Continuous cleaning process for large size silicon carbide wafers

Abstract

The application provides a large-size silicon carbide wafer continuous cleaning process and relates to the technical field of semiconductor cleaning, and comprises the following steps: S1, placing a silicon carbide wafer in an edge limiting device and performing primary cleaning; S2, after the primary cleaning is completed, first controlling the end of the limiter to extend and abut against the center position of the silicon carbide wafer, then controlling the edge limiting device to unfold and controlling the telescopic limiting assembly to elongate, and controlling the edge position of the silicon carbide wafer to be staggered with the edge limiting device to realize secondary cleaning. The application is suitable for batch continuous cleaning of large-size SiC wafers, and greatly improves the cleaning cleanliness and the automatic production rhythm.

Description

Technical Field

[0001] This invention relates to the field of semiconductor cleaning technology, and more particularly to a continuous cleaning process for large-size silicon carbide wafers. Background Technology

[0002] Traditional large-size silicon carbide wafer cleaning relies solely on edge clamping for fixation. The edge clamping area of ​​the wafer will form a cleaning blind spot. Silicon carbide is hard and brittle, and its size is large. Single-sided single cleaning cannot remove particles, polishing residue, and metal impurities at the edge clamping area. Repeated manual flipping can easily cause wafer edge chipping, scratches, and cracking. Moreover, the single-wafer cleaning process is fragmented and cannot be continuously automated.

[0003] Patent document CN116921337B discloses a centralized cleaning device and method for silicon carbide wafers. It controls a first cleaning fixture to flip over and place it above a second cleaning fixture so that their positions correspond to form a cleaning area. During the cleaning process, the wafer can be controlled to move within the cleaning area, allowing different positions of the silicon carbide wafer to contact different inner walls within the cleaning area. This exposes the circumferential edges of the silicon carbide wafer within the cleaning area, improving the cleaning effect of the mega-sound cleaning equipment on the wafer edges and avoiding the residue of contaminants. However, because large-sized silicon carbide wafers are harder and more brittle, the edge pressure is greater and gradually changes during the flipping process, which can easily cause damage during the overall flipping cleaning process.

[0004] Patent documents CN115799122B and CN118522682B disclose a wafer stable cleaning device and cleaning method, and a wafer double-sided cleaning device and method, respectively. The above technical solutions can more stably clean a single large-size wafer. However, due to the limitations of the specific cleaning structure and process, a single cleaning can only perform deep cleaning on both sides of a wafer, resulting in low overall cleaning efficiency. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a continuous cleaning process for large-size silicon carbide wafers. This invention is suitable for batch continuous cleaning of large-size SiC wafers, significantly improving cleaning cleanliness and automated production cycle time.

[0006] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0007] A continuous cleaning process for large-size silicon carbide wafers utilizes a continuous cleaning device for large-size silicon carbide wafers. The device includes a cleaning chamber, an edge limiting device located within the cleaning chamber that can be raised and lowered to limit the movement of the silicon carbide wafer, and a center limiting device above the edge limiting device. The center limiting device includes multiple telescopic limiting components and a center limiter located at the telescopic end of the telescopic limiting components. The center limiter includes a limiter body and a telescopic limiter end. The process includes the following steps: S1, placing the silicon carbide wafer within the edge limiting device and performing a first cleaning; S2, after the first cleaning, first controlling the end of the limiter to extend and abut against the center of the silicon carbide wafer, then controlling the edge limiting device to unfold and controlling the telescopic limiting components to extend, thus controlling the edge position of the silicon carbide wafer to be offset from the edge limiting device to achieve a second cleaning.

[0008] Preferably, the end of the limiter includes a limit piston and a limit post, and a water spray channel is formed inside the limit piston and the limit post to inject cleaning liquid into the limiter body. While pushing the end of the limiter to extend, the cleaning liquid is sprayed towards the center of the silicon carbide wafer.

[0009] Preferably, the outer side of the limiting post is also provided with a plurality of water spray holes in a circumferential manner. The water spray holes are connected to the water spray channel. The size of the water spray holes is smaller than the size of the water spray channel. After the end of the limiting post extends out and is completely attached to the surface of the silicon carbide wafer, the cleaning liquid is sprayed out from the plurality of water spray holes.

