A cleaning device and method for single wafer

Abstract

The application discloses a single wafer cleaning device and method, which comprises a ring-shaped vacuum liquid suction assembly arranged above a wafer to be cleaned and having a first distance from the edge of the wafer to be cleaned in the horizontal direction. The ring-shaped vacuum liquid suction assembly comprises a body, the body comprising a ring-shaped gas-liquid cavity and a vacuum suction nozzle. The ring-shaped gas-liquid cavity is arranged in the interior of the body, communicates with the outside, and is coaxial with the ring-shaped vacuum liquid suction assembly. The vacuum suction nozzle is arranged at the bottom of the body and communicates with the ring-shaped gas-liquid cavity. The vacuum suction nozzle is used for absorbing waste liquid on the surface of the wafer. The cleaning device adopts a non-contact mode to absorb waste liquid and has no abrasion problem. Moreover, the cleaning device does not rotate together with the chuck, so that the load of the rotating shaft system is light and the rotating inertia is small. The waste liquid can be completely absorbed through vacuum suction, and an additional blocking ring is not needed, so that the structure is simplified.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a cleaning apparatus and method for monolithic wafers. Background Technology

[0002] In semiconductor manufacturing, wafer cleaning is a critical process that directly impacts chip yield, performance, and reliability. Wafer cleaning removes four key contaminants from the wafer surface, restoring atomic-level cleanliness, eliminating interface defect states, preventing cross-contamination, and improving the process window for subsequent processes such as photolithography, etching, and deposition. Furthermore, to prevent warping and breakage of thin wafers, during dicing, grinding, and cleaning, wafers can be attached to an adhesive film and fixed to a ring-shaped metal or plastic frame, forming a framed wafer.

[0003] Existing cleaning equipment for framed wafers typically employs contact sealing technology, which is prone to wear and has a large rotational inertia. Furthermore, it lacks reliable frame fixation for framed wafers. For example, the wafer processing equipment disclosed in patent CN106057705A uses a sealing lip pressed against a UV film to form a first layer of seal, and reinforcing ribs of a carrier pressed against the UV film to form a second layer of seal. The sealing lip and carrier are fixed to a cover ring, which is in direct contact with the carrier (chuck) holding the framed wafer, forming a sealed area. This sealed area is connected to a vacuum, providing the force needed to hold the cover ring in place during the entire chuck rotation. Simultaneously, the internal and external pressure difference allows the sealing lip and the carrier's reinforcing ribs to press against the UV film with a certain force. It also includes a retaining ring on the outside of the rotating chuck to block liquid and guide waste liquid generated during the cleaning process. It can be seen that CN106057705A only applies a vacuum to the protective area formed by the sealing ring, and the frame is naturally placed in this vacuum without reliable fixation. During cleaning and drying, when the rotation accelerates or decelerates, it cannot provide the torque required for rotation, resulting in relative movement between the UV film and the frame. At the same time, due to the large mass and rotational inertia of the frame, in the case of incomplete dynamic balance of the system, eccentricity, vibration, etc., will also cause relative movement between the UV film and the frame. This relative movement will distort the UV film, which may lead to chip damage and detachment of the frame from the UV film. Summary of the Invention

[0004] To address some or all of the problems in the existing technology, and to avoid wear, reduce rotational inertia, and simultaneously fix the frame, the first aspect of this invention provides a cleaning device for a single-wafer, which employs non-contact frame protection technology and includes an annular vacuum suction assembly. The annular vacuum suction assembly is disposed above the wafer to be cleaned and is at a first horizontal distance from the edge of the wafer. The annular vacuum suction assembly includes: An annular gas-liquid cavity is disposed inside the body of the annular vacuum liquid suction assembly and communicates with the outside. The annular gas-liquid cavity is coaxial with the annular vacuum liquid suction assembly. A vacuum nozzle is located at the bottom of the main body and communicates with the annular gas-liquid chamber for absorbing cleaning waste liquid. A drain connector is disposed on the surface of the body and communicates with the annular gas-liquid cavity.

