A chemical mechanical polishing device for preventing over-polishing of edges in silicon wafer processing.

Abstract

This invention relates to the field of chemical mechanical polishing (CMP) technology and discloses an edge-protecting CMP polishing device for silicon wafer processing, comprising a polishing module, wherein the polishing module includes a base, and a polishing disc is rotatably connected inside the base. This edge-protecting CMP polishing device for silicon wafer processing effectively solves the problem in existing CMP equipment where the limiting ring adopts an integrated fixed design. The inner diameter of the limiting ring is usually slightly larger than the diameter of the silicon wafer. However, due to the brittle nature and poor impact resistance of the silicon wafer itself, the edge of the silicon wafer is easily squeezed and rubbed against the inner wall of the limiting ring during loading, which easily leads to silicon wafer breakage and edge chipping. If the inner diameter of the limiting ring is designed to be too large than the diameter of the silicon wafer to avoid breakage during loading, although the risk of collision during loading can be reduced, the silicon wafer will shift and wobble within the limiting ring during polishing, affecting the surface smoothness and processing accuracy of the silicon wafer.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, and more specifically to a chemical mechanical polishing device for preventing over-polishing of edges in silicon wafer processing. Background Technology

[0002] Chemical mechanical polishing (CMP) is a key process for achieving global planarization of semiconductor silicon wafers. During CMP, the silicon wafer is fixed to a polishing head, and pressure is applied while it is rotated to bring it into contact with a high-speed rotating polishing pad. Simultaneously, a polishing slurry is continuously supplied. Through the combined action of chemical etching and mechanical abrasion, material removal is achieved. To ensure the silicon wafer remains stable during polishing, prevent it from flying off, and control the polishing effect at the edges, a limiting ring is typically installed on the polishing head.

[0003] In existing technologies, the limiting ring in chemical mechanical polishing equipment adopts an integrated fixed design. The inner diameter of the limiting ring is usually slightly larger than the diameter of the silicon wafer. However, due to the brittle nature and poor impact resistance of the silicon wafer itself, if the gap between the inner diameter of the limiting ring and the diameter of the silicon wafer is too small, the edge of the silicon wafer is easily squeezed and rubbed against the inner wall of the limiting ring during loading, which can easily cause the silicon wafer to break or chip, resulting in the scrapping of the silicon wafer and increasing processing costs. If the inner diameter of the limiting ring is designed to be too large than the diameter of the silicon wafer to avoid the problem of breakage during loading, although the risk of collision during loading can be reduced, the silicon wafer will shift and shake within the limiting ring during the polishing process, which will affect the polishing flatness and processing accuracy of the silicon wafer surface. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, this invention provides an edge-protecting chemical mechanical polishing (CMP) device for silicon wafer processing. This device effectively solves the problem in existing CMP devices where the limiting ring is an integrated design. The inner diameter of the limiting ring is typically slightly larger than the silicon wafer diameter. However, due to the brittle nature and poor impact resistance of silicon wafers, the gap between the inner diameter of the limiting ring and the wafer diameter is too small. During loading, the edge of the silicon wafer is easily squeezed and rubbed against the inner wall of the limiting ring, easily leading to wafer breakage and chipping, resulting in wafer scrap and increased processing costs. If the inner diameter of the limiting ring is designed to be too large than the wafer diameter to avoid breakage during loading, although this reduces the risk of collision, the silicon wafer will shift and wobble within the limiting ring during polishing, affecting the surface smoothness and processing accuracy.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a chemical mechanical polishing device for preventing over-polishing of edges in silicon wafer processing, comprising: A polishing module, comprising a base, a polishing disc rotatably connected inside the base, and a polishing pad mounted on the upper surface of the polishing disc; A grinding module, comprising a spindle, a bearing head fixedly connected to the bottom end of the spindle, a carrier film mounted on the lower surface of the bearing head, and a positioning component for positioning a silicon wafer provided by a receiving groove formed on the outer surface of the bearing head; The trimming module includes a swing shaft rotatably connected to the upper surface of the base, a trimming arm fixedly connected to the top end of the swing shaft, and a diamond disc fixedly connected to the outer end of the trimming arm.