[0010] Preferably, a limiting ring is rotatably connected to the outer side of the limiting post, the limiting post is rotatably connected to the limiting piston, and a driving element for controlling the rotation of the limiting post is also included.

[0011] Preferably, the telescopic limiting assembly includes a limiting housing, inside which a control piston and a control rod are disposed. The control piston divides the interior of the limiting housing into a first control chamber and a second control chamber. A control channel is formed inside the control piston and the control rod, which connects the first control chamber to the interior of the limiting device body. The first control chamber is also connected to a pumping pipe for pumping cleaning liquid.

[0012] Preferably, a first spring is provided between the limiter body and the retractable limiter end, and a second spring is provided between the control rod and the limiter housing. The elastic resistance of the first spring is greater than that of the second spring. After the cleaning liquid is pumped into the first control chamber, the limiter end is first controlled to extend and clamp the silicon carbide wafer, and then the control rod is pushed to extend and control the edge position of the silicon carbide wafer to be offset from the edge limiter device to achieve secondary cleaning.

[0013] Preferably, the second control chamber is also connected to a control pipe with a built-in first solenoid valve, and the first solenoid valve opens after the end of the limiter extends out to clamp the silicon carbide wafer.

[0014] Preferably, the edge limiting device includes a first limiting component, a second limiting component, and a hydraulic telescopic structure located between the first limiting component and the second limiting component.

[0015] Preferably, the hydraulic telescopic structure is connected to the first control chamber via a connecting pipe, and the connecting pipe contains a second solenoid valve.

[0016] Preferably, a limiter end is provided on both sides of the central limiter located in the middle, and a limiter end is provided on the inner side of the central limiter located at the edge.

[0017] The beneficial effects of this invention are as follows:

[0018] Compared with existing technologies, this invention adopts a dual-station continuous cleaning logic of edge clamping initial cleaning and center positioning re-cleaning, which completely eliminates the blind spots of wafer edge clamping and realizes full-area cleaning of the entire silicon carbide wafer, including both sides and edges, without dead angles. The equipment automatically switches the clamping mode throughout the process, eliminating the need for manual handling and flipping, and eliminating the risk of edge chipping, surface scratches and scrap caused by manual operation of large-size wafers. It is suitable for batch continuous cleaning of large-size SiC wafers, and greatly improves the cleaning cleanliness and automated production cycle. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the present invention.

[0020] Figure 2 This is a three-dimensional structural diagram of the large-size silicon carbide wafer continuous cleaning equipment of the present invention.

[0021] Figure 3 For the present invention Figure 2 A schematic diagram of the main structure.

[0022] Figure 4 For the present invention Figure 2 A top-view structural diagram.

[0023] Figure 5 This is a three-dimensional structural diagram of the central limiter of the present invention.

[0024] Figure 6 For the present invention Figure 5 A side view structural diagram.

[0025] Figure 7 For the present invention Figure 6 A schematic diagram of the AA-direction cross-section structure.

[0026] Figure 8This is a schematic diagram of the internal structure of the telescopic limiting component of the present invention.

[0027] In the diagram: 100, cleaning chamber; 110, lifting device; 200, edge limiting device; 210, first limiting assembly; 220, hydraulic telescopic structure; 230, second limiting assembly; 300, center limiting device; 310, connecting beam; 320, telescopic limiting assembly; 3201, first control chamber; 3202, second control chamber; 321, limiting housing; 322, control piston; 323, control rod; 324, second spring; 325, control pipe; 400, center limiter; 410, limiter body; 411, guide hole; 420, limiter end; 421, limit piston; 422, first spring; 423, limiting post; 4231, spiral blade; 4232, water spray hole; 424, limiting ring. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] To address the problems mentioned in the background art, see Appendix Figure 1 -Appendix Figure 8 A continuous cleaning process for large-size silicon carbide wafers is disclosed, which uses a continuous cleaning device for large-size silicon carbide wafers. The continuous cleaning device for large-size silicon carbide wafers includes a cleaning chamber 100 and an edge limiting device 200 located in the cleaning chamber 100 that can be lifted and moved to limit the silicon carbide wafers. A center limiting device 300 is also provided above the edge limiting device 200. The edge limiting device 200 and the center limiting device 300 alternately limit multiple large-size silicon carbide wafers to ensure that the large-size silicon carbide wafers are in a relatively stable state during the cleaning process.