[0005] Furthermore, in the working state, the annular vacuum liquid suction component and the wafer to be cleaned are at a first distance in the vertical direction, and the first distance is determined according to the thickness of the water film.

[0006] Furthermore, the annular vacuum liquid suction assembly includes at least one set of vacuum nozzles and a corresponding annular gas-liquid chamber, wherein each set of nozzles is circumferentially and evenly distributed at the bottom of the body and communicates with the corresponding annular gas-liquid chamber.

[0007] Furthermore, the apertures of the vacuum nozzles are different in each group, with the aperture of the vacuum nozzle being larger the closer it is to the center of the wafer to be cleaned.

[0008] Furthermore, the number of vacuum nozzles in each group is different, with fewer nozzles being closer to the center of the wafer to be cleaned.

[0009] Furthermore, the vacuum nozzles are staggered to reduce blank areas.

[0010] Furthermore, the bottom of the innermost vacuum nozzle includes a stepped surface, the height difference of which is determined according to the thickness of the water film.

[0011] Furthermore, the annular vacuum liquid suction assembly also includes: A lifting drive module, which is connected to the main body, is used to control the annular vacuum liquid suction assembly to move vertically to get closer to or away from the wafer to be cleaned; A liquid suction drive module, connected to the liquid discharge connector, is used to provide power to the vacuum nozzle and discharge waste liquid. The liquid suction drive module includes: A waste liquid tank, which is connected to the drain connector via a first pneumatic switch valve; A vacuum pump, connected to the waste liquid tank, is used to provide vacuum pressure to the waste liquid tank in order to draw out the waste liquid; A drain pump, connected to the outlet of the waste tank via a second pneumatic switch valve, is used to discharge at least a portion of the liquid in the waste tank when the liquid level in the waste tank reaches a threshold.

[0012] Furthermore, the cleaning apparatus also includes a fixing module for fixing the framed wafer, and includes: The lower chuck is connected to the shaft at its bottom. The upper chuck is fixedly disposed above the lower chuck, and a vacuum area is designed between the upper chuck and the lower chuck. The central area of ​​the upper chuck is provided with micropores to adsorb the UV film of the framed wafer. The frame clamping assembly includes a plurality of clamping pins distributed circumferentially along the upper chuck to fix the frame of the framed wafer, and the clamping pins are driven by a cylinder.

[0013] Based on the cleaning apparatus described above, a second aspect of the present invention provides a cleaning method for a monolithic wafer, comprising: Secure the framed wafer and clean it; After cleaning, the annular vacuum liquid suction assembly is brought close to the framed wafer, wherein the distance between the annular vacuum liquid suction assembly and the framed wafer is determined according to the thickness of the water film of the residual waste liquid. Start the vacuum pump to provide negative pressure to the waste liquid tank to absorb the waste liquid, and at the same time control the opening of the mass flow meter according to the pressure in the waste liquid tank; When the liquid level in the waste liquid tank reaches the discharge threshold, the second pneumatic switch valve and the discharge pump are opened to discharge the liquid until the liquid level reaches the low liquid level threshold.

[0014] This invention provides a cleaning apparatus and method for monolithic wafers, featuring non-contact protection. It uses a ring-shaped vacuum nozzle to absorb waste liquid generated during the cleaning process, preventing the cleaning solution from contacting the frame and eliminating wear issues. The ring-shaped vacuum nozzle is located within the cleaning chamber but is not fixed to the chuck, thus it does not rotate with the chuck, resulting in a lighter load and lower rotational inertia on the shaft system. Vacuum suction allows for complete absorption of the cleaning waste liquid, eliminating the need for an additional retaining ring structure and simplifying the design. Furthermore, the cleaning apparatus uses a vacuum microporous suction cup to fix the UV film and a cylinder and clamping pins to secure the frame, ensuring reliable frame fixation and reducing the risk of chip damage and frame detachment from the UV film. Attached Figure Description

