Wafer fixing device and wafer drying device

Abstract

The application discloses a wafer fixing device and a wafer drying device. The wafer fixing device comprises a fixing base and a rotating base, and the rotating base is fixedly provided with an electrostatic chuck. A plurality of centering assemblies are uniformly distributed on the circumferential side of the rotating base, each of the centering assemblies comprises an outer shell, an upper flexible pad and a lower flexible pad which are symmetrically arranged on the outer shell along the axial direction of the wafer, the outer shell can move radially along the rotating base, the upper flexible pad and the lower flexible pad are both in arc-shaped structure, and the rotating base is provided with a linear driver for driving the outer shell to move. The flexible pads are driven by the circumferential centering assemblies to form surface contact with the edge of the wafer, high-precision centering and stress dispersion are realized, the wafer is finally fixed by the electrostatic chuck, then the wafer is driven to rotate at high speed and is dried in cooperation with nitrogen blowing, and the wafer is ensured to be clean and undamaged.

Description

Technical Field

[0001] This invention relates to the field of wafer drying technology, specifically to a wafer fixing device and a wafer drying device. Background Technology

[0002] In semiconductor manufacturing, the drying process after wafer cleaning demands extremely high cleanliness and surface integrity. Current technologies often employ mechanical grippers or multiple limiting rods to hold and secure the wafer at its edges. However, these rigid contact structures can obstruct fluid flow during rinsing and drying, causing particles to be blocked and accumulate in the gripping area, creating contamination dead zones. Simultaneously, the gripped areas cannot be effectively covered by the cleaning fluid or drying airflow, resulting in incomplete rinsing or drying in certain areas, severely impacting process yield.

[0003] For example, CN116864425A discloses a wafer cleaning and drying apparatus, including a turntable, a first fluid disk and a second fluid disk. The turntable is provided with a clamping mechanism for fixing the wafer. The first fluid disk and the second fluid disk are symmetrically arranged on both sides of the wafer and are fixed relative to the turntable. The surfaces of the first fluid disk and the second fluid disk facing the wafer are provided with a plurality of nozzles suitable for spraying fluid. The nozzles are inclined towards the outside of the wafer, and the fluid includes nitrogen gas. The clamping mechanism includes an axial moving ring, a reciprocating drive, at least three first clamping heads, and at least three second clamping heads. The axial moving ring is slidably mounted on the turntable and can only slide along the axial direction of the turntable. The reciprocating drive is used to drive the axial moving ring to slide back and forth along the axial direction of the turntable. The at least three first clamping heads and at least three second clamping heads are spaced apart and fixed on the axial moving ring in the circumferential direction, and the at least three first clamping heads and at least three second clamping heads form a circular clamping area on one side of the turntable. Both the first clamping heads and the second clamping heads are used to clamp the wafer.

[0004] This wafer cleaning and drying apparatus uses at least three first clamping heads to clamp the wafer, while at least three second clamping heads release the wafer; conversely, when the first clamping heads release the wafer, the second clamping heads clamp the wafer. However, the clamping switching process easily causes micro-displacement of the wafer, and rigid contact can easily cause stress damage to ultra-thin wafers, making it difficult to meet the high requirements of cleanliness and non-destructive processing in advanced processes. Therefore, there is a current need for a wafer fixing device and a wafer drying device that combine non-destructive flexible fixation, high-precision automatic alignment, and integrated drying functions. Summary of the Invention

