Liquid supply assembly, wafer processing apparatus, and wafer processing method

Abstract

The application provides a liquid supply assembly, a wafer processing device and a wafer processing method, and belongs to the technical field of wafer processing. The liquid supply assembly comprises a liquid supply nozzle for releasing fluid onto a wafer. The liquid supply nozzle has a first channel for conveying fluid and a second channel for conveying gas. The first channel comprises at least two branch channels that are connected in parallel with each other to synchronously convey fluid. The plurality of branch channels are scattered and then re-converged. The second channel has a back suction structure that is in communication with the outlet ends of the branch channels. The second channel passes between any adjacent branch channels of the plurality of branch channels. When wafer processing is completed and fluid conveying is stopped, the second channel can suck back the residual fluid at the outlet ends of the first channel through the back suction structure under the action of an input gas flow, thereby realizing back suction and discharge of the residual fluid in the liquid supply nozzle and avoiding fluid droplets from affecting the processing quality of the wafer.

Description

[0001] This application is a divisional application of the invention patent application filed on March 23, 2026, with application number 2026103532474. Technical Field

[0002] This application belongs to the field of wafer processing technology, and more specifically, relates to a liquid supply component, a wafer processing apparatus, and a wafer processing method. Background Technology

[0003] In integrated circuit fabrication, conductive layers, semiconducting layers, or insulating layers are deposited sequentially on semiconductor wafers. Each of these steps requires planarization of the wafer layers to meet the deposition requirements of the next layer. Chemical mechanical polishing (CMP) is currently the industry-recognized method for wafer planarization. It utilizes the synergistic effect of chemical etching and mechanical abrasion to remove unevenness on the wafer surface, ensuring the precision of subsequent processing steps. After wafer polishing, further processing is required to remove surface impurities. Summary of the Invention

[0004] In view of the above problems, this application provides a liquid supply component, a wafer processing apparatus and a wafer processing method, thereby solving or at least alleviating the problem of residual fluid in the liquid supply nozzle dripping onto the wafer surface after wafer processing in the prior art.

[0005] A first aspect of this application provides a wafer processing apparatus, including a carrier disk, a swing arm, and a liquid supply assembly. The carrier disk is used to drive the wafer to rotate; the swing arm is oscillating above the carrier disk; and the liquid supply assembly is disposed at the swing end of the swing arm and is used to release a liquid supply nozzle onto the wafer. The liquid supply nozzle has a first channel for conveying fluid and a second channel for conveying gas; The first channel includes at least two branch channels that are connected in parallel to each other to deliver fluid synchronously; The second channel has a back suction structure, which is connected to the outlet end of the branch channel. When wafer processing is completed and fluid delivery stops, the second channel can use the negative pressure of the back suction structure to draw back the fluid remaining at the outlet of the first channel under the action of the input airflow, so as to prevent the fluid from dripping onto the wafer surface.

[0006] In one possible implementation, the first channel further includes an inlet channel that is connected to the inlet end of the branch channel and an outlet channel that is connected to the outlet end of the branch channel. The second channel is located between the inlet channel and the outlet channel. The back suction structure is connected to the outlet channel. The back suction structure can draw back the fluid remaining in the outlet channel under negative pressure after the gas is input.

[0007] In one embodiment, the inlet channel and the outlet channel are arranged vertically and vertically, and are connected by a connecting channel. The back suction structure is arranged intersectingly with the connecting channel and is interconnected. A sealing element is provided in the connecting channel above the back suction structure. The sealing element is used to separate the inlet channel and the outlet channel so that the fluid in the inlet channel can only flow to the branch channel, and the negative pressure of the back suction structure only acts on the fluid in the outlet channel.

[0008] In one embodiment, there are two branch channels, namely a first branch and a second branch. The inlet ends of the first branch and the second branch are respectively connected to the liquid inlet channel, and the outlet ends of the first branch and the second branch are respectively connected to the liquid outlet channel. The back suction structure is located between the first branch and the second branch.

[0009] In one possible implementation, the backflow structure includes: An air-feeding constrictor is installed on the second channel and connected to the air inlet of the second channel. The air-feeding constrictor has a constriction channel through which gas passes and gathers. The receiving constriction head is set on the second channel and connected to the outlet end of the second channel. A back suction gap is formed between the receiving constriction head and the supply constriction head. The back suction gap is connected to the outlet end of the branch channel. The receiving constriction head has a receiving channel for receiving the gas delivered by the supply constriction head and the fluid back suctioned by the back suction structure. When the gas supply neck head delivers gas to the gas receiving neck head, the back suction gap can create a negative pressure to back suction the fluid at the outlet end of the first channel and discharge the fluid through the gas receiving neck head and the second channel.

[0010] In one embodiment, the air supply necking head has an extension cone extending toward the air receiving necking head, the air receiving necking head has a conical groove into which the extension cone extends, a necking channel is disposed on the extension cone, a receiving channel is disposed through the bottom wall of the conical groove, and a back suction gap is formed between the extension cone and the conical groove.

[0011] In one embodiment, from the center of the back suction structure to the outer periphery of the back suction structure, the end face of the air receiving constriction head is gradually inclined away from the air supply constriction head, so as to guide the fluid into the back suction gap and allow the fluid to be discharged through the air receiving constriction head and the second channel.

[0012] In one embodiment, the minimum inner diameter of the constriction channel and the aperture of the receiving channel are both X, 0.2mm≤X≤3mm, so that the airflow increases in speed when passing through and forms negative pressure in the back suction gap.

[0013] In one possible implementation, the liquid supply assembly further includes: The liquid delivery pipe is connected to the liquid supply nozzle and is connected to the inlet end of the branch channel. It is used to deliver fluid to the branch channel. The liquid delivery pipe is equipped with a liquid delivery valve. An air supply pipe is connected to the liquid supply nozzle and is connected to the air inlet of the second channel. It is used to supply gas to the second channel. An air supply valve is provided on the air supply pipe. The discharge pipe is connected to the liquid supply nozzle and communicates with the gas outlet of the second channel. It is used to discharge gas and reabsorb fluid. The discharge pipe is equipped with a discharge valve. When wafer processing is complete, close the liquid supply valve and open the gas supply valve and discharge valve to create a negative pressure at the back suction structure to back suction the fluid at the outlet end of the first channel and discharge the fluid through the discharge pipe.

[0014] In one embodiment, the discharge pipe is further provided with a discharge necking member, which is located inside the discharge pipe. The discharge necking member has a necking hole, which is used to reduce the flow cross-sectional area of ​​the fluid to cooperate with the negative pressure back suction effect of the back suction structure to accelerate the discharge of the fluid.

[0015] In one embodiment, the distance between the drain neck and the outlet end of the drain pipe is Y, 300mm≤Y≤1200mm, so as to connect with the back suction structure to realize the external discharge of fluid.

[0016] In one possible implementation, the discharge pipe includes a first pipe section and a second pipe section, which are connected by a sealing connector. The discharge necking member is located at the outlet end of the first pipe section and is disposed adjacent to the sealing connector.

[0017] In one possible implementation, the outlet end of the discharge pipe is also provided with a backflow bend, which is bent downwards to buffer the fluid backflowed in the discharge pipe and prevent the fluid from dripping back.

