should be noted that, regardless of the shape of the first through-holes 110, a diameter setting of the first through-holes 110 of the protection plate 100 meets the requirement that the plasma cannot pass through. Thus, the plasma can be effectively prevented from entering the lower sub-chamber below the protection plate 100 and causing the sub-chamber to spark.

[0046] In embodiments of the present disclosure, as shown in FIG. 10, the plurality of first through-holes 110 are arranged in three circles around the center through-hole 120 of the protection plate 100. The first through-holes 110 of each circle can be evenly distributed along a circumference of the protection plate 100. Such an arrangement can ensure that the airflow and particle impurities in the upper sub-chamber can flow into the first through-holes 110 in a stable and sequential manner. Of course, in other embodiments of the present disclosure, no limitation can be imposed on a number of the circles of the first through-holes 110, a number of the first through-holes 110 of each circle, and whether the first through-holes 110 are evenly distributed.

[0047] The collection plate 210 can be arranged on a side of a gas outlet end of the first through-holes 110, that is, opposite to a gas outlet direction of the first through-holes 110, and can be configured to capture the particle impurities in at least a part of the semiconductor pre-cleaning chamber passing through the first through-holes 110. Since the collection plate 210 is opposite to the air outlet direction of the first through-holes 110, the airflow carrying a large amount of particle impurities can collide with the surface of the collection plate 210. Thus, the particle impurities can be effectively collected on the surface of the collection plate 210. Thus, the remaining particle impurities in the pre-cleaning chamber can be greatly reduced and even without residue. Therefore, the inner wall of the semiconductor pre-cleaning chamber can be difficult to be contaminated to reduce the risk of contaminating the wafer the second time. In addition, when the collection assembly of the present disclosure needs to be cleaned, the collection assembly can be dissembled for cleaning, which has strong maintainability.

[0048] In some optional embodiments, the collection plate 210 can be arranged in parallel to the protection plate 100. Of course, in practical applications, the collection plate 210 and the protection plate 100 can also form an included angle.

[0049] In some optional embodiments, the collection plate 210 can be annular and arranged oppositely to the protection plate 100. Orthographic projections of all the first through-holes 110 of the protection plate 100 on a horizontal plane can be within an orthographic projection of the collection plate 210 on the horizontal plane. Thus, the gas flowing out from all the first through-holes 110 can be ensured to collide with the surface of the collection plate 210 to further improve the collection effect of the particle impurities.

[0050] In embodiments of the present disclosure, as shown in FIG. 1, the collection plate 210 and the protection plate 100 have a same outer diameter. That is, contours of two orthogonal projections of the collection plate 210 and the protection plate 100 on the horizontal plane coincide. However, in some other embodiments of the present disclosure, the contours of the orthogonal projections of the collection plate 210 and the protection plate 100 on the horizontal plane may not coincide. For example, as shown in FIG. 2, an outer diameter of the collection plate 210 is greater than an outer diameter of the protection plate 100. That is, the contour of the orthogonal projection of the collection plate 210 on the horizontal plane is outside the contour of the orthogonal projection of the protection plate 100. For another example, as shown in FIG. 3, the outer diameter of the collection plate 210 is smaller than the outer diameter of the protection plate 100. That is, the contour of the orthogonal projection of the collection plate 210 on the horizontal plane is inside the contour of the orthogonal projection of the protection plate 100. Regardless of the orthographic projections of the protection plate 100 and the collection plate 210 on the horizontal plane, as long as the orthogonal projections of all the first through-holes 110 of the protection plate 100 on the horizontal plane are within the orthogonal projection of the collection plate 210 on the horizontal plane to ensure the gas flowing out of all the first through-holes 110 to be able to collide with the surface of the collection plate 210.

[0051] In embodiments of the present disclosure, as shown in FIG. 1, a surface of the collection plate 210 opposite to the protection plate 100 is a plane. The plane is parallel to the protection plate 100. With such an arrangement, the particle impurities discharged by the first through-holes 110 can collide reliably with the surface of the collection plate 210 to facilitate the collection of the particle impurities. Of course, in practical applications, the plane can also be inclined relative to the protection plate 100.

[0052] However, in some other embodiments of the present disclosure, the surface of the collection plate 210 opposite to the protection plate 100 may not be limited to a plane and may also have a concave structure. The concave structure can be beneficial for the particle impurities to rebound and collide between the surfaces of the protection plate 100 and the collection plate 210 opposite to each other to improve a collection rate of the particle impurities. In some embodiments, as shown in FIG. 7, the concave structure includes an annular groove 211 arranged around the circumference of the collection plate 210. A longitudinal cross-sectional shape of the annular groove 211 can include a rectangle, an arc, or a triangle. For example, the annular groove 211 shown in FIG. 7 has a rectangular longitudinal cross-sectional shape. The annular groove 211 shown in FIG. 8 has an arc-shaped longitudinal cross-section shape. The annular groove 211 shown in FIG. 9 has a triangular longitudinal cross-sectional shape. In addition, the longitudinal cross-sectional shape of the annular groove 211 can further be a stepped shape (not shown).