[0015] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the various embodiments of the present invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0016] Figure 1 This diagram illustrates the structure of a cleaning apparatus for a monolithic wafer according to an embodiment of the present invention. Figure 2This diagram illustrates the structure of an annular vacuum liquid suction assembly according to an embodiment of the present invention. Figure 3 This diagram shows a partially enlarged structural schematic of an annular vacuum liquid suction assembly according to an embodiment of the present invention; Figure 4 This diagram illustrates the structure of the liquid suction drive module of an annular vacuum liquid suction assembly according to an embodiment of the present invention. Figure 5 This diagram illustrates the structure of a fixing module according to an embodiment of the present invention. Figure 6 This diagram shows a partially enlarged structural schematic of a fixing module according to an embodiment of the present invention. Detailed Implementation

[0017] The invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that the components in the drawings may be shown exaggeratedly for illustrative purposes and are not necessarily to scale. In the drawings, the same reference numerals are used for components that are identical or have the same function.

[0018] In this invention, unless otherwise specified, "arranged on," "arranged above," and "arranged on" do not exclude the possibility of an intermediate element between them. Furthermore, "arranged on or above" merely indicates the relative positional relationship between two components, and in certain cases, such as when the product orientation is reversed, it can also be converted to "arranged below or under," and vice versa.

[0019] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0020] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.

[0021] It should also be noted that, in the embodiments of the present invention, only a portion of the parts or components may be shown for clarity and simplicity. However, those skilled in the art will understand that, under the teachings of the present invention, the required parts or components can be added as needed for specific scenarios.

[0022] It should also be noted that, within the scope of this invention, the terms "same," "equal," and "equal to" do not imply that the two values ​​are absolutely equal, but rather allow for a certain reasonable margin of error. In other words, the terms also encompass "substantially the same," "substantially equal," and "substantially equal to." Similarly, in this invention, the directional terms "perpendicular to," "parallel to," etc., also encompass the meanings of "substantially perpendicular to" and "substantially parallel to."

[0023] To address the problems of wear and high rotational inertia associated with existing wafer cleaning devices using contact sealing methods, this invention provides a cleaning device and method for monolithic wafers. The device includes an annular vacuum nozzle to prevent the wafer frame from contacting the cleaning fluid, a liquid path system forming the annular vacuum nozzle, and a gas-assisted system. The annular vacuum nozzle absorbs waste fluid generated during wafer cleaning, preventing liquid contact with the wafer frame—a non-contact protection method that eliminates wear issues. Furthermore, the annular vacuum nozzle is fixed within the cleaning chamber rather than on a chuck, and does not rotate with the chuck, effectively reducing the load and rotational inertia of the spindle system. In addition, the cleaning device includes a holding section for the wafer with the wafer frame, improving frame stability and reducing wafer damage caused by relative displacement.

[0024] The present invention will be further described below with reference to the accompanying drawings of the embodiments.

[0025] Figure 1 This diagram illustrates the structure of a cleaning apparatus for a monolithic wafer according to an embodiment of the present invention. Figure 1 As shown, a cleaning device for a single-wafer includes an annular vacuum nozzle assembly 101. The annular vacuum suction assembly 101 is disposed above the wafer 001 to be cleaned and is at a first distance in the horizontal direction from the edge of the wafer 001 to be cleaned.

[0026] Figure 2 A schematic diagram of the structure of an annular vacuum liquid suction assembly according to an embodiment of the present invention is shown, and Figure 3 This diagram shows a partially enlarged structural schematic of an annular vacuum liquid suction assembly according to an embodiment of the present invention. As shown, the annular vacuum liquid suction assembly includes a body 201, which includes an annular gas-liquid chamber and a vacuum nozzle. The annular gas-liquid chamber is disposed inside the body 201 and communicates with the outside to provide suction for the vacuum nozzle and form a drainage channel. To ensure uniform suction, the annular gas-liquid chamber is coaxial with the annular vacuum liquid suction assembly. The vacuum nozzle is disposed at the bottom of the body 201 and communicates with the annular gas-liquid chamber, and is used to absorb waste liquid on the wafer surface. Absorbing waste liquid by vacuum suction avoids direct contact with the wafer, thus eliminating wear issues. It also eliminates the need for the annular vacuum liquid suction assembly to rotate with the chuck holding the wafer, reducing the load on the spindle system and simplifying rotation management. Furthermore, vacuum suction is highly efficient; by properly controlling the pressure, waste liquid can be completely absorbed.