[0018] In one embodiment, the backflow bend includes a lower bend, an extension, and an upper bend connected in sequence. The upper and lower bends extend vertically, and the extension extends horizontally. The extension is used to receive the fluid from the lower bend and buffer the residual fluid from the backflow.

[0019] In one embodiment, the distance between the back suction bend and the outlet end of the discharge pipe is n, where n ≤ 400 mm, in order to shorten the discharge path of the back suction fluid.

[0020] A second aspect of the embodiments of this application provides a liquid supply assembly for being disposed at the swing end of a swing arm, the liquid supply assembly including a liquid supply nozzle for discharging fluid onto a wafer; The liquid supply nozzle has a first channel for conveying fluid and a second channel for conveying gas; The first channel includes at least two branch channels that are connected in parallel to each other to deliver fluid synchronously; The second channel has a back suction structure, which is connected to the outlet end of the branch channel. When wafer processing is completed and fluid delivery stops, the second channel can use the negative pressure of the back suction structure to draw back the fluid remaining at the outlet of the first channel under the action of the input airflow, so as to prevent the fluid from dripping onto the wafer surface.

[0021] The aforementioned liquid supply assembly is used to release fluid to the wafer surface during the wafer cleaning process. After the wafer cleaning is completed, the fluid supply to the first channel is stopped, and airflow is introduced into the second channel to create a negative pressure at the back suction structure. This draws the residual fluid at the outlet of the first channel back into the second channel, thereby achieving the back suction and discharge of the residual fluid in the liquid supply nozzle and preventing fluid dripping from affecting the cleaning quality of the wafer.

[0022] A third aspect of this application provides a wafer processing method, which cleans a wafer using a wafer processing apparatus, including: The carrier disk is controlled to rotate the wafer, and the liquid supply nozzle is controlled to release fluid onto the wafer to clean it. When wafer processing is complete, control stops supplying fluid to the first channel and controls the input of gas into the second channel to create a negative pressure at the back suction structure to draw back the fluid at the outlet of the branch channel, thus preventing fluid from dripping onto the wafer surface and contaminating the wafer.

[0023] The beneficial effects of this application embodiment are as follows: when the wafer processing is completed, the fluid supply to the first channel is stopped, and the airflow is input into the second channel. The airflow forms a stable negative pressure environment at the back suction gap of the back suction structure, thereby drawing the fluid remaining at the outlet of the first channel back into the second channel through the back suction structure, realizing the back suction and export of the residual fluid in the liquid supply nozzle, and avoiding fluid dripping that affects the wafer cleaning quality. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a partial front cross-sectional view of a wafer processing apparatus provided in an embodiment of this application; Figure 2 For this application Figure 1 Enlarged cross-sectional view of AA; Figure 3 For this application Figure 1 A magnified cross-sectional view of the middle section of BB; Figure 4 For this application Figure 1 A partially enlarged structural diagram of section I; Figure 5 For this application Figure 1 A schematic diagram of the isometric structure of the liquid supply assembly.

[0026] Figure label: 1. Swing arm; 11. Liquid delivery pipe; 12. Air delivery pipe; 13. Discharge pipe; 131. First pipe section; 132. Second pipe section; 2. Liquid supply nozzle; 21. Upper spray body; 22. Lower spray body; 3. Back suction bend; 31. Lower bend section; 32. Extension section; 33. Upper bend section; 4. First channel; 411. First branch; 412. Second branch; 42. Liquid inlet channel; 43. Liquid outlet channel; 44. Connecting channel; 45. Sealing component; 5. Second channel; 51. Back suction structure; 52. Air delivery necking head; 521. Necking channel; 522. Extension cone; 53. Air receiving necking head; 531. Receiving channel; 532. Conical groove; 54. Back suction gap; 6. Discharge necking component; 7. Sealing connection component. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments in the specific implementation of this application should fall within the protection scope of the embodiments of this application.

[0028] To keep the drawings concise, each drawing only schematically shows the parts relevant to the disclosure; these do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one," and "several" includes "two" and "more than two."

[0029] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through other features between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] It should be understood that, unless the context clearly states otherwise, the terms "comprising," "including," or "having" as used herein refer to the presence of an element, but do not exclude the presence or addition of one or more other elements. Furthermore, "comprising" and / or "including" as used herein specify the presence of shapes, numbers, steps, operations, members, elements, and / or combinations thereof, and do not exclude the presence or addition of one or more other shapes, numbers, operations, elements, and / or combinations thereof. Some embodiments of this application are described in detail below with reference to the accompanying drawings. Where there is no conflict between the embodiments, the following embodiments and features can be combined with each other. The steps in the following method embodiments are for illustrative purposes only and are not intended to limit this application.

[0034] With the rapid development of chip technology, wafer cleaning has become a crucial step in wafer fabrication. After chemical mechanical polishing (CMP), abrasive particles and chemical reagents remain on the wafer surface. Therefore, a liquid supply assembly is needed to release fluid onto the wafer surface to clean and remove these impurities, thereby ensuring wafer quality. The liquid supply assembly can be mounted on a swing arm 1, which moves the assembly to release fluid to different locations on the wafer surface. After cleaning, the liquid supply assembly stops releasing fluid and is moved away from the top of the wafer by the swing arm 1.

[0035] The existing liquid supply structure has significant technical defects. First, when the swing arm 1 moves the liquid supply structure, residual fluid within the structure is prone to dripping due to the swinging and shaking of the swing arm 1. This dripping fluid can contaminate the cleaned wafers, affecting the wafer cleaning quality. Second, some equipment introduces components such as back suction valves to address the dripping problem, but these components suffer from unstable back suction and small back suction volume, still resulting in occasional dripping and failing to completely eliminate the contamination risk. Furthermore, each back suction valve costs over 20,000 RMB, requiring multiple valves in a single machine, significantly increasing the overall manufacturing cost. Additionally, existing back suction valves are bulky and difficult to integrate into the limited space of the swing arm 1, increasing manufacturing costs and installation space requirements, hindering miniaturization and mass production applications.

[0036] Based on the above technical problems, a wafer processing device is needed to specifically solve the problems of residual fluid dripping and unstable backflow during wafer processing. The structure, principle and working process of the liquid supply component are described in detail below.

[0037] Please see Figures 1 to 5 In a first aspect, this application provides a wafer processing apparatus, including a carrier disk for rotating a wafer, a swing arm 1 oscillating above the carrier disk, and a liquid supply assembly disposed at the swing end of the swing arm 1. The liquid supply assembly includes a liquid supply nozzle 2, which has a first channel 4 and a second channel 5. The first channel 4 is used to transport fluid, and the second channel 5 is used to transport gas. The first channel 4 includes at least two branch channels, the input ends of each branch channel are connected in parallel, and the output ends of each branch channel serve as the outlet ends of the first channel 4, realizing synchronous fluid transport. The second channel 5 is provided with a back suction structure 51. When wafer processing is completed and fluid transport is stopped, that is, when wafer cleaning is completed, gas is input into the second channel 5. The airflow forms a negative pressure at the back suction structure 51. Since the back suction structure 51 is connected to the outlet ends of each branch channel, the negative pressure acts on the outlet ends of each branch channel, forming an effective back suction of residual fluid in the branch channel. The back suction structure 51 effectively blocks the fluid dripping path, structurally solving the problems of residual fluid dripping and unstable back suction in the prior art. During this process, the swing arm 1 drives the liquid supply component to swing outward above the wafer, and the swing action is performed after the back suction is completed, which effectively prevents residual fluid from dripping onto the cleaned wafer surface during the swing process.