[0053] In some optional embodiments, as shown in FIG. 8, an annular protrusion 212 extending toward a direction close to the protection plate 100 is arranged at an outer peripheral edge of the collection plate 210. A gap is provided between an end of the annular protrusion 212 close to the protection plate 100 and the protection plate 100. With such an arrangement, it is beneficial for the particle impurities to bounce between the collection plate 210 and the protection plate 100 to further facilitate capturing and collecting the particle impurities to improve the collection rate.

[0054] In some optional embodiments, the collection assembly can further include a distance adjustment structure configured to adjust the distance between the collection plate 210 and the protection plate 100. By adjusting the distance between the collection plate 210 and the protection plate 100, a flowing guidance between the collection plate 210 and the protection plate 100 can be adjusted, that is, the ability to allow the gas to pass between the collection plate 210 and the protection plate 100. Thus, an air inlet volume and an air inlet speed of the semiconductor pre-cleaning chamber can be adjusted. In some embodiments, when the distance between the collection plate 210 and the protection plate 100 is smaller, the air inlet speed can be smaller, and the collection rate can be higher. On the contrary, when the distance between the collection plate 210 and the protection plate 100 is larger, the air inlet speed can be greater, and the collection rate can be lower. Based on this, when a relatively high requirement is imposed on the residue of the particle impurities of the surface of the wafer 800, the distance between the collection plate 210 and the protection plate 100 can be appropriately reduced to slow the air inlet speed to increase the collection rate. When a relatively low requirement is imposed on the residue of the particle impurities of the surface of the wafer 800, or a certain requirement is imposed on the air inlet speed, the distance between the collection plate 210 and the protection plate 100 can be appropriately increased to increase the air inlet speed.

[0055] In some optional embodiments, the distance between the collection plate 210 and the protection plate 100 can be greater than or equal to 3 mm and less than or equal to 20 mm.

[0056] In addition, adjusting the distance between the collection plate 210 and the protection plate 100 by the above distance adjustment structure can be applied to different processes. Thus, the semiconductor pre-cleaning chamber can be integrated with functions of various processing apparatuses to reduce the apparatus cost.

[0057] The above distance adjustment structure can have various structures. For example, as shown in FIGS. 1 to 4, the above distance adjustment structure includes at least a distance adjustment piece 300. The at least a distance adjustment piece 300 can be arranged between the collection plate 210 and the protection plate 100 and located at the inner peripheral edge or the outer peripheral edge of the protection plate 100. By setting a number and/or a thickness of the distance adjustment piece 300, the distance between the collection plate 210 and the protection plate 100 can be adjusted. The distance adjustment piece 300 can include, for example, a washer. In some embodiments, an inner diameter of the washer can be same as a diameter of the center through-hole 120.

[0058] Surfaces of the distance adjustment member 300 and the surfaces of the collection plate 210 opposite to the protection plate 100 can be roughened surfaces. For example, the surface of the collection plate 210 opposite to the protection plate 100 can be a surface treated by sandblasting or melting spray. With such an arrangement, the surface of the collection plate 210 can be beneficial to capture and store the particle impurities to further improve the collection effect.

[0059] In embodiments of the present disclosure, as shown in FIG. 1, one collection plate 210 is provided.

[0060] However, in some other embodiments of the present disclosure, as shown in FIG. 5 and FIG. 6, a number of collection plates 210 is not limited to one. At least two collection plates 210 are provided and arranged at intervals along a direction away from the protection plate 100. In the at least two collection plates 210, except for the collection plate 210 farthest from the protection plate 100, the other collection plates 210 can all be provided with a plurality of second through-holes 215. Axes of the second through-holes 215 of two adjacent collection plates 210 cannot coincide. Axes of the second through-holes 215 of the collection plate 210 closest to the protection plate 100 cannot coincide axes of the first through-holes 110 of the protection plate 100.

[0061] By arranging the plurality of collection plates 210, the particle impurities can be filtered and collected layer by layer to further improve the collection rate of the particle impurities. Simultaneously, by causing the axes of the second through-holes 215 of the collection plate 210 closest to the protection plate 100 to not coincide with axes of the first through-hole 110 of the protection plate 100, the particle impurities discharged from the first through-holes 110 can be effectively prevented from continuing to transfer directly from the second through-holes 215 of the collection plate 210 closest to the protection plate 100, which can increase the probability of the collision between the particle impurities and the surface of the collection plate 210 and is beneficial to increase the collection rate of the particle impurities. By causing the axes of the second through-holes 215 of the two adjacent collection plates 210 to not coincide, the particle impurities discharged from the collection plate 210 can be effectively prevented from continuing to transfer directly from the second through-holes 215 of the next adjacent collection plate 210. Thus, the possibility of the particle impurities colliding with the surface of the next collection plate 210 can be increased to be beneficial for the next collection plate 210 to capture the particle impurities. Therefore, the utilization rate of the next collection plate 210 can be increased. The increment of the utilization reate of the collection plates 210 can be beneficial to increase the collection rate by using all the collection plates as a whole for the particle impurities.

