Wafer drying device and wafer drying method

Abstract

The present invention discloses a wafer drying device and a wafer drying method. The wafer drying device comprises: a chuck; a support member, which is arranged on the chuck and is used to support the wafer; a rotating mechanism, which is connected to the chuck and is used to drive the chuck to rotate; a liquid recovery mechanism, which is arranged in a ring shape on the radially outer side of the chuck and is used to receive the liquid thrown outward by the wafer rotation; a recessed portion is circumferentially arranged at the edge of the upper surface of the chuck, and there is a smooth transition between the lowest point of the recessed portion and the edge of the upper surface of the chuck. The wafer drying method is implemented by the wafer drying device. By adopting the above technical scheme, the wafer drying device and the wafer drying method of the present invention optimize the discharge path of the liquid, ensure that the droplets quickly enter the liquid recovery mechanism, and improve the drying effect and liquid recovery efficiency.

Description

Technical Field

[0001] The invention relates to a wafer drying device and a drying method, belonging to the technical field of chip manufacturing. Background Art

[0002] In the semiconductor manufacturing process, the drying step after wafer cleaning is crucial, which usually includes centrifugal drying, nitrogen purging, Marangoni drying, thermal drying, vacuum drying and plasma drying. Each drying method is selected and used in combination according to the surface condition of the wafer, the type of cleaning liquid and the subsequent process requirements to ensure that the wafer surface is thoroughly dried without residual moisture, so as to ensure the high yield and reliability of the production process. Centrifugal drying is a commonly used wafer drying technology in semiconductor manufacturing. It uses the centrifugal force generated by high-speed rotation to remove the residual liquid on the surface of the wafer. This method is not only efficient, but also avoids water stains or particle contamination. It is one of the key drying steps after wafer cleaning. First, the wafer is fixed on a rotating platform, usually fixed by a vacuum chuck or mechanical clamp to ensure that the wafer does not move or slip during high-speed rotation. When the wafer is fixed, the rotating platform starts to rotate at high speed. The typical rotation speed can range from a few hundred to a few thousand revolutions per minute, depending on the size of the wafer, the viscosity of the liquid and the required drying effect. As the wafer rotates, the centrifugal force causes the liquid to move rapidly from the surface of the wafer to the edge. As the liquid is affected by centrifugal force, it overcomes the adhesion of the wafer surface and flies out radially. Usually, most of the liquid on the wafer surface will be discharged within a few seconds after the rotation starts. The liquid thrown out will not fly around at will, but will be collected in a liquid recovery device surrounding the wafer. This device is usually a ring structure with a liquid drainage groove, which is specially used to collect and guide the liquid into the waste liquid collection system to prevent contamination of the operating environment or the wafer surface. The liquid recovery structure is generally arranged on the outside of the clamping component, and the liquid recovery structure surrounds the clamping component in a state opposite to the clamping component. The liquid recovery structure is used to recover the cleaning liquid thrown out by the clamping component driving the wafer to rotate. In addition, the liquid recovery structure also includes a chemical liquid recovery structure and a water recovery structure. The chemical liquid recovery structure is used to recover the chemical liquid thrown out by the clamping component driving the wafer to rotate, and the water recovery structure is used to recover the cleaning water and cleaning liquid thrown out by the clamping component driving the wafer to rotate. At the same time, a lifting mechanism is provided to connect with the clamping component, which is used to drive the clamping component to lift and lower, so that the clamping component corresponds to the chemical liquid recovery structure, or corresponds to the water recovery structure.

[0003] like Figure 1As shown, when the wafer 100 is rotated to throw out the liquid, ideally the liquid will be thrown into the channel A for collecting the liquid. However, since the centrifugal force is often insufficient when the wafer is rotated to throw out the liquid, the droplets 200 initially land on the chuck 1. The droplets 200 at this landing point will partially roll into the gap B between the recovery structure and the chuck during the continuous rotation of the chuck, resulting in the inability to be effectively recovered. Summary of the invention

[0004] Therefore, the purpose of the present invention is to overcome the defect that liquid droplets falling into the gap between the recovery structure and the chuck cannot be effectively recovered, thereby providing a wafer drying device and a wafer drying method.