[0038] It should be noted that you should refer to [link / reference]. Figure 1In the diagram, solid arrows indicate the flow direction of the fluid, while hollow arrows indicate the flow direction of the gas, as well as the flow direction of the gas and the recirculated fluid. Furthermore, wafer cleaning primarily removes contaminants such as particles, organic residues, metallic impurities, and oxide layers adhering to the wafer surface through physical scouring, chemical dissolution, surface tension regulation, and gas-liquid two-phase disturbance. The fluids used include, but are not limited to, deionized water, isopropanol, ethanol, acetone, organic solvents, and gas-liquid mixtures, and are flexibly selected according to the requirements of the wafer cleaning process.

[0039] Specifically, the first channel 4 employs at least two parallel and interconnected branch channels to synchronously transport fluid. The inlet and outlet ends of each branch channel are connected, and the outlet ends are all connected to the back-suction structure 51. This ensures that the negative pressure generated by the second channel 5 is evenly applied to the outlet end of each branch channel, guaranteeing that residual fluid at the outlet ends of all branch channels can be effectively back-suctioned. This prevents residual fluid from dripping onto the wafer surface due to failure to back-suction in a single branch channel, completely resolving the problems of unstable back-suction and accidental droplet dripping in existing back-suction elements. Based on the above structure, multiple branch channels can merge at their inlet ends and outlet ends. In this case, the back-suction structure 51 is used to back-suction the residual fluid at the outlet ends of multiple branch channels and within the merging area of ​​the outlet ends.

[0040] The back-suction structure 51 on the second channel 5 creates negative pressure based on Bernoulli's principle through a constriction structure. After the fluid in the first channel 4 stops flowing, negative pressure is generated by inputting airflow into the second channel 5 to achieve the back-suction of residual fluid. No additional drive components are needed; the back-suction structure 51 alone can collect the residual fluid, simplifying the overall structure of the liquid supply assembly, reducing its size, and helping to lower its manufacturing cost. For example, if a single machine requires more than 15 back-suction valves, compared to the existing cost of over 20,000 yuan per valve, using the liquid supply assembly in this embodiment can reduce the equipment cost of a single machine by approximately 300,000 yuan, effectively lowering the equipment's manufacturing cost.

[0041] During wafer processing, the swing arm 1 moves the liquid supply assembly above the wafer and can move radially along the wafer while it rotates, preventing fluid from being concentrated at the wafer center and causing inconsistent cleaning effects between the wafer center and edges. Furthermore, the moving liquid supply nozzle 2, in conjunction with the rotating wafer, generates more complex hydrodynamic effects, helping to more effectively flush away impurity particles adhering to different radii on the wafer surface.

[0042] In existing technologies, equipment using traditional back-suction valves has an effective back-suction length of only 4–10 mm for fluid to be drawn back into the discharge pipe 13. After wafer processing, there is a 10% probability of fluid sticking to the wall and dripping. However, by using the liquid supply assembly of this application, the effective back-suction length in the discharge pipe 13 can be increased to 60–90 mm, improving the back-suction efficiency by 6–9 times. Furthermore, there is no wall sticking or dripping within the liquid outlet channel 43.

[0043] In one possible implementation, please refer to Figure 2 The branch channel inlet is connected to a liquid inlet channel 42, which is connected to an external liquid delivery pipe 11, delivering fluid from the liquid delivery pipe 11 to multiple branch channels. The branch channel outlet is connected to a liquid outlet channel 43, through which fluid from the multiple branch channels is released to the wafer surface. The second channel 5 is located in the area between the liquid inlet channel 42 and the liquid outlet channel 43. The back suction structure 51 is connected to the liquid outlet channel 43 but not to the liquid inlet channel 42. The back suction structure 51 can draw back the residual fluid in the liquid outlet channel 43 under negative pressure after the gas is input.

[0044] In this embodiment, the cleaning fluid delivered by the liquid delivery pipe 11 is diverted through the liquid inlet channel 42 into multiple parallel branch channels. The parallel structure of the branch channels enables synchronous fluid delivery. Correspondingly, the outlet end of each branch channel is connected to an outlet channel 43. The fluid delivered by each branch channel is collected in the outlet channel 43 and then uniformly released onto the wafer surface through the outlet channel 43. This adapts to the liquid supply requirements when the swing arm 1 rotates to the center position of the wafer, ensuring that the fluid is released onto the wafer surface in an orderly manner. The liquid inlet channel 42 and the outlet channel 43 can be directly formed on the liquid supply nozzle 2, or they can be formed by the liquid supply nozzle 2 and the external pipeline.

[0045] In the vertical direction, the second channel 5 is located below the inlet channel 42 and above the outlet channel 43, intersecting with both the inlet and outlet channels 42. This facilitates efficient use of the internal space of the supply nozzle 2 and adapts to the miniaturized design requirements of the swing arm 1. Two or three branch channels can be configured, with multiple branch channels scattering from the inlet channel 42 and then converging again at the outlet channel 43. The second channel 5 passes between any adjacent branch channels among multiple branch channels, and connects the back suction structure 51 with the liquid outlet channel 43. This ensures that the airflow in the second channel 5 can only act on the liquid outlet channel 43 through the back suction structure 51, keeping the back suction structure 51 and the liquid inlet channel 42 disconnected. This ensures that the back suction structure 51 acts precisely on the fluid in the liquid outlet channel 43, guaranteeing the back suction effect on the fluid without interfering with the fluid not being transported in the liquid inlet channel 42. This ensures the targetedness and stability of the back suction, eliminates the problem of accidental dripping caused by unstable back suction, and avoids the impact of the back suction process on subsequent liquid supply operations.

[0046] As a specific example, please refer to Figure 2 There are two branch channels: a first branch 411 and a second branch 412. The inlets of the first branch 411 and the second branch 412 are connected to the liquid inlet channel 42, and their outlets are connected to the liquid outlet channel 43. The back suction structure 51 is located between the first branch 411 and the second branch 412. The fluid in the external liquid delivery pipe 11 enters through the liquid inlet channel 42 and flows into the first branch 411 and the second branch 412. The first branch 411 and the second branch 412 simultaneously deliver the fluid to the liquid outlet channel 43, and the fluid is then released onto the wafer surface through the liquid outlet channel 43 to achieve the wafer cleaning operation.

[0047] It should be noted that, for ease of manufacturing, the liquid supply nozzle 2 can be manufactured in two parts, including an upper spray body 21 and a lower spray body 22 connected below the upper spray body 21. A sealing groove and a sealing ring are provided between the two to ensure the sealing of the fluid flow. The upper spray body 21 and the lower spray body 22 are connected by connectors or adhesive to form the first branch 411 and the second branch 412. At the same time, the paths of the first branch 411 and the second branch 412 are both formed into a V-shape, and the two V-shapes are arranged opposite each other. For ease of manufacturing, the upper half of the first branch 411 and the second branch 412 extends outward and downward while penetrating the peripheral wall of the liquid supply nozzle 2, and is sealed by a sealing block. The lower half of the first branch 411 and the second branch 412 converges inward and downward to ensure that the fluid can flow along the V-shaped path of the first branch 411 and the second branch 412 into the liquid outlet channel 43.