[0006] Furthermore, it also includes a liquid supply pipe for supplying polishing liquid, and the lower surface of the liquid supply pipe has a drip outlet.

[0007] Furthermore, the limiting component includes a limiting arc plate, a cylinder is fixedly connected to the inner wall side of the receiving groove, and a movable seat that fits against the bottom of the inner wall of the receiving groove is fixedly connected to the output end of the cylinder.

[0008] Furthermore, a limiting post is fixedly connected to the upper surface of the limiting arc plate, and a connecting ear is sleeved on the outer circumference of the limiting post and fixedly connected to the outer surface of the movable seat. A spring is sleeved on the outer circumference of the limiting post and connected to the upper surface of the limiting arc plate.

[0009] Furthermore, four limiting arc plates are provided, and the four limiting arc plates are arranged in a circular array around the main axis, forming a circular structure together.

[0010] Furthermore, the limiting arc plate is internally slidably connected to an abutment rod, the lower surface of the bearing head is provided with a groove that fits against the upper surface of the abutment rod, the end of the abutment rod away from the bearing head is fixedly connected to an end plate, the side of the end plate near the bearing head is provided with a tension spring that connects to the outer surface of the limiting arc plate, the outer side of the abutment rod is provided with a friction groove, and the limiting arc plate is provided with a fixing member through a receiving cavity opened at its end.

[0011] Furthermore, the fixing member includes a locking rod that is slidably connected inside the receiving cavity. The end of the locking rod near the abutment rod is provided with a friction surface that fits against the friction groove. The end of the locking rod away from the abutment rod extends to the outer end of the limiting arc plate and adopts an arc surface design. A connecting plate is fixedly connected to the middle of the locking rod. A spring is provided on the outer surface of the connecting plate that connects to the side wall of the receiving cavity.

[0012] Furthermore, the end of the abutment rod near the bearing head is designed with a concave arc surface, and a rubber pad is provided at the end of the abutment rod near the bearing head.

[0013] The technical solution provided by this invention has the following advantages compared with the prior art: This invention features a support head and a limiting component, resolving the safety hazards associated with existing integrated limiting rings for wafer loading and reducing silicon wafer loss. Through the expandable design of the limiting component, the limiting arc plate can be driven by a cylinder to expand outwards synchronously before clamping the silicon wafer. This maximizes the radius of the circle formed by the rubber pads at the ends of multiple abutment rods, providing ample space for silicon wafer loading. This completely avoids the squeezing and friction between the silicon wafer and the fixed integrated limiting ring during loading, solving the technical hazard of silicon wafer breakage during loading with existing equipment, reducing silicon wafer scrap rates, and lowering processing costs. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0015] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the polishing disc, bearing head, and trimming module according to an embodiment of the present invention; Figure 3 This is a front view of the polishing pad, bearing head, and trimming module according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the grinding module and the silicon wafer being processed according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the grinding module from another perspective in an embodiment of the present invention; Figure 6 This is a cross-sectional structural diagram of the bearing head, carrier membrane, and abutment rod according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the state transformation structure of the limiting arc plate and locking rod in an embodiment of the present invention; Figure 8 This is an embodiment of the present invention. Figure 7 A magnified structural diagram of part A in the middle; Figure 9 This is an embodiment of the present invention. Figure 7 A magnified structural diagram of section B in the middle.

