Substrate processing apparatus and recovery ring
By employing a liftable recycling ring structure in the substrate processing equipment, the problem of liquid cross-contamination is solved, achieving pure separation of process liquids and simplifying equipment maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GRAND PLASTIC TECH
- Filing Date
- 2025-05-29
- Publication Date
- 2026-05-22
AI Technical Summary
In existing single-wafer rotary etching and cleaning equipment, the fluid recovery mechanism is complex in design, which leads to a high risk of liquid cross-contamination, affecting process stability and efficiency.
It adopts a structure of multiple liftable recovery rings, and through guidance and protection design, ensures that different process liquids are recovered separately to avoid cross-contamination.
It effectively reduces the risk of cross-contamination of liquids, ensures the purity and stability of the process, and simplifies the equipment maintenance process.
Smart Images
Figure CN224267215U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor manufacturing, and more particularly to a substrate processing apparatus and a recycling ring. Background Technology
[0002] Existing single-wafer rotary etching and cleaning equipment utilizes a rotating platform to support the substrate, and applies process liquids (such as etching solutions or cleaning solutions) to the substrate surface through an overhead liquid supply device to perform corresponding microstructure processes. Such equipment requires precise control of the supply and recovery efficiency of the process liquids to ensure process uniformity, repeatability, and final product yield.
[0003] However, current fluid recovery systems often employ multi-layered collection structures and complex drainage channels. While these designs enable multi-liquid stratified recovery, they can result in an overly cumbersome system architecture, increasing the burden of equipment control and assembly, as well as raising maintenance costs and operational risks. Furthermore, when multiple process liquids are used interchangeably, different liquids can easily mix into the recovery pipeline, leading to cross-contamination and consequently affecting recovery efficiency and process stability.
[0004] In view of this, it is necessary to provide a substrate processing apparatus and a recycling ring to solve the above-mentioned technical problems. Utility Model Content
[0005] To address the problems of the prior art, the purpose of this application is to provide a substrate processing apparatus and a recycling ring that can reduce the risk of liquid cross-contamination.
[0006] In a first aspect, this application provides a substrate processing apparatus, comprising: a rotary table for carrying a substrate; a liquid supply device disposed above the rotary table for applying multiple process liquids to the substrate; and a liquid recovery assembly disposed outside the rotary table, wherein the liquid recovery assembly includes multiple recovery rings arranged sequentially from top to bottom and movable relative to the rotary table to collect corresponding multiple process liquids; wherein at least one of the recovery rings includes: a pair of concentrically arranged and spaced apart annular sidewalls; and a bottom wall laterally connected to the pair of annular sidewalls, wherein... The bottom wall and the inner sidewall connected to the pair of annular sidewalls define a receiving cavity for containing process liquid, and the outer sidewall connected to the bottom wall and the pair of annular sidewalls serves as a stop structure for another recovery ring below, for introducing another process liquid into the other recovery ring; a shielding wall is disposed on the outer sidewall and located at the junction of the bottom wall and the pair of annular sidewalls, for guiding the other process liquid flowing along the outer sidewall to drip vertically into the other recovery ring below; and a drain pipe penetrates the bottom wall and communicates with the receiving cavity for discharging the process liquid in the receiving cavity.
[0007] In some embodiments, the shielding wall extends longitudinally from the bottom wall in a direction away from the annular sidewalls.
[0008] In some embodiments, the at least one of the recycling rings further includes an inclined wall connected to the lower end of the shielding wall, and together with the shielding wall, forming a barbed structure.
[0009] In some embodiments, the inclined wall is continuously formed within the area corresponding to the drain pipe and terminates at a position spaced a distance from the drain pipe.
[0010] In some embodiments, the drain pipe extends vertically through the other recovery ring located below it, and the at least one of the recovery rings further includes a leak-proof cap that surrounds the drain pipe and is disposed at the junction of the drain pipe and the other recovery ring.
[0011] Secondly, this application also provides a recovery ring disposed on the outside of a rotating platform for collecting process liquid splashed from the rotating platform. The recovery ring includes: a pair of concentrically arranged and spaced apart annular sidewalls; a bottom wall laterally connected to the pair of annular sidewalls, wherein the inner sidewall of the bottom wall connected to the pair of annular sidewalls defines a receiving cavity for receiving process liquid, and wherein the outer sidewall of the bottom wall connected to the pair of annular sidewalls serves as a stop structure for another recovery ring below, for guiding another process liquid into the other recovery ring; a shielding wall disposed on the outer sidewall and located at the junction of the bottom wall and the pair of annular sidewalls, for guiding the other process liquid flowing along the outer sidewall to drip vertically into the other recovery ring below; and a drain pipe penetrating the bottom wall and communicating with the receiving cavity for draining the process liquid in the receiving cavity.