[0048] The arrangement of the first branch 411 and the second branch 412 allows negative pressure to act simultaneously and evenly on the outlet areas of both branches, resulting in a faster back-suction response and a more balanced back-suction coverage. This avoids situations where residual fluid cannot be back-suctioned in certain areas, further improving back-suction stability. The symmetrical arrangement of the first branch 411 and the second branch 412 ensures consistent flow resistance during fluid diversion and transportation, resulting in smoother fluid delivery. This avoids supply fluctuations caused by uneven branch numbers or asymmetrical arrangements, improving the stability of the supply and the uniformity of the output during the cleaning process.

[0049] Furthermore, the inlet channel 42 and the outlet channel 43 are arranged vertically correspondingly, and are connected by a connecting channel 44. This arrangement facilitates the one-time machining of the inlet channel 42 and the outlet channel 43, reducing machining difficulty and manufacturing costs. At this time, the back suction structure 51 and the connecting channel 44 are arranged in a cross configuration, interconnected. The sealing element 45 within the connecting channel 44 is located above the back suction structure 51, effectively separating the inlet channel 42 and the outlet channel 43. This allows the fluid in the inlet channel 42 to bypass the connecting channel 44 and instead flow through the branch channel. The negative pressure of the back suction structure 51 acts only on the fluid in the outlet channel 43, not on the fluid in the inlet channel 42. In addition, the back suction structure 51 can also act on a small portion of the fluid at the outlet of the branch channel, achieving a good back suction effect.

[0050] However, it should be noted that the back suction effect of the back suction structure 51 should be set within a reasonable range. If the back suction effect is insufficient, droplets that have not been completely back suctioned will remain at the outlet end of the liquid outlet channel 43. These droplets will crystallize due to capillary action. If these crystals fall onto the wafer surface, they will scratch the wafer. In addition, if the back suction is too strong, it will easily disperse the droplets, resulting in droplets remaining at the outlet end of the liquid outlet channel 43. These residual droplets will also crystallize due to capillary action, thus scratching the wafer.

[0051] Therefore, the inner diameter and length of the liquid outlet channel 43 need to be limited to ensure that no residual droplets remain during negative pressure back suction and to prevent crystallization from scratching the wafer. The liquid outlet channel 43 is set vertically or nearly vertically, and its effective length is the length between the back suction structure 51 and the outlet end of the liquid outlet channel 43. This length value L is limited to 3mm≤L≤50mm. When the effective length of the liquid outlet channel 43 is greater than 50mm, the negative pressure back suction force decreases with the increase of length, and the droplets at the outlet end cannot be effectively back suctioned, easily forming crystals due to capillary effect; when the length is less than 3mm, the connection between the liquid outlet channel 43 and the outlet end of the liquid supply nozzle 2 is too short, which easily causes the fluid to spray and scatter during cleaning, making it impossible to form a stable liquid flow to cover the wafer surface, affecting the uniformity of cleaning. If the liquid outlet channel 43 is a non-vertical micro-bend structure, its equivalent straight length must meet the above-mentioned requirements. The equivalent straight length refers to the straight distance between the back suction structure 51 and the outlet end of the micro-bend structure. At the same time, the radius of curvature of the bend section is not less than 5 times the inner diameter of the liquid outlet channel 43 to avoid the formation of fluid stagnation dead angles at the bend.

[0052] Meanwhile, the inner diameter of the outlet channel 43 is limited to 0.2mm ≤ D ≤ 4mm. These parameters match the standard fluid flow rate for wafer cleaning, ensuring sufficient flushing force during cleaning while allowing for more efficient interaction between the airflow and fluid during negative pressure backflow, achieving effective fluid backflow. When the inner diameter of the outlet channel 43 is less than 0.2mm, it does not meet the requirements for the passage of trace particles in the cleaning fluid. Furthermore, due to capillary effect, the fluid is easily adsorbed onto the inner wall of the outlet channel 43, forming a residual liquid film. After drying, this film crystallizes, and subsequent crystal shedding can easily scratch the wafer surface. When the inner diameter of the outlet channel 43 is greater than 4mm, the Bernoulli negative pressure cannot evenly cover the interior of the outlet channel 43, easily forming liquid columns in dead corners. When the swing arm 1 swings, dripping can easily occur, contaminating the cleaned wafer. At the same time, the inner diameter of the liquid outlet channel 43 needs to match the inner diameter of the upstream branch channel. The inner diameter of the branch channel should be 0.2mm to 0.5mm smaller than the inner diameter of the liquid outlet channel 43, so that there is no turbulent dead zone when the fluid flows into the liquid outlet channel 43, and further reduces fluid residue.

[0053] Based on this, the length L of the outlet channel 43 and its inner diameter D must satisfy the ratio L / D ≤ ​​10, meaning the channel length cannot exceed 10 times its inner diameter. This ratio takes into account the synergistic effect of back suction, capillary effect, and process liquid supply. The length and inner diameter of the outlet channel 43 are determined by taking the intersection of L and D through the above three constraints. As a specific example, if the inner diameter D is 2mm and the length is 14mm, the L / D ratio is 7, which is within the optimal matching range for negative pressure back suction and capillary effect avoidance, and can adapt to the actual process scenario of wafer cleaning.

[0054] Preferably, the inner wall of the liquid outlet channel 43 is polished to reduce the adsorption force between the fluid and the inner wall, and further avoid capillary residue; at the same time, the outlet end of the liquid outlet channel 43 is chamfered to avoid liquid dripping at the edge of the outlet end and prevent sharp edges from scratching the wafer.

[0055] In one possible implementation, please refer to Figure 1 , Figure 3 and Figure 4The back-suction structure 51 includes an air-supplying constrictor 52 and an air-receiving constrictor 53 disposed on the second channel 5. The air-supplying constrictor 52 is connected to the air inlet end of the second channel 5 and has a constriction channel 521 for gas to pass through and gather. The air-receiving constrictor 53 is connected to the air outlet end of the second channel 5. A back-suction gap 54 is formed between the air-receiving constrictor 53 and the air-supplying constrictor 52. The back-suction gap 54 is connected to the outlet end of the branch channel. The air-receiving constrictor 53 has a receiving channel 531 for receiving the gas delivered by the air-supplying constrictor 52 and the fluid back-suctioned by the back-suction structure 51. When the air-supplying constrictor 52 delivers gas to the air-receiving constrictor 53, the back-suction gap 54 can form a negative pressure to back-suction the fluid at the outlet end of the first channel 4 and discharge the fluid through the air-receiving constrictor 53 and the second channel 5.

[0056] Based on this, the opening at the end of the air supply pipe 12 connected to the liquid supply nozzle 2 gradually expands, increasing the flow cross-section of the airflow entering the air supply constriction head 52. Until the airflow enters the middle and rear part of the air supply constriction head 52, the flow area suddenly decreases, increasing the change range of the flow cross-section of the back suction structure 51, thereby improving the back suction capacity of the back suction structure 51.