[0030] The aforementioned center limiting device 300 includes a plurality of telescopic limiting components 320 and a center limiter 400 located at the telescopic end of the telescopic limiting components 320. The center limiter 400 includes a limiter body 410 and a telescopic limiter end 420. The center position of the silicon carbide wafer is limited and fixed by controlling the extension of the limiter end 420.

[0031] The cleaning chamber 100 is equipped with a lifting device 110, which can drive the edge limiting device 200 and related structures of the silicon carbide wafer to move up and down. The cleaning chamber 100 is equipped with cleaning liquid and ultrasonic cleaning equipment, which can perform deep cleaning on both sides of the silicon carbide wafer.

[0032] The present invention specifically includes the following steps:

[0033] S1. Place the silicon carbide wafer within the edge limiting device 200 and perform a cleaning; at this time, the main focus is on the exposed part in the middle of the silicon carbide wafer to complete efficient cleaning.

[0034] S2. After the first cleaning is completed, the end of the limiter 420 is first extended and pressed against the center of the silicon carbide wafer. Then, the edge limiter 200 is unfolded and the telescopic limiter 320 is extended so that the edge of the silicon carbide wafer is offset from the edge limiter 200, and a second cleaning is carried out. At this time, efficient cleaning of the area around the silicon carbide wafer is achieved.

[0035] The aforementioned limiter end 420 is in a clean state before it comes into contact with the limiter, so as to avoid surface impurities causing secondary contamination to the silicon carbide wafer after the first cleaning.

[0036] S3. After the secondary cleaning is completed, multiple silicon carbide wafers are first adsorbed and positioned by a negative pressure device to ensure the stability of the silicon carbide wafers. Then, the end of the limiter is controlled to retract 420° to release the limit and fixation of the silicon carbide wafers. Finally, the negative pressure gripping device drives the silicon carbide wafers out to complete the unloading operation of multiple silicon carbide wafers.

[0037] This process uses an edge limiting device 200 to complete the first round of basic cleaning of the entire surface. After cleaning, the central limiting device 300 positions and clamps the wafer from the center, releasing the edge limiting mechanism to fully expose the original clamping blind area for unobstructed secondary full-area cleaning. The two cleaning steps are completed continuously in the same cleaning chamber without the need for manual transfer and flipping. This avoids scratches on the wafer surface caused by multiple transfers of silicon carbide wafers and greatly improves the surface cleaning efficiency of silicon carbide wafers. At the same time, the edge limiting device 200 and the central limiting device 300 can simultaneously and stably limit and deeply clean multiple silicon carbide wafers, further increasing wafer cleaning capacity.

[0038] In summary, this invention employs a dual-station continuous cleaning logic of edge clamping initial cleaning and center positioning re-cleaning, completely eliminating blind spots in wafer edge clamping and achieving thorough cleaning of the entire silicon carbide wafer, including both sides and edges, without any dead angles. The equipment automatically switches clamping methods throughout the process, eliminating the need for manual handling and flipping, thus preventing the risk of edge chipping, surface scratches, and scrapping caused by manual operation of large-size wafers. It is suitable for batch continuous cleaning of large-size SiC wafers, significantly improving cleaning cleanliness and automated production cycle.

[0039] Specifically, the limiter end 420 includes a limit piston 421 and a limit post 423, which are internally connected to form a water spray channel. Cleaning liquid is introduced into the limiter body 410. The hydraulic pressure pushes the limiter end 420 outward on one hand, and simultaneously sprays the cleaning liquid towards the center of the silicon carbide wafer on the other hand. The cleaning liquid is a high-purity, pollution-free clean medium. Before the limiter end 420 is pressed into contact with the surface of the silicon carbide wafer, the central area of ​​the wafer is pre-rinsed to squeeze out residual cleaning liquid carrying contaminants, thereby avoiding contaminants from being trapped between the limiter end 420 and the wafer contact surface and improving the overall cleanliness of the silicon carbide wafer.