[0016] The labels in the diagram represent: 100. Silicon wafers; 1. Polishing module; 11. Base; 12. Polishing disc; 13. Polishing pad; 2. Grinding module; 21. Spindle; 22. Bearing head; 221. Receiving groove; 222. Slot; 23. Carrier membrane; 24. Limiting component; 241. Limiting arc plate; 2411. Receiving cavity; 242. Cylinder; 243. Moving seat; 2431. Connecting ear; 244. Limiting post; 245. Spring; 246. Abutment rod; 2461. End plate; 2462. Tension spring; 2463. Friction groove; 2464. Rubber pad; 25. Fixing component; 251. Locking rod; 2511. Friction surface; 252. Connecting plate; 253. Spring; 3. Trimming module; 31. Swing shaft; 32. Trimming arm; 33. Diamond disc; 4. Liquid supply pipe; 41. Drip port. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] The present invention will be further described below with reference to embodiments.

[0019] Example:

[0020] Please see Figures 1-9 This invention provides a technical solution: a chemical mechanical polishing device for edge anti-overpolishing in silicon wafer processing, comprising: Polishing module 1 includes a base 11, a polishing disc 12 is rotatably connected inside the base 11, and a polishing pad 13 is installed on the upper surface of the polishing disc 12. The grinding module 2 includes a spindle 21, a bearing head 22 is fixedly connected to the bottom end of the spindle 21, a carrier film 23 is installed on the lower surface of the bearing head 22, and a limiting component 24 for positioning the silicon wafer 100 is provided on the bearing head 22 through a receiving groove 221 formed on its outer surface. The trimming module 3 includes a swing shaft 31 that is rotatably connected to the upper surface of the base 11. A trimming arm 32 is fixedly connected to the top end of the swing shaft 31, and a diamond disc 33 is fixedly connected to the outer end of the trimming arm 32.

[0021] It also includes a liquid supply pipe 4 for supplying polishing liquid, and a drip outlet 41 is provided on the lower surface of the liquid supply pipe 4.

[0022] The limiting component 24 includes a limiting arc plate 241, a cylinder 242 is fixedly connected to the inner wall side of the receiving groove 221, and a movable seat 243 that fits against the bottom of the inner wall of the receiving groove 221 is fixedly connected to the output end of the cylinder 242.

[0023] A limiting post 244 is fixedly connected to the upper surface of the limiting arc plate 241. A connecting ear 2431, which is fixedly connected to the outer surface of the movable seat 243, is sleeved on the outer circumference of the limiting post 244. A spring 245, which is connected to the upper surface of the limiting arc plate 241, is sleeved on the outer circumference of the limiting post 244.

[0024] Four limiting arc plates 241 are provided. The four limiting arc plates 241 are arranged in a circular array around the main shaft 21, and the four limiting arc plates 241 together form a circular structure.

[0025] The limiting arc plate 241 has two slidingly connected abutment rods 246. The two abutment rods 246 are symmetrically distributed around the cylinder 242. The lower surface of the bearing head 22 is provided with a groove 222 that fits against the upper surface of the abutment rod 246. This groove is used to limit and guide the sliding stroke and movement posture of the abutment rod 246. At the same time, the groove 222 can accommodate the abutment rod 246 to float up and down in the vertical direction with the limiting arc plate 241. The end of the abutment rod 246 away from the bearing head 22 is fixedly connected to an end plate 2461. The side of the end plate 2461 near the bearing head 22 is provided with a tension spring 2462 that connects to the outer surface of the limiting arc plate 241. The outer side of the abutment rod 246 is provided with a friction groove 2463. The limiting arc plate 241 is provided with a fixing member 25 through a receiving cavity 2411 opened at its end.

[0026] The fixing member 25 includes a locking rod 251 that is slidably connected inside the receiving cavity 2411. The end of the locking rod 251 near the abutment rod 246 is provided with a friction surface 2511 that fits against the friction groove 2463. The end of the locking rod 251 away from the abutment rod 246 extends to the outer end of the limiting arc plate 241 and adopts an arc surface design. A connecting plate 252 is fixedly connected to the middle of the locking rod 251. A spring 253 connected to the inner wall side of the receiving cavity 2411 is provided on the outer surface of the connecting plate 252.

[0027] The end of the abutment rod 246 near the bearing head 22 has a concave arc surface design, and a rubber pad 2464 is provided at the end of the abutment rod 246 near the bearing head 22.