[0005] To address the problems existing in the prior art, the present invention provides a wafer fixing device and a wafer drying device. The circumferential centering component drives each flexible pad to form surface contact with the edge of the wafer, achieving high-precision centering and stress dispersion. Combined with an electrostatic chuck, the wafer is finally fixed. Subsequently, the wafer is driven to rotate at high speed and nitrogen gas is sprayed to dry it in a coordinated manner, ensuring that the wafer is clean and undamaged.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0007] According to one aspect of the present invention, a wafer holding device is provided, comprising a fixed base and a rotating base disposed thereon, wherein an electrostatic chuck for adsorbing a wafer is fixedly disposed on the rotating base, and further comprising a plurality of centering components evenly distributed around the periphery of the rotating base. When all centering components are in operation, the wafer is centered on the electrostatic chuck. Each centering component includes a housing and an upper flexible pad and a lower flexible pad symmetrically disposed on the housing along the wafer axis. The housing is capable of radial movement along the rotating base. Both the upper and lower flexible pads are arc-shaped structures, and the curvature of the arc-shaped contact surfaces of the upper and lower flexible pads matches the wafer edge profile to increase the contact area and reduce local pressure. The rotating base is provided with a linear actuator for driving the housing to move. When the housing moves inward, the upper flexible pad and the top edge of the wafer, and the lower flexible pad and the bottom edge of the wafer are in a surface-to-surface flexible contact state.

[0008] In one embodiment, the lower flexible pad is fixedly connected to the housing, and the upper flexible pad can move vertically relative to the lower flexible pad on the housing to adjust the distance between them. The housing is provided with a lifting driver for driving the upper flexible pad to move.

[0009] In one embodiment, the inner bottom edge of the upper flexible pad and the inner top edge of the lower flexible pad are both chamfered, and the two chamfers are arranged opposite to each other to form a clamping gap for accommodating and flexibly covering the edge of the wafer.

[0010] In one embodiment, the linear actuator includes a slide rail and a slider, the slide rail being fixedly mounted on a rotating base and extending radially therefrom, and the slider being slidably mounted on the slide rail and fixedly connected to a housing.

[0011] In one embodiment, the housing is provided with a movable block and a fixed block for mounting an upper flexible pad and a lower flexible pad, the bottom of the housing is provided with a support for the fixed block to be fixedly connected, and the housing is provided with a groove along its height direction for the movable block to slide therein.

[0012] In one embodiment, the fixed block is provided with a guide rod extending vertically upward, the movable block is provided with a guide sleeve that slides with the guide rod, and a compression spring sleeved on the guide rod to assist the movable block in resetting upward is fixedly connected between the guide sleeve and the fixed block.

[0013] In one embodiment, the fixed block is provided with a pressure sensor for detecting the compression force of the compression spring, and the pressure sensor is electrically connected to the lifting drive.

[0014] In one embodiment, both the upper and lower flexible pads are made of absorbent material, and both the upper and lower flexible pads have heating tubes inside for introducing heating medium to dry the pads after they have absorbed water.

[0015] According to a second aspect of the invention, a wafer drying apparatus is provided, including a rotary driver mounted on a fixed base for driving a rotating base to rotate about its axis, and the wafer fixing device.

[0016] In one embodiment, the wafer drying apparatus further includes a fluid jetting system comprising a jetting frame and a plurality of nitrogen nozzles circumferentially arranged on the jetting frame above a rotating base.

[0017] Compared with the prior art, this application has at least the following beneficial effects:

[0018] (1) This invention employs a method of first placing the wafer in a non-powered state, and then synchronously advancing it radially using circumferentially distributed centering components. By utilizing the flexible upper and lower arc-shaped pads to form a flexible surface-to-surface contact with the wafer edge, high-precision automatic centering is achieved while effectively dispersing clamping stress and avoiding edge chipping or micro-cracks. Throughout the process, no hard components contact the chip area, significantly reducing local stress and the risk of scratches. It can also adapt to wafer warpage or dimensional tolerances, ensuring uniform and reliable centering. After centering, the combination of electrostatic chuck adsorption and gentle constraint by the flexible pads provides a stable and blind-zone-free clean processing foundation for subsequent high-speed rotary drying.