[0040] A water spray channel is formed through the internal connection between the limiting piston 421 and the limiting post 423. After the cleaning liquid enters the main body 410 of the limiter, the hydraulic pressure simultaneously achieves two functions: pushing the end of the overall limiter to extend and press against the center of the wafer, while the medium is sprayed directly onto the contact surface of the wafer center along the channel; the hydraulic medium is driven by an integrated system and sprays liquid synchronously. One set of hydraulic circuits completes clamping and positioning and in-situ pre-rinsing at the same time, eliminating the need to add separate spray pipes and drive cylinders, simplifying the internal pipeline layout of the equipment; the cleaning liquid is sprayed synchronously at the wafer center clamping contact position to pre-disperse any contaminants that may remain at the center contact point, preventing impurities from being squeezed and adhered to the wafer surface after clamping and pressing, thus reducing cleaning defects in the center area from the source.

[0041] It should be noted that when the water spray channel sprays liquid outward, the silicon carbide wafer is kept stable by the edge limiting device 200, and the sprayed liquid will not change the wafer's posture; at the same time, the ends of the limiters 420 on both sides of the silicon carbide wafer are sprayed synchronously, and the impact force of the water flow on both sides cancels each other out, further preventing the wafer from being deflected or shaking due to force.

[0042] Furthermore, multiple sets of water spray holes 4232 are arranged circumferentially on the outer side of the limiting post 423. The water spray holes 4232 are interconnected with the internal water spray channel. The diameter of the water spray holes 4232 is smaller than that of the main water spray channel. Only when the end of the limiting device 420 is fully extended and attached to the surface of the silicon carbide wafer, the cleaning liquid is sprayed outward from each water spray hole 4232.

[0043] The limiting post 423 is surrounded by multiple sets of water spray holes 4232, with a diameter smaller than the internal main water spray channel. The cleaning medium is sprayed only when the end of the limiting post is completely in contact with the wafer surface. The high-pressure fan-shaped water flow is formed through the small-diameter water spray holes, which diffuses radially outward along the wafer's central contact surface, covering the annular area around the central clamp and washing away impurities to the outside of the wafer. The differential design of the hole diameter creates a throttling and pressurizing effect. Effective high-pressure spraying can only be formed after contact with the wafer. There is no high-pressure water flow leakage when not in contact with the wafer, saving cleaning solution. The annular multi-directional water spraying has no cleaning dead angles, solving the problem of narrow cleaning range and impurity residue in single-point direct spraying.

[0044] Furthermore, a limiting ring 424 is rotatably mounted on the outer side of the limiting post 423, and the limiting post 423 is rotatably connected to the limiting piston 421; the equipment is equipped with a driving element to drive the limiting post 423 to rotate. The limiting post 423 is rotatably mounted to the limiting piston, and the limiting ring 424 is rotatably sleeved on the outer side, with an independent driving element controlling the rotation of the post.

[0045] During the cleaning process, the rotation of the limiting post 423 drives the jet water to rotate synchronously in the circumferential direction. The annular water spray forms a rotating vortex to scour the wafer. The vortex disturbance can peel off the nano-level polishing residue with strong adhesion to the wafer surface. At the same time, the rotating limiting ring 424 flexibly fits the wafer, reducing the probability of hard contact scratches. The rotating spray greatly improves the cleaning uniformity of the central area, which is compatible with the high-precision cleanliness production standards of silicon carbide wafers.

[0046] The aforementioned driving element can be a conventional electric drive structure to directly drive the limiting post 423 to rotate in a directional manner; alternatively, a spiral blade 4231 can be set in the water spray channel inside the limiting post 423. When the cleaning liquid flows through the spiral blade 4231 at high speed, it generates a lateral thrust, which automatically drives the limiting post 423 to rotate synchronously, and achieves self-rotation cleaning without external power by relying on the kinetic energy of the liquid.