[0005] In order to achieve the above-mentioned purpose, a wafer drying device of the present invention includes: a chuck; a support member, which is arranged on the chuck and is used to support the wafer; a rotating mechanism, which is connected to the chuck and is used to drive the chuck to rotate; a liquid recovery mechanism, which is arranged in a ring shape on the radial outside of the chuck and is used to receive the liquid thrown outward by the rotation of the wafer; a recessed portion is circumferentially arranged at the edge of the upper surface of the chuck, and the lowest point of the recessed portion smoothly transitions to the edge of the upper surface of the chuck.

[0006] The chuck comprises a mounting portion located in the middle, and the support member is arranged on the mounting portion; the height of the edge of the upper surface of the chuck is lower than the height of the mounting portion.

[0007] The recessed portion includes a slope section connected to the mounting portion and an arc section connected to the slope section, the arc section extends to an edge position of an upper surface of the chuck, and the slope section is tangent to the arc section.

[0008] The horizontal distance between the lowest point of the recessed portion and the edge of the upper surface of the chuck is less than 1 / 3 of the horizontal distance between the outer edge of the mounting portion and the edge of the upper surface of the chuck.

[0009] The radius of the arc segment is 15 mm to 25 mm.

[0010] The angle between the slope section and the horizontal plane is 1°~30°.

[0011] A plurality of groups of supporting members for supporting wafers of different sizes are arranged on the chuck; the supporting members for supporting small-sized wafers are located on the inner side, and the supporting members for supporting large-sized wafers are located on the outer side.

[0012] The support member is columnar, and a support position is arranged on the support member, and the wafer can be supported by the support position; the height of the support position for supporting a small-sized wafer is lower than the height of the support position for supporting a large-sized wafer.

[0013] The support member includes a first cylindrical portion located at an upper portion and a second cylindrical portion located at a lower portion, and an outer diameter of the first cylindrical portion is smaller than an outer diameter of the second cylindrical portion.

[0014] A step surface is formed between the first cylindrical portion and the second cylindrical portion, and the step surface is a conical surface. When the support member supports the wafer, the edge of the wafer is restricted at a position where the step surface intersects the first cylindrical portion.

[0015] The angle between the inclined height of the cone surface and the horizontal plane is 12°~20°.

[0016] The support member further includes a chamfered portion located above the first cylindrical portion.

[0017] The included angle between two opposite sides in the longitudinal section of the chamfered portion is 32° to 45°.

[0018] The liquid recovery mechanism includes a first isolation ring and a second isolation ring, the second isolation ring is located radially inward of the first isolation ring, the second isolation ring can be lowered to a low position to form a first channel for collecting liquid between the first isolation ring and the second isolation ring, and the second isolation ring can be raised to a high position to form a second channel for collecting liquid between the second isolation ring and the chuck.

[0019] An anti-splashing structure for preventing liquid droplets from splashing back is also arranged between the first isolation ring and the second isolation ring.

[0020] The anti-splashback structure comprises a louver ring structure, wherein the louver ring structure comprises a plurality of blades, wherein the blades are conical rings, and the lower ends of the blades are inclined radially outward.

[0021] The angle between the oblique height of the conical ring and the vertical direction is 35°~50°.

[0022] A first air duct is also arranged on the outer side of the louver ring structure.

[0023] The rotating mechanism is provided with a second air exhaust duct, and the second air exhaust duct is connected to the top of the chuck.

[0024] The present invention also provides a wafer drying method, which is implemented by the wafer drying device as described above, comprising:

[0025] The wafer is fixed on a support on a chuck, and the chuck is driven by a rotating mechanism to drive the wafer to rotate so that the liquid on the surface of the wafer is thrown outward, and the liquid thrown outward by the rotation of the wafer is received and recovered by a liquid recovery mechanism.

[0026] By adopting the above technical solution, the wafer drying device and the wafer drying method of the present invention have the following beneficial effects compared with the prior art:

[0027] 1. A recessed portion is provided on the upper surface of the chuck, and an upwardly curved smooth transition section is formed from the bottom of the recessed portion to the edge of the upper surface of the chuck. The main purpose of the recessed portion is to play a guiding role. When the droplets thrown out by the wafer during rotation cannot be thrown into the channel for collecting the liquid due to insufficient centrifugal force, the droplets can fall into the recessed portion and, as the chuck rotates, are thrown out obliquely upward along the smooth transition section of the recessed portion, thereby throwing the droplets farther. Such a design optimizes the liquid discharge path, ensures that the droplets quickly enter the liquid recovery mechanism, and improves the drying effect and liquid recovery efficiency.

