Device for preventing wafer adhesion
By designing a closed circuit for the clamping clips and grounding rings to eliminate residual charge on the electrostatic chuck, the problems of wafer sticking and skipping are solved, ensuring stable wafer transport and recycling, and is especially suitable for wafers made of special materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-04-07
AI Technical Summary
JR-type electrostatic chucks have difficulty quickly and completely eliminating static charge after the process, causing the wafer to stick to the chuck, affecting transport and recycling, and even causing problems such as fragmentation or positional displacement, which is more serious when using wafers of special materials.
Design a device to prevent wafer sticking, including a clip, a grounding pressure ring and a supporting bottom ring. The clip is not grounded during the coating process, but is vertically raised to ground after the process is completed, forming a closed circuit with the grounding pressure ring to eliminate residual charge.
This effectively solves the problem of wafer fragmentation or inability to be properly recycled due to excessive residual charge sticking to the electrostatic chuck, ensuring the stability and integrity of the wafer during the transport process.
Smart Images
Figure CN121816004A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor and integrated circuit manufacturing technology, and specifically to a device for preventing wafer sticking. Background Technology
[0002] In semiconductor manufacturing, electrostatic chucks (ESCs) are typically used to fix and support wafers. By applying an electrostatic field, opposite charges are induced on the wafer surface, causing the wafer to adhere to the chuck through electrostatic force. Due to their minimal wafer damage, high processing precision, high cleanliness, and high thermal conductivity, ESCs are widely used in plasma and vacuum processes, such as thin film deposition, ion implantation, and etching.
[0003] Currently, mainstream electrostatic chucks are mainly divided into two categories according to their working principle: Coulomb type and Johnson-Labec type (JR type). (1) Coulomb type electrostatic chucks mainly rely on the Coulomb force between the wafer and the electrode to adsorb the wafer, and its adsorption force is relatively weak. (2) The dielectric layer of the JR type electrostatic chuck is not a complete insulator. Charged particles will migrate under the action of the electric field and gather near the surface of the dielectric layer, which can generate extremely strong adsorption force at a low voltage. Therefore, it is favored in applications where the adsorption force requirement is high.
[0004] However, the working principle of the JR-type electrostatic chuck also brings a significant technical challenge: severe residual charge after the process. Its adsorption mechanism relies on the charge being deeply "trapped" within the dielectric. After the process ends and the applied voltage is stopped, the charge cannot dissipate quickly and naturally, resulting in a persistent electrostatic force between the ESC and the wafer. Transporting the wafer under these conditions leads to a series of problems and consequences: (1) Glue: When the lift pin rises to lift the wafer, the residual electrostatic force will hinder the separation of the wafer from the ESC surface, causing the wafer to "stick" to the chuck, resulting in the failure of the robotic arm to pick up the wafer, interrupting the production process, and in severe cases, it will cause the arm to collide with the wafer, resulting in serious consequences such as wafer scratches or arm breakage.
[0005] (2) Wafer jumping: When the wafer is lifted, it receives both an upward force and a downward electrostatic force. The wafer may slide sideways, bounce, or even flip violently when it is separated from the ESC due to the sudden release of electrostatic force. This will not only cause the wafer to shift position and make the robotic arm misaligned, affecting the coating accuracy of subsequent processes, but in severe cases, it may also cause the wafer to break or collide with the robotic arm or the inner wall of the chamber, resulting in wafer breakage and chamber contamination.
[0006] When the wafer material to be processed is special (such as SiC / GaN / GaAs / Glass, etc.) or the surface substrate structure is special (such as a large oxide layer thickness), its surface resistivity will be higher than that of ordinary silicon wafers, making it more difficult to eliminate static charge, and the above problems will be more frequent and severe.
[0007] To address the aforementioned technical problems, existing technologies typically employ the following solutions: 1. Option 1: After the process is completed, apply a reverse voltage to the ESC to neutralize the original electric field and eliminate static charge. The above option has the following technical drawbacks: (1) Poor stability: The reverse voltage is generally executed according to the preset time and voltage parameters, which is difficult to control precisely. The neutralization effect is unstable. If the neutralization is insufficient, the static electricity elimination effect is poor. If the neutralization is excessive, it is easy to reverse charge, which aggravates the problem.