[0027] As mentioned above, the annular vacuum suction assembly does not directly contact the wafer to be cleaned; that is, in the working state, the annular vacuum suction assembly 101 and the wafer to be cleaned 001 maintain a second distance in the vertical direction. In one embodiment of the present invention, the second distance is determined based on parameters such as water film thickness and vacuum pump power, and is preferably 0.5 to 1 mm.

[0028] In one embodiment of the present invention, since the liquid used for wafer cleaning may be corrosive, the main body of the annular vacuum liquid suction assembly is made of corrosion-resistant engineering plastics such as PP, PVDF, PTFE, PFA, etc., to avoid damage.

[0029] To improve absorption efficiency, in one embodiment of the present invention, the annular vacuum liquid suction assembly includes at least one set of vacuum nozzles and a corresponding annular gas-liquid chamber. To ensure uniform suction, in one embodiment of the present invention, each set of nozzles is circumferentially and evenly distributed at the bottom of the body, and communicates with the corresponding annular gas-liquid chamber. Figure 2 and Figure 3 In the illustrated embodiment, the annular vacuum suction assembly includes two sets of vacuum nozzles. However, it should be understood that in other embodiments of the present invention, the number of vacuum nozzles may be increased or decreased according to actual needs, such as process parameters like cleaning fluid capacity and cycle requirements, as well as structural parameters like wafer size and chuck size.

[0030] In comparison, the closer to the center of the wafer to be cleaned, the greater the amount of liquid that needs to be absorbed. Therefore, in one embodiment of the present invention, the apertures of each set of vacuum nozzles are different, wherein the closer to the center of the wafer to be cleaned, the larger the aperture of the vacuum nozzle, thereby providing a greater absorption flow rate.

[0031] Meanwhile, when the vacuum nozzles are located away from the center of the wafer to be cleaned, a higher density of vacuum nozzles is needed to better absorb any waste liquid missed by the inner ring nozzles. This means the number of vacuum nozzles in each group can vary, with fewer nozzles required closer to the center of the wafer. Furthermore, the vacuum nozzles are preferably staggered to reduce blank areas.

[0032] by Figure 2 and Figure 3Taking a ring-shaped vacuum suction assembly with two sets of vacuum nozzles as an example, the arrangement of the vacuum nozzles is explained in detail. As shown in the figure, the set of vacuum nozzles closer to the wafer to be cleaned has a larger aperture, for example, 2 mm, serving as the main suction port 311. The main suction ports are evenly distributed in the circumferential direction, with a distribution circle diameter of 155 to 159 mm. To better absorb waste liquid, the main suction ports should be densely distributed, with a number N1 of at least 180. In actual operation, the main suction ports absorb a gas-liquid mixture, which then enters the corresponding inner ring gas-liquid chamber 312. The set of vacuum nozzles farther from the wafer to be cleaned has a smaller aperture, for example, 1 mm, serving as the secondary suction ports 321. Similarly, the secondary suction ports are evenly distributed in the circumferential direction, with a distribution circle diameter of 162 to 164 mm. As mentioned above, the distribution of the secondary suction ports should be even denser, with a number N2 of at least 360. With a denser distribution, the secondary suction holes can fill the blank areas between adjacent primary suction holes. Similarly, the liquid absorbed by the secondary suction holes is still a gas-liquid mixture, which enters the corresponding outer annular gas-liquid chamber 322.

[0033] In one embodiment of the present invention, considering the thickness of the water film and the liquid absorption, a step surface can be formed by cutting on the circle where the innermost vacuum nozzle is located. There is a height difference ΔH between the step surface 314 and the lower surface 313 of the vacuum nozzle. The height difference ΔH is determined according to parameters such as the thickness of the water film and the power of the vacuum pump, and is preferably 0.5 to 1 mm.