[0028] 2. Multiple sets of support parts are arranged on the chuck to support wafers of different sizes, so that small-sized wafers can be supported at a low position inside, and large-sized wafers can be supported at a high position outside. Wafers of various sizes can be supported and dried simultaneously or individually, reducing the operation of manually changing the chuck and improving the convenience of use.

[0029] 3. The design of the support member includes setting a step surface and a chamfered portion. A support position is formed at the intersection of the step surface and the first cylindrical portion to support the edge of the wafer, which can reduce the contact area between the wafer and the support member, thereby reducing the risk of surface scratches and damage caused by friction; the chamfered portion can play a guiding role in placing the wafer.

[0030] 4. An anti-splashback structure is arranged between the first isolation ring and the second isolation ring to prevent liquid from splashing back and causing a complex environment in the channel, thereby further ensuring the effect of the drying process and the cleanliness of the wafer surface; the anti-splashback structure is set as a louver ring structure, and the lower end of each conical ring-shaped blade is inclined radially outward. After the liquid droplets pass through the gap between two adjacent blades, they enter the outside of the louver ring structure, so that they can be blocked by the louver ring structure after splashing back, so that the louver ring structure forms an isolation structure.

[0031] 5. The design of multiple exhaust ducts can effectively remove droplets and volatiles generated during the drying process in different areas, reduce the risk of secondary pollution, and ensure the cleanliness of the drying environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the state in which a liquid droplet is thrown off the wafer and falls into the gap between the recovery structure and the chuck in the prior art.

[0033] Figure 2 It is a schematic structural diagram of the wafer drying device of the present invention.

[0034] Figure 3 It is a schematic diagram of the state in which the liquid droplets in the present invention are thrown off the wafer and fall into the recovery channel.

[0035] Figure 4 It is a partial view of the recessed portion.

[0036] Figure 5 Schematic diagram of the top view of three different sized wafers placed on the chuck.

[0037] Figure 6 for Figure 3 Side view of.

[0038] Figure 7 A schematic structural diagram of an implementation scheme of a support member.

[0039] Figure 8 Schematic diagram of the state where splashing occurs after a droplet passes through the louver ring structure.

[0040] Fig. 9 It is a schematic diagram of the state in which the second isolation ring rises to a high position.

[0041] 1. Chuck; 100. Wafer; 10. Recessed portion; 12. Mounting portion; 102. Sloped section; 103. Arc section; 101. Lowest point; 200. Droplet; 2. Rotating mechanism; 31. First isolation ring; 32. Second isolation ring; 310. First channel; 320. Second channel; 41. Opening and closing support member; 42. Columnar support member; 421. First cylindrical portion; 422. Second cylindrical portion; 423. Step surface; 424. Chamfered portion; 5. Louver ring structure; 51. Blades; 61. First exhaust duct; 62. Second exhaust duct. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below through the accompanying drawings and specific embodiments.

[0043] like Figure 2 As shown, a wafer drying device of the present invention comprises a chuck 1, a support, a rotating mechanism 2 and a liquid recovery mechanism. The chuck 1 is mounted on the rotating mechanism 2, the support is arranged on the chuck 1, the wafer is placed on the support, and the chuck 1, the support and the wafer can be driven by the rotating mechanism 2 to rotate synchronously.

[0044] During the rotation of the wafer, the liquid can be thrown radially outward due to the centrifugal force. The liquid recovery mechanism is arranged in a ring shape on the radial outside of the chuck 1, and is used to receive the liquid thrown outward by the rotation of the wafer. In this embodiment, the liquid recovery mechanism includes a first isolation ring 31 and a second isolation ring 32, and the second isolation ring 32 is located on the radial inside of the first isolation ring 31. The second isolation ring 32 can be lowered to a low position so that a first channel 310 for collecting liquid is formed between the first isolation ring 31 and the second isolation ring 32; the second isolation ring 32 can be raised to a high position so that a second channel 320 for collecting liquid is formed between the second isolation ring 32 and the chuck 1.