[0019] (2) This invention achieves adaptive flexible wrapping of wafers with different thicknesses and edge deformations by using a vertically adjustable structure of the upper flexible pad relative to the lower flexible pad, combined with the contour matching clamping gap formed by the inner chamfers of the two. Under the control of the lifting actuator, the upper and lower flexible pads work together to gently clamp the edge of the wafer, avoiding centering misalignment due to excessive gap and preventing overpressure damage. The double chamfer structure guides the formation of a gradually narrowing and fitting receiving space, so that the contact force is evenly distributed on the arc surface, effectively eliminating stress concentration, ensuring non-destructive, stable and highly adaptable edge constraints, and providing a reliable positioning basis for subsequent high-speed rotation.

[0020] (3) This invention uses a rotary driver to drive an electrostatic chuck and wafer to rotate at high speed, combined with circumferentially uniformly arranged nitrogen nozzles to synchronously spray high-purity nitrogen. The combined effect of centrifugal force and airflow achieves efficient, blind-zone-free drying of the wafer surface and edges. During the drying process, the flexible pad, made of absorbent material, actively absorbs residual moisture and, after drying, self-dries itself by introducing a heating medium through a built-in heating tube, avoiding cross-contamination. The entire drying process is completed in a stable state with precise centering and no eccentric vibration, ensuring a clean and spotless wafer surface and providing high reliability for subsequent processes. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram showing the top surface orientation of a wafer fixing device and a wafer drying device according to an embodiment of the present invention.

[0022] Figure 2 This is a three-dimensional structural diagram of a wafer fixing device and a wafer drying device according to an embodiment of the present invention, showing the bottom surface facing outwards.

[0023] Figure 3 This is a partial three-dimensional structural cross-sectional view of a wafer fixing device and a wafer drying device according to an embodiment of the present invention.

[0024] Figure 4 This is a planar sectional view of a wafer fixing device and a wafer drying device according to an embodiment of the present invention.

[0025] Figure 5 This is a partial three-dimensional cross-sectional view of multiple alignment components of a wafer fixing device and a wafer drying device according to an embodiment of the present invention. Figure 1 .

[0026] Figure 6 This is a partial three-dimensional cross-sectional view of multiple alignment components of a wafer fixing device and a wafer drying device according to an embodiment of the present invention. Figure 2 .

[0027] Figure 7 This is a three-dimensional structural diagram of a single centering component of a wafer fixing device and a wafer drying device according to an embodiment of the present invention.

[0028] Figure 8 This is a partial three-dimensional cross-sectional view of a single centering component of a wafer fixing device and a wafer drying device according to the present invention.

[0029] Figure 9 This is a partial three-dimensional structural cross-sectional view of the lower flexible pad and heating tube of a wafer fixing device and a wafer drying device according to an embodiment of the present invention.

[0030] Figure 10 yes Figure 9Enlarged diagram of point A in the middle.

[0031] Explanation of reference numerals in the attached drawings: 1. Wafer; 2. Fixed base; 3. Rotating base; 31. Slide rail; 32. Slider; 4. Centering assembly; 41. Housing; 411. Movable block; 412. Fixed block; 4121. Guide rod; 4122. Guide sleeve; 4123. Compression spring; 413. Support part; 42. Upper flexible pad; 421. Heating tube; 43. Lower flexible pad; 5. Electrostatic chuck; 6. Spray frame; 61. Nitrogen nozzle. Detailed Implementation

[0032] To further understand the features, technical means, and specific objectives and functions achieved by the present invention, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