[0034] In one embodiment of the present invention, by adjusting the first horizontal distance between the annular vacuum liquid suction component 101 and the edge of the wafer 001 to be cleaned, and / or by adjusting parameters such as vacuum pump power and vacuum opening, the suction force can be controlled, which can effectively ensure that the waste liquid is completely absorbed.

[0035] As mentioned above, in the embodiments of the present invention, the annular vacuum suction assembly is disposed in a non-contact manner with the wafer to be cleaned. To facilitate wafer placement and removal and provide a safe height space for wafer handling, the annular vacuum suction assembly may further include a lifting drive module 205, which is connected to the body 201 and used to control the vertical movement of the annular vacuum suction assembly to move closer to or further away from the wafer to be cleaned. Figure 1 , Figure 2 As shown, the annular vacuum liquid suction assembly has several support blocks 202 on its side. The support blocks 202 are connected to a bottom support member 204 via support rods 203. The lifting drive module 205 is connected to the bottom support member 204 to drive the bottom support member 204 to move vertically, thereby causing the annular vacuum liquid suction assembly body 201 to move vertically. Figure 1As shown, the support blocks 202 are evenly distributed circumferentially on the side of the body 201. In one embodiment of the present invention, the lifting drive module 205 may employ common lifting drive structures such as ball screws, worm gears, hydraulic lifting structures, pneumatic lifting structures, gear racks, synchronous belts, and chain sprockets, which will not be described in detail here.

[0036] In order to better control the distance between the annular vacuum suction assembly and the wafer to be cleaned, in one embodiment of the present invention, a distance sensor (not shown in the figure) is provided at the bottom of the body 201 of the annular vacuum suction assembly. The distance sensor can be clamped and fixed at the bottom of the body 201 by a fastener, and is used to measure the distance between the annular vacuum suction assembly and the wafer to be cleaned.

[0037] As previously described, the annular gas-liquid chamber 211 is connected to the outside to provide suction for the vacuum nozzle 212 and to provide a discharge channel for waste liquid. In one embodiment of the present invention, the annular gas-liquid chamber 211 is connected to the liquid suction drive module 105. As shown in the figure, each group of vacuum nozzles is connected to an independent drain pipe. Figure 5 Taking a cleaning device comprising two sets of vacuum nozzles as an example, a schematic diagram of the liquid suction drive module of an annular vacuum liquid suction assembly according to an embodiment of the present invention is shown. Figure 4As shown, the two drainage pipelines include drainage connectors 331 and 332, first pneumatic switching valves 411 and 412, waste liquid tanks 421 and 422, second pneumatic switching valves 431 and 432, vacuum pump 404, and drainage pump 405. Drainage connectors 331 and 332 are disposed on the surface of the body 201 and are respectively connected to the annular gas-liquid chambers 312 and 322. Waste liquid tanks 421 and 422 are respectively connected to drainage connectors 331 and 332 through first pneumatic switching valves 411 and 412. Vacuum pumps 404 are respectively connected to waste liquid tanks 421 and 422 to provide vacuum pressure for waste liquid tanks 421 and 422 to draw up waste liquid. Drainage pumps 405 are respectively connected to the outlets of waste liquid tanks 421 and 422 through second pneumatic switching valves 431 and 432 to discharge at least a portion of the liquid in waste liquid tanks 421 and 422 when the liquid level in waste liquid tanks 421 and 422 reaches a threshold. Waste liquid tanks 421 and 422 are vacuum pressure vessels, and their pressure is preferably negative, from -10 kPa to -100 kPa, thereby providing suction for vacuum nozzles. To achieve closed-loop control, in one embodiment of the present invention, the waste liquid tanks 421 and 422 are further equipped with a liquid level sensor, vacuum digital display pressure sensors 461 and 462, and mass flow meters 471 and 472. When the pressure inside the waste liquid tank 421 or 422 increases, the opening degree of the corresponding mass flow meter increases, the flow rate of the pipeline system increases, and thus the pressure inside the corresponding waste liquid tank decreases; conversely, the opening degree of the corresponding mass flow meter decreases. When the liquid level inside the waste liquid tank 421 or 422 reaches the drainage threshold, the corresponding second pneumatic switch valve and drainage pump 405 are opened to drain the corresponding waste liquid tank. When the liquid level drops to the low liquid level threshold, the corresponding second pneumatic switch valve and drainage pump 405 are closed.