[0045] When the chuck 1 is driven by the rotating mechanism 2 to rotate, two layers of isolation rings are set to separate liquids of different properties, so that they rise and fall to form two channels to meet the requirements of separating and recovering liquids. That is, when the second isolation ring 32 is lowered to a low position and the first isolation ring 31 is raised to a high position, the top of the second isolation ring 32 is located near the outer edge of the chuck 1, and a first channel 310 is formed between the first isolation ring 31 and the second isolation ring 32 to ensure that the liquid drips into the first channel 310. Fig. 9 As shown, when the first isolation ring 31 and the second isolation ring 32 are simultaneously raised to a high position, the top of the second isolation ring 32 is higher than the outer edge of the chuck 1 , and a second channel 320 is formed between the second isolation ring 32 and the chuck 1 , and the liquid thrown out by the wafer drips into the second channel 320 .

[0046] By setting up two layers of isolation rings and using them to rise and fall to form two different channels, it is possible to effectively separate and recycle liquids of different properties, avoid mixed contamination, and improve the recovery efficiency and environmental friendliness of the liquid. The height of the isolation ring is adjustable and can be flexibly adjusted according to the requirements of different drying processes to ensure that the liquid can accurately enter the designated channel, improving the adaptability and process flexibility of the equipment. In addition, through the design of the isolation ring, the liquid being thrown out can also be effectively controlled to reduce the risk of liquid splashing and contamination, and ensure the cleanliness of the drying environment and the cleanliness of the wafer. By forming an independent recovery channel, it is ensured that different liquids will not cross-mix, which improves the recovery efficiency and reduces the complexity of subsequent processing.

[0047] When drying the wafer, liquid can be sprayed onto the wafer through the nozzle on the wafer drying device to clean the wafer, and the chuck can be used to drive the wafer to rotate to throw the liquid into the first channel 310; then another liquid can be sprayed onto the surface of the wafer to perform another cleaning on the wafer, and then the liquid can be thrown into the second channel 320; finally, drying gas can be sprayed onto the surface of the wafer, and the surface of the wafer can be dried seamlessly in conjunction with the wafer rotation process.

[0048] In the above process, if the liquid is not recovered to the corresponding channel, it means that the recovery path of the liquid does not match the preset path, and the following problems may occur:

[0049] 1. The liquid falls into the wrong channel, making the liquid recovery process more difficult;

[0050] 2. Liquid splashes on the isolation ring or chuck surface used to form the channel, forming tiny droplets that are suspended inside the cavity and pollute the overall environment inside the cavity.

[0051] 3. Small droplets may also stick back to the wafer surface, reducing the cleanliness of the wafer and increasing the difficulty of cleaning.

[0052] 4. Small droplets suspended inside the cavity will affect the overall humidity in the cavity. The wafer may also generate static electricity due to contact and friction with the small droplets during rotation. The static electricity on the surface of the wafer will cause pollutants in the cavity to gather on the surface of the wafer, further reducing the cleanliness of the wafer and increasing the difficulty of cleaning.

[0053] In view of this, the present application provides a wafer drying device, comprising: a chuck; a support member, arranged on the chuck, for supporting the wafer; a rotating mechanism, connected to the chuck, for driving the chuck to rotate; a liquid recovery mechanism, arranged in a ring shape on the radial outside of the chuck, for receiving the liquid thrown outward by the rotation of the wafer.

[0054] like Figure 3 , Figure 4 As shown, a recessed portion 10 is circumferentially provided at the edge of the upper surface of the chuck 1 , and a smoothly transitioned upturned structure is formed between the lowest point 101 of the recessed portion 10 and the edge of the upper surface of the chuck 1 .

[0055] This structural design can change the conventional path of the original droplets with smaller centrifugal force. Since a curved path for changing the flow direction of the liquid is added at the edge of the upper surface of the chuck 1, the droplets can still be ejected again through the recessed portion 10 when the landing point is close, instead of flowing down naturally at the edge of the chuck 1. This ensures that the droplets can be smoothly recovered along the set path, and avoids the mixing of liquids of different properties by entering other channels along the gaps during the liquid collection process, thereby achieving effective separation and collection of liquids of different properties, avoiding the generation of small droplets, ensuring that the cavity environment meets the standards, preventing the wafer surface from being difficult to clean due to static electricity or back-sticking of small droplets, and improving the cleaning effect.

[0056] In this embodiment, the recessed portion 10 is made of a smooth hydrophobic material, so that the droplets can be smoothly ejected for a second time at the upturned structure behind the recessed portion 10 without being dispersed into small droplets, and fewer droplets remain in the recessed portion 10 .