[0057] When the gas is delivered to the second channel 5, the gas flows through the constriction channel 521 of the gas delivery constriction head 52, gathers and accelerates in the constriction channel 521, forming a high-speed airflow. After the high-speed airflow flows out of the constriction channel 521, it enters the back suction gap 54 between the gas delivery constriction head 52 and the gas receiving constriction head 53, and then flows into the receiving channel 531 of the gas receiving constriction head 53, and finally is discharged through the gas outlet end of the second channel 5. During this process, based on Bernoulli's principle, the high-speed airflow creates a low-pressure region within the back suction gap 54, while the fluid remaining at the branch channel outlet and in the liquid outlet channel 43 is in a relatively static state with an internal pressure of atmospheric pressure. This creates a stable pressure difference with the low-pressure region within the back suction gap 54. Under the influence of this pressure difference, the fluid remaining at the branch channel outlet and in the liquid outlet channel 43 is drawn into the back suction gap 54 by negative pressure and enters the receiving channel 531 of the air receiving constriction head 53 along with the high-speed airflow. It is then discharged through the air outlet of the second channel 5, achieving complete back suction of the residual fluid and preventing fluid from dripping during the swing of the swing arm 1.

[0058] The constriction channel 521 can precisely increase the airflow velocity, ensuring that the negative pressure intensity meets the back-suction requirements of residual fluid, avoiding problems such as insufficient negative pressure and unstable back-suction due to insufficient airflow velocity, and completely solving the shortcomings of unstable back-suction and accidental dripping of liquid droplets in existing back-suction devices. The receiving channel 531 of the air-receiving constriction head 53 can accurately receive the high-speed airflow delivered by the air-supplying constriction head 52, guide the airflow smoothly through the back-suction gap 54 and discharge it, avoid airflow turbulence causing uneven negative pressure distribution in the back-suction gap 54, and further improve back-suction stability.

[0059] Meanwhile, the air supply neck head 52 and the air receiving neck head 53 are both integrated on the second channel 5, without increasing the overall volume of the liquid supply component. This adapts to the miniaturization design requirements of the swing arm 1, solves the problem of the large volume ratio of the existing back suction device, and makes it easier to further control equipment costs compared to the existing expensive back suction device.

[0060] It should be noted that the outlet of the second channel 5 contains not only gas but also fluid drawn back from the liquid outlet channel 43. After being drawn back, the fluid is discharged through the air inlet neck 53 and the second channel 5 with the airflow. It will not remain in the back suction structure 51 or the second channel 5, thus avoiding the accumulation of residual fluid that may affect the subsequent back suction effect and ensuring the continuous working stability of the liquid supply component.

[0061] In one embodiment, please refer to Figure 3 The air-feeding constrictor head 52 has an extension cone 522 that extends toward the air-receiving constrictor head 53. The air-receiving constrictor head 53 has a conical groove 532 into which the extension cone 522 extends. A constriction channel 521 is provided on the extension cone 522, and its inner diameter decreases from large to small along the airflow direction to increase the airflow speed. The receiving channel 531 is provided through the bottom wall of the conical groove 532 and is connected to the rear half of the second channel 5. The second channel 5 is provided with a conical inner hole for dispersing the airflow in the receiving channel 531. A back suction gap 54 is formed between the extension cone 522 and the conical groove 532. The fluid in the liquid outlet channel 43 enters the receiving channel 531 through the back suction gap 54 under negative pressure. Meanwhile, from the center of the back suction structure 51 to the outer periphery of the back suction structure 51, the end face of the air receiving constriction head 53 is gradually inclined away from the air supply constriction head 52, so as to guide the fluid into the back suction gap 54 and allow the fluid to be discharged through the air receiving constriction head 53 and the second channel 5.

[0062] Specifically, the back suction gap 54 is connected to the outlet of the necking channel 521 and the inlet of the receiving channel 531. During the wafer cleaning process, the fluid is released to the wafer surface sequentially through the inlet channel 42, the first branch 411 or the second branch 412, and the outlet channel 43. At this time, the second channel 5 is in a non-gas-supply state, and there is no negative pressure at the back suction gap 54 formed by the extension cone 522 and the conical groove 532, which does not affect the normal transport of the fluid. When the processing is completed and the fluid transport stops, the gas is input through the inlet end of the second channel 5, flows through the necking channel 521 of the extension cone 522, gathers and accelerates to form a high-speed airflow, and smoothly enters the receiving channel 531 of the receiving necking head 53 along the annular back suction gap 54 between the outer wall of the extension cone 522 and the inner wall of the conical groove 532. During this process, based on Bernoulli's principle, the high-speed airflow in the back suction gap 54 creates a uniform and stable low-pressure zone in the area, forming a pressure difference with the atmospheric pressure at the outlet end of the branch channel and the outlet channel 43. Under the action of the pressure difference, the residual fluid in the outlet channel 43 and the outlet end of the branch channel is continuously drawn into the back suction gap 54 and discharged with the high-speed airflow through the receiving channel 531 and the outlet end of the second channel 5.

[0063] It should be noted that the conical surface design of the extension cone 522 and the conical groove 532 makes the back suction gap 54 form a regular annular structure. Compared with irregular gaps, this allows high-speed airflow to flow smoothly along the conical surface, avoiding the generation of eddies or turbulence in the airflow. This ensures the uniformity of negative pressure distribution within the back suction gap 54, structurally eliminating negative pressure dead zones. This allows the residual fluid at the outlets of the first branch 411 and the second branch 412 to be back suctioned synchronously and efficiently, preventing fluid from stagnating and accumulating within the back suction gap 54. This ensures the cleanliness of the back suction structure 51 and prevents stagnant fluid from affecting the subsequent airflow velocity and negative pressure formation, thus completely solving the problem of accidental droplet dripping caused by unstable back suction.

[0064] Meanwhile, the structure of the extension cone 522 extending into the conical groove 532 enables the fitting assembly of the air supply neck head 52 and the air receiving neck head 53. This eliminates the need for additional positioning components, ensuring their coaxiality and guaranteeing a continuous and smooth airflow path between the necking channel 521, the back suction gap 54, and the receiving channel 531. This improves airflow transmission efficiency and further enhances the stability of the negative pressure. Furthermore, the design of the necking channel 521 being located on the extension cone 522 and the receiving channel 531 penetrating the bottom wall of the conical groove 532 integrates the core functional area of ​​the back suction structure 51 into the conical mating area, significantly reducing the space occupied by the back suction structure 51 and meeting the miniaturization design requirements. The conical mating structure is easy to process, and the assembly of the air supply neck head 52 and the air receiving neck head 53 is convenient, reducing processing and assembly costs.

[0065] In one embodiment, the minimum inner diameter of the constriction channel 521 and the aperture of the receiving channel 531 are both X, 0.2mm ≤ X ≤ 3mm, to increase the speed of airflow and create negative pressure within the back suction gap 54. After the gas enters the constriction channel 521 through the second channel 5, the size of the constriction channel 521 is smaller than the aperture of the second channel 5, allowing the gas to accumulate and increase in speed. The high-speed airflow enters the annular back suction gap 54 and then smoothly exits through the receiving channel 531 of the same size. The aforementioned size range balances airflow resistance and speed increase, ensuring the formation of a stable negative pressure, avoiding blockage problems caused by excessively small sizes, and avoiding unstable back suction performance caused by excessively large sizes. This also prevents droplets from crystallizing at the outlet end of the liquid outlet channel 43 due to capillary effect.