[0008] (2) Poor repeatability: The amount of residual charge generated after each process is not constant and it is difficult to eliminate it perfectly with a fixed set of reverse voltage parameters.
[0009] 2. Option Two: After the wafer fabrication process is completed, back-blown gas is continuously introduced to the back of the wafer via an electrostatic chuck to neutralize and control the charge. The above option has the following technical drawbacks: The main function of backblown gas is heat conduction. It is less efficient at eliminating residual static electricity and may cause an imbalance in charge distribution, thus failing to completely solve the transmission problem caused by electrostatic adsorption.
[0010] JR-type electrostatic chucks have difficulty quickly and completely eliminating the static charge accumulated on the chuck and wafer surface, causing products to fail to adhere properly to the chuck and be transferred normally. Summary of the Invention
[0011] This invention addresses the technical problems existing in the prior art by providing a device for preventing wafer adhesion.
[0012] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A device for preventing wafer sticking includes: a clamping clip, a grounding ring, and a supporting bottom ring. The supporting bottom ring is horizontally arranged and has an elastic component mounted on it. The grounding ring is horizontally distributed on the supporting bottom ring, and the elastic component presses against the grounding ring. The grounding ring is used to support the wafer. Alternatively, the grounding ring is horizontally fixed on the supporting bottom ring, and a semiconductor electrode is provided on its upper surface; The clips are in the form of a ring and are horizontally distributed above the grounding ring. The clips are connected to the grounding ring through conductive components to press the wafer. After being raised vertically, the clips are grounded and together with the grounding ring form a closed circuit to eliminate residual charge on the wafer.
[0013] The beneficial effects of the present invention are: during use, the clip remains ungrounded during the wafer coating process and is pressed against the grounding ring by its own weight, so as to compress the elastic component to the shortest distance, ensuring that the grounding ring will not contact the clip and avoid affecting the normal process; After the wafer coating process is completed, the clamp is lifted vertically and grounded instantly. Due to the reduced force on the elastic component, the grounding pressure ring is lifted by the elastic component and comes into contact with the wafer. The conductive component connects the grounding pressure ring and the clamp. At this time, the wafer can be grounded at all edges before it is ready for recycling, eliminating some of the residual charge on the wafer surface. This effectively solves the problem of wafers sticking to the electrostatic chuck due to excessive residual charge, resulting in fragmentation or inability to be recycled normally.
[0014] This invention has a simple structure and reasonable design. During the wafer coating process, the clamp is not grounded. After the wafer coating process is completed, the clamp is raised vertically to ground and forms a closed circuit with the grounding pressure ring to eliminate the residual charge on the wafer. This effectively solves the problem of wafers sticking to the electrostatic chuck due to excessive residual charge, resulting in fragmentation or inability to be properly recycled.
[0015] Based on the above technical solution, the present invention can be further improved as follows.
[0016] Furthermore, a raised ring extends from the upper edge of the grounding ring, and the raised ring is used to support the wafer.
[0017] The advantages of adopting the above-mentioned further solution are that the structure is simple, and the protruding ring extending from the upper edge of the grounding ring is more reasonable. This facilitates the assembly of the grounding ring and supports the wafer, making the operation easier.
[0018] Furthermore, the raised ring is provided with a plurality of positioning grooves evenly spaced along its circumference, and the clamping piece is provided with a plurality of positioning pins evenly spaced vertically along its circumference, with the lower ends of the plurality of positioning pins extending into the plurality of positioning grooves respectively.
[0019] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The multiple positioning pins assembled on the clamp plate correspond one-to-one with the multiple positioning grooves set on the protruding ring, so that the clamp plate and the grounding pressure ring are aligned, which facilitates the rapid assembly of the clamp plate and the grounding pressure ring, with high assembly efficiency and saving time and effort.