[0057] The chuck 1 includes a mounting portion 12 in the middle, the support member is disposed on the mounting portion 12, and the upper surface edge height of the chuck 1 is lower than the height of the mounting portion 12. Thus, the liquid thrown off the wafer can be smoothly received by the recessed portion at the upper surface edge, further ensuring that the liquid droplets smoothly flow into the corresponding channel.

[0058] In this embodiment, the recessed portion 10 includes a slope section 102 connected to the mounting portion 12 and an arc section 103 connected to the slope section 102, the arc section 103 extends to the edge of the upper surface of the chuck 1, and the slope section 102 is tangent to the arc section 103. The tangent slope section 102 and arc section 103 can make the recessed portion 10 smoothly transition, without corners and other locations where liquid is easily accumulated, further ensuring the smooth discharge of the liquid.

[0059] Preferably, the horizontal distance X between the lowest point 101 of the recessed portion 10 and the upper surface edge of the chuck 1 is less than 1 / 4 to 2 / 5 of the horizontal distance between the outer edge of the mounting portion and the upper surface edge of the chuck. If the horizontal distance X between the lowest point and the upper surface edge is greater than 2 / 5, the distance may be too far so that the droplet cannot be smoothly thrown out. If it is less than 1 / 4, a secondary rebound may not be achieved. Therefore, by making the horizontal distance X between the lowest point 101 of the recessed portion 10 and the upper surface edge of the chuck 1 less than 1 / 4 to 2 / 5 of the horizontal distance between the outer edge of the mounting portion and the upper surface edge of the chuck, it can be ensured that the liquid enters the corresponding channel according to the preset secondary rebound path after being thrown out by the wafer. Furthermore, the horizontal distance between the lowest point of the recessed portion and the upper surface edge of the chuck is less than 1 / 3 of the horizontal distance between the outer edge of the mounting portion and the upper surface edge of the chuck. By limiting the horizontal distance from the lowest point 101 of the recessed portion 10 to the edge of the chuck 1 to less than 1 / 3 of the horizontal distance between the outer edge of the mounting portion and the edge of the upper surface of the chuck, the path of the liquid ejection can be precisely controlled to ensure that the liquid is guided to a predetermined position during rotation and better enters the recovery channel.

[0060] The radius R of the arc segment 103 is 15 mm to 25 mm. The radius of the arc segment 103 is set within the range of 15 mm to 25 mm, which helps to smooth the transition and liquid flow, reduce turbulence and liquid retention, and improve liquid separation and recovery efficiency.

[0061] The angle c between the slope section 102 and the horizontal plane is 1° to 30°. In addition, the angle between the slope section 102 and the horizontal plane is designed to be 1° to 30°, which can adapt to different operating conditions (such as rotation speed, liquid properties, etc.), ensure that the liquid can be thrown out smoothly and prevent backflow or residue, and further improve the drying effect.

[0062] In the above process, liquid enters the first channel 310 between the first isolation ring 31 and the second isolation ring 32, and some droplets will still float in the form of mist. At the same time, since the surface of the first isolation ring 31 has a hydrophobic layer, some droplets will touch the first isolation ring and form splashback, resulting in a complex environment in the first channel 310, which affects the drying effect of the wafer. Therefore, as a further improvement of the present invention, an anti-splashback structure is provided between the first isolation ring 31 and the second isolation ring 32 to prevent droplet splashback. The anti-splashback structure may be a plate with a hydrophilic layer on the surface, so that droplets touching the plate are subjected to tension and will not splash back. Of course, the anti-splashback structure may also be in other forms. For example, in the present embodiment, Figure 2 , Figure 8 As shown, the anti-splashback structure includes a louver ring structure 5, and the louver ring structure 5 includes a plurality of blades 51, and the blades 51 are conical rings, and the lower ends of the blades 51 are inclined radially outward. The angle between the inclined height of the conical ring and the vertical direction is preferably 35° to 50°. When a droplet passes through the gap between two adjacent blades 51 and enters the outside of the louver ring structure 5, it can also be blocked by the louver ring structure 5 after splashback, so that the louver ring structure 5 forms an isolation structure, which reduces the impact of droplet splashback on the environment in the channel.