[0033] See Figures 1-6 and Figure 10 As shown, an embodiment of the present invention provides a wafer fixing device including a fixed base 2 and a rotating base 3 disposed thereon. An electrostatic chuck 5 for adsorbing a wafer 1 is fixedly disposed on the rotating base 3. The device also includes a plurality of centering components 4 evenly distributed around the rotating base 3. When all centering components 4 are in operation, the wafer 1 is centered on the electrostatic chuck 5. Each centering component 4 includes a housing 41 and an upper flexible pad 42 and a lower flexible pad 43 symmetrically disposed on the housing 41 along the axial direction of the wafer 1. The outer shell 41 can move radially along the rotating base 3. The upper flexible pad 42 and the lower flexible pad 43 are both arc-shaped structures. The curvature of the arc-shaped contact surface of the upper flexible pad 42 and the lower flexible pad 43 matches the edge contour of the wafer 1 to increase the contact area and reduce the local pressure. The rotating base 3 is provided with a linear actuator for driving the outer shell 41 to move. When the outer shell 41 moves inward, the upper flexible pad 42 and the top edge of the wafer 1 and the lower flexible pad 43 and the bottom edge of the wafer 1 are in a flexible contact state between surfaces.

[0034] After wafer 1 is fed into the device, it is first placed with the chip facing upwards on the electrostatic chuck 5 in the center of the rotating base 3, at which point the electrostatic chuck 5 is not energized. Subsequently, multiple alignment components 4 distributed around the rotating base 3 are simultaneously activated, and the linear actuators in each component drive the housing 41 to move radially inwards along the rotating base 3. As the housing 41 gradually approaches the edge of wafer 1, the upper flexible pad 42 and the lower flexible pad 43 mounted on it also move closer to wafer 1.

[0035] Since both the upper flexible pad 42 and the lower flexible pad 43 are arc-shaped structures, when they contact the top and bottom edges of wafer 1, respectively, pressure is not applied in a point or line manner. Instead, through the elastic deformation of the flexible material itself, continuous and close surface-to-surface contact is formed with the edge of wafer 1. This surface contact significantly increases the actual force-bearing area, effectively dispersing the local stress generated during clamping and avoiding damage such as edge chipping and microcracks caused by stress concentration in traditional rigid grippers.

[0036] During the synchronous inward movement of all alignment components 4, each set of upper flexible pads 42 and lower flexible pads 43 apply alignment force uniformly from the circumference of wafer 1, pushing wafer 1 to slowly slide on the surface of electrostatic chuck 5 until its geometric center is completely aligned with the rotation axis of electrostatic chuck 5 and rotating base 3, thus achieving high-precision automatic alignment.

[0037] After alignment, wafer 1 is stably positioned in the ideal processing location, laying the foundation for subsequent high-speed rotary drying. The entire alignment process is completed by the flexible pad contacting the edge of wafer 1, without any metal or hard parts directly touching the effective area of ​​wafer 1, greatly reducing the risk of particle shedding and surface scratches.

[0038] Meanwhile, because the contact surface is an arc-shaped surface that matches the edge contour of wafer 1, the flexible pad can adaptively fit even if wafer 1 has slight warping or dimensional tolerances, ensuring uniform distribution of alignment force and avoiding deformation of wafer 1 or failure of adsorption due to local overpressure. In addition, this structure can maintain a gentle clamping state after alignment and is fixed by the electrostatic chuck 5, thereby drying the cleaned electrostatic chuck 5 by centrifugation during the high-speed rotation phase, providing a reliable guarantee for the comprehensive cleaning treatment of the wafer 1 surface.

[0039] See Figures 3-6 and Figure 10 As shown, the lower flexible pad 43 is fixedly connected to the outer shell 41, and the upper flexible pad 42 can move vertically relative to the lower flexible pad 43 on the outer shell 41 to adjust the distance between the two. The outer shell 41 is provided with a lifting driver for driving the upper flexible pad 42 to move.

[0040] During the alignment process, to accommodate wafers 1 of varying thicknesses or compensate for minor deformations at the edges of wafer 1, the upper flexible pad 42 can be vertically adjusted relative to the lower flexible pad 43. Once wafer 1 is in place, the lifting driver is activated, pushing the upper flexible pad 42 downwards, gradually reducing the distance between it and the lower flexible pad 43. As the gap decreases, the upper flexible pad 42 gently approaches the top edge of wafer 1 from above, while the lower flexible pad 43 supports the bottom edge of wafer 1 from below. Together, they stably clamp the edge of wafer 1 between them.