[0020] Furthermore, the conductive component includes flexible conductive sheets, with two conductive sheets disposed opposite each other between the clamp and the grounding ring; the two conductive sheets are respectively vertically arranged, with their two ends connected to the clamp and the protruding ring respectively.
[0021] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The conductive sheet is used to connect the clamping plate and the grounding pressure ring so that a closed circuit is formed between the clamping plate and the grounding pressure ring, which facilitates the elimination of residual charge on the wafer and effectively solves the problem of wafer fragmentation or inability to be properly recycled due to excessive residual charge sticking to the electrostatic chuck. In addition, the two conductive plates mentioned above are made of flexible material and are reasonably designed to ensure that the conductive plates will not break during the lifting and lowering of the clamp and grounding ring, thereby ensuring the normal operation of the entire equipment.
[0022] Furthermore, the two conductive sheets are copper sheets.
[0023] The advantages of adopting the above-mentioned further solution are that the structure is simple, and it is more reasonable to use copper sheets for the two conductive sheets. This can not only realize the connection between the clamp and the grounding pressure ring to achieve conductivity, but also prevent the conductive sheets from breaking during the lifting and lowering of the clamp and the grounding pressure ring, thereby ensuring the normal operation of the entire equipment.
[0024] Furthermore, the upper ends of the two conductive sheets are respectively connected to the clamping piece via right-angle fixing pieces.
[0025] The advantages of adopting the above-mentioned further solution are that the structure is simple, the upper ends of the two conductive sheets are connected by right-angle fixing plates and clamps, which is more reasonable, avoids mutual interference between the various components, and is easy to assemble.
[0026] Furthermore, the upper ends of the two conductive sheets are respectively connected to the protruding ring through square fixing pieces, and the protruding ring is provided with a pair of mounting grooves facing each other, with the two square fixing pieces distributed opposite each other in the pair of mounting grooves.
[0027] The advantages of adopting the above-mentioned further solution are that the structure is simple, the lower ends of the two conductive sheets are reasonably connected to the raised ring with square fixing plates, which avoids mutual interference between the various components and is easy to assemble.
[0028] Furthermore, the elastic component includes a plurality of springs, which are evenly distributed at intervals along the circumference of the support bottom ring between the support bottom ring and the grounding pressure ring, with their two ends respectively abutting against the support bottom ring and the grounding pressure ring.
[0029] The beneficial effect of adopting the above-mentioned further solution is that during use, the clip remains ungrounded during the wafer coating process and is pressed against the grounding pressure ring by its own weight, so as to compress multiple springs to the shortest distance, ensuring that the grounding pressure ring will not contact the clip and avoid affecting the normal process. After the wafer coating process is completed, the clamp is lifted vertically and grounded instantly. As the force on the multiple springs decreases, the grounding pressure ring is lifted by the multiple springs and comes into contact with the wafer. The conductive component connects the grounding pressure ring and the clamp. At this time, the wafer can be grounded at all edges before it is ready for recycling, eliminating some of the residual charge on the wafer surface. This effectively solves the problem of wafers sticking to the electrostatic chuck due to excessive residual charge, resulting in fragmentation or inability to be recycled normally.
[0030] Furthermore, the support bottom ring is provided with a plurality of limiting grooves evenly spaced along its circumference, and the plurality of springs are vertically distributed in the plurality of limiting grooves, with their upper ends extending to the outside of the plurality of limiting grooves and respectively abutting against the grounding pressure ring.
[0031] The advantages of adopting the above-mentioned further solution are that the structure is simple, and it is reasonable to set multiple limiting grooves at even intervals on the support bottom ring, which can not only assemble multiple springs, but also ensure the stability of the assembly of multiple springs.
[0032] Furthermore, multiple limiting posts are fixedly connected at uniform intervals along the circumference of the lower surface of the grounding pressure ring. The multiple limiting posts are vertically distributed and their lower ends extend into the multiple limiting grooves. The multiple springs are slidably sleeved on the multiple limiting posts.
