Wafer vacuum suction method and floating vacuum supply structure outside a carrier

Abstract

The application relates to the field of wafer processing, in particular to a wafer vacuum adsorption method and a floating type vacuum supply structure outside a wafer table. A wafer table moves to a wafer transfer position, at which time a floating gas distribution block and a docking block are docked by a driving mechanism. Since the floating gas distribution block is connected with a large-flow air exhaust system, the large-flow air exhaust system sequentially passes through the floating gas distribution block, the docking block and an air exhaust channel to perform large-flow air exhaust on the surface of the wafer table, a large instantaneous negative pressure is formed on the surface of the wafer table, a wafer with partial warping is flatly attached to the surface of the wafer table, and then a wafer table adsorption system establishes a vacuum to adsorb the wafer on the upper surface of the wafer table. After the wafer table adsorption system establishes the vacuum, the floating gas distribution block and the docking block are separated, the wafer table moves with the wafer, the large-flow air exhaust system does not move with the wafer table, and a vacuum pipeline of the large-flow air exhaust system does not need to be arranged on a tow chain of the wafer table, so that the wafer table has a simple structure.

Description

Technical Field

[0001] This application relates to the field of wafer fabrication, and in particular to a wafer vacuum adsorption method and a floating vacuum supply structure around the stage. Background Technology

[0002] A wafer is a silicon wafer used to fabricate silicon semiconductor circuits; its raw material is silicon. High-purity polycrystalline silicon is dissolved, doped with silicon seed crystals, and then slowly pulled out to form a cylindrical single-crystal silicon ingot. After grinding, polishing, and slicing, the silicon ingot forms a silicon wafer. Domestic wafer production equipment mainly uses 8-inch and 12-inch wafers. Wafers are relatively thin and prone to deformation. When a wafer is handed over to a wafer carrier, the deformed or warped portion detaches from the carrier, preventing the establishment of a vacuum and halting equipment operation, thus affecting work efficiency. Summary of the Invention

[0003] The purpose of this application is to provide a wafer vacuum adsorption method that facilitates better vacuum establishment on the wafer stage and improves working efficiency, as well as a floating vacuum supply structure around the stage.

[0004] Firstly, the wafer vacuum adsorption method provided in this application adopts the following technical solution: including: Step 1: The wafer stage with the adsorption structure on its surface is moved to the product handover position; Step 2: Place the wafer on the wafer carrier; Step 3: The adsorption structure of the wafer stage is connected to the floating gas distribution block and the high-flow-rate gas extraction system is turned on to perform high-flow-rate gas extraction on the wafer stage. At the same time, the stage vacuum adsorption system on the wafer stage is turned on to adsorb the product; or the stage vacuum adsorption system on the wafer stage is turned on after the high-flow-rate gas extraction system is turned on and before it is turned off. Step 4: The high-flow-rate extraction system is shut down, and the floating gas distribution block is detached from the wafer stage; Step 5: The stage vacuum adsorption system detects whether a vacuum has been established on the wafer stage. If a vacuum has been established, the wafer stage leaves the product handover position and enters the next workstation; if a vacuum has not been established, the equipment alarms.

[0005] By adopting the above technical solution, if the wafer is partially warped or deformed after being placed on the wafer carrier, a high-flow-rate vacuum system is used to instantly pump out a large amount of air, causing the warped part of the wafer to adhere to the surface of the wafer carrier under a large negative pressure. This facilitates the wafer carrier to better establish a vacuum through the carrier adsorption system, allowing the wafer to be adsorbed on the wafer carrier and improving work efficiency.

[0006] Secondly, the floating vacuum supply structure around the stage provided in this application adopts the following technical solution: The device includes a wafer stage, on which an adsorption structure is provided. The adsorption structure is connected to a stage vacuum adsorption system, including a high-flow-rate pumping system. The high-flow-rate pumping system includes a vacuum pipe, a drive mechanism, and a floating gas distribution block connected to the vacuum pipe. The stage adsorption structure includes a pumping hole, a pumping channel, and a docking block connected in sequence. The drive mechanism drives the floating gas distribution block to move closer to or away from the docking block, so that the floating gas distribution block docks or detaches from the docking block.