[0066] The minimum inner diameter of the necking channel 521 matches the aperture of the receiving channel 531, ensuring smooth airflow, preventing airflow turbulence, ensuring uniform negative pressure, and improving the back suction effect and wafer cleaning consistency. Based on this, the width of the back suction gap 54 of the back suction structure 51 is set to 0.1–0.5 mm. This range matches the minimum inner diameter of the necking channel 521 and the aperture of the receiving channel 531 (0.2–3 mm), ensuring no negative pressure attenuation and allowing it to act directly and efficiently inside the liquid outlet channel 43.

[0067] In one possible implementation, the liquid supply assembly's liquid delivery pipe 11 is connected to the inlet end of the branch channel for supplying fluid to the branch channel, and a liquid delivery valve is provided on the liquid delivery pipe 11; the gas delivery pipe 12 is connected to the gas inlet end of the second channel 5 for supplying gas to the second channel 5, and a gas delivery valve is provided on the gas delivery pipe 12; the discharge pipe 13 is connected to the gas outlet end of the second channel 5 for discharging gas and re-suctioning fluid, and a discharge valve is provided on the discharge pipe 13; when the wafer processing is completed, the liquid delivery valve is closed, and the gas delivery valve and the discharge valve are opened to create a negative pressure at the re-suction structure 51 to re-suction the fluid at the outlet end of the first channel 4, and to discharge the fluid through the discharge pipe 13.

[0068] By coordinating the liquid delivery valve, the discharge valve, and the gas delivery valve, the on / off control of gas and fluid is achieved. Closing the liquid delivery valve blocks fluid delivery, while simultaneously opening the gas delivery valve and the discharge valve, allowing the gas delivery pipe 12 to stably deliver gas to the second channel 5, and the discharge pipe 13 to smoothly discharge gas and the re-absorbed fluid. This ensures that the re-absorption structure 51 can quickly and stably form a negative pressure, achieving precise re-absorption and discharge of residual fluid at the outlet of the first channel 4, significantly improving the controllability and stability of the re-absorption process.

[0069] In one embodiment, the discharge pipe 13 is further provided with a drain constriction member 6 located inside the discharge pipe 13. The drain constriction member 6 has a constriction hole, which is used to reduce the flow cross-sectional area of ​​the fluid. When the back-suction fluid and the gas in the second channel 5 flow through the constriction hole, the flow rate is effectively increased, which increases the pressure difference between the discharge pipe 13 and the liquid column in the liquid outlet channel 43, forming a siphon effect. This makes it easier for the residual fluid to be drawn into the discharge pipe 13, which can not only accelerate the discharge of the fluid, but also help maintain the stability of the back-suction negative pressure, forming a synergistic effect. This avoids the problem of slow discharge and easy stagnation and backflow of the back-suction fluid, and can further enhance the reliability of back-suction.

[0070] In one embodiment, the distance between the drain necking member 6 and the outlet end of the discharge pipe 13 is Y, 300mm≤Y≤1200mm, to connect with the back suction structure 51 and achieve fluid discharge. Specifically, it can be set to 300mm, 500mm, 800mm, or 1200mm. This provides sufficient buffer and guiding space for the accelerated fluid, preventing turbulence caused by excessively short distances and high flow rates, preventing fluid stagnation or backflow into the second channel 5, and ensuring stable discharge of fluid along the discharge pipe 13. If Y is less than 300mm, the buffer space is insufficient, and the fluid is prone to turbulence and stagnation, affecting discharge efficiency and potentially weakening negative pressure stability. If Y is greater than 1200mm, the pipeline is too long, increasing fluid flow resistance, reducing discharge efficiency, and potentially causing fluid stagnation within the pipeline. Simultaneously, this distance allows the drain necking member 6 and the back suction structure 51 to work synergistically. The guiding effect generated by the accelerated fluid discharge from the necking orifice further helps maintain the negative pressure stability of the back suction structure 51 and enhances the back suction effect.

[0071] In one possible implementation, the discharge pipe 13 includes a first pipe section 131 and a second pipe section 132 connected by a sealing connector 7. A drain necking member 6 is located at the outlet end of the first pipe section 131 and is disposed adjacent to the sealing connector 7. To facilitate the arrangement of the pipeline on the swing arm 1, the discharge pipe 13 adopts a structure combining the first pipe section 131 and the second pipe section 132, which facilitates the installation and arrangement of the drain necking member 6. The sealing connector 7 is a threaded sealing joint or a welded seal, ensuring the sealing of the connection between the first pipe section 131 and the second pipe section 132.

[0072] For further details, please refer to Figure 1 and Figure 5To reduce the complexity of pipeline layout, a liquid delivery pipe 11 and a discharge pipe 13 located on the side of the liquid delivery pipe 11 away from the liquid supply nozzle 2 can be installed on the same pipeline. A pipe connected to the liquid delivery pipe 11 is installed above the middle of this pipeline. The discharge pipe 13 includes the part installed on the above-mentioned pipeline and the part connected to the liquid supply nozzle 2. A partition can be installed between the discharge pipe 13 and the liquid delivery pipe 11, or it can be omitted. Since the gas or fluid delivery time is different for the two, there will be no problem of cross-contamination between the pipes.

[0073] In one possible implementation, the outlet end of the discharge pipe 13 is further provided with a backflow bend 3. The backflow bend 3 is bent downwards to buffer the fluid backflowed in the discharge pipe 13 and prevent the fluid from flowing back and dripping. The backflow bend 3 includes a lower bend section 31, an extension section 32, and an upper bend section 33 connected in sequence. The upper bend section 33 and the lower bend section 31 both extend vertically, while the extension section 32 extends horizontally. The extension section 32 is used to receive the fluid from the lower bend section 31 and buffer the residual fluid backflowed.

[0074] The recirculated gas-liquid mixture flows into the recirculation bend 3 through the discharge pipe 13, first flowing downwards through the lower bend section 31, then entering the horizontal extension section 32 for buffering, and finally exiting through the upper bend section 33. The downward bend and the buffering effect of the extension section 32 effectively prevent backflow caused by airflow fluctuations or pipeline vibrations, creating a liquid seal within the extension section 32. The gravity of the liquid column then blocks gas backflow, preventing the backflowing fluid from dripping onto the processed wafer surface. This structural bend achieves fluid backflow prevention, simplifying the structure and reducing costs.

[0075] In one embodiment, the distance between the back suction bend 3 and the outlet end of the discharge pipe 13 is n, where n ≤ 400 mm, to shorten the discharge path of the back suction fluid. The gas-liquid mixture back suctioned by the back suction structure 51, after being transported to the outlet end through the discharge pipe 13, can quickly enter the back suction bend 3 with a distance not exceeding 400 mm, so as to significantly shorten the fluid discharge path, reduce the residence time of the fluid in the pipeline, reduce the flow resistance, and ensure that the back suction fluid quickly enters the back suction bend 3 for buffering and discharge, avoiding fluid accumulation and retention due to an excessively long path.