[0033] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. By using multiple springs and multiple limit posts, it is possible to achieve stable assembly of multiple springs and stable lifting and lowering of the grounding pressure ring, making the operation more convenient. Attached Figure Description
[0034] Figure 1 This is one of the assembly drawings in the wafer coating process of this invention; Figure 2 This is the second assembly diagram of the wafer coating process in this invention; Figure 3 This is the third assembly diagram in the wafer coating process of this invention; Figure 4 This is the fourth assembly diagram of the wafer coating process in this invention; Figure 5 This is an overall cross-sectional view of the wafer coating process in this invention; Figure 6 This is a partial cross-sectional view of the wafer coating process in this invention; Figure 7 This is one of the assembly drawings after the wafer coating process is completed in this invention; Figure 8 This is the second assembly drawing after the wafer coating process is completed in this invention; Figure 9This is the third assembly drawing after the wafer coating process is completed in this invention; Figure 10 This is the fourth assembly drawing after the wafer coating process is completed in this invention; Figure 11 This is an overall cross-sectional view of the wafer coating process completed in this invention; Figure 12 This is a schematic diagram illustrating charge elimination after the wafer coating process in this invention. Figure 13 This is one of the overall exploded views of the present invention; Figure 14 This is the second exploded view of the present invention; Figure 15 This is the third exploded view of the present invention; Figure 16 This is one of the structural schematic diagrams of the grounding pressure ring in this invention; Figure 17 This is the second schematic diagram of the grounding pressure ring in this invention; Figure 18 This is a schematic diagram of the supporting bottom ring structure in this invention.
[0035] The attached diagram lists the components represented by each number as follows: 1. Positioning pin; 2. Hex bolt; 3. Clamping plate; 4. Grounding pressure ring; 41. Raised ring; 42. Positioning groove; 43. Mounting groove; 44. Limiting post; 5. Right-angle fixing plate; 6. Spring; 7. Square fixing plate; 8. Support bottom ring; 81. Limiting groove; 9. Conductive plate; 10. Electrostatic chuck; 11. Wafer. Detailed Implementation
[0036] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0037] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0038] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this technology based on the specific circumstances.
[0039] In the description of this application, spatial relation terms such as "below," "under," "below," "below," "above," "over," etc., are used herein to describe the relationship between one element or feature shown in the figures and other elements or features. It should be understood that, in addition to the orientation shown in the figures, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figures is flipped, an element or feature described as "below" or "under" or "below" of other elements or features will be oriented "above" other elements or features. Therefore, the exemplary terms "below" and "under" can include both upper and lower orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein are interpreted accordingly.
[0040] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.
[0041] Example 1 like Figures 1 to 18 As shown, this embodiment provides a device for preventing wafer sticking, including: a clamping piece 3, a grounding pressure ring 4, and a supporting bottom ring 8. The supporting bottom ring 8 is horizontally arranged and an elastic component is installed on it. The grounding pressure ring 4 is horizontally distributed on the supporting bottom ring 8, and the elastic component presses against the grounding pressure ring 4. The grounding pressure ring 4 is used to support the wafer 11. Alternatively, the grounding ring 4 is horizontally fixed on the supporting bottom ring 8, and a semiconductor electrode is provided on its upper surface; The clip 3 has a circular structure and is horizontally distributed above the grounding pressure ring 4. The clip 3 is connected to the grounding pressure ring 4 through a conductive component to press the wafer 11. After it is vertically raised, it is grounded and together with the grounding pressure ring 4, it forms a closed circuit to eliminate the residual charge on the wafer 11.
[0042] During use, the clip 3 remains ungrounded during the wafer 11 coating process and is pressed against the grounding ring 4 by its own weight to compress the elastic component to the shortest distance, ensuring that the grounding ring 4 does not contact the clip 3 and avoid affecting the normal process. After the coating process of wafer 11 is completed, the clamp 3 is lifted vertically and grounded instantly. Due to the reduced force on the elastic component, the grounding pressure ring 4 is lifted by the elastic component and comes into contact with wafer 11. The conductive component connects the grounding pressure ring 4 and the clamp 3. At this time, the entire edge of wafer 11 can be grounded before it is ready for recycling, eliminating some of the charge remaining on the surface of wafer 11. This effectively solves the problem of wafer 11 sticking to the electrostatic chuck 10 due to excessive residual charge, resulting in fragmentation or inability to be recycled normally.