[0012] In some embodiments, the shielding wall extends longitudinally from the bottom wall in a direction away from the annular sidewalls.
[0013] In some embodiments, the at least one of the recycling rings further includes an inclined wall connected to the lower end of the shielding wall, and together with the shielding wall, forming a barbed structure.
[0014] In some embodiments, the inclined wall is continuously formed within the area corresponding to the drain pipe and terminates at a position spaced a distance from the drain pipe.
[0015] In some embodiments, the drain pipe extends vertically through the other recovery ring located below it, and the at least one of the recovery rings further includes a leak-proof cap that surrounds the drain pipe and is disposed at the junction of the drain pipe and the other recovery ring.
[0016] Compared to previous technologies, this application, by setting corresponding auxiliary guiding and protective structures in each recovery ring, can effectively prevent liquid from entering the unexpected containment cavity, further avoid cross-contamination between different process liquids, and thus ensure the purity and stability of the process. Attached Figure Description
[0017] The following detailed description of the specific embodiments of this application, in conjunction with the accompanying drawings, will make the technical solution and other beneficial effects of this application readily apparent.
[0018] Figure 1 This diagram shows a first operation of the substrate processing apparatus according to an embodiment of this application.
[0019] Figure 2 show Figure 1 An enlarged view of part A.
[0020] Figure 3 show Figure 1 An enlarged view of part B.
[0021] Figure 4 This diagram illustrates the second operation of a substrate processing apparatus according to an embodiment of this application.
[0022] Figure 5 show Figure 4 An enlarged view of part C. Detailed Implementation
[0023] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0024] Please refer to Figure 1This diagram illustrates the first operation of a substrate processing apparatus according to an embodiment of this application. The substrate processing apparatus 1 can be used to perform various substrate processing operations, such as wet etching or surface particle removal. The substrate processing apparatus 1 mainly includes a rotary table 10, a liquid supply device 20, a liquid recovery assembly 30, and a bottom tank 40. The rotary table 10 is used to support a substrate (not shown in the diagram). It is designed to rotate around an axis and can be fixed to the substrate using vacuum adsorption or mechanical clamping. The substrate can be a circular wafer or a square substrate, and is not limited to a specific shape. The liquid supply device 20 is located above the rotary table 10 and is used to spray various process liquids onto the substrate, such as different types of etching solutions and deionized water (DI water). The liquid recovery assembly 30 is located outside the rotary table 10 and includes multiple recovery rings (first recovery ring 31, second recovery ring 32, and third recovery ring 33) arranged sequentially from top to bottom. These multiple recovery rings can move independently relative to the rotary table 10 to collect the process liquids used in different process stages. A bottom tank 40 is positioned below the liquid recovery assembly 30 and houses the plurality of recovery rings within its tank. It should be understood that the bottom tank 40 can also be considered a type of recovery ring, the main difference being that it lacks the lifting function relative to the rotary table 10. However, its purpose is similar to that of the aforementioned recovery rings, all used to collect liquids generated during the process, particularly suitable for collecting deionized water.
[0025] The substrate processing equipment 1 of this application is used to perform a single-wafer rotary wet process. The process includes: applying a first process liquid to the substrate for cleaning or etching; cleaning the substrate with deionized water to remove residual first process liquid; applying a second process liquid for further processing; cleaning again with deionized water; and finally drying the substrate by high-speed rotation. During the deionized water cleaning step, if the substrate has a large area or a significant surface elevation difference, deionized water can easily splash from the rotating substrate surface to non-target recycling ring inlets, causing contamination inside the non-designated recycling rings and thus affecting its recycling purity.
[0026] To address the aforementioned issues, the liquid recovery assembly 30 disclosed in this application employs an independently movable and retractable design for each recovery ring. When different process liquids are sprayed and recovered, the corresponding recovery ring can descend to a predetermined position to recover the designated liquid. During deionized water cleaning, all recovery rings rise and seal shut, preventing splashed deionized water from flowing into any recovery ring; instead, the water flows directly into the lower tank 40, effectively preventing contamination of the recovery rings by cleaning wastewater. In other words, the recovery rings in this application are only used to recover corrosive or reusable process liquids, not for recovering deionized water, thus ensuring the purity of the liquid separation and ease of equipment maintenance.