[0028] In the initial state, the spindle 21 in the grinding module 2 drives the bearing head 22 to be positioned above the polishing pad 13. At this time, the equipment is in standby mode, and all components are in their initial positions. Under the pull of the tension spring 2462, the end plate 2461 is located on the side of its stroke range near the outer circumference of the limiting arc plate 241. At the same time, the abutment rod 246, which is fixedly connected to the end plate 2461, is located on the side of its stroke range near the axis of the bearing head 22. The circle formed by the rubber pads 2464 at the ends of the multiple abutment rods 246 has the smallest radius. The four limiting arc plates 241 are in a closed state, forming a complete annular structure. The locking rod 251 is in an extended state under the elastic force of the spring 253. The friction surface 2511 at its end is tightly fitted with the inner wall of the friction groove 2463 on the side of the abutment rod 246, realizing the relative fixation between the abutment rod 246 and the limiting arc plate 241. Spring 245 is in a naturally extended state, the limiting post 244 and the connecting ear 2431 remain relatively stationary, the moving seat 243 is located at the inner end of the receiving groove 221, and the cylinder 242 is in a retracted state.

[0029] The process of clamping and loading silicon wafer 100: Before clamping the silicon wafer 100, the limiting component 24 needs to be unfolded to facilitate the loading of the silicon wafer 100. At this time, four cylinders 242 are activated simultaneously, and the output ends of the cylinders 242 extend outward, driving the movable seat 243, which is in a retracted state, to unfold outward along the bottom of the inner wall of the receiving groove 221. Since the connecting ear 2431 is fixedly connected to the movable seat 243 and is sleeved on the outer circumferential surface of the limiting post 244, the movable seat 243, during its movement, drives the limiting post 244 to move outward synchronously through the connecting ear 2431, thereby driving the limiting arc plate 241, which is fixedly connected to the limiting post 244, to unfold outward synchronously. The four limiting arc plates 241 unfold circumferentially synchronously, and the end faces of two adjacent limiting arc plates 241 gradually separate, no longer tightly fitted, and the inner diameter of the combined annular structure gradually increases. During this process, the arc surfaces of the locking rods 251 at the ends of the two adjacent limiting arc plates 241 no longer press against each other, and the spring 253 in the receiving cavity 2411 returns to its natural extended state, causing the connecting plate 252 to unfold outward, so that the side of the connecting plate 252 fits against the inner wall surface of the receiving cavity 2411. Under the action of the connecting plate 252, the outer end of the arc surface of the locking rod 251 protrudes to the end of the limiting arc plate 241. At this time, the friction surface 2511 at the inner end of the locking rod 251 no longer fits against the inner wall of the friction groove 2463 on the side of the abutment rod 246, releasing the locking of the abutment rod 246. The abutment rod 246 can slide freely inside the limiting arc plate 241. When the cylinder 242 outputs to its maximum stroke, the limiting arc plate 241 stops moving. At this time, the limiting arc plate 241 is located on the side away from the axis of the bearing head 22 within its stroke range. The area enclosed by multiple limiting arc plates 241 is the largest. At the same time, the radius of the circle enclosed by the rubber pads 2464 at the ends of multiple abutment rods 246 is also the largest, leaving enough space for the subsequent loading of silicon wafers 100.