[0047] Specifically, the telescopic limiting assembly 320 includes a limiting housing 321, inside which a control piston 322 and a control rod 323 are assembled. The control piston 322 divides the inner cavity of the limiting housing 321 into a first control chamber 3201 and a second control chamber 3202. A control channel is opened inside the control piston 322 and the control rod 323, with one end of the control channel connected to the first control chamber 3201 and the other end connected to a through hole 411 opened on the side wall of the limiter body 410. The first control chamber 3201 is connected to a pumping pipe for pumping cleaning liquid. The cleaning liquid is sent into the first control chamber 3201 through the pumping pipe and then into the interior of the limiter body 410 through the control channel.

[0048] The telescopic limit assembly has a built-in dual-chamber hydraulic drive structure. The pumping pipeline delivers cleaning liquid to the first control chamber, and the medium is synchronously introduced into the body of the limiter through the control channel, so that the liquid supply drive of the central limiter and the power supply of the telescopic assembly are from the same source.

[0049] By sharing a single cleaning fluid pumping system, there is no need to add an independent hydraulic oil station, avoiding oil leakage that could contaminate the high-purity cleaning environment and meeting the requirements for dust-free cleaning of semiconductor wafers. The single-channel medium is synchronously delivered to the central limiter and the telescopic drive cavity, resulting in strong linkage between actions, unified control logic, and a compact equipment structure that is suitable for the arrangement of small, enclosed, dust-free spaces in the cleaning room.

[0050] Furthermore, a first spring 422 is assembled between the limiter body 410 and the retractable limiter end 420, and a second spring 324 is assembled between the control rod 323 and the limiter housing 321; the elastic resistance of the first spring 422 is greater than the elastic resistance of the second spring 324; after the cleaning liquid is pumped into the first control chamber 3201, the hydraulic pressure first overcomes the resistance of the first spring 422 to push the limiter end 420 out to clamp the silicon carbide wafer, and then overcomes the resistance of the second spring 324 to push the control rod 323 to extend, so that the edge of the silicon carbide wafer is staggered from the edge limiter device 200, thus completing the secondary cleaning operation.

[0051] A first spring 422 is provided between the main body and the end of the limiter, and a second spring 324 is provided between the control rod and the limiter housing. The elastic resistance of the first spring is greater than that of the second spring. After the liquid is pumped in, it first overcomes the large elastic force to extend the end of the limiter to clamp the wafer, and then pushes the control rod to extend and offset the edge limiter.

[0052] This invention relies on the difference in spring force to achieve automatic timing of center clamping followed by edge avoidance. It does not require separate step-by-step programming control by PLC. It is a pure hydraulic mechanical timing linkage, and there is no risk of electronic sensor failure in dust-free and humid cleaning environments. The clamping action is executed first to ensure that the wafer is firmly positioned in the center before releasing the edge limit, preventing the wafer from shifting, falling, or being damaged by bumps during the switching clamping process, thus improving the stability of large-size wafer transfer and cleaning.

[0053] The second control chamber 3202 is also connected to a control pipe 325 equipped with a built-in first solenoid valve. The first solenoid valve opens to release pressure only after the end 420 of the limiter extends and clamps the silicon carbide wafer. The second control chamber is connected to a control pipe with a first solenoid valve, and the solenoid valve opens to release pressure only after the wafer is clamped at the end of the limiter.

[0054] During the clamping phase, the second control chamber remains sealed and pressurized, assisting in locking the extension length of the limit switch to prevent water pressure fluctuations from causing the central clamp to loosen. After clamping in place, the solenoid valve opens to release pressure, releasing the resistance of the control rod extension and retraction, facilitating the smooth extension of the subsequent extension components. The segmented pressure control allows the clamping and displacement actions to be segmented and controllable, with smooth transitions without impact, protecting the brittle silicon carbide wafer.