[0027] Please refer to Figure 1The following describes the specific structure and operating status of the liquid recovery component 30. Figure 1 The image shows the first recovery ring 31 in the raised position. It should be understood that each recovery ring can be raised or lowered via a corresponding lifting mechanism, which can be any existing lifting device and will not be described in detail in this embodiment. When the first recovery ring 31 rises, an opening is formed between it and the second recovery ring 32, increasing the channel size between them and creating a flow guide space. In this state, the liquid supply device 20 sprays the first process liquid onto the substrate (not shown) on the rotary table 10. Due to the high-speed rotation of the substrate, some liquid is thrown out. This liquid will enter the interior of the second recovery ring 32 through the flow guide channel between the first recovery ring 31 and the second recovery ring 32 and be collected in its receiving cavity.
[0028] Specifically, such as Figure 1 As shown, the first recovery ring 31 includes a first ring wall 311 and a stop wall 312. The first ring wall 311 is located outside the rotating platform 10 and extends downwards from its end adjacent to the rotating platform 10, connecting its end to the stop wall 312. The stop wall 312 extends vertically to guide the direction of liquid flow. Please refer to further details. Figure 2 , it is Figure 1 An enlarged view of region A. The second recovery ring 32 includes a second ring wall 321, a pair of concentrically arranged and spaced-apart first annular sidewalls 322, and a first bottom wall 323 laterally connecting the opposite sidewalls. A first inner sidewall 3241, connected to the first bottom wall 323 and the opposite first annular sidewalls 322, defines a first receiving cavity 325 for receiving and storing the first process liquid. Notably, the first receiving cavity 325 is located at a position corresponding to and directly below the stop wall 312. When the first recovery ring 31 and the second recovery ring 32 are in a closed state, the stop wall 312 is contained within the first receiving cavity 325.
[0029] like Figure 1 As shown, during operation, the first annular wall 311 and the second annular wall 321 maintain a vertical distance, forming a guide inlet, allowing the first process liquid to be smoothly ejected from the rotary table 10 and guided into the channel. When the liquid moves laterally, its direction of movement changes after colliding with the stop wall 312, and it drips vertically downwards, eventually entering the first receiving cavity 325 of the second recovery ring 32 to complete the recovery operation.
[0030] Please refer to further details. Figure 3 Its display Figure 1An enlarged view of part B. The second recovery ring 32 also includes a first drain pipe 327. The first drain pipe 327 penetrates the first bottom wall 323 of the second recovery ring 32 and communicates with the first receiving cavity 325 to discharge the process liquid in the first receiving cavity 325.
[0031] like Figure 1 and Figure 2 As shown, the first bottom wall 323 of the second recovery ring 32 and the first outer wall 3242 of the first annular side wall 322 together form the stop structure of the lower third recovery ring 33, which is used to introduce another process liquid into the interior of the third recovery ring 33.
[0032] For example, when the first recovery ring 31 and the second recovery ring 32 are raised, an opening is formed between the second recovery ring 32 and the third recovery ring 33, and the channel size between them is enlarged, thereby creating a guiding space that facilitates liquid flow. In this state, the liquid supply device 20 sprays the second process liquid onto the substrate disposed on the rotary table 10. During the high-speed rotation of the substrate, some of the second process liquid is thrown off and enters the channel between the second recovery ring 32 and the third recovery ring 33. After entering the channel laterally, this second process liquid impacts the first outer wall 3242 of the second recovery ring 32, thus changing its direction of movement from horizontal flow to vertical downward flow, and then dripping into the third recovery ring 33 below, and finally collecting in the receiving cavity defined by the third recovery ring 33.
[0033] like Figure 1 and Figure 2 As shown, the second recovery ring 32 further includes a first shielding wall 326, which is disposed on the first outer side wall 3242 and located at the junction of the first bottom wall 323 and the first annular side wall 322. The first shielding wall 326 extends longitudinally from the first bottom wall 323 in a direction away from the first annular side wall 322 to form a guiding structure, restricting the liquid from further diffusing to the surface of the first bottom wall 323 as it flows down the first outer side wall 3242.