[0041] If wafer 1 is thinner, the lift driver will control the upper flexible pad 42 to move downwards by a larger amount to ensure contact and fit. If wafer 1 is thicker, the downward movement will be reduced to avoid overpressure. Throughout the adjustment process, the upper flexible pad 42 maintains compliant contact with the edge of wafer 1, ensuring clamping stability and preventing centering misalignment due to excessive gaps or edge damage due to excessive pressure. It accurately adapts to various wafer 1 sizes, achieving reliable alignment while maintaining a low-stress, non-destructive clamping state.

[0042] See Figures 3-6 and Figure 10 As shown, the inner bottom edge of the upper flexible pad 42 and the inner top edge of the lower flexible pad 43 are both chamfered. The two chamfers are arranged opposite each other and together form a clamping gap to accommodate and flexibly cover the edge of the wafer 1.

[0043] As the upper flexible pad 42 and the lower flexible pad 43 approach the edge of wafer 1, the chamfers on their inner bottom and top edges first contact the upper and lower rounded corner areas of the edge of wafer 1. As they continue to close, these two opposing chamfers cooperate to form a gradually narrowing and contour-matching clamping gap around the edge of wafer 1. This gap is not rigidly closed, but relies on the elasticity of the flexible material to conform to the actual shape of the edge of wafer 1, gently covering the edge of wafer 1 from both the top and bottom, thus avoiding stress concentration caused by sharp edges on wafer 1 and ensuring a smooth transition in the contact area.

[0044] During the clamping process, the edge of wafer 1 is completely contained within the space enclosed by the double chamfers, and the force is evenly distributed across the entire arc-shaped contact surface, effectively preventing local crushing or edge chipping. At the same time, it provides reliable support for stable positioning during subsequent rotation, achieving a non-destructive, close fit, and highly adaptable edge constraint effect.

[0045] See Figure 5 As shown, the linear actuator includes a slide rail 31 and a slider 32. The slide rail 31 is fixedly mounted on the rotating base 3 and extends radially therein. The slider 32 is slidably mounted on the slide rail 31 and is fixedly connected to the housing 41.

[0046] When the centering action is initiated, the housing 41 needs to move precisely inward or outward along the radial direction of the rotating base 3. At this time, the slider 32, which is fixedly connected to the housing 41, slides smoothly along the slide rail 31, which is fixed to the rotating base 3 and extends radially, guiding the housing 41 to travel strictly in a straight radial direction. Since the slide rail 31 is rigidly connected to the rotating base 3, even during high-speed rotation or frequent reciprocating motion, it can be ensured that the movement trajectory of the housing 41 always remains aligned with the rotation center, avoiding swaying or jamming.

[0047] The cooperation between slider 32 and slide rail 31 provides high guiding accuracy and good load-bearing capacity, ensuring that multiple centering components 4 are subjected to uniform force and consistent displacement during the synchronous advancement of housing 41, thereby guaranteeing that wafer 1 is pushed to the center position uniformly and symmetrically. The entire movement process is smooth and reliable, laying the mechanical foundation for achieving high repeatability automatic centering.

[0048] See Figure 8 As shown, the outer casing 41 is provided with a movable block 411 and a fixed block 412 for mounting the upper flexible pad 42 and the lower flexible pad 43. The bottom of the outer casing 41 is provided with a support part 413 for the fixed block 412 to be fixedly connected. The outer casing 41 is provided with a sliding groove along its height direction for the movable block 411 to be slidably disposed therein.

[0049] Inside the outer casing 41, the lower flexible pad 43 is securely connected to the support portion 413 at the bottom of the outer casing 41 via the fixing block 412, and its position remains unchanged. The upper flexible pad 42 is mounted on the movable block 411, which is constrained within a groove opened along the height direction of the outer casing 41 and can only slide up and down in the vertical direction.