[0038] In one embodiment of the present invention, the pressure values ​​of the waste liquid tanks in different drainage pipelines can be different. Under the condition of meeting the process requirements, the flow rates of the two pipelines can be flexibly allocated to improve efficiency and avoid energy waste.

[0039] In one embodiment of the present invention, the various drainage pipelines may share the vacuum pump 404 and the drainage pump 405.

[0040] To better control flow rate and suction, in one embodiment of the present invention, a flow regulating valve 481 and a flow meter 491 are respectively installed between the waste liquid tank 421 and the drain connector 331, and between the waste liquid tank 422 and the drain connector 332. The flow regulating valves 481 and 482 are used to regulate the flow rate of the gas-liquid mixture. The flow rate can be determined based on the vacuum value of the waste liquid tanks 421 and 422 and the pipe size. In one embodiment of the present invention, taking an embodiment with two sets of vacuum nozzles as an example, the inner ring flow rate can be set to, for example, 100 L / min to 300 L / min, and the outer ring flow rate can be set to, for example, 50 L / min to 150 L / min.

[0041] Back Figure 1 In one embodiment of the present invention, the cleaning device further includes a fixing module 102 for fixing the framed wafer. Figure 5 A schematic diagram of the structure of a fixing module according to an embodiment of the present invention is shown, and Figure 6 The figure shows a partially enlarged structural diagram of a fixing module according to an embodiment of the present invention. As shown, the fixing module includes an upper chuck 501, a lower chuck 502, and a frame clamping assembly. The wafer to be cleaned, particularly a framed wafer, is placed on the fixing module. On one hand, its UV film is adsorbed and fixed by the vacuum area between the upper chuck 501 and the lower chuck 502; on the other hand, its frame 011 is fixed by the frame clamping assembly.

[0042] As shown in the figure, the upper chuck 501 has a circular structure, including an inner ring and an outer ring, wherein the inner ring is glued to the outer ring. In one embodiment of the present invention, the inner ring adopts a microporous ceramic structure, corresponding to the position of the UV film and the wafer body of the framed wafer. According to the common framed wafer size, the outer diameter of the inner ring is preferably 340 to 350 mm. The outer ring is used to fix the mounting and fixing part of the upper chuck. The upper chuck 501 is mounted on the lower chuck 502. As mentioned above, a vacuum region is provided between the upper chuck 501 and the lower chuck 502, so that the UV film can be adsorbed through the micropores of the upper chuck 501. In one embodiment of the present invention, a two-ring support structure is provided in the vacuum region to support the upper chuck. In one embodiment of the present invention, the vacuum region is realized by a vacuum supply system 104.

[0043] In one embodiment of the invention, the upper chuck 501 is fixed to the lower chuck 502 by fixing bolts 504. The lower chuck 502 contacts the upper end face of the rotating shaft 505 and is connected by fasteners such as bolts. The rotary joint 506 contacts the lower surface of the rotating shaft 505, and bolts pass through the flange of the rotary joint 506 and are screwed into the rotating shaft 505. The vacuum supply system includes a vacuum pressure reducing valve, a vacuum digital display pressure sensor, a two-position three-way solenoid valve, an air filter, and a vacuum digital display pressure sensor. After the digital display pressure gauge, a pipeline is connected to the vacuum pipe connector of the rotary joint 506. The outlet of the rotary joint 506 is connected to the inlet of the rotating shaft 505. The vacuum passage 553 of the rotating shaft 505 passes through the center line of the shaft. The end of the rotating shaft 505 is embedded in the lower chuck 502 and sealed by an O-ring, thereby forming a vacuum. During the cavitation process, the air passes through a filter (3nm or 10nm), a two-position three-way solenoid valve, and a vacuum digital pressure gauge before flowing into the rotary joint 506, the rotating shaft 505, and the lower chuck 502.