[0055] Specifically, the edge limiting device 200 includes a first limiting component 210, a second limiting component 230, and a hydraulic telescopic structure 220 arranged between the first limiting component 210 and the second limiting component 230. The edge limiting device is composed of two sets of limiting components and a middle hydraulic telescopic structure, which achieves synchronous clamping and synchronous unfolding on both sides by means of hydraulic telescopic movement.

[0056] With the first limiting component 210 and the second limiting component 230 providing dual-sided synchronous hydraulic clamping, the edge of the large-sized wafer is subjected to uniform force, preventing unilateral extrusion and warping, and avoiding localized stress concentration that could cause microcracks in the wafer. The hydraulic extension stroke is adjustable, which can accommodate silicon carbide wafers of different diameters. During the initial cleaning stage, the wafer is stably enclosed and limited, and during the secondary cleaning stage, it is synchronously opened to completely avoid the edge of the wafer, without any local obstruction.

[0057] Furthermore, the hydraulic telescopic structure 220 is connected to the first control chamber 3201 via a connecting pipe, and a second solenoid valve is built into the connecting pipe. The hydraulic telescopic structure is connected to the first control chamber via the connecting pipe with the second solenoid valve, and they share the cleaning fluid medium as the hydraulic power source.

[0058] The edge opening action and the center clamping drive use the same medium, and the two mechanisms are linked and controllable in sequence. The second solenoid valve independently manages the edge hydraulic circuit, which can precisely control the timing of the edge limit opening. Only after the center has fully clamped the wafer will the solenoid valve be turned on to release pressure and open the edge, forming a closed-loop interlock logic to eliminate the risk of wafer falling off during the clamping and switching process. The overall hydraulic circuit is integrated, reducing the risk of cleanliness contamination caused by the mixing of multiple media.

[0059] Finally, it should be noted that the center limiters 400 in the array arrangement are divided into two types: central limiters and edge limiters. The central limiters 400 located in the middle of the array are equipped with limiter ends 420 on both sides; the central limiters 400 located at the edge of the array have only a single set of limiter ends 420 on their inner side; multiple sets of dual-sided limiting center limiters 400 are arranged in the middle region of the array, which can simultaneously limit and clamp the silicon carbide wafers on both the left and right sides. The array arrangement of center limiters distinguishes between central and edge structures; central limiters have limiter ends extending from both sides, while edge limiters have only a single set of limiter ends on their inner side.

[0060] The array-type central limiting multi-point balanced support for large-size wafers, the bidirectional clamping in the middle to ensure symmetrical force at the center, and the single-sided limiting at the edge to avoid interference with the side wall of the cleaning chamber; the multi-point distributed clamping greatly reduces the contact pressure per unit area, preventing deformation and micro-cracks caused by pressure on the center of the wafer; the modular arrangement of the limiters of different specifications allows for flexible addition or removal of limit points according to different wafer sizes, making the equipment highly versatile.

[0061] In summary, this invention addresses industry pain points in the cleaning of large-size silicon carbide wafers, such as blind spots in clamping, easy edge chipping and scratching, inability to continuously and automatically flip wafers, and substandard cleanliness. It innovatively designs a continuous process of initial edge cleaning and center-positioning re-cleaning, employing a homogeneous hydraulic medium to achieve integrated drive for clamping, spraying, and displacement. Mechanical automation is achieved through spring force differences and solenoid valve interlocking, coupled with a rotating annular high-pressure spray and a multi-point, size-specific center-limiting structure. The entire process operates continuously in a sealed single chamber, eliminating the need for manual wafer transfer and completely eliminating blind spots in clamping and cleaning, significantly improving the cleanliness of the wafer surface, edges, and center areas. The mechanically linked action sequence results in a low failure rate in the dust-free cleaning environment, effectively reducing the scrap rate of SiC wafers during cleaning. It is suitable for the high-precision, high-cleanliness, and automated continuous cleaning production requirements of large-size silicon carbide wafers for third-generation semiconductors.