[0030] After the limiting component 24 is deployed, the silicon wafer 100 to be polished is precisely placed on the upper surface of the polishing pad 13 via the loading arm, and the center of the silicon wafer 100 coincides with the axis of the spindle 21 to ensure uniform force on the silicon wafer 100. After the silicon wafer 100 is loaded, the spindle 21 starts, driving the carrier head 22 to slowly move above the silicon wafer 100 to be polished. After precisely aligning with the silicon wafer 100, the spindle 21 drives the carrier head 22 to slowly descend. During the descent of the carrier head 22, the lower surface of the limiting arc plate 241 will first contact the upper surface of the polishing pad 13. As the carrier head 22 continues to descend, the polishing pad 13 generates an upward reaction force on the limiting arc plate 241. This reaction force is transmitted to the spring 245 through the limiting arc plate 241, causing the spring 245 to compress and deform. The spring 245 generates a downward elastic force and also acts as a buffer for the limiting arc plate 241, preventing rigid collision between the limiting arc plate 241 and the polishing pad 13. The carrier head 22 continues to descend until the upper surface of the silicon wafer 100 to be polished is in close contact with the lower surface of the carrier film 23. At this point, the spindle 21 stops descending. The distance from the lower surface of the limiting arc plate 241 to the lower surface of the carrier film 23 is equal to the thickness of the silicon wafer 100. The carrier film 23 is in close contact with the surface of the silicon wafer 100, which provides a guarantee for subsequent negative pressure adsorption and polishing. At the same time, the limiting arc plate 241 plays a preliminary limiting role in the circumferential direction of the silicon wafer 100.

[0031] After the silicon wafer 100 is bonded to the carrier film 23, the limiting component 24 begins to retract, achieving precise clamping and positioning of the silicon wafer 100. At this time, the output end of the cylinder 242 begins to retract, driving the moving seat 243 to move inward along the lower surface of the inner wall of the receiving groove 221. During the movement, the moving seat 243 drives the limiting post 244 to move inward synchronously through the connecting lug 2431, thereby driving the limiting arc plate 241 to retract synchronously in the direction of the silicon wafer 100. During this process, because the abutment rod 246 is always in the direction of the axis of the bearing head 22 under the tension of the tension spring 2462, as the limiting arc plate 241 retracts towards the silicon wafer 100, the rubber pad 2464 at the inner end of the abutment rod 246 will first come into contact with the side wall of the silicon wafer 100. As the limiting arc plate 241 continues to retract, the squeezing pressure between the rubber pad 2464 and the side wall of the silicon wafer 100 gradually increases, and the rubber pad 2464 undergoes slight deformation, tightly adhering to the side wall of the silicon wafer 100, thus achieving the initial limiting of the silicon wafer 100.

[0032] When the rubber pads 2464 at the inner ends of the multiple abutment rods 246 are all in contact with the sidewall of the silicon wafer 100, as the limiting arc plate 241 continues to contract, the abutment rods 246 will remain relatively stationary with the silicon wafer 100. At this time, the limiting arc plate 241 continues to move inward, and a relative displacement occurs between the abutment rods 246 and the limiting arc plate 241. The abutment rods 246 slide along the inside of the limiting arc plate 241 in a direction away from the axis of the bearing head 22, and the tension spring 2462 is further stretched, generating a greater tension force, which further increases the compressive force between the rubber pads 2464 and the sidewall of the silicon wafer 100, thereby improving the limiting stability. At this time, the four limiting arc plates 241 have not yet closed into a whole ring shape, there is still a gap between two adjacent limiting arc plates 241, the locking rod 251 is still in the extended state, and the friction surface 2511 at its end is not in contact with the inner wall of the friction groove 2463 on the side of the abutment rod 246, so the abutment rod 246 can continue to slide along the limiting arc plate 241.

