Drop-proof lifting mechanism, chemical mechanical polishing unit and chemical mechanical polishing equipment

Abstract

The invention provides an anti-droplet lifting mechanism, a chemical mechanical polishing unit and chemical mechanical polishing equipment, the anti-droplet lifting mechanism comprises a sleeve, a guide cylinder and a lifting rod which are sequentially arranged from outside to inside, the upper end of the lifting rod is fixedly connected with the top surface of the sleeve, and the sleeve is driven to synchronously ascend and descend; a plurality of stopping blocks are arranged on the outer surface of the guide cylinder at intervals in a staggered manner and are used for stopping liquid drops from entering the upper surface of the guide cylinder along a gap between the sleeve and the guide cylinder and guiding the liquid drops to flow down along at least one surface of the stopping blocks; therefore, liquid drops are effectively prevented from entering the lifting mechanism, the maintenance and cleaning cost is reduced, shutdown maintenance caused by damage of the lifting mechanism is prevented, and the wafer production efficiency and yield are improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing equipment, and in particular to a droplet-proof lifting mechanism, a chemical mechanical polishing unit, and a chemical mechanical polishing device. Background Art

[0002] Chemical Mechanical Polishing (CMP) is a method for achieving global planarization in integrated circuit manufacturing. A large amount of polishing liquid and water are used in the chemical polishing process. The centrifugal force generated by the rotation of moving parts such as the polishing head and the polishing disk will throw the liquid to the periphery of the polishing disk. The polishing liquid splashes to various parts of the polishing space and is difficult to clean completely. The polishing liquid crystallizes into particles in the polishing space. Even very small particles can become a source of pollution in the entire working environment, which may cause scratches on the surface of the wafer and reduce the wafer yield.

[0003] The prior art proposes a lifting ring for blocking liquid, which is installed on the lifting mechanism. When performing chemical mechanical polishing, the lifting mechanism drives the ring to rise above the polishing plate. However, this brings new problems. A large amount of liquid adheres to the lifting mechanism and enters the lifting mechanism as the lifting mechanism rises and falls, affecting the operation of the lifting mechanism. Summary of the invention

[0004] The embodiments of the present application provide an anti-droplet lifting mechanism, a chemical mechanical polishing unit and a chemical mechanical polishing device, which are intended to solve at least one of the technical problems existing in the prior art.

[0005] An embodiment of the present application provides a droplet-proof lifting mechanism, comprising a sleeve, a guide sleeve and a lifting rod arranged in sequence from the outside to the inside, the upper end of the lifting rod is fixedly connected to the top surface of the sleeve, driving the sleeve to rise and fall synchronously, and the outer surface of the guide sleeve is provided with a plurality of blocking blocks at intervals and staggered thereon, for blocking droplets from entering the upper surface of the guide sleeve along the gap between the sleeve and the guide sleeve and guiding droplets to flow down along at least one surface of the blocking blocks.

[0006] In one embodiment, the blocking blocks are arranged in multiple layers, the blocking blocks in each layer are at the same height, and the blocking blocks in two adjacent layers are staggered in a direction along the outer surface of the guide cylinder.

[0007] In one embodiment, the blocking block includes a top surface, two side surfaces, a bottom surface and a front surface, and the top surface includes a first downward slope surface with a certain arc or angle from the middle to the two side surfaces, respectively, for guiding the droplets on the top surface to flow downward obliquely.

[0008] In one embodiment, each of the two side surfaces comprises a second slope surface which is downwardly sloping at a certain arc or angle toward the middle direction of the bottom surface, so as to guide the liquid droplets on the two side surfaces to flow downward obliquely.

[0009] In one embodiment, the bottom surface includes a third slope surface extending downward from the middle to the two side surfaces at a certain arc or angle, respectively, for guiding the liquid droplets on the lower surface to flow downward obliquely.

[0010] In one embodiment, the blocking blocks of the two adjacent layers are staggered in a direction along the outer surface of the guide tube, including that droplets flowing obliquely along the second slope surface or the third slope surface of the blocking block of the upper layer gather at the junction of the second slope surface and the third slope surface and then drip downward onto the first slope surface of the blocking block of the next layer.

[0011] In one embodiment, the upper surface of the guide tube includes a fourth downward sloped surface with a certain arc or angle from the center to the outer surface, which is used to guide the droplets on the upper surface of the guide tube to flow down obliquely; the edge of the upper surface of the guide tube includes a plurality of drainage grooves arranged at intervals, and the bottom surface of the drainage groove is consistent with the outer surface of the guide tube in the vertical direction, and the distance between the surface of the spacing portion between the plurality of drainage grooves and the inner wall of the sleeve is greater than the distance between the front face of the blocking block and the inner wall of the sleeve.

[0012] Another embodiment of the present application provides a chemical mechanical polishing unit, comprising a carrier head, a polishing disc, a polishing pad, a dressing device, a polishing liquid supply device and a plurality of anti-drip lifting mechanisms provided by any of the aforementioned embodiments, wherein the plurality of anti-drip lifting mechanisms are arranged at equal intervals on the periphery of the circumference of the polishing disc, and a retaining ring surrounding the polishing disc is commonly installed on the sleeves of the plurality of anti-drip lifting mechanisms; when the chemical mechanical polishing unit uses the carrier head, the polishing disc, the polishing pad, the dressing device and the polishing liquid supply device to perform polishing and cleaning operations, the lifting rods of the plurality of anti-drip lifting mechanisms rise synchronously, so that the retaining ring is higher than the polishing disc, so as to prevent the liquid on the polishing disc from splashing around; the retaining ring is configured not to affect the polishing and cleaning operations.

[0013] Another embodiment of the present application provides a chemical mechanical polishing device, comprising the chemical mechanical polishing unit provided in the aforementioned embodiment, wherein the chemical mechanical polishing unit is used to perform chemical mechanical polishing on a wafer.

[0014] In one embodiment, the chemical mechanical polishing equipment also includes a loading and unloading part, and the carrying head moves between a polishing position and an interaction position, the polishing position is a position for performing polishing and cleaning operations, and the polishing position is above the polishing disk; the interaction position is a position for interacting the wafer with the loading and unloading part, and the interaction position is outside the retaining ring.

[0015] The beneficial effects of the embodiments of the present application include: effectively blocking liquid droplets from entering the interior of the lifting mechanism, reducing maintenance and cleaning costs, preventing downtime maintenance caused by damage to the lifting mechanism, and improving wafer production efficiency and yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic diagram of a polishing unit and a loading and unloading part in a chemical mechanical polishing device in the prior art.

[0018] Figure 2 yes Figure 1 Schematic diagram of the lifting mechanism and retaining ring of the middle polishing unit in the low and high positions.

[0019] Figures 3 to 5 yes Figure 2 Schematic diagram of droplets gathering and entering the interior of the lifting mechanism during repeated lifting.

[0020] Figure 6 It is a structural schematic diagram of the anti-drip lifting mechanism of the present application.

[0021] Figure 7 yes Figure 6 Schematic diagram of the middle anti-drip lifting mechanism sleeve when it is raised.

[0022] Figure 8 yes Figure 6 Schematic diagram of the three-dimensional structure of the guide cylinder of the anti-droplet lifting mechanism.

[0023] Fig. 9 yes Figure 6 Schematic diagram of the longitudinal section of the middle anti-drip lifting mechanism.

[0024] Fig.10 yes Figure 6 Front view of the blocking block of the middle anti-drip lifting mechanism.

[0025] Fig.11 yes Figure 6Schematic diagram of the anti-droplet lifting mechanism blocking and directing droplets.