[0062] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A continuous cleaning process for large-size silicon carbide wafers, comprising a continuous cleaning device for large-size silicon carbide wafers, characterized in that: The large-size silicon carbide wafer continuous cleaning equipment includes a cleaning chamber (100) and an edge limiting device (200) located in the cleaning chamber (100) that can be raised and lowered to limit the silicon carbide wafer. A center limiting device (300) is also provided above the edge limiting device (200). The center limiting device (300) includes multiple telescopic limiting components (320) and a center limiter (400) located at the telescopic end of the telescopic limiting components (320). The center limiter (400) includes a limiter body (410) and a telescopic limiter end (420). Includes the following steps: S1. Place the silicon carbide wafer in the edge limiting device (200) and clean it once; S2. After the first cleaning is completed, the end of the limiter (420) is first extended and pressed against the center of the silicon carbide wafer. Then the edge limiter (200) is unfolded and the telescopic limiter (320) is extended. The edge position of the silicon carbide wafer is staggered from the edge limiter (200) to achieve a second cleaning.

2. The continuous cleaning process for large-size silicon carbide wafers according to claim 1, characterized in that, The end of the limiter (420) includes a limit piston (421) and a limit post (423). The limit piston (421) and the limit post (423) form a water spray channel inside, injecting cleaning liquid into the limiter body (410) and pushing the end of the limiter (420) to extend while spraying cleaning liquid towards the center of the silicon carbide wafer.

3. The continuous cleaning process for large-size silicon carbide wafers according to claim 2, characterized in that, The limiting post (423) is also provided with a plurality of water spray holes (4232) circumferentially. The water spray holes (4232) are connected to the water spray channel. The size of the water spray holes (4232) is smaller than the size of the water spray channel. After the end of the limiting device (420) extends out and is fully attached to the surface of the silicon carbide wafer, the cleaning liquid is sprayed out from the plurality of water spray holes (4232).

4. The continuous cleaning process for large-size silicon carbide wafers according to claim 3, characterized in that, The limiting post (423) is rotatably connected to the outer side of the limiting ring (424), and the limiting post (423) is rotatably connected to the limiting piston (421). It also includes a driving element for controlling the rotation of the limiting post (423).

5. The continuous cleaning process for large-size silicon carbide wafers according to claim 2, characterized in that, The telescopic limiting assembly (320) includes a limiting housing (321), inside which a control piston (322) and a control rod (323) are provided. The control piston (322) divides the inside of the limiting housing (321) into a first control chamber (3201) and a second control chamber (3202). A control channel is formed inside the control piston (322) and the control rod (323), which connects the first control chamber (3201) and the inside of the limiting body (410). The first control chamber (3201) is also connected to a pumping pipe for pumping cleaning liquid.

6. The continuous cleaning process for large-size silicon carbide wafers according to claim 5, characterized in that, A first spring (422) is provided between the limiter body (410) and the retractable limiter end (420), and a second spring (324) is provided between the control rod (323) and the limiter housing (321). The elastic resistance of the first spring (422) is greater than that of the second spring (324). After the cleaning liquid is pumped into the first control chamber (3201), the limiter end (420) is first controlled to extend and clamp the silicon carbide wafer, and then the control rod (323) is pushed to extend and control the edge position of the silicon carbide wafer to be staggered from the edge limiter device (200) to achieve secondary cleaning.

7. The continuous cleaning process for large-size silicon carbide wafers according to claim 5, characterized in that, The second control chamber (3202) is also connected to a control pipe (325) with a built-in first solenoid valve. After the end of the limiter (420) extends out to clamp the silicon carbide wafer, the first solenoid valve opens.

8. The continuous cleaning process for large-size silicon carbide wafers according to claim 5, characterized in that, The edge limiting device (200) includes a first limiting component (210), a second limiting component (230), and a hydraulic telescopic structure (220) located between the first limiting component and the second limiting component (230).

9. The continuous cleaning process for large-size silicon carbide wafers according to claim 8, characterized in that, The hydraulic telescopic structure (220) is connected to the first control chamber (3201) through a connecting pipe, and the connecting pipe has a built-in second solenoid valve.

10. The continuous cleaning process for large-size silicon carbide wafers according to any one of claims 1-9, characterized in that, The center limiter (400) located in the middle has limiter ends (420) on both sides, and the center limiter (400) located at the edge has a limiter end (420) on the inner side.

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