[0033] As cylinder 242 continues to contract, it drives the limiting arc plate 241 to move further inward. The ends of two adjacent limiting arc plates 241 gradually approach each other. When the four limiting arc plates 241 are about to close into a complete circular shape, the arc ends of the locking rods 251 at the ends of the two adjacent limiting arc plates 241 come into contact with each other. As the limiting arc plate 241 continues to move, a mutual squeezing force is generated between the two locking rods 251. This force pushes the locking rods 251 to contract into the receiving cavity 2411. The locking rods 251 slide inside the receiving cavity 2411, driving the connecting plate 252 to move inward synchronously. The connecting plate 252 squeezes the spring 253, causing the spring 253 to undergo elastic deformation and be in a compressed state. When the four limiting arc plates 241 are completely closed into a single ring, the locking rod 251 is completely retracted into the receiving cavity 2411. At this time, the friction surface 2511 at the inner end of the locking rod 251 is in close contact with the inner wall of the friction groove 2463 on the side of the abutment rod 246. Since the friction surface 2511 adopts a rough structure design, it can increase the friction between it and the inner wall of the friction groove 2463, thereby firmly fixing the abutment rod 246 in the current position, realizing the relative fixation between the abutment rod 246 and the limiting arc plate 241, further improving the limiting stability of the silicon wafer 100, and preventing the silicon wafer 100 from shifting during the polishing process. At this time, the rubber pad 2464 maintains a stable compressive force with the sidewall of the silicon wafer 100 to ensure the limiting effect. The spring 245 is in a compressed state and generates a downward elastic force on the limiting arc plate 241, so that the lower surface of the limiting arc plate 241 is always in close contact with the upper surface of the polishing pad 13, forming a supporting effect on the edge of the silicon wafer 100, and avoiding over-polishing of the edge of the silicon wafer 100 due to excessive force during the polishing process.

[0034] After the limiting component 24 completes the clamping and positioning of the silicon wafer 100, it activates the negative pressure adsorption tube inside the carrier head 22. The upper surface of the silicon wafer 100 is adsorbed and fixed by negative pressure adsorption, so that the silicon wafer 100 is firmly fixed between the carrier film 23 and the abutment rod 246, further improving the positioning stability of the silicon wafer 100 and preventing the silicon wafer 100 from loosening or shifting during the polishing process.

[0035] The process of polishing and grinding the lower surface of silicon wafer 100: After the silicon wafer 100 is fixed, the polishing module 1, trimming module 3, and liquid supply pipe 4 are activated to begin chemical mechanical polishing of the silicon wafer 100. The polishing disc 12 rotates at a constant speed under the drive of the base 11, causing the polishing pad 13 on its surface to rotate synchronously. The spindle 21 drives the bearing head 22 to rotate at a constant speed, thereby causing the silicon wafer 100 to rotate synchronously. The lower surface of the silicon wafer 100 is in close contact with the rotating polishing pad 13, removing protrusions from the surface of the silicon wafer 100 through mechanical abrasion. Simultaneously, the liquid supply pipe 4 continuously drips polishing liquid onto the surface of the polishing pad 13 through the drip nozzle 41. Under the rotation of the polishing pad 13, the polishing liquid is evenly distributed between the polishing pad 13 and the silicon wafer 100. The chemical substances in the polishing liquid react chemically with the substances on the surface of the silicon wafer 100, generating easily removable compounds, which are then removed by the mechanical abrasion of the polishing pad 13, achieving planarization polishing of the surface of the silicon wafer 100.

[0036] During the polishing process, the trimming module 3 operates synchronously. The swing shaft 31 drives the trimming arm 32 to swing at a uniform speed. The trimming arm 32 drives the diamond disc 33 on its lower outer surface to swing synchronously. The lower surface of the diamond disc 33 is in close contact with the upper surface of the polishing pad 13, trimming the surface of the polishing pad 13 and removing wear and debris caused by grinding. This ensures that the surface of the polishing pad 13 remains flat and clean, guaranteeing that the grinding force of the polishing pad 13 on the silicon wafer 100 is uniform and consistent, further preventing over-polishing of the edges of the silicon wafer 100. At the same time, the limiting component 24 always provides a stable limiting effect on the silicon wafer 100. The rubber pad 2464 at the end of the abutment rod 246 is in close contact with the sidewall of the silicon wafer 100, preventing the silicon wafer 100 from shifting and providing buffer protection for the edges of the silicon wafer 100. This balances the grinding force between the edges and the center area of ​​the silicon wafer 100, effectively preventing over-polishing of the edges.