[0043] Preferably, in this embodiment, the clamping piece 3, the grounding pressure ring 4, and the supporting bottom ring 8 are all preferably circular ring structures, which are reasonably designed, convenient for assembly, and can be matched with the wafer 11 to facilitate the coating of the wafer 11.
[0044] This embodiment has a simple structure and reasonable design. During the wafer coating process, the clamp is not grounded. After the wafer coating process is completed, the clamp is raised vertically to ground and forms a closed circuit with the grounding pressure ring to eliminate the residual charge on the wafer. This effectively solves the problem of wafers being fragmented or unable to be properly recycled due to excessive residual charge sticking to the electrostatic chuck.
[0045] Example 2 Based on Embodiment 1, in this embodiment, a raised ring 41 extends from the upper edge of the grounding ring 4, and the raised ring 41 is used to support the wafer 11.
[0046] The design is simple in structure. The protruding ring 41 extending from the upper edge of the grounding ring 4 is reasonable. It facilitates the assembly of the grounding ring 4 and supports the wafer 11, making the operation easier.
[0047] Preferably, in this embodiment, the protruding ring 41 is preferably a circular ring structure.
[0048] Example 3 Based on Embodiment 2, in this embodiment, the protruding ring 41 is provided with a plurality of positioning grooves 42 evenly spaced along its circumference, and the clamping piece 3 is provided with a plurality of positioning pins 1 evenly spaced vertically along its circumference, with the lower ends of the plurality of positioning pins 1 extending into the plurality of positioning grooves 42 respectively.
[0049] The scheme has a simple structure and reasonable design. It utilizes the multiple positioning pins 1 mounted on the clamping plate 3 to correspond one-to-one with the multiple positioning grooves 42 set on the protruding ring 41, so that the clamping plate 3 and the grounding pressure ring 4 are aligned, which facilitates the rapid assembly of the clamping plate 3 and the grounding pressure ring 4, with high assembly efficiency and saving time and effort.
[0050] Preferably, in this embodiment, the number of the above-mentioned positioning pins 1 is three, and the three positioning pins 1 are evenly distributed on the clip 3.
[0051] In addition, the clip 3 is provided with three through holes that pass through from top to bottom at even intervals, and three positioning pins 1 are fixedly inserted into the three through holes.
[0052] Preferably, in this embodiment, the number of the above-mentioned positioning grooves 42 is preferably three, and the three positioning grooves 42 are preferably semi-circular grooves, which are convenient to cooperate with the three positioning pins 1 respectively.
[0053] Example 4 Based on any one of Embodiments 2 to 3, in this embodiment, the conductive component includes a flexible conductive sheet 9, and two conductive sheets 9 are disposed opposite to each other between the clamping piece 3 and the grounding ring 4; the two conductive sheets 9 are respectively vertically arranged, and their two ends are respectively connected to the clamping piece 3 and the protruding ring 41.
[0054] During use, the clip 3 remains ungrounded during the wafer 11 coating process and is pressed against the grounding ring 4 by its own weight to compress the elastic component to the shortest distance, ensuring that the grounding ring 4 does not contact the clip 3 and avoid affecting the normal process. After the coating process of wafer 11 is completed, the clamping piece 3 is lifted vertically and grounded instantly. Due to the reduced force on the elastic component, the grounding pressure ring 4 is lifted by the elastic component and comes into contact with wafer 11. The two conductive pieces 9 connect the grounding pressure ring 4 and the clamping piece 3. At this time, the wafer 11 can be grounded at all edges before it is ready for recycling, eliminating some of the charge remaining on the surface of wafer 11. This effectively solves the problem that wafer 11 is stuck to the electrostatic chuck 10 due to excessive residual charge, resulting in fragments or inability to be recycled normally.