[0034] As illustrated above, when the first recovery ring 31 and the second recovery ring 32 are raised, the first outer wall 3242 forms a stop structure for the third recovery ring 33. At this time, the function of the first shielding wall 326 is to guide the second process liquid to drip vertically along the first outer wall 3242 into the lower third recovery ring 33. It is particularly important to note that the first shielding wall 326 effectively prevents the second process liquid from flowing along the first outer wall 3242 to the first bottom wall 323, and then spreading along the outer surface of the first bottom wall 323 to the outer wall of the first drain pipe 327, causing adhesion and dripping. This phenomenon may cause liquid to seep into unintended containment chambers due to capillary action, resulting in cross-contamination between different process liquids and affecting the overall process quality. The first shielding wall 326 significantly reduces this risk of contamination, ensuring the separation and purity of the liquid recovery path.
[0035] Furthermore, such as Figure 3 As shown, the second recovery ring 32 also includes a first inclined wall 328, which is connected to the lower end of the first shielding wall 326. The first inclined wall 328 extends from its end connected to the first shielding wall 326, inclined upwards and outwards, thus forming a hook-shaped structure together with the first shielding wall 326 to guide the liquid away from the lower area. It should be particularly noted that, as... Figure 2 and Figure 3 As shown, the first inclined wall 328 is a partial feature and not a continuous ring. Specifically, the first inclined wall 328 is formed continuously only within the area where the first drain pipe 327 is located, and terminates at a position that is a distance away from the first drain pipe 327.
[0036] Continuing the previous example, after the first recovery ring 31 and the second recovery ring 32 rise, the first outer wall 3242 of the second recovery ring 32 forms the stop structure of the third recovery ring 33. At this time, the second process liquid will flow down along the first outer wall 3242. Through the setting of the first inclined wall 328, the second process liquid from above will be discharged away from the first drain pipe 327 along the guide groove formed by it and the first shielding wall 326, thereby effectively preventing the second process liquid from dripping and splashing around the first drain pipe 327, further preventing the second process liquid from adhering to the outer wall of the first drain pipe 327 and causing a drooping phenomenon, reducing the risk of cross-contamination.
[0037] In addition, such as Figure 1 and Figure 3As shown, the first drain pipe 327 further penetrates vertically through the third recovery ring 33 below it. However, due to manufacturing tolerance limitations, a small gap inevitably exists between the first drain pipe 327 and its corresponding through hole, which may cause liquid to seep into unintended receiving cavities along the gap, resulting in liquid cross-contamination. To solve this problem, the substrate processing apparatus 1 disclosed in this application further includes a first leak-proof cover 329. The first leak-proof cover 329 is disposed around the periphery of the first drain pipe 327 and fixedly configured at the junction of the first drain pipe 327 and the third recovery ring 33, in order to seal the gap and prevent liquid from leaking into areas that should not enter, thereby improving the sealing performance and reliability of the overall liquid recovery system.
[0038] Please refer to Figure 4 and Figure 5 , Figure 4 A schematic diagram showing the second operation of the substrate processing apparatus according to an embodiment of this application, and Figure 5 show Figure 4 An enlarged view of part C. The following will be presented as... Figure 4 and Figure 5 This describes the specific structure and operating status of the liquid recovery component 30 during the deionized water cleaning step. Figure 4 The image shows the first recovery ring 31, the second recovery ring 32, and the third recovery ring 33 all in the raised position. When these three rings rise, an opening is formed between the third recovery ring 33 and the bottom tank 40, increasing the channel size and creating a flow space. In this state, the liquid supply device 20 sprays deionized water onto the substrate (not shown) on the rotating platform 10. Due to the high-speed rotation of the substrate, some of the deionized water is ejected and enters the bottom tank 40 through the flow channel between the third recovery ring 33 and the bottom tank 40, where it is collected. Furthermore, the first recovery ring 31 is equipped with a longitudinally extending blocking ring, positioned near one end of the first ring wall of the rotating platform 10. This blocking ring covers the openings of all closed recovery rings. When all the recovery rings rise as a whole, the blocking ring maintains a certain distance from the rotating platform 10, ensuring a sealing effect and preventing liquid from splashing into areas where it should not enter.