[0037] After the silicon wafer 100 is polished, the polishing module 1, trimming module 3, and liquid supply pipe 4 are shut down, and the rotation of the polishing disc 12, spindle 21, and swing shaft 31, as well as the supply of polishing liquid, are stopped. Then, the negative pressure adsorption tube inside the bearing head 22 is closed to release the negative pressure adsorption on the silicon wafer 100. Then, the four cylinders 242 are started simultaneously, causing the output end of the cylinder 242 to extend outward, driving the moving seat 243 and the limiting arc plate 241 to unfold outward again. The two adjacent limiting arc plates 241 separate, and the locking rod 251 extends under the elastic force of the spring 253, releasing the lock on the abutment rod 246. The abutment rod 246 resets under the tension of the tension spring 2462, separating from the side wall of the silicon wafer 100, and releasing the limitation on the silicon wafer 100. Finally, the spindle 21 drives the bearing head 22 to rise, away from the polishing pad 13 and the silicon wafer 100, and the polished silicon wafer 100 is removed by the loading arm, completing one chemical mechanical polishing operation of the silicon wafer 100.

[0038] In summary, this chemical mechanical equipment offers the following advantages when polishing silicon wafer 100: Firstly, it solves the safety hazards of existing integrated limiting ring feeding systems and reduces silicon wafer 100 loss. Existing equipment uses an integrated fixed limiting ring design, with a fixed gap between the inner diameter of the limiting ring and the diameter of the silicon wafer 100. Either the gap is too small, causing the edge of the silicon wafer 100 to collide and rub against the inner wall of the limiting ring during feeding, easily leading to breakage and chipping; or the gap is too large, causing positioning failure. However, this equipment, through the unfoldable design of the limiting component 24, allows the limiting arc plate 241 to unfold synchronously outward via the cylinder 242 before clamping the silicon wafer 100. This maximizes the radius of the circle formed by the rubber pads 2464 at the ends of the multiple abutment rods 246, reserving sufficient space for the silicon wafer 100 feeding. This completely avoids collisions and friction between the silicon wafer 100 and the limiting component during feeding, fundamentally solving the technical hazard of easy breakage during feeding on existing equipment, reducing the scrap rate of silicon wafer 100, and reducing processing costs.

[0039] Secondly, the existing integrated limiting ring structure is fixed and cannot be fine-tuned according to the actual placement position of the silicon wafer 100. Furthermore, excessive gaps can cause the silicon wafer 100 to wobble or slide circumferentially, affecting processing accuracy. This equipment achieves precise positioning through multi-layer limiting cooperation. First, four limiting arc plates 241 are arranged in a circumferential array around the main shaft 21, forming a circular structure after closing, achieving a uniform circumferential limiting reference. During the closing process of the limiting arc plates 241, the abutment rod 246, under the action of the tension spring 2462, always tends to move towards the axis of the bearing head 22. Its end rubber pad 2464 can tightly adhere to the sidewall of the silicon wafer 100, achieving flexible and precise abutment. Meanwhile, when the limiting arc plate 241 is closed, the locking rod 251 in the fixing member 25 is tightly fitted with the friction groove 2463 of the abutment rod 246 through the friction surface 2511, so as to realize the relative fixation of the abutment rod 246 and the limiting arc plate 241, further improving the limiting stability. Finally, in conjunction with the negative pressure adsorption tube inside the bearing head 22, the silicon wafer 100 is firmly fixed between the carrier film 23 and the abutment rod 246, completely avoiding the silicon wafer 100 from shifting or loosening during the polishing process, and ensuring the processing accuracy.

[0040] Thirdly, existing equipment lacks a dedicated edge protection structure. During polishing, the edge of the silicon wafer 100 is prone to greater force than the center area, easily leading to over-polishing and uneven thickness of the silicon wafer 100. This equipment, through the close-fitting support design of the limiting arc plate 241 and the polishing pad 13, ensures that after the bearing head 22 descends into position, the spring 245 is compressed, generating a downward elastic force on the limiting arc plate 241. This keeps the lower surface of the limiting arc plate 241 in close contact with the upper surface of the polishing pad 13, providing stable support for the edge of the silicon wafer 100. Simultaneously, the flexible buffering effect of the rubber pad 2464 balances the grinding force between the edge and center areas of the silicon wafer 100. Combined with the real-time trimming of the polishing pad 13 by the trimming module 3, this ensures that the grinding force of the polishing pad 13 on the silicon wafer 100 is uniform and consistent, effectively preventing over-polishing and improving the surface flatness and processing quality of the silicon wafer 100.