[0007] By adopting the above technical solution, the wafer stage moves to the product handover position. At this time, the driving mechanism drives the floating gas distribution block to dock with the docking block. The high-flow-rate vacuum system sequentially pumps air through the floating gas distribution block, docking block, vacuum channel, and vacuum hole to create a large instantaneous negative pressure on the wafer stage surface. This causes partially warped or deformed wafers to flatten and adhere to the wafer stage surface, thus enabling the stage vacuum adsorption system to better establish a vacuum and improve work efficiency, adsorbing the wafers onto the surface of the wafer stage. When the stage... After the vacuum adsorption system successfully establishes a vacuum, the high-flow-rate pumping system shuts down, the floating gas distribution block detaches from the docking block, and the wafer stage moves with the wafer. The high-flow-rate pumping system does not move with the wafer stage, thus eliminating the need to arrange the vacuum pipes of the high-flow-rate pumping system on the wafer stage's cable chain. This simplifies the wafer stage's structure. Furthermore, to achieve instantaneous high-flow-rate pumping, the diameter of the high-flow-rate pumping system's vacuum pipes can be designed to be larger, resulting in better pumping performance. Moreover, a larger diameter vacuum pipe does not affect the wafer stage's cable chain structure.

[0008] This application further specifies that: a pluggable docking component is provided between the docking block and the floating gas distribution block, the docking component includes a docking nozzle disposed on the docking block and a vacuum interface disposed on the floating gas distribution block, the docking nozzle includes a docking part and a retractable telescopic tube, and the docking part and the vacuum interface are plugged into each other.

[0009] By adopting the above technical solution, when the drive mechanism pushes the floating gas distribution block to the docking block side, the docking part is inserted into the vacuum interface. Since the telescopic tube is telescopic and has a certain elasticity, the floating gas distribution blocks can be buffered by the telescopic tube when docking with each other. The floating gas distribution block will not directly hit the wafer stage, so as to avoid the wafer stage being affected by sudden external force and affecting the assembly accuracy of the wafer stage. The floating gas distribution block and the docking block can be docked by approaching each other from left to right or from top to bottom.

[0010] This application further specifies that: a pushing block is provided at one end of the floating gas distribution block near the driving mechanism, the pushing block is slidably connected to the floating gas distribution block, and the pushing block is connected to the driving mechanism.

[0011] By adopting the above technical solution, when the floating gas distribution block is connected to the docking block and the high-flow-rate suction system is activated, the telescopic tube is under negative pressure. The telescopic tube contracts under this negative pressure, generating a pulling force on the floating gas distribution block. This pulling force causes the floating gas distribution block to slide relative to the docking block. Therefore, during the shortening of the telescopic tube, because the floating gas distribution block can slide relative to the docking block, the floating gas distribution block and the drive mechanism will not pull on the wafer stage, preventing the wafer stage from being subjected to hard pulling force and deformation, effectively maintaining the precision of the wafer stage.

[0012] This application further specifies that the high-flow-rate pumping system includes a control valve and a gas storage tank, wherein the gas storage tank, the control valve, and the floating gas distribution block are connected in sequence through a vacuum pipeline.

[0013] By adopting the above technical solution, after the control valve controls the floating gas distribution block to connect to the gas storage tank, the high-flow-rate gas extraction system is turned on. The gas pressure in the gas storage tank can instantly and with a large flow rate extract gas from the surface of the wafer stage, so that the wafer can better fit with the wafer stage.

[0014] This application further specifies that the control valve is a three-way solenoid valve, used to control the floating gas distribution block to connect to the gas storage tank or the atmosphere.