[0076] In some embodiments, the wafer fabrication apparatus further includes a controller, specifically used to control the execution of the following steps: When the rotational speed of the carrier disk is greater than or equal to the first speed, fluid is supplied to the first channel 4 and released to the wafer surface. At this time, there is no gas input and gas-liquid discharge in the second channel 5. When the wafer processing is completed, the fluid supply to the first channel 4 is stopped, and at the same time, airflow is input into the second channel 5 to draw back the fluid remaining in the first channel 4 under negative pressure. After the wafer processing is completed and the airflow into the second channel 5 reaches the preset time, the airflow into the second channel 5 is stopped. At this time, no gas or liquid is discharged from the second channel 5. The swing arm 1 is controlled to swing to the outside of the wafer, and the rotation of the carrier plate is stopped.

[0077] The controller is electrically connected to the liquid supply valve, the air supply valve, and the discharge valve to achieve on / off control. In the above process, the first step is to trigger the liquid supply process by starting the carrier plate to rotate. When the rotation speed of the carrier plate reaches the first speed, which can be 300 rpm or 400 rpm, the liquid supply valve is opened to deliver fluid to the first channel 4. The fluid is released to the wafer surface after converging through at least two parallel branch channels. At this time, the air supply valve and the discharge valve remain closed to avoid airflow interference with the liquid supply.

[0078] The above state continues until the wafer processing is completed, at which point the trigger back suction stage is entered. The controller immediately closes the liquid delivery valve to stop the fluid delivery, and at the same time opens the air delivery valve and the discharge valve to input airflow into the second channel 5, so that the back suction gap 54 of the back suction structure 51 forms a negative pressure to adsorb the fluid remaining at the outlet end of the first channel 4.

[0079] Afterwards, the pressure holding and back suction state is maintained, and the air supply valve and discharge valve are kept open for a preset time so that the residual fluid is completely discharged through the back suction structure 51, the second channel 5, the discharge pipe 13 and the back suction bend 3. After the back suction maintenance time ends, the final shutdown stage begins. The controller controls the closing of the air supply valve and discharge valve, controls the swing arm 1 to swing to the outside of the wafer, and the carrier plate stops rotating.

[0080] Setting the liquid delivery valve to open when the carrier plate reaches the first speed ensures that the centrifugal force generated by the wafer rotation allows the liquid to spread evenly before supplying liquid, avoiding the accumulation of liquid on the wafer surface at low speeds. At the same time, the closed air supply valve and exhaust valve can completely eliminate airflow interference with the supply and spreading of liquid, meeting the liquid supply conditions during wafer processing.

[0081] When controlling the liquid delivery valve and the air delivery valve, the flow rates are not simply set to a fixed value. Instead, the liquid flow rate in the first channel 4 and the air flow rate in the second channel 5 are matched in a ratio of 1:2 to 1:3. For example, the fluid delivery velocity in the first channel 4 is 0.8 to 1.5 m / s, which is suitable for the cleaning requirements of advanced process wafers. The air flow input velocity in the second channel 5 is 2 to 3 m / s. This setting ensures that after the airflow is accelerated by the back suction structure 51, the negative pressure formed in the back suction gap 54 is just enough to overcome the surface tension and viscosity of the liquid flow in the branch channel, achieving efficient adsorption of residual liquid. This solves the problems of insufficient negative pressure leading to incomplete adsorption due to flow rate mismatch, and excessive negative pressure leading to crystallization caused by droplet residue in the first channel 4.

[0082] At the same time, through precise control of airflow velocity, the negative pressure formed by the back suction gap 54 is only applied to the liquid outlet channel 43 and the branch channel outlet end of the first channel 4, and will not be transmitted in reverse to the liquid inlet channel 42. Combined with the structural setting of the sealing component 45, a double constraint is formed to avoid the negative pressure from interfering with the fluid in the liquid inlet channel 42, thus ensuring the back suction function of the back suction structure 51.

[0083] The operation of closing the liquid supply valve and simultaneously opening the gas supply valve and the discharge valve is triggered synchronously when the wafer processing meets the standards. This can eliminate the time difference of step-by-step control and prevent residual liquid in the branch channels from dripping due to gravity during the time difference.

[0084] After the airflow is accelerated by the back suction structure 51, a stable negative pressure is formed in the back suction gap 54, maintaining the negative pressure back suction state of the back suction structure 51. The negative pressure is allowed to continue for a preset time, and the negative pressure only acts on the liquid outlet channel 43 of the first channel 4 and the outlet end of the branch channel, so as to achieve back suction without residue.

[0085] In this embodiment, the preset pressure holding and back suction time is determined collaboratively by the kinematic viscosity of the wafer cleaning fluid, the flow rate of the cleaning fluid in the first channel 4, and the airflow input flow rate in the second channel 5. Specifically, the kinematic viscosity ν is determined according to the type of fluid required for the wafer cleaning process, and is obtained by combining the fluid delivery flow rate v1 and the airflow input flow rate v2 set for the cleaning process using the following formulas: Viscosity correlation formula T 11 =k1×ν+T0 (where, T) 11 : Preset pressure holding and back suction time, in seconds; k1: Viscosity correction factor, in seconds s / mm²; ν: kinematic viscosity of the cleaning fluid, in mm² / s; T0: basic holding time, in seconds). Flow velocity correlation formula T 12 =k2×v1+T1 (where, T) 12 : Preset pressure holding and back suction time, in seconds; k2: Liquid flow rate correction coefficient, in seconds. 2 / m; v1: refers to the fluid transport velocity in the first channel 4, in m / s; T1: refers to the basic pressure holding time of the fluid flow, in seconds (s). Airflow correlation formula T 13 =k3 / v2+T2 (where, T) 13 : Preset pressure holding and back suction time, in seconds; k3: refers to the airflow velocity correction coefficient, in meters; v2: refers to the airflow delivery velocity of the second channel 5, in meters per second; T2: refers to the basic pressure holding time of the airflow, in seconds.

[0086] The basic holding pressure duration T0, liquid flow basic holding pressure duration T1, and airflow basic holding pressure duration T2 are all benchmark parameters pre-calibrated through multiple orthogonal or single-factor experiments, specifically for the flow channel structure, cleaning fluid type, and process conditions of this wafer cleaning system. During calibration, the criteria for determining the wafer surface—no cleaning fluid residue, no water stains, and no chemical residue—were used to determine the minimum holding pressure and backflow times required at standard viscosity, standard liquid flow rate, and standard airflow rate, which are the specific values ​​of T0, T1, and T2. Three theoretical holding pressure durations were calculated using the above three formulas, and the average of these three theoretical values ​​was taken as the final preset holding pressure duration.

[0087] For example, when using SC-1 standard cleaning fluid (kinematic viscosity ν≈12mm² / s) for wafer cleaning, with the process settings of fluid delivery velocity v1=1.5m / s and airflow input velocity v2=2.5m / s, the calculated viscosity-related theoretical value T... 11 =0.06×12+1.6=2.32s, flow velocity related theoretical value T 12 =0.6×1.5+1.3=2.2s, airflow correlation theoretical value T 13 =1.2 / 2.5+0.9=1.38s, take the average value T=(2.32+2.2+1.38) / 3≈1.97s, and finally set the preset pressure holding and back suction time to 2.0s. This time is suitable for the viscosity of the cleaning fluid and the residual amount required by the high liquid flow rate, and also matches the discharge efficiency of the medium air flow rate, so as to achieve residue-free back suction of cleaning fluid residue, avoid the formation of water stains or chemical residues on the wafer surface, and improve the wafer cleaning yield.