[0039] Specifically, such as Figure 4 and Figure 5As shown, the third recovery ring 33 includes a third annular wall 331, a pair of concentrically arranged and spaced apart second annular sidewalls 332, and a second bottom wall 333 laterally connected to the opposite sidewalls. A second inner sidewall 3341, connected to the opposite second annular sidewalls 332, defines a second receiving cavity 335 for receiving and storing the aforementioned second process liquid. Furthermore, the third recovery ring 33 also includes a second drain pipe 337. The second drain pipe 337 penetrates the second bottom wall 333 of the third recovery ring 33 and communicates with the second receiving cavity 335 to drain the process liquid from the second receiving cavity 335. It is noteworthy that the second receiving cavity 335 is located at a position corresponding to the first bottom wall 323 and the opposite first annular sidewalls 322 of the second recovery ring 32, and is located directly below the first bottom wall 323 and the opposite first annular sidewalls 322. When the second recovery ring 32 and the third recovery ring 33 are in a closed state, the first bottom wall 323 of the second recovery ring 32 and the first annular side wall 322 will be housed in the second receiving cavity 335.
[0040] like Figure 4 and Figure 5 As shown, the second bottom wall 333 of the third recovery ring 33 and the second outer side wall 3342 of the second annular side wall 332 together form a stop structure for the lower bottom tank 40, used to guide deionized water into the bottom tank 40. During operation, the deionized water is ejected by the rotating table 10 and guided into the channel between the third annular wall 331 and the bottom tank 40. When the liquid moves laterally, its direction of movement changes after colliding with the second outer side wall 3342, and it drips vertically downwards, thus entering the bottom tank 40 to complete the recovery operation. Similarly, the bottom tank 40 includes a third drain pipe 41. The third drain pipe 41 penetrates the bottom wall of the bottom tank 40 and communicates with the second drain pipe 337 to discharge the process liquid collected by the third recovery ring 33.
[0041] like Figure 4 and Figure 5As shown, the third recovery ring 33 is further provided with a second shielding wall 336, which is disposed on the second outer wall 3342 and located at the junction of the second bottom wall 333 and the second annular side wall 332. The second shielding wall 336 extends longitudinally from the second bottom wall 333 in a direction away from the second annular side wall 332, forming a guiding structure. Its main function is to restrict the diffusion of liquid from the second outer wall 3342 to the surface of the second bottom wall 333. In other words, the second shielding wall 336 can effectively guide deionized water to drip vertically along the second outer wall 3342 and flow directly into the bottom tank 40 below it. It is particularly noteworthy that the second shielding wall 336 can prevent deionized water from flowing into the surface of the second bottom wall 333, avoiding further diffusion of liquid along the surface to the outer wall of the second drain pipe 337. This can suppress liquid adhesion and dripping phenomena, thereby preventing capillary action from causing liquid to seep into the containment cavity that should not enter, avoiding cross-contamination between different process liquids, and ensuring the purity and reliability of the overall process. The second shielding wall 336 effectively separates the liquid recovery paths, which helps to improve recovery efficiency and process quality.
[0042] Furthermore, such as Figure 4 and Figure 5 As shown, the third recovery ring 33 also includes a second inclined wall 338, which is connected to the lower end of the second shielding wall 336. The second inclined wall 338 extends outward from its connection point and slopes upward from the inside to the outside, thus forming a hook-shaped structure together with the second shielding wall 336 to guide the liquid away from the area below. It should be noted that the second inclined wall 338 is a partial installation and not a continuous formation throughout the entire ring. Specifically, the second inclined wall 338 is continuously formed only within the area where the first drain pipe 327 and the second drain pipe 337 are correspondingly installed, and terminates at a position separated from the first drain pipe 327 or the second drain pipe 337 by a distance.
[0043] like Figure 4 and Figure 5 As shown, when deionized water flows down the second outer wall 3342, it is guided by the flow channel formed between the second inclined wall 338 and the second shielding wall 336, allowing the liquid to flow away from the first drain pipe 327 and the second drain pipe 337. This guiding design effectively prevents deionized water from dripping and splashing around the drain pipes, thus avoiding liquid adhering to the outer wall of the drain pipes and causing dripping. This helps reduce the risk of cross-contamination and ensures the separation and purity of the recovered liquid.
[0044] In addition, such as Figure 4As shown, both the first drain pipe 327 and the second drain pipe 337 vertically penetrate the bottom tank 40 below them. Considering the limitations of equipment manufacturing precision, there are inevitably tiny gaps between the drain pipes and their corresponding through holes, which may cause liquid to seep into unexpected containment spaces. To solve this problem, the bottom tank 40 is further provided with a second leak-proof cover 339. The second leak-proof cover 339 is arranged around the periphery of the first drain pipe 327 and the second drain pipe 337, and is fixedly installed at the junction of the plurality of drain pipes and the bottom tank 40, in order to seal potential gaps and prevent liquid leakage, thereby effectively improving the sealing performance and operational reliability of the overall liquid recovery system.