[0050] When the clamping gap needs to be adjusted, the movable block 411 moves smoothly in the slide, causing the upper flexible pad 42 to move closer to or further away from the lower flexible pad 43. The entire movement is precisely guided by the sidewall of the slide, preventing skewing or shaking. This ensures that the upper flexible pad 42 remains axially aligned with the lower flexible pad 43 during the lifting and lowering process, enabling them to work together to uniformly cover the edge of the wafer 1. This achieves adaptive clamping of wafers 1 of different thicknesses while maintaining the stability and repeatability of the clamping action.

[0051] See Figure 8 As shown, the fixed block 412 is provided with a guide rod 4121 extending vertically upward, and the movable block 411 is provided with a guide sleeve 4122 that slides with the guide rod 4121. A compression spring 4123, which is sleeved on the guide rod 4121 and used to assist the movable block 411 in resetting upward, is fixedly connected between the guide sleeve 4122 and the fixed block 412.

[0052] When the upper flexible pad 42 needs to move downward to clamp the wafer 1, the movable block 411 presses down vertically, causing the guide sleeve 4122 to slide synchronously on the guide rod 4121, while simultaneously compressing the compression spring 4123 located between the guide sleeve 4122 and the fixed block 412. The compression spring 4123 stores elastic potential energy after being compressed and applies an upward restoring force to the movable block 411. Once the external downward pressure is removed or reduced, the compression spring 4123 releases its energy, pushing the guide sleeve 4122 upward along the guide rod 4121, thereby smoothly resetting the movable block 411 and the upper flexible pad 42 to their initial positions.

[0053] Throughout the process, the cooperation between the guide rod 4121 and the guide sleeve 4122 ensures the verticality and stability of the lifting trajectory of the movable block 411, preventing deflection or jamming. The compression spring 4123 not only realizes the automatic reset function, but also provides buffering and flexibility for the clamping process, so that the upper flexible pad 42 can fit the edge of the wafer 1 with controllable force, avoiding rigid impact, improving the reliability of clamping and the protection effect of the wafer 1.

[0054] See Figure 8 and Figure 9 As shown, the fixed block 412 is equipped with a pressure sensor for detecting the compression force of the compression spring 4123, and the pressure sensor is electrically connected to the lifting drive.

[0055] As the upper flexible pad 42 moves downward to clamp the wafer 1, the compression spring 4123 is gradually compressed. The reaction force generated by the spring acts synchronously on the pressure sensor, which monitors the compression force on the compression spring 4123 in real time and converts the corresponding force signal into an electrical signal and transmits it to the lifting driver. The lifting driver dynamically adjusts its output action according to the received pressure feedback.

[0056] When the clamping force is detected to be close to the preset safety threshold, the downward pressure is immediately reduced or stopped to prevent excessive contact force from damaging the edge of wafer 1. If the clamping force is insufficient, the position is further fine-tuned to ensure effective adhesion. The entire clamping process achieves active adjustment of the contact force, ensuring stable positioning of wafer 1 while maintaining a non-destructive and flexible clamping force range, thereby improving the device's adaptability to wafers 1 of different thicknesses and warpages and enhancing process reliability.

[0057] See Figures 3-6 As shown, this embodiment of the invention also provides a wafer drying apparatus, including a rotary driver mounted on a fixed base 2 for driving a rotating base 3 to rotate around its axis, and a wafer fixing device as described above.

[0058] At the start of the drying process, the wafer 1, which has been aligned and attracted by the electrostatic chuck 5, is started together with the rotating base 3. At this time, the rotary driver mounted on the fixed base 2 drives the rotating base 3 to rotate at high speed around its axis, so that the wafer 1 enters a high-speed rotation state synchronously. Since the wafer 1 has been precisely centered by the flexible alignment component 4 and firmly attracted by the electrostatic chuck 5, the entire rotation process is smooth and without eccentricity, avoiding surface damage or positioning failure caused by vibration or slippage.