[0044] In one embodiment of the present invention, the frame clamping assembly includes a plurality of clamping pins 531 distributed circumferentially along the upper chuck 501 to fix the frame of the framed wafer, and the clamping pins are driven by a cylinder 532. As shown in the figure, the frame is held in place by the clamping force of the clamping pins 531 against the lower chuck 502. The frame clamping cylinder 532 is fixed to the back of the lower chuck 502 by bolts, and the clamping pins 531 are connected to the cylinder 532 by bolts. In one embodiment of the present invention, four clamping pins 531 are provided, which respectively clamp four flat edges of the frame. The cylinder 532 is a double-acting cylinder; when the cylinder piston extends, the clamping pins 531 open, releasing the frame; when the cylinder piston retracts, the clamping pins 531 close, clamping the frame.

[0045] Based on this, the rotary joint 506 is provided with 4 channels, one of which is reserved, and the other three channels correspond one-to-one with the three air passages of the rotating shaft 505. Specifically, the three air passages at the inlet of the rotary joint 506 are the cylinder extension air passage, the cylinder retraction air passage, and the adsorption vacuum air passage. The gas outlet of the rotary joint 506 is connected to the inlet connector of the rotating shaft 505, and the outlet of the rotating shaft 505 is connected to the cylinder 532 and the lower chuck 502. The CDA gas passes sequentially through the pneumatic triplet of the CDA supply system 103, the digital display pressure sensor, and the three-position five-way solenoid valve. After the two speed control valves, two air pipes are respectively connected to the cylinder air pipe connector 561 and the cylinder retraction air pipe connector 562 of the rotary joint 506. The outlet of the rotary joint 506 is connected to the inlet connectors 551 and 552 of the rotating shaft 505, and the outlet of the rotating shaft 505 is divided into 4 paths, which are respectively connected to the 4 cylinders 532. The clamping force of the clamping buckle 531 can be controlled by adjusting the triplet; the speed of the cylinder 532 can be controlled by adjusting the speed control valve.

[0046] The frame is secured by four cylinders and clamping clips, ensuring that the framed wafer system has no relative movement to the upper and lower chucks, eliminating the risk of chip damage and frame detachment from the UV film.

[0047] Based on the cleaning apparatus described above, the present invention also provides a cleaning method for a monolithic wafer, comprising: First, the framed wafer is fixed and cleaned. The wafer is placed on the surface of the upper chuck. The UV film is adsorbed through the vacuum area between the upper and lower chucks and the empty structure of the upper chuck. The clamping buckles are closed by controlling the cylinder to clamp the frame, thus fixing the framed wafer. Then, the cleaning is carried out according to the conventional procedure. Next, after cleaning is completed, the annular vacuum liquid suction assembly is brought close to the framed wafer, wherein the distance between the annular vacuum liquid suction assembly and the framed wafer is determined according to the thickness of the water film of the residual waste liquid, the power of the vacuum pump, the opening degree, etc. Finally, the vacuum pump is started to provide negative pressure to the waste liquid tank to absorb the waste liquid. At the same time, the opening of the mass flow meter is controlled according to the pressure in the waste liquid tank. When the liquid level in the waste liquid tank reaches the discharge threshold, the second pneumatic switch valve and the discharge pump are opened to discharge the liquid until the liquid level reaches the low liquid level threshold.

[0048] In one embodiment of the present invention, waste liquid is absorbed by a multi-ring vacuum nozzle. The absorption capacity of each ring can be individually controlled for vacuum value and waste liquid discharge. Considering cost, two waste liquid tanks share a vacuum pump and a discharge pump. A liquid level sensor determines which waste liquid tank needs to be discharged, and then opens the corresponding discharge valve. A vacuum pressure sensor in the waste liquid tank can determine the pressure deviation and feed it back to the MFC to adjust the exhaust volume and control the pressure of the discharge tank.