[0088] First, the air supply valve and the exhaust valve are closed. Then, the swing arm 1 is controlled to swing to the outside of the wafer. Finally, the carrier plate is controlled to stop rotating. The above timing arrangement avoids the airflow disturbance caused by the swing arm 1 swinging and the inertial force of the carrier plate decelerating, which would cause the residual liquid to drip again after back suction. It not only achieves the simple back suction function, but also achieves anti-drip through full-process timing control, ensuring the effective coordination of the action timing.

[0089] A second aspect of the embodiments of this application provides a liquid supply assembly for being disposed at the swing end of a swing arm, the liquid supply assembly including a liquid supply nozzle for discharging fluid onto a wafer; The liquid supply nozzle has a first channel 4 for conveying fluid and a second channel 5 for conveying gas; The first channel 4 includes at least two branch channels that are connected in parallel to each other to transport fluid synchronously; The second channel 5 has a back suction structure 51, which is connected to the outlet end of the branch channel. When the wafer processing is completed and the fluid delivery stops, the second channel 5 can use the negative pressure of the back suction structure 51 to back suction the fluid remaining at the outlet of the first channel 4 under the action of the input airflow, so as to prevent the fluid from dripping onto the wafer surface.

[0090] The above-mentioned liquid supply component is used to release fluid to the wafer surface during the wafer cleaning process. After the wafer cleaning is completed, the fluid supply to the first channel 4 is stopped, and airflow is introduced into the second channel 5 to create a negative pressure at the back suction structure 51, which draws back the fluid remaining at the outlet of the first channel 4 into the second channel 5, thereby realizing the back suction and discharge of the residual fluid in the liquid supply nozzle and preventing fluid dripping from affecting the cleaning quality of the wafer.

[0091] A third aspect of this application provides a wafer processing method, which cleans a wafer using a wafer processing apparatus, including: The carrier disk is controlled to rotate the wafer, and the liquid supply nozzle 2 is controlled to release fluid onto the wafer to clean it; When wafer processing is complete, control stops supplying fluid to the first channel 4 and controls the input of gas into the second channel 5 to create a negative pressure at the back suction structure 51 to back suction the fluid at the outlet of the branch channel, thus preventing fluid from dripping onto the wafer surface and contaminating the wafer.

[0092] When gas is introduced into the second channel 5, a negative pressure is formed at the back suction structure 51 based on Bernoulli's principle. This negative pressure acts directly on the outlet end of the branch channel or the liquid outlet channel 43, promptly drawing back the residual fluid. This prevents the swing arm 1 from dripping onto the already processed wafer surface due to gravity and shaking during its movement out of the process area, thus avoiding wafer contamination caused by fluid dripping. More importantly, it also avoids the problem of droplet dispersion and crystallization due to excessive negative pressure or residual droplet crystallization due to insufficient negative pressure. This prevents crystallized material from scratching the wafer surface or clogging the back suction structure 51, ensuring the wafer cleaning quality and reducing the equipment manufacturing cost.

[0093] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A liquid supply assembly, for use at the swing end of a swing arm, characterized in that, The liquid supply assembly includes a liquid supply nozzle for discharging fluid onto the wafer; The liquid supply nozzle has a first channel for conveying fluid and a second channel for conveying gas; The first channel includes at least two branch channels that are connected in parallel to transport fluid synchronously, and the multiple branch channels are separated in a scattering manner and then converge again; The second channel has a back suction structure, which is connected to the outlet end of the branch channel. The second channel passes through any adjacent branch channel among the plurality of branch channels. When wafer processing is completed and fluid delivery stops, the second channel can draw back the fluid remaining at the outlet of the first channel through the negative pressure of the back-suction structure under the action of the input airflow, so as to prevent the fluid from dripping onto the wafer surface.

2. The liquid supply assembly as described in claim 1, characterized in that, The first channel further includes an inlet channel that is connected to the inlet end of the branch channel and an outlet channel that is connected to the outlet end of the branch channel. The back suction structure is connected to the outlet channel, so that the airflow of the second channel can only act on the outlet channel through the back suction structure, ensuring the stability of the back suction and avoiding interference with the fluid in the inlet channel.

3. The liquid supply assembly as described in claim 2, characterized in that, The number of branch channels is two, namely the first branch and the second branch. The inlet ends of the first branch and the second branch are respectively connected to the liquid inlet channel, and the outlet ends of the first branch and the second branch are respectively connected to the liquid outlet channel. The back suction structure is located between the first branch and the second branch. The paths of the first branch and the second branch are both formed into V-shaped structures, and the V-shaped structures of the two are arranged opposite to each other.

4. The liquid supply assembly as described in claim 3, characterized in that, The back-suction structure includes an air-supplying constriction head and an air-receiving constriction head integrated on the second channel. The air-supplying constriction head has a constriction channel, and the air-receiving constriction head has a receiving channel. A back-suction gap is formed between the air-receiving constriction head and the air-supplying constriction head. The minimum inner diameter of the constriction channel and the aperture of the receiving channel are both X, where 0.2mm≤X≤3mm.

5. The liquid supply assembly as described in claim 4, characterized in that, The air supply necking head has an extension cone extending toward the air receiving necking head. The air receiving necking head has a conical groove into which the extension cone extends. The necking channel is disposed on the extension cone. The receiving channel is disposed through the bottom wall of the conical groove. The design of the extension cone and the conical surface of the conical groove makes the back suction gap form a regular annular structure.

6. The liquid supply assembly as described in claim 2, characterized in that, The length between the back suction structure and the outlet end of the liquid outlet channel is L, 3mm≤L≤50mm, so as to form a stable liquid flow to cover the wafer surface and prevent the fluid from crystallizing.

7. The liquid supply assembly as described in any one of claims 1 to 6, characterized in that, It also includes a liquid delivery pipe, an air delivery pipe, and a discharge pipe connected to the liquid supply nozzle. The discharge pipe is also provided with a discharge necking component. The discharge necking component has a necking hole, which is used to reduce the flow cross-sectional area of ​​the fluid to cooperate with the negative pressure back suction effect of the back suction structure to accelerate the discharge of the fluid.

8. The liquid supply assembly as described in claim 7, characterized in that, The outlet end of the discharge pipe is also provided with a back suction bend, which is bent downwards. The distance between the back suction bend and the outlet end of the discharge pipe is n, where n≤400mm.

9. A wafer processing apparatus, characterized in that, The device includes a carrier disk for rotating a wafer, a swing arm oscillating above the carrier disk, and a liquid supply assembly as described in any one of claims 1 to 8, wherein the liquid supply assembly is disposed on the swing arm.

10. A wafer fabrication method, characterized in that, Processing a wafer using the wafer processing apparatus of claim 9 includes: The carrier disk is controlled to rotate the wafer, and the liquid supply nozzle is controlled to release fluid onto the wafer to process the wafer; When wafer processing is complete, control stops supplying fluid to the first channel and controls the input of gas into the second channel to create a negative pressure at the back suction structure to draw back the fluid at the outlet of the branch channel, thus preventing fluid from dripping onto the wafer surface and contaminating the wafer.

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