[0045] In summary, by setting appropriate auxiliary guiding and protective structures in each recovery ring, this application can effectively prevent liquid from seeping into unexpected containment cavities, further avoid cross-contamination between different process liquids, and thus ensure the purity and stability of the process.
[0046] The foregoing has provided a detailed description of a substrate processing apparatus and a recycling ring provided in the embodiments of this application. Specific embodiments have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions in the embodiments of this application.
Claims
1. A substrate processing apparatus, characterized in that, include: A rotary table, used to support the substrate; A liquid supply device is disposed above the rotary table for applying multiple process liquids to the substrate; as well as A liquid recovery assembly is disposed on the outside of the rotary table. The liquid recovery assembly includes multiple recovery rings arranged sequentially from top to bottom and movable up and down relative to the rotary table to collect the corresponding multiple process liquids respectively. Wherein, at least one of the recycling rings includes: A pair of concentrically arranged and spaced apart annular sidewalls; The bottom wall is laterally connected to the pair of annular sidewalls, wherein the inner sidewall connected to the bottom wall and the pair of annular sidewalls defines a receiving cavity for receiving process liquid, and wherein the outer sidewall connected to the bottom wall and the pair of annular sidewalls serves as a stop structure for another recovery ring below, for introducing another process liquid into the other recovery ring. A shielding wall, disposed on the outer side wall and located at the junction of the bottom wall and the opposite annular side walls, is used to guide the other process liquid flowing along the outer side wall to drip vertically into the other recovery ring below; and A drain pipe penetrates the bottom wall and communicates with the receiving cavity to drain the process liquid from the receiving cavity.
2. The substrate processing apparatus as described in claim 1, characterized in that, The shielding wall extends longitudinally from the bottom wall in a direction away from the pair of annular sidewalls.
3. The substrate processing apparatus as described in claim 2, characterized in that, The at least one of the recycling rings further includes an inclined wall connected to the lower end of the shielding wall, and together with the shielding wall, forming a barbed structure.
4. The substrate processing apparatus as described in claim 3, characterized in that, The inclined wall is continuously formed within the area where the drain pipe is correspondingly provided, and terminates at a position that is a distance away from the drain pipe.
5. The substrate processing apparatus as described in claim 1, characterized in that, The drain pipe extends vertically through the other recovery ring located below it, and the at least one of the recovery rings further includes a leak-proof cover surrounding the drain pipe and positioned at the junction of the drain pipe and the other recovery ring.
6. A recovery ring, disposed on the outside of a rotating platform, for collecting process liquid splashed from the rotating platform, characterized in that, The recycling ring includes: A pair of concentrically arranged and spaced apart annular sidewalls; The bottom wall is laterally connected to the pair of annular sidewalls, wherein the inner sidewall connected to the bottom wall and the pair of annular sidewalls defines a receiving cavity for receiving process liquid, and wherein the outer sidewall connected to the bottom wall and the pair of annular sidewalls serves as a stop structure for another recovery ring below, for introducing another process liquid into the other recovery ring. A shielding wall, disposed on the outer side wall and located at the junction of the bottom wall and the opposite annular side walls, is used to guide the other process liquid flowing along the outer side wall to drip vertically into the other recovery ring below; and A drain pipe penetrates the bottom wall and communicates with the receiving cavity to drain the process liquid from the receiving cavity.
7. The recycling ring as described in claim 6, characterized in that, The shielding wall extends longitudinally from the bottom wall in a direction away from the pair of annular sidewalls.
8. The recycling ring as described in claim 6, characterized in that, The at least one of the recycling rings further includes an inclined wall connected to the lower end of the shielding wall, and together with the shielding wall, forming a barbed structure.
9. The recycling ring as described in claim 8, characterized in that, The inclined wall is continuously formed within the area where the drain pipe is correspondingly provided, and terminates at a position that is a distance away from the drain pipe.
10. The recycling ring as described in claim 6, characterized in that, The drain pipe extends vertically through the other recovery ring located below it, and the at least one of the recovery rings further includes a leak-proof cover surrounding the drain pipe and positioned at the junction of the drain pipe and the other recovery ring.