[0049] Although various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A cleaning apparatus for a single-wafer wafer, characterized in that, The device includes an annular vacuum liquid aspiration assembly, which is disposed above the wafer to be cleaned, and its inner wall is horizontally separated from the edge of the wafer. The annular vacuum liquid aspiration assembly includes a body, and the body includes: An annular gas-liquid cavity is disposed inside the body and communicates with the outside. The annular gas-liquid cavity is coaxial with the annular vacuum suction assembly. A vacuum nozzle is located at the bottom of the body, communicates with the annular gas-liquid cavity, and is configured to absorb waste liquid from the wafer surface.

2. The cleaning device as described in claim 1, characterized in that, In operation, there is a second distance between the bottom of the annular vacuum liquid suction component and the wafer to be cleaned in the vertical direction, and the second distance is determined according to the thickness of the water film.

3. The cleaning device as described in claim 1, characterized in that, The annular vacuum liquid suction assembly includes at least one set of vacuum nozzles and a corresponding annular gas-liquid chamber, wherein each set of vacuum nozzles is circumferentially evenly distributed at the bottom of the body and communicates with the corresponding annular gas-liquid chamber.

4. The cleaning device as described in claim 3, characterized in that, The aperture of each set of vacuum nozzles is different, and the closer the distance to the center of the wafer to be cleaned, the larger the aperture of the vacuum nozzle.

5. The cleaning device as described in claim 3, characterized in that, The number of vacuum nozzles varies in each group, with fewer nozzles being closer to the center of the wafer to be cleaned.

6. The cleaning apparatus as described in claim 3, characterized in that, The vacuum nozzles are staggered to reduce blank areas.

7. The cleaning apparatus as described in claim 3, characterized in that, The bottom of the innermost vacuum nozzle includes a stepped surface, the height difference of which is determined according to the thickness of the water film.

8. The cleaning apparatus as described in claim 1, characterized in that, The annular vacuum liquid suction assembly further includes: A lifting drive module, connected to the main body, is configured to control the vertical movement of the annular vacuum suction assembly to move closer to or further away from the wafer to be cleaned; and A liquid suction drive module, connected to the body, configured to power the vacuum nozzle and discharge waste liquid, the liquid suction drive module comprising: A drain connector is disposed on the surface of the body and communicates with the annular gas-liquid cavity; A waste liquid tank, which is connected to the drain connector via a first pneumatic switch valve; A vacuum pump, connected to the waste liquid tank, is configured to provide a negative pressure to the waste liquid tank to drive the vacuum nozzle to draw in the waste liquid; and A drain pump, which is connected to the outlet of the waste tank via a second pneumatic switch valve, is configured to discharge at least a portion of the liquid in the waste tank when the liquid level in the waste tank reaches a threshold.

9. The cleaning apparatus as described in claim 1, characterized in that, It also includes a fixing module configured to fix the framed wafer, and includes: The lower chuck is connected to the shaft at its bottom. The upper chuck is fixedly disposed above the lower chuck, and a vacuum area is designed between the upper chuck and the lower chuck. The central area of ​​the upper chuck is provided with micropores to adsorb the UV film of the framed wafer. The frame clamping assembly includes a plurality of clamping buckles distributed circumferentially along the upper chuck to fix the frame of the framed wafer, and the clamping buckles are driven by a cylinder.

10. A cleaning method for a single-wafer, characterized in that, include: Secure the framed wafer and clean it; After cleaning, the annular vacuum liquid suction assembly as described in any one of claims 1 to 9 is brought close to the framed wafer, wherein the distance between the annular vacuum liquid suction assembly and the framed wafer is determined according to the thickness of the water film of the residual waste liquid; Start the vacuum pump to provide negative pressure to the waste liquid tank to absorb the waste liquid, and at the same time control the opening of the mass flow meter according to the pressure in the waste liquid tank; When the liquid level in the waste liquid tank reaches the discharge threshold, the second pneumatic switch valve and the discharge pump are opened to discharge the liquid until the liquid level reaches the low liquid level threshold.

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