[0059] As the rotational speed rapidly increases to the set value, the residual cleaning solution on the surface of wafer 1 is quickly flung outward radially under centrifugal force, detaching from the surface and edge areas of wafer 1. The entire rotary drying process relies on the coordinated operation of high-precision fixation and stable drive to ensure that wafer 1 is dried in a clean, undamaged, and blind-zone-free state, providing high-quality surface conditions for subsequent processes.

[0060] See Figure 4 As shown, it also includes a fluid jetting system, which includes a jetting frame 6 and a plurality of nitrogen nozzles 61 arranged circumferentially around the rotating base 3 on the jetting frame 6.

[0061] As wafer 1 rotates at high speed with the rotating base 3, multiple nitrogen nozzles 61 arranged circumferentially above it are activated simultaneously, spraying high-purity nitrogen gas from the spray frame 6 onto the surface of wafer 1. The airflow sweeps across the front area of ​​wafer 1 in a uniform manner, working in conjunction with centrifugal force to quickly blow away and remove residual water film and tiny droplets.

[0062] Because the nitrogen nozzles 61 are symmetrically distributed circumferentially, the airflow covers all areas without dead zones, effectively removing any moisture that may be trapped near the edge of wafer 1 and the contact area with the flexible pad, preventing water stains or particle deposition. Simultaneously, the inert nitrogen environment inhibits the re-adhesion of airborne impurities onto the surface of wafer 1, further enhancing the drying and cleanliness.

[0063] See Figure 7 , Figure 9 and Figure 10 As shown, both the upper flexible pad 42 and the lower flexible pad 43 are made of water-absorbing material, and both the upper flexible pad 42 and the lower flexible pad 43 are provided with heating tubes 421 for introducing heating medium to dry the pads after they have absorbed water.

[0064] During the drying process of wafer 1, the upper flexible pad 42 and the lower flexible pad 43, due to their water-absorbing material properties, will actively absorb the residual moisture that was not completely removed from the edge of wafer 1 during high-speed rotation, and achieve efficient and traceless drying in conjunction with subsequent nitrogen blowing.

[0065] After the drying stage, external equipment introduces a heating medium into the heating tube 421, or the heating tube 421 itself is set to electric heating, raising the overall temperature of the pad. The moisture adsorbed inside evaporates due to the heat and is carried away by the airflow, thus achieving rapid drying of the pad itself. This ensures that the flexible pad is restored to a dry state before the next process, avoiding cross-contamination due to residual moisture or affecting the cleanliness of subsequent wafer 1 clamping.

[0066] In this embodiment, wafer 1 is placed first in a de-energized state, and then synchronously radially advanced by the circumferential alignment component 4. The curved upper flexible pad 42 and lower flexible pad 43 form a surface-to-surface flexible contact with the edge of wafer 1, achieving high-precision automatic alignment and effectively dispersing clamping stress. Combined with the vertically adjustable structure of the upper flexible pad 42 and the contour-matching clamping gap formed by the double chamfers, it adapts to different thicknesses and warped wafers 1, avoiding edge chipping, micro-cracks, or overpressure damage.

[0067] Throughout the clamping process, no hard parts come into contact with the chip area, reducing the risk of scratches. After alignment, the electrostatic chuck 5 holds the wafer 1 in place, gently constrained by the pad, and achieves high-speed, stable rotation driven by the rotary driver. Simultaneously, circumferentially arranged nitrogen nozzles 61 spray high-purity nitrogen, working in conjunction with centrifugal force to efficiently remove surface and edge moisture, eliminating drying blind spots. The pad uses absorbent material for active moisture absorption and is self-drying via built-in heating tube 421, preventing cross-contamination and ensuring a clean, damage-free, and highly reliable process throughout.