[0015] By adopting the above technical solution, the equipment control system can achieve automated control of the three-way solenoid valve. The function of the three-way solenoid valve is to control the floating gas distribution block to connect to the gas storage tank or to the atmosphere. When the three-way solenoid valve connects to the gas storage tank, the high-flow-rate pumping system is activated, allowing the wafer stage to be flattened and adsorbed by partially deformed or warped wafers. When the three-way solenoid valve controls the floating gas distribution block to connect to the atmosphere, the high-flow-rate pumping system is closed, allowing the docking block, floating gas distribution block, and the pumping channel to return to normal pressure. At this time, the negative pressure in the telescopic tube disappears and returns to its initial length. The floating gas distribution block moves along the slide rail towards the pushing block under its own weight, and under the action of the drive mechanism, the docking part of the docking nozzle is pulled out from the vacuum interface. During the process of the docking nozzle being pulled out from the vacuum interface, only the friction between the two needs to be overcome, and the wafer stage is subjected to less force, thereby reducing the impact on the accuracy of the wafer stage.

[0016] This application further specifies that: the stage adsorption structure is provided with two sets of air extraction channels, the two sets of air extraction channels are independently set, the two sets of air extraction channels can be connected to a high-flow-rate air extraction system respectively, the wafer stage is provided with two sets of air extraction holes respectively corresponding to the two sets of air extraction channels, and the high-flow-rate air extraction system has two control valves, the two control valves respectively corresponding to the control valves of the two sets of air extraction channels.

[0017] By employing the above technical solution, two sets of suction channels enable the wafer stage to accommodate two common wafer sizes—12-inch and 8-inch. When a 12-inch wafer is placed on the wafer stage, two control valves connect the two sets of suction channels to the gas storage tank, allowing both suction ports to simultaneously draw in large volumes of air. This provides the 12-inch wafer with a larger area of ​​negative pressure, resulting in more uniform stress on the wafer and ensuring it is flatly adsorbed onto the wafer stage. When an 8-inch wafer is placed on the wafer stage, the corresponding 12-inch suction channel is disconnected from the gas storage tank under the control of the control valve, while the corresponding 8-inch suction channel is connected to the gas storage tank under the control of the control valve. This allows the corresponding 8-inch suction port to draw in large volumes of air, ensuring the 8-inch wafer is flatly adsorbed onto the wafer stage. The wafer stage is suitable for both 8-inch and 12-inch wafers, thus broadening its application range.

[0018] This application is further configured such that: a venting groove is provided on the back side of the wafer stage, the venting groove is annular, the cross-sectional shape of the venting groove is U-shaped, the opening of the venting groove and the back side of the wafer stage are sealed to form an air extraction channel, and the docking block is fixed and connected to the venting groove.

[0019] By adopting the above technical solution, the venting channel is formed by splicing the U-shaped ventilation groove and the wafer stage, which facilitates the installation and maintenance of the wafer stage; the docking block is fixed and connected to the ventilation groove, so that the two can be assembled as a whole.

[0020] This application further specifies that: the adsorption structure includes an adsorption hole disposed on the wafer stage, and the stage vacuum adsorption system includes a vacuum nozzle fixed to the wafer stage, the vacuum nozzle being in communication with the adsorption hole.

[0021] By adopting the above technical solution, the stage vacuum adsorption system and the high-flow-rate pumping system are set up independently. The stage vacuum adsorption system adsorbs wafers through adsorption holes, and the high-flow-rate pumping system pumps gas through extraction holes. The two work together to better adsorb the wafers flatly on the wafer stage, making the stage vacuum adsorption system establish a vacuum more efficiently.

[0022] This application further specifies that the driving mechanism includes a cylinder, which is fixed to the device.

[0023] By adopting the above technical solution, the cylinder drives the floating air distribution block to move, which can enable the floating air distribution block to quickly dock with the docking block.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. The high-flow-rate pumping system enables the wafer stage to achieve high-flow-rate pumping. Even if the wafer is deformed or warped, it can still be flat and adhered to the surface of the wafer stage, which facilitates the vacuum adsorption system of the stage to establish a vacuum better and improves work efficiency. 2. The high-flow-rate pumping system is only connected to the wafer stage when the wafer stage is receiving the wafer. Once the stage vacuum adsorption system establishes a stable vacuum, the high-flow-rate pumping system is separated from the wafer stage. Therefore, there is no need to arrange the piping of the high-flow-rate pumping system in the wafer stage cable chain, which simplifies the piping layout. 3. Since the high-flow-rate extraction system and the platform can be separated from each other, the control valve can be installed as close to the platform as possible, and through the action of the air tank, the high-flow-rate extraction system can provide a faster response speed when it is turned on. 4. The floating air distribution block can slide relative to the pushing block. When the high-flow-rate air extraction system is turned on, the floating air distribution block slides relative to the pushing block, so the platform is not subjected to hard tension and does not deform. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of Embodiment 2 of this application; Figure 2 This is a schematic diagram of the wafer stage structure in Example 2; Figure 3 This is an exploded view of the wafer stage in Example 2; Figure 4 This is a schematic diagram of the structure in Example 2 where the suction nozzle is not inserted into the vacuum interface. Figure 5 This is a schematic diagram of the structure of Example 3; Figure 6 This is a schematic diagram of the wafer stage in Example 3.

[0026] In the diagram, 1. Equipment; 2. Wafer stage; 21. Adsorption structure; 211. Adsorption trench; 212. Vacuum port; 213. Adsorption hole; 22. Ventilation groove; 221. First ventilation groove; 222. Second ventilation groove; 223. Sealing ring; 23. Docking block; 24. Docking nozzle; 241. Telescopic tube; 242. Docking part; 243. Sealing ring; 25. Pressure block; 26. Vacuum nozzle; 3. High-flow-rate vacuum system; 31. Gas storage tank; 32. Control valve; 33. Floating gas distribution block; 331. Pushing block; 332. Slide rail; 333. Slider; 334. Vacuum interface; 34. Cylinder; 35. Vacuum pipeline. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1 - Appendix Figure 6 This application will be described in further detail below.

[0028] Example 1: A wafer vacuum adsorption method for a wafer stage includes: Step 1: The wafer stage 2 with the adsorption structure 21 on its surface is moved to the wafer junction position; Step 2: Place the wafer on wafer stage 2; Step 3: The adsorption structure 21 of the wafer stage 2 is connected to the high-flow-rate pumping system 3 through the floating gas distribution block 33, and the high-flow-rate pumping system 3 is turned on and maintained for a predetermined time, which is set to 1-5 seconds in this embodiment. At the same time, the stage vacuum adsorption system is turned on to adsorb the wafer; or after the high-flow-rate pumping system 3 is turned on and before it is turned off, the adsorption structure 21 of the wafer stage 2 turns on the stage vacuum adsorption system. Step 4: After the high-flow-rate extraction system 3 is shut down, the floating gas distribution block 33 detaches from the wafer stage 2; Step 5: The vacuum adsorption system of the stage is detected by detecting the air pressure in the system to determine whether a vacuum has been established. If the air pressure value meets the preset value, the wafer stage 2 leaves the wafer transfer position and enters the next station; if the air pressure value does not reach the preset value, the equipment 1 will alarm.

[0029] Example 2: Reference Figure 1 A floating vacuum supply structure for a wafer stage includes a wafer stage 2 and an adsorption structure 21 disposed on the wafer stage 2. The adsorption structure 21 can be connected to a high-flow-rate pumping system 3 and a stage vacuum adsorption system, which are independent of each other. The high-flow-rate pumping system 3 is used when the wafer is placed on the wafer stage 2. When the wafer is deformed or warped, the high-flow-rate pumping system 3 rapidly pumps air, causing the warped or deformed parts of the wafer to be flattened and adsorbed onto the wafer stage 2 under negative pressure. Then, the stage vacuum adsorption system establishes a vacuum within the wafer stage 2 to adsorb the wafer. After the wafer is adsorbed, the wafer stage 2 carries the wafer to the next workstation.

[0030] This application is applicable to various types of devices 1 with wafer stage 2. Regarding the structure of device 1, the accompanying drawings have been simplified, and the relevant structures supporting the wafer stage 2 and driving the movement of the wafer stage 2 are not shown in the drawings.

[0031] Reference Figure 1 , Figure 2The adsorption structure 21 includes several arc-shaped adsorption grooves 211 disposed on the surface of the wafer stage 2, the center of the several arc-shaped adsorption grooves 211 overlapping with the center of the wafer stage 2; the stage vacuum adsorption system includes several vacuum nozzles 26, the vacuum nozzles 26 are fixed to the wafer stage 2, the wafer stage 2 is provided with adsorption holes 213, the adsorption holes 213 are disposed at the bottom of the adsorption grooves 211, the adsorption holes 213 are connected to the vacuum nozzles 26, the vacuum nozzles 26 are connected to a vacuum device (not shown in the figure), the stage vacuum adsorption system is turned on after the high-flow pumping system 3 makes the wafer completely adhere to the wafer stage 2, and the stage vacuum adsorption system provides negative pressure to adsorb the wafer.

[0032] Reference Figure 1 , Figure 3 The adsorption structure 21 also includes a venting groove 22 disposed on the back side of the wafer stage 2. The venting groove 22 is annular, and its diameter and installation position are related to the size of the wafer to be adsorbed. A venting groove 22 of appropriate size is designed according to the wafer size. In this embodiment, there is one venting groove 22 used to adsorb wafers of a specific size. The cross-section of the venting groove 22 is U-shaped, and a sealing ring 223 is provided at the opening of the U-shaped venting groove 22. The opening of the U-shaped venting groove 22 is in close contact with the back side of the wafer stage 2, and the sealing ring 223 achieves a seal between the venting groove 22 and the wafer stage 2, forming an annular air extraction channel between the venting groove 22 and the wafer stage 2. The wafer stage 2 has multiple venting holes 212 at positions corresponding to the venting slot 22. These venting holes 212 connect to venting channels. The number of venting holes 212 can be set according to the wafer size. For example, for a 12-inch wafer, 10 venting holes 212 can be provided; for an 8-inch wafer, the number of venting holes 212 can be reduced to 6. A pressure block 25 is provided on the back of the wafer stage 2, and is fixed to the wafer stage 2 with fasteners. The pressure block 25 is used to press the venting slot 22 against the back of the wafer stage 2. A docking block 23 is fixedly connected to the venting slot 22. The docking block 23 extends out of the wafer stage 2, with one end connected to the venting slot 22 and the other end equipped with a docking nozzle 24, which communicates with the venting slot 22 through the docking block 23.

[0033] Reference Figure 1 The high-flow-rate vacuum system 3 includes a cylinder 34 fixed to the device 1 and a gas storage tank 31, a control valve 32, and a floating gas distribution block 33 connected in sequence by a vacuum pipe 35. The gas storage tank 31 is connected to a vacuum device, which is used to evacuate the gas storage tank 31. Figure 1(The supporting structure of the vacuum equipment and the gas storage tank is not shown). The control valve 32 is a three-way solenoid valve, which enables the control system of equipment 1 to automatically control the three-way solenoid valve. The three-way solenoid valve is used to control the floating gas distribution block 33 to connect to the gas storage tank 31 (when the high-flow-rate pumping system 3 is turned on) or to connect to the atmosphere (when the high-flow-rate pumping system 3 is turned off). The floating gas distribution block 33 is provided with a vacuum interface 334, which is connected to the vacuum pipe 35. The vacuum interface 334 is located directly below the docking nozzle 24. By moving the floating gas distribution block 33 up and down, the docking nozzle 24 can be inserted into or removed from the vacuum interface 334. As another embodiment, the vacuum nozzle 26 can be installed on the floating gas distribution block 33, and the vacuum interface 334 can be set on the docking block 23.

[0034] Reference Figure 1 and Figure 4 The nozzle 24 includes a docking part 242 and a telescopic tube 241. One end of the telescopic tube 241 is fixed to the docking block 23, and the other end is fixed to the docking part 242. The telescopic tube 241 has a certain degree of elasticity. The docking part 242 is used to dock with the vacuum interface 334. A sealing ring 243 is fitted on the docking part 242 to maintain a seal between the docking part 242 and the vacuum interface 334. A push block 331 is provided on the side of the floating gas distribution block 33 near the cylinder 34. The push block 331 is fixed to the piston rod of the cylinder 34. The extension and retraction of the piston rod of the cylinder 34 can control the push block 331 to move up and down. The push block 331 abuts against the bottom of the floating gas distribution block 33, so that when the piston rod of the cylinder 34 extends and retracts, it can drive the floating gas distribution block 33 to rise or fall. When the cylinder 34 pushes the floating gas distribution block 33 upward, the docking part 242 inserts into the vacuum interface 334. Buffered by the telescopic tube 241, the floating gas distribution block 33 does not forcefully press against the wafer stage 2, thus preventing excessive external force from affecting the accuracy of the wafer stage 2. A vertically arranged slide rail 332 is provided on the pushing block 331. A slider 333 is fixed to the floating gas distribution block 33, and the slider 333 slides along the slide rail 332, allowing the floating gas distribution block 33 to slide vertically along the slide rail 332. A limiting piece is provided at the end of the slide rail 332 away from the pushing block 331, which limits the extreme position of the slider 333 relative to the slide rail 332. When the control valve 32 on the vacuum pipeline 35 is connected to the gas storage tank 31, the high-flow-rate pumping system is activated, and the telescopic pipe 241 is under negative pressure. The telescopic pipe 241 contracts under the action of negative pressure, and the floating gas distribution block 33 is pulled by the contraction of the telescopic pipe 241. The floating gas distribution block 33 will move along the slide rail 332 in the direction of the telescopic pipe 241. Therefore, during the contraction of the telescopic pipe 241, the floating gas distribution block 33 slides relative to the pushing block 331. The floating gas distribution block 33 and the cylinder 34 will not pull the wafer stage 2. The stage is not subjected to hard pulling force and does not deform, effectively maintaining the accuracy of the wafer stage 2.

[0035] Reference Figure 1 and Figure 4 When the wafer is placed on the wafer stage 2, the control valve 32 controls the floating gas distribution block 33 to connect to the gas storage tank 31, and the high-flow-rate vacuum system 3 is activated. Due to the design of the gas storage tank 31, the moment the control valve 32 connects to the gas storage tank 31, it can provide an instantaneous high-flow-rate vacuum to the wafer stage 2, allowing the wafer, which has a certain degree of warping and deformation, to quickly adhere to the wafer stage 2. It should be noted that the control valve 32 needs to be as close as possible to the floating gas distribution block 33 to provide the fastest response speed during wafer stage 2 adsorption. After the stage vacuum adsorption system of the wafer stage 2 successfully establishes a vacuum and adsorbs the wafer, the control valve 32 controls the floating gas distribution block 33 to connect to the atmosphere, and the high-flow-rate vacuum system 3 is closed, so that the ventilation slot 22, the docking block 23, and the floating gas distribution block 33 return to the normal pressure state. At this time, the negative pressure in the telescopic tube 241 no longer exists and is reset. The floating gas distribution block 33 moves along the slide rail 332 toward the push block 331 under its own weight. The piston rod of the cylinder 34 retracts, and the push block 331 drives the floating gas distribution block 33 to reset. The docking part 242 of the docking nozzle 24 is pulled out from the vacuum interface 334. The high-flow pumping system 3 is separated from the wafer stage 2. The stage vacuum adsorption system of the wafer stage 2 adsorbs the wafer and moves it to the next station.

[0036] With the above structure, this embodiment does not require the installation of the vacuum pipe 35 of the high-flow-rate pumping system 3 on the drag chain of the wafer stage 2. The wafer stage 2 will not be hindered by the vacuum pipe 35 of the high-flow-rate pumping system 3 during movement. Therefore, in this embodiment, in order to ensure a larger pumping volume of the high-flow-rate pumping system 3, a larger vacuum pipe 35 can be selected without considering the factor of wafer movement on the stage 2.

[0037] As one embodiment, the control valve 32 may not be a three-way solenoid valve, but a solenoid valve with only on / off function. A vent hole connected to the suction channel is provided in the venting groove 22 (shown in the attached figure). When the control valve 32 is open, the venting groove 22 is connected to the gas storage tank 31, and the vent hole and the suction port 212 simultaneously perform high-flow-rate suction. By setting a vent hole with an appropriate orifice diameter, the suction port 212 maintains an appropriate suction force so that the wafer can be suctioned onto the wafer stage 2. When the control valve 32 is closed, the vent hole can restore the internal pressure of the venting groove 22, the docking block 23, and the floating gas distribution block 33 to a normal atmospheric pressure state, so that the docking nozzle 24 can be disengaged from the floating gas distribution block 33.

[0038] Example 3: Reference Figure 5 , Figure 6The difference between this embodiment and Embodiment 2 is that the venting slots 22 are provided in two sets: a first venting slot 221 and a second venting slot 222. The first venting slot 221 corresponds to a 12-inch wafer, and the second venting slot 222 corresponds to an 8-inch wafer. The first venting slot 221 and the second venting slot 222 are independently provided. The first venting slot 221 is connected to a first docking block 23, and the second venting slot 222 is connected to a second docking block 23. Both the first docking block 23 and the second docking block 23 are provided with docking nozzles 24. Two sets of suction holes 212 are provided on the wafer stage 2. One set of suction holes 212 is used to match 12-inch wafers. There are a total of 10 suction holes 212, which are evenly arranged in a circle and communicate with the first venting slot 221. Another set of vent holes 212 is used to match the 8-inch wafer. There are a total of 6 vent holes 212. These 6 vent holes 212 are evenly arranged in a circle and are connected to the second ventilation groove 222.

[0039] Reference Figure 5 , Figure 6 The floating gas distribution block 33 is provided with two vacuum ports 334, which are used to dock with the docking nozzles 24 on the first docking block 23 and the second docking block 23, respectively. The two vacuum ports 334 are respectively connected to two independent vacuum pipes 35. The two sets of vacuum pipes 35 are connected to the same gas storage tank 31. The two sets of vacuum pipes 35 are respectively provided with control valves 32 to realize the individual control of the first ventilation slot 221 and the second ventilation slot 222.

[0040] Reference Figure 5 , Figure 6 When the wafer stage 2 needs to adsorb a 12-inch wafer, the floating gas distribution block 33 mates with the docking nozzles 24 on the first docking block 23 and the second docking block 23. The two control valves 32 simultaneously control the first docking block 23 and the second docking block 23 to connect to the gas storage tank 31, so that the two sets of evacuation holes 212 can simultaneously perform high-flow-rate evacuation, so that the 12-inch wafer is flatly adsorbed on the wafer stage 2, which facilitates the efficient establishment of vacuum in the stage vacuum adsorption system. When the wafer stage 2 needs to adsorb an 8-inch wafer, the control valve 32 corresponding to the first vent 221 controls the vent 221 to connect to the atmosphere, and the control valve 32 corresponding to the second vent 222 controls the second vent 222 to connect to the gas storage tank 34, so that the evacuation hole 212 corresponding to the 8-inch wafer can perform high-flow-rate evacuation, so that the 8-inch wafer is flatly adsorbed on the wafer stage 2, which allows the stage vacuum adsorption system to efficiently establish vacuum. This embodiment can be matched with two common types of 8-inch and 12-inch wafers, making it more widely applicable.

[0041] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A wafer vacuum adsorption method, comprising: Step 1: The wafer stage (2) with the adsorption structure (21) on its surface is moved to the product handover position; Step 2: Place the wafer on the wafer stage (2); Step 3: The adsorption structure (21) of the wafer stage (2) is connected to the high-flow-rate pumping system (3) via the floating gas distribution block (33), and the high-flow-rate pumping system (3) is turned on to pump the wafer stage (2) at a high flow rate. At the same time, the stage vacuum adsorption system on the wafer stage (2) is turned on to adsorb the product; or the stage vacuum adsorption system on the wafer stage (2) is turned on after the high-flow-rate pumping system (3) is turned on and before it is turned off. Step 4: The high-flow-rate pumping system (3) is shut down, and the floating gas distribution block (33) is detached from the wafer stage (2). Step 5: The vacuum adsorption system of the stage detects whether the wafer stage (2) has established a vacuum. If a vacuum has been established, the wafer stage (2) leaves the product handover position and enters the next work station; if a vacuum has not been established, the equipment (1) will alarm.

2. A floating vacuum supply structure for a wafer stage, comprising a wafer stage (2), wherein an adsorption structure (21) is disposed on the wafer stage (2), and the adsorption structure (21) is connected to a vacuum adsorption system for the stage, characterized in that: It also includes a high-flow-rate pumping system (3), which includes a vacuum pipe (35), a drive mechanism, and a floating gas distribution block (33) connected to the vacuum pipe (35); the adsorption structure (21) includes a pumping hole (212), a pumping channel, and a docking block (23) connected in sequence, and the drive mechanism drives the floating gas distribution block (33) to move closer to or away from the docking block (23) so that the floating gas distribution block (33) docks with or separates from the docking block (23).

3. The floating vacuum supply structure around the stage according to claim 2, characterized in that: A pluggable docking assembly is provided between the docking block (23) and the floating gas distribution block (33). The docking assembly includes a docking nozzle (24) disposed on the docking block (23) and a vacuum interface (334) disposed on the floating gas distribution block (33). The docking nozzle (24) includes a docking part (242) and a retractable telescopic tube (241). The docking part (242) and the vacuum interface (334) are plugged into each other.

4. The floating vacuum supply structure around the stage according to claim 3, characterized in that: The floating gas distribution block (33) is provided with a push block (331) at one end near the drive mechanism. The push block (331) is slidably connected to the floating gas distribution block (33) and is connected to the drive mechanism.

5. The floating vacuum supply structure around the stage according to claim 4, characterized in that: The high-flow-rate air extraction system (3) includes a control valve (32) and an air storage tank (31), wherein the air storage tank (31), the control valve (32) and the floating air distribution block (33) are connected in sequence through a vacuum pipe (35).

6. The floating vacuum supply structure around the stage according to claim 5, characterized in that: The control valve (32) is a three-way solenoid valve used to control the floating gas distribution block (33) to connect to the gas storage tank (31) or the atmosphere.

7. The floating vacuum supply structure around the stage according to claim 2, characterized in that: The adsorption structure (21) is provided with two sets of air extraction channels. The two sets of air extraction channels are set independently. The two sets of air extraction channels can be connected to the high-flow air extraction system (3) respectively. The wafer stage (2) is provided with two sets of air extraction holes (212) corresponding to the two sets of air extraction channels respectively. The high-flow air extraction system (3) has two control valves (32). The two control valves (32) correspond to the control valves (32) of the two sets of air extraction channels respectively.

8. The floating vacuum supply structure around the stage according to claim 2, characterized in that: The wafer stage (2) has a ventilation groove (22) on the back side. The ventilation groove (22) is annular and has a U-shaped cross-section. The opening of the ventilation groove (22) and the back side of the wafer stage (2) are sealed to form an air extraction channel. The docking block (23) is fixed and connected to the ventilation groove (22).

9. The floating vacuum supply structure around the stage according to claim 2, characterized in that: The adsorption structure (21) includes an adsorption hole (213) disposed on the wafer stage (2), and the stage vacuum adsorption system includes a vacuum nozzle (26) fixed on the wafer stage (2), the vacuum nozzle (26) being connected to the adsorption hole (213).

10. The floating vacuum supply structure around the stage according to claim 4, characterized in that: The drive mechanism includes a cylinder (34), which is fixed to the device (1).

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