[0055] The scheme has a simple structure and reasonable design. It uses conductive sheet 9 to connect clamp 3 and grounding ring 4 so that clamp 3 and grounding ring 4 form a closed circuit, which facilitates the elimination of residual charge on wafer 11 and effectively solves the problem of wafer 11 being fragmented or unable to be properly recycled due to excessive residual charge sticking to electrostatic chuck 10. In addition, the two conductive plates mentioned above are made of flexible material and are reasonably designed to ensure that the conductive plates will not break during the lifting and lowering of the clamp and grounding ring, thereby ensuring the normal operation of the entire equipment.
[0056] Preferably, in this embodiment, the two conductive sheets 9 are respectively elongated sheet-like structures.
[0057] Example 5 Based on Example 4, in this example, the two conductive sheets 9 are copper sheets.
[0058] The scheme has a simple structure. It is more reasonable to use copper sheets for the two conductive plates 9. This can not only realize the connection between the clamp 3 and the grounding pressure ring 4 to achieve conductivity, but also prevent the conductive plates 9 from breaking during the lifting and lowering of the clamp 3 and the grounding pressure ring 4, thus ensuring the normal operation of the entire equipment.
[0059] Preferably, in this embodiment, the copper sheet is a thin copper sheet with a thickness of <0.2mm, has a fixed length and width, deforms but does not break when the clamping plate 3 rises, connects the clamping plate 3 and the grounding pressure ring 4, so that the clamping plate 3 and the grounding pressure ring 4 are electrically connected, and has good conductivity and flexibility.
[0060] Example 6 Based on any one of Embodiments 4 to 5, in this embodiment, the upper ends of the two conductive sheets 9 are respectively connected to the clamping sheet 3 by right-angle fixing pieces 5.
[0061] The scheme has a simple structure. The upper ends of the two conductive sheets 9 are connected to the clamping sheet 3 by a right-angle fixing piece 5, which is more reasonable, avoids mutual interference between the components, and is easy to assemble.
[0062] Preferably, in this embodiment, one end of each right-angle fixing piece 5 extends horizontally and is fixedly connected to the clamping piece 3 by a hexagonal bolt 2.
[0063] In addition, the other end of each of the right-angle fixing pieces 5 extends vertically and is fixedly connected to the corresponding conductive piece 9 by bolts.
[0064] Moreover, the aforementioned right-angle fixing piece 5 is a square patch.
[0065] Alternatively, an arc-shaped fixing piece can be used instead of the right-angle fixing piece 5 mentioned above.
[0066] Example 7 Based on any one of Embodiments 4 to 6, in this embodiment, the upper ends of the two conductive sheets 9 are respectively connected to the protruding ring 41 through square fixing pieces 7, and a pair of mounting grooves 43 are provided on the protruding ring 41, with the two square fixing pieces 7 distributed opposite to each other in the pair of mounting grooves 43.
[0067] The design is simple in structure. The lower ends of the two conductive sheets 9 are connected to the raised ring 41 by square fixing pieces 7, which is reasonable and avoids mutual interference between the components. It is also easy to assemble.
[0068] Preferably, the pair of mounting slots 43 are rectangular slots, the specific shape of which is adapted to the two square fixing pieces 7 so as to facilitate the assembly of the square fixing pieces 7.
[0069] In addition, the aforementioned square fixing piece 7 is a square patch.
[0070] Example 8 Based on the above embodiments, in this embodiment, the elastic component includes a plurality of springs 6, which are evenly distributed at intervals along the circumference of the support bottom ring 8 between the support bottom ring 8 and the grounding pressure ring 4, with their two ends abutting against the support bottom ring 8 and the grounding pressure ring 4 respectively.