[0041] Fourth, the existing integrated limiting ring structure is fixed and cannot adjust the inner diameter. When changing silicon wafers 100 of different specifications, the entire limiting ring must be disassembled and replaced, which is cumbersome, has high maintenance costs, and affects the efficiency of continuous operation. This equipment, through the adjustable design of the limiting component 24, can adjust the expansion range of the limiting arc plate 241 through the cylinder 242, and adapt to silicon wafers 100 of different diameters through the sliding cooperation of the abutment rod 246. Without disassembling or replacing any limiting components, it can achieve precise positioning and polishing of silicon wafers 100 of different specifications, greatly improving the practicality of the equipment, reducing maintenance costs, and avoiding the operation interruption caused by replacing the limiting ring, thus ensuring continuous production.

[0042] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chemical mechanical polishing (CMP) device for edge anti-overpolishing in silicon wafer processing, characterized in that, include: A polishing module, comprising a base, a polishing disc rotatably connected inside the base, and a polishing pad mounted on the upper surface of the polishing disc; A grinding module, comprising a spindle, a bearing head fixedly connected to the bottom end of the spindle, a carrier film mounted on the lower surface of the bearing head, and a positioning component for positioning a silicon wafer provided by a receiving groove formed on the outer surface of the bearing head; The trimming module includes a swing shaft rotatably connected to the upper surface of the base, a trimming arm fixedly connected to the top end of the swing shaft, and a diamond disc fixedly connected to the outer end of the trimming arm.

2. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 1, characterized in that: It also includes a liquid supply pipe for supplying polishing liquid, and the lower surface of the liquid supply pipe has a drip outlet.

3. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 1, characterized in that: The limiting component includes a limiting arc plate, and a cylinder is fixedly connected to the inner wall side of the receiving groove. The output end of the cylinder is fixedly connected to a movable seat that fits against the bottom end of the inner wall of the receiving groove.

4. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 3, characterized in that: The upper surface of the limiting arc plate is fixedly connected to a limiting post, the outer circumference of the limiting post is fitted with a connecting ear that is fixedly connected to the outer surface of the movable seat, and the outer circumference of the limiting post is fitted with a spring that is connected to the upper surface of the limiting arc plate.

5. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 4, characterized in that: The limiting arc plate is provided in four ways. The four limiting arc plates are arranged in a circular array around the main axis, and together they form a circular structure.

6. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 5, characterized in that: The limiting arc plate is internally slidably connected to an abutment rod. The lower surface of the bearing head is provided with a groove that fits against the upper surface of the abutment rod. The end of the abutment rod away from the bearing head is fixedly connected to an end plate. The side of the end plate near the bearing head is provided with a tension spring that connects to the outer surface of the limiting arc plate. The outer side of the abutment rod is provided with a friction groove. The limiting arc plate is provided with a fixing member through a receiving cavity opened at its end.

7. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 6, characterized in that: The fixing component includes a locking rod that is slidably connected inside the receiving cavity. The end of the locking rod near the abutment rod is provided with a friction surface that fits into the friction groove. The end of the locking rod away from the abutment rod extends to the outer end of the limiting arc plate and adopts an arc surface design. A connecting plate is fixedly connected to the middle of the locking rod. A spring plate is provided on the outer surface of the connecting plate that connects to the side wall of the receiving cavity.

8. The edge anti-overpolishing chemical mechanical polishing equipment for silicon wafer processing according to claim 7, characterized in that: The end of the abutment rod near the bearing head has a concave arc surface design, and a rubber pad is provided at the end of the abutment rod near the bearing head.

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