[0068] The above embodiments only illustrate one or more implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of protection of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A wafer fixing device characterized by comprising: The utility model relates to a wafer centering device for electrostatic chucking, comprising: a fixed base (2) and a rotating base (3) arranged thereon, the rotating base (3) being fixedly provided with an electrostatic chuck (5) for chucking a wafer (1); a plurality of centering assemblies (4) evenly arranged on the circumferential side of the rotating base (3), the position of the wafer (1) on the electrostatic chuck (5) being in a centered state when all the centering assemblies (4) are in a working state; wherein each centering assembly (4) comprises an outer shell (41) and an upper flexible pad (42) and a lower flexible pad (43) arranged on the outer shell (41) in an axial symmetry with respect to the wafer (1); the outer shell (41) being capable of moving radially along the rotating base (3); the upper flexible pad (42) and the lower flexible pad (43) each being in an arc shape; the curvature of the arc contact surfaces of the upper flexible pad (42) and the lower flexible pad (43) matching the edge profile of the wafer (1) so as to increase the contact area and reduce the local pressure; the rotating base (3) being provided with a linear driver for driving the outer shell (41) to move; when the outer shell (41) moves inward, the upper flexible pad (42) and the top edge of the wafer (1) and the lower flexible pad (43) and the bottom edge of the wafer (1) are in a flexible contact state of surface-to-surface.

2. The wafer fixing device according to claim 1, characterized by: the lower flexible pad (43) being fixedly connected with the outer shell (41), the upper flexible pad (42) being capable of moving vertically on the outer shell (41) relative to the lower flexible pad (43) so as to adjust the distance therebetween, the outer shell (41) being provided with a lifting driver for driving the upper flexible pad (42) to move.

3. The wafer fixing device according to claim 2, characterized by: the inner bottom edge of the upper flexible pad (42) and the inner top edge of the lower flexible pad (43) each being provided with a chamfer, the two chamfers being oppositely arranged and jointly forming a clamping gap for accommodating and flexibly covering the edge of the wafer (1).

4. The wafer fixing device according to claim 1, characterized by: the linear driver comprising a sliding rail (31) and a sliding block (32), the sliding rail (31) being fixedly arranged on the rotating base (3) and extending radially therefrom, the sliding block (32) being slidingly arranged on the sliding rail (31) and fixedly connected with the outer shell (41).

5. The wafer fixing device according to claim 2, characterized by: the outer shell (41) being provided with a movable block (411) and a fixed block (412) for mounting the upper flexible pad (42) and the lower flexible pad (43), the bottom of the outer shell (41) being provided with a support portion (413) for fixedly connecting the fixed block (412), the outer shell (41) being provided with a sliding groove along the height direction thereof for slidingly arranging the movable block (411) therein.

6. The wafer fixing device according to claim 5, characterized by: the fixed block (412) being provided with a guide rod (4121) extending vertically upward, the movable block (411) being provided with a guide sleeve (4122) slidingly matched with the guide rod (4121), a compression spring (4123) being fixedly connected between the guide sleeve (4122) and the fixed block (412) and sleeved on the guide rod (4121) for assisting the upward reset of the movable block (411).

7. The wafer fixing device according to claim 6, characterized by: the fixed block (412) being provided with a pressure sensor for detecting the compression force of the compression spring (4123), the pressure sensor being electrically connected with the lifting driver.

8. The wafer fixation device of claim 1, wherein: The upper flexible pad (42) and the lower flexible pad (43) are made of water-absorbing material, and the inside of the upper flexible pad (42) and the lower flexible pad (43) is provided with a heating pipe (421) for passing in heating medium to dry the water-absorbed pad.

9. A wafer drying apparatus comprising a rotation driver installed on a fixed base (2) to drive a rotating base (3) to rotate around its axis, characterized in that, Also included is the wafer fixing device of any one of claims 1-8.

10. The wafer drying apparatus according to claim 9, wherein Also included is a fluid spraying system, which comprises a spraying frame (6) and a plurality of nitrogen gas nozzles (61) arranged on the spraying frame (6) in a circumferential manner above the rotating base (3).

Images