[0071] During use, the clip 3 remains ungrounded during the wafer 11 coating process and presses against the grounding ring 4 by its own weight to compress the multiple springs 6 to the shortest distance, ensuring that the grounding ring 4 does not contact the clip and avoid affecting the normal process. After the coating process of wafer 11 is completed, the clamp 3 is lifted vertically and grounded instantly. As the force on multiple springs 6 decreases, the grounding pressure ring 4 is lifted by multiple springs 6 and comes into contact with wafer 11. The conductive component connects the grounding pressure ring 4 and the clamp 3. At this time, the edge of wafer 11 can be grounded before it is ready for recycling, eliminating some of the charge remaining on the surface of wafer 11. This effectively solves the problem of wafer 11 sticking to the electrostatic chuck 10 due to excessive residual charge, resulting in fragmentation or inability to be recycled normally.
[0072] Example 9 Based on embodiment 8, in this embodiment, the supporting bottom ring 8 is provided with a plurality of limiting grooves 81 evenly spaced along its circumference, and the plurality of springs 6 are vertically distributed in the plurality of limiting grooves 81, with their upper ends extending to the outside of the plurality of limiting grooves 81 and respectively abutting against the grounding pressure ring 4.
[0073] The design is simple in structure. It is reasonable to set multiple limiting grooves 81 at even intervals on the supporting bottom ring 8, which can not only assemble multiple springs 6, but also ensure the stability of the assembly of multiple springs 6.
[0074] Alternatively, a large spring can be used to replace the multiple small springs 6 mentioned above. In this case, the two ends of the large spring abut against the clamp 3 and the grounding pressure ring 4, respectively.
[0075] In addition, when a large spring is used to replace the multiple small springs 6, a limiting annular groove can be set on the support bottom ring 8, and the large spring is distributed in the limiting annular groove.
[0076] Example 10 Based on Embodiment 9, in this embodiment, a plurality of limiting posts 44 are fixedly connected at uniform intervals along the circumference of the lower surface of the grounding pressure ring 4. The plurality of limiting posts 44 are vertically distributed and their lower ends extend into the plurality of limiting grooves 81. The plurality of springs 6 are slidably sleeved on the plurality of limiting posts 44.
[0077] The scheme has a simple structure and reasonable design. By using multiple springs 6 and multiple limiting posts 44, it can achieve stable assembly of multiple springs 6 and stable lifting and lowering of grounding pressure ring 4, making the operation more convenient.
[0078] Alternatively, when a limiting annular groove is provided on the support bottom ring 8, the lower surface of the grounding pressure ring 4 can extend downward to the limiting ring, the lower end of which extends into the limiting annular groove, and the large spring is sleeved outside the limiting ring.
[0079] This invention provides a device for preventing wafer sticking, the working principle of which is as follows: During use, the clip 3 remains ungrounded during the wafer 11 coating process and presses against the grounding ring 4 by its own weight to compress the multiple springs 6 to the shortest distance, ensuring that the grounding ring 4 does not contact the clip and avoid affecting the normal process. After the coating process of wafer 11 is completed, the clamp 3 is lifted vertically and grounded instantly. As the force on multiple springs 6 decreases, the grounding pressure ring 4 is lifted by multiple springs 6 and comes into contact with wafer 11. The conductive component connects the grounding pressure ring 4 and the clamp 3. At this time, the edge of wafer 11 can be grounded before it is ready for recycling, eliminating some of the charge remaining on the surface of wafer 11. This effectively solves the problem of wafer 11 sticking to the electrostatic chuck 10 due to excessive residual charge, resulting in fragmentation or inability to be recycled normally.
[0080] In the process of wafer 11 coating, the release of accumulated charge can be accelerated by increasing the back He gas.
[0081] Furthermore, the contact point between the upper surface of the grounding ring 4 and the wafer 11 can be designed to be on the same plane as the electrostatic chuck, and a layer of semiconductor electrodes can be designed on the surface. When the charge on the wafer 11 reaches a certain level, the semiconductor electrodes will conduct and ground. This design allows the device to be adapted to a variety of products, such as thin wafers 11 of varying thicknesses, thus eliminating the need for spring components. The grounding ring 4 and the support bottom ring 8 can be integrated into one unit, avoiding the risk of fragmentation caused by frequent movement of this component.