[0062] In some other embodiments of the present disclosure, as shown in FIG. 5 and FIG. 6, when at least two collection plates 210 are provided. The distance adjustment piece 300 is also arranged between the two adjacent collection plates 210 to adjust the distance between the two adjacent collection plates 210.

[0063] In some optional embodiments, as shown in FIG. 2 and FIG. 3, a connection member 220 is further arranged at the collection plate 210. The connection member 220 can be arranged at the inner peripheral edge of the collection plate 210. In some embodiments, as shown in FIG. 2 and FIG. 3, the connection member 220 is a ring body. An outer diameter of the ring body can be smaller than the outer diameters of the collection plate 210 and the protection plate 100. An inner diameter of the ring body can be the same as the diameter of the central through-hole 120. The ring body can be arranged coaxially with the central through-hole 120. Thus, a gap can be provided between a part of the collection plate 210 outside the connection member 220 and the protection plate 100 and configured to allow airflow to flow out during the processes.

[0064] Moreover, a plurality of threaded holes 213 can be correspondingly arranged at the connection member 220, the distance adjustment member 300, and the protection plate 100, and can be distributed at intervals along the circumference of the protection plate 100. As shown in FIG. 1, the collection assembly further includes a plurality of fastening screws 214. The fastening screws 214 can be threadedly connected to the threaded holes 213 in a one-to-one correspondence and can be configured to fixedly connect the connection member 220, the distance adjustment member 300, and the protection plate 100.

[0065] In some other optional embodiments, as shown in FIG. 4, the connection member 220 is further arranged at the outer periphery of the collection plate 210. In some embodiments, the connection member 220 can be a ring body. An outer diameter of the ring body can be equal to the outer diameter of the protection plate 100. An inner diameter of the ring body can be larger than the diameter of the center through-hole 120. The ring body and the center through-hole 120 can be arranged coaxially. Thus, a gap can be arranged between the part of the collection plate 210 on an inner side of the connection member 220 and the protection plate 100 and be configured for the airflow to flow out during the processes. Then, the airflow can flow out through the center through-hole of the collection plate 210.

[0066] In some other embodiments of the present disclosure, as shown in FIG. 5 and FIG. 6, when the number of collection plates 210 is at least two, each collection plate 210 is provided with a connection member 220. A collection plate 210 closest to the protection plate 100 can be a first collection plate. The other collection plates 210 can be second collection plates. A connection member 220 of the first collection plate can be arranged between the first collection plate and the protection plate 100. A connection member 220 of a second collection plate can be arranged between two neighboring second collection plates.

[0067] In some embodiments, the connection members 220 on the at least two collection plates 210 can be arranged at the inner or outer peripheral edges of the collection plates 210, or connection members 220 of some collection plates 210 can also be arranged t the inner peripheral edges of the collection plates 210, and connection members 220 of some other collection plates 210 can be arranged at the outer peripheral edge of the collection plates 210. For example, as shown in FIG. 5 and FIG. 6, the connection member 220 of the first collection plate of the collection plates 210 closest to the protection plate 100 is arranged at the outer peripheral edge of the collection plate 210 and can block the airflow from passing through between the protection plate 100 and the first collection plate. Thus, the airflow can flow out through the second through-holes 215. The connection member 220 of the second collection plate can be arranged at the inner peripheral edge of the collection plate 210. Moreover, the threaded holes may also not be arranged at the connection member 220 of the first collection plate. The threaded holes can be arranged at a position of the first collection plate corresponding to the threaded holes 213 of the connection member 220 of the second collection plate. Thus, the first collection plate and the second collection plate can be fixedly connected through the fastening screws 314.

[0068] Finally, it should be noted that in the specification, relational terms such as “first” and “second” are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Furthermore, the term “comprising,” “including,” or any other variation thereof is intended to cover a non-exclusive inclusion. Thus, a process, method, article, or apparatus comprising a set of elements that includes a series of elements includes not only those elements, but also includes elements not expressly listed, or elements inherent in such a process, method, article, or apparatus.

[0069] With the above description of the disclosed embodiments, those skilled in the art can implement or use the present disclosure. Various modifications to the embodiments are apparent to those skilled in the art. The general principle defined in the specification may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments shown in the specification but conforms to the widest scope consistent with the principles and novel features disclosed in the specification.