[0063] By setting an anti-splashback structure between the first isolation ring 31 and the second isolation ring 32, such as a plate or a louver ring structure 5 with a hydrophilic layer surface, the droplet splashback phenomenon can be effectively reduced, the negative impact on the wafer drying effect can be reduced, and the environment in the channel can be improved. The blade design of the louver ring structure 5 enables the droplets to be blocked after passing through the gap between the blades 51, preventing the droplets from rebounding back to the area where the wafer is located, thereby maintaining the stability of the environment in the channel and helping to improve the drying effect. The louver ring structure 5 can also enhance liquid control, which can not only prevent the droplets from rebounding, but also guide the liquid to enter the recovery channel smoothly, effectively control the flow path of the liquid, and improve the efficiency and effect of the overall drying process. The louver ring structure 5 in the design provides multi-level droplet control, which not only prevents splashback, but also plays an isolation role, reducing the risk of mixing liquids of different properties during the recovery process. Setting the angle between the oblique height of the conical ring and the vertical direction to 35°~50° can effectively prevent the droplets from bouncing back. This angle range ensures that the droplets can be guided outward when touching the surface of the conical ring, rather than directly bouncing back to the area where the wafer is located, reducing the interference of the droplet backsplash on the drying effect. At the same time, the angle of 35°~50° can provide the best liquid guiding effect, allowing the droplets to smoothly pass through the gaps between the blades 51 of the louver ring structure and enter the outside, thereby further reducing the possibility of the droplets flowing back or accumulating in the area where the wafer is located.

[0064] Within this angle range, the design of the conical ring can better control the flow of air and liquid in the channel, avoid turbulence or environmental complications caused by droplet splashback, and thus improve the stability and effect of the drying process. In addition, a first exhaust duct 61 is also provided on the outside of the louver ring structure 5, which is used to recover the mist-like floating droplets formed in the channel by negative pressure suction.

[0065] At the same time, a second exhaust duct 62 is also provided on the rotating mechanism 2, and the second exhaust duct 62 is connected to the top of the chuck 1, and is used to suck and recover the mist floating droplets formed under the wafer. By designing exhaust structures for different areas, the mist floating droplets generated during the drying process can be effectively removed, the risk of secondary pollution can be reduced, and the cleanliness of the drying environment can be ensured.

[0066] In addition, most of the existing wafer cleaning equipment uses manually replaced multi-size chucks, which is inconvenient to use and increases the risk of human contact with the chemical solution and the possibility of secondary contamination inside the chamber.

[0067] To this end, in the present application, multiple groups of support members for supporting wafers of different sizes are provided on the chuck 1. Figure 5 , 6 As shown, in the embodiment, taking supporting 4-inch, 6-inch and 8-inch wafers as an example, three groups of support members are arranged on the chuck 1, the support members for supporting small-sized wafers are located on the inner side, and the support members for supporting large-sized wafers are located on the outer side.

[0068] A support position is provided on the support member, and the wafer can be supported by the support position; the height of the support position for supporting a small-sized wafer is lower than the height of the support position for supporting a large-sized wafer. In this embodiment, the support position height of an 8-inch wafer is p, the support position height of a 6-inch wafer is n, and the support position height of a 4-inch wafer is m, wherein p=n+x=m+2x, and the value of x can be set according to actual conditions. Among them, the support member located on the outermost side for supporting an 8-inch wafer can adopt a conventional side clamping opening and closing support member 41, and the support member used to support 6-inch and 4-inch wafers is a columnar support member 42, and the columnar support member 42 is provided on the outer side of the entire circumference of the wafer to form a group of 6, wherein 5 columnar support members 42 are clamped on the arc edge of the wafer 100, and 1 columnar support member 42 is in contact with the cut edge 100a of the wafer 100, so as to realize the overall guidance and fall-back clamping of the wafer, and can avoid the hidden danger of flying wafers generated during acceleration and deceleration and high-speed rotation.

[0069] By setting up multiple groups of support parts, it is possible to be compatible with wafers of different sizes (such as 4 inches, 6 inches and 8 inches in this embodiment, and of course other different sizes in other embodiments, such as 12 inches), thereby improving the versatility and adaptability of the equipment and reducing the frequency and difficulty of replacing the chuck 1.

[0070] The columnar support member 42 can provide uniform support around the entire outer circumference of the wafer, especially by contacting the cut edge of the wafer with one support member, thereby achieving overall guidance and firm clamping of the wafer, avoiding the risk of the wafer flying out or shifting during rotation.

[0071] The reasonable layout and height design of the supports can effectively prevent the wafer from being subjected to unnecessary mechanical stress during acceleration, deceleration and high-speed rotation, reduce the risk of wafer breakage and surface damage, and also reduce back side contamination and structural interference during wafer drying.

[0072] The use of support positions at different heights allows for quick adjustment and support of wafers of different sizes without changing equipment, improving operational convenience and efficiency.

[0073] like Figure 7 As shown, the columnar support member 42 includes a first cylindrical portion 421 located at the upper part and a second cylindrical portion 422 located at the lower part, and the outer diameter of the first cylindrical portion 421 is smaller than the outer diameter of the second cylindrical portion 422. A step surface 423 is formed between the first cylindrical portion 421 and the second cylindrical portion 422, and the step surface 423 is a conical surface. When the support member supports the wafer 100, the edge of the wafer 100 is limited to the position where the step surface 423 intersects with the first cylindrical portion 421. A support position is formed at the position where the step surface 423 intersects with the first cylindrical portion 421 to support the edge of the wafer, which can reduce the contact area between the wafer and the support member, thereby reducing the risk of surface scratches and damage caused by friction, and maintaining the surface quality of the wafer. The angle b between the oblique height of the conical surface and the horizontal plane is preferably 12°~20°. This angle range can not only avoid stress concentration at the edge of the wafer, but also provide good support for the wafer, and reduce the stress and deformation of the wafer caused by uneven support. The design of the support position formed between the step surface 423 and the first cylindrical portion 421 makes the wafer more stable during rotation, effectively reduces the sliding and displacement of the wafer, especially during acceleration, deceleration and high-speed rotation, thereby improving the reliability of equipment operation.

[0074] The support member further includes a chamfered portion 424 located above the first cylindrical portion 421. The angle a between two opposite sides in the longitudinal section of the chamfered portion 424 is preferably 32° to 45°. When placing a wafer, the chamfered portion 424 can provide a good guiding effect on the wafer, making it easier for the wafer to be quickly and accurately positioned at the support position, thereby improving the accuracy and efficiency of the operation.

[0075] When multiple groups of support members are set to support wafers of different sizes, the chuck 1 rotates at a certain speed. Obviously, the edge of the small-sized wafer has the smallest linear velocity, and it is at the lowest position, so it is easy for the centrifugal force to fail to throw the liquid on its surface to a farther position. Once the landing point is on the chuck 1, it is easy to roll until it flows down the edge of the chuck 1, which makes it impossible for the liquid to enter the predetermined channel for collection. Therefore, the design of the above-mentioned recessed portion is mainly used to ensure that the droplets quickly enter the liquid recovery mechanism when drying small-sized wafers (such as 4-inch wafers), thereby improving the drying effect and liquid recovery efficiency. Similarly, the mounting portion in the above scheme refers to the mounting portion of the support member for mounting small-sized wafers. Of course, it can also be used for wafers of other sizes, all within the scope of protection of this application.

[0076] Another embodiment of the present application provides a wafer drying method, which is implemented by the wafer drying device as described above.

[0077] The wafer drying method includes: fixing the wafer on a support on a chuck, driving the chuck to rotate the wafer through a rotating mechanism to throw liquid on the surface of the wafer outward, and receiving and recovering the liquid thrown out by the rotation of the wafer through a liquid recovery mechanism.

[0078] After the wafer drying device is applied, when there is insufficient centrifugal force, the recessed portion provided on the upper surface of the chuck can play a guiding role. Specifically, an upwardly curved smooth transition section is formed between the bottom of the recessed portion and the edge of the upper surface of the chuck. When the droplets thrown out by the wafer during rotation cannot be thrown into the channel for collecting liquid due to insufficient centrifugal force, they can fall into the recessed portion and, as the chuck rotates, are thrown out obliquely upward along the smooth transition section of the recessed portion, thereby throwing the droplets further. Such a design optimizes the discharge path of the liquid, ensures that the droplets quickly enter the liquid recovery mechanism, and improves the drying effect and liquid recovery efficiency.

[0079] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the protection scope of the invention.

Claims

1. A wafer drying device, characterized in that: include: Chuck; A support member, disposed on the chuck, for supporting the wafer; A rotating mechanism, connected to the chuck, for driving the chuck to rotate; A liquid recovery mechanism is arranged in a ring shape on the radially outer side of the chuck and is used to receive liquid thrown outward by the wafer when it rotates; A recessed portion is circumferentially arranged at the edge of the upper surface of the chuck, and a smoothly transitioned upward structure is formed between the lowest point of the recessed portion and the edge of the upper surface of the chuck.

2. The wafer drying device according to claim 1, characterized in that: The chuck comprises a mounting portion located in the middle, and the support member is arranged on the mounting portion; the height of the edge of the upper surface of the chuck is lower than the height of the mounting portion.

3. The wafer drying device according to claim 2, characterized in that: The recessed portion includes a slope section connected to the mounting portion and an arc section connected to the slope section, the arc section extends to an edge position of an upper surface of the chuck, and the slope section is tangent to the arc section.

4. The wafer drying device according to claim 3, characterized in that: The horizontal distance between the lowest point of the recessed portion and the edge of the upper surface of the chuck is less than 1 / 3 of the horizontal distance between the outer edge of the mounting portion and the edge of the upper surface of the chuck.

5. The wafer drying device according to claim 3, characterized in that: The radius of the arc segment is 15 mm to 25 mm.

6. The wafer drying device according to claim 3, characterized in that: The angle between the slope section and the horizontal plane is 1°~30°.

7. The wafer drying device according to any one of claims 1 to 6, characterized in that: A plurality of groups of supporting members for supporting wafers of different sizes are arranged on the chuck; the supporting members for supporting small-sized wafers are located on the inner side, and the supporting members for supporting large-sized wafers are located on the outer side.

8. The wafer drying device according to claim 7, characterized in that: The support member is columnar, and a support position is arranged on the support member, and the wafer can be supported by the support position; the height of the support position for supporting a small-sized wafer is lower than the height of the support position for supporting a large-sized wafer.

9. The wafer drying device according to claim 7, characterized in that: The support member includes a first cylindrical portion located at an upper portion and a second cylindrical portion located at a lower portion, and an outer diameter of the first cylindrical portion is smaller than an outer diameter of the second cylindrical portion.

10. The wafer drying device according to claim 9, characterized in that: A step surface is formed between the first cylindrical portion and the second cylindrical portion, and the step surface is a conical surface. When the support member supports the wafer, the edge of the wafer is restricted at a position where the step surface intersects the first cylindrical portion.

11. The wafer drying device according to claim 10, characterized in that: The angle between the inclined height of the cone surface and the horizontal plane is 12°~20°.

12. The wafer drying device according to claim 9, characterized in that: The support member further includes a chamfered portion located above the first cylindrical portion.

13. The wafer drying device according to claim 12, characterized in that: The included angle between two opposite sides in the longitudinal section of the chamfered portion is 32° to 45°.

14. The wafer drying device according to any one of claims 1 to 6, characterized in that: The liquid recovery mechanism includes a first isolation ring and a second isolation ring, the second isolation ring is located radially inward of the first isolation ring, the second isolation ring can be lowered to a low position to form a first channel for collecting liquid between the first isolation ring and the second isolation ring, and the second isolation ring can be raised to a high position to form a second channel for collecting liquid between the second isolation ring and the chuck.

15. The wafer drying device according to claim 14, characterized in that: An anti-splashing structure for preventing liquid droplets from splashing back is also arranged between the first isolation ring and the second isolation ring.

16. The wafer drying device according to claim 15, characterized in that: The anti-splashback structure comprises a louver ring structure, wherein the louver ring structure comprises a plurality of blades, wherein the blades are conical rings, and the lower ends of the blades are inclined radially outward.

17. The wafer drying device according to claim 16, characterized in that: The angle between the oblique height of the conical ring and the vertical direction is 35°~50°.

18. The wafer drying device according to claim 16, characterized in that: A first air duct is also arranged on the outer side of the louver ring structure.

19. The wafer drying device according to any one of claims 1 to 6, characterized in that: A second air exhaust duct is arranged on the rotating mechanism, and the second air exhaust duct is connected to the top of the chuck.

20. A wafer drying method, characterized in that: The method is implemented by the wafer drying device according to any one of claims 1 to 19, comprising: The wafer is fixed on a support on a chuck, and the chuck is driven by a rotating mechanism to drive the wafer to rotate so that the liquid on the surface of the wafer is thrown outward, and the liquid thrown outward by the rotation of the wafer is received and recovered by a liquid recovery mechanism.

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