[0082] This invention proposes a device for preventing wafer sticking. The design of the internal component structure of this device is a solution to the problem of residual charge. The core of the solution lies in the design of a contactable grounding liner mechanism. During the wafer transfer stage after the process is completed, the liner mechanism can move and make physical contact with the wafer to be transferred, providing a low-impedance grounding path for residual static charge on the wafer surface. This enables rapid and sufficient charge discharge, effectively preventing wafer sticking and skipping.
[0083] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the above embodiments are merely exemplary embodiments or examples, and the scope of the invention is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as the technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.
Claims
1. A device for preventing wafer sticking, characterized in that, include: The clamping plate (3), the grounding pressure ring (4) and the supporting bottom ring (8) are arranged horizontally and an elastic component is installed on it; the grounding pressure ring (4) is horizontally distributed on the supporting bottom ring (8) and the elastic component presses against the grounding pressure ring (4); the grounding pressure ring (4) is used to support the wafer (11). Alternatively, the grounding ring (4) is horizontally fixed on the supporting bottom ring (8), and a layer of semiconductor electrode is provided on its upper surface; The clip (3) has a ring-shaped structure and is horizontally distributed above the grounding pressure ring (4). The clip (3) is connected to the grounding pressure ring (4) through a conductive component to press the wafer (11). After it is vertically raised, it is grounded and forms a closed circuit with the grounding pressure ring (4) to eliminate the residual charge on the wafer (11).
2. The device for preventing wafer adhesion according to claim 1, characterized in that, The upper edge of the grounding ring (4) extends into a raised ring (41), which is used to support the wafer (11).
3. The device for preventing wafer adhesion according to claim 2, characterized in that, The protruding ring (41) is provided with a plurality of positioning grooves (42) evenly spaced along its circumference, and the clamping piece (3) is provided with a plurality of positioning pins (1) evenly spaced vertically along its circumference, with the lower ends of the plurality of positioning pins (1) extending into the plurality of positioning grooves (42).
4. The device for preventing wafer adhesion according to claim 2, characterized in that, The conductive component includes a flexible conductive sheet (9), and two conductive sheets (9) are disposed opposite to each other between the clamp (3) and the grounding ring (4); the two conductive sheets (9) are respectively vertically disposed, and their two ends are respectively connected to the clamp (3) and the protruding ring (41).
5. The device for preventing wafer adhesion according to claim 4, characterized in that, The two conductive sheets (9) are copper sheets.
6. The apparatus for preventing wafer adhesion according to claim 4, characterized in that, The upper ends of the two conductive sheets (9) are respectively connected to the clamp (3) by right-angle fixing pieces (5).
7. The apparatus for preventing wafer adhesion according to claim 4, characterized in that, The upper ends of the two conductive pieces (9) are respectively connected to the protruding ring (41) through square fixing pieces (7), and a pair of mounting grooves (43) are provided on the protruding ring (41) opposite to each other, and the two square fixing pieces (7) are distributed opposite to each other in the pair of mounting grooves (43).
8. The apparatus for preventing wafer adhesion according to any one of claims 1-7, characterized in that, The elastic component includes a plurality of springs (6), which are evenly distributed around the support bottom ring (8) and the grounding pressure ring (4) along the circumference of the support bottom ring (8), with their two ends abutting against the support bottom ring (8) and the grounding pressure ring (4) respectively.
9. The apparatus for preventing wafer adhesion according to claim 8, characterized in that, The supporting bottom ring (8) is provided with a plurality of limiting grooves (81) evenly spaced along its circumference. The plurality of springs (6) are vertically distributed in the plurality of limiting grooves (81), and their upper ends extend to the outside of the plurality of limiting grooves (81) and abut against the grounding pressure ring (4).
10. The apparatus for preventing wafer adhesion according to claim 9, characterized in that, On the lower surface of the grounding ring (4), a plurality of limiting posts (44) are fixedly connected at uniform intervals along its circumference. The plurality of limiting posts (44) are vertically distributed and their lower ends extend into the plurality of limiting grooves (81). The plurality of springs (6) are slidably sleeved on the plurality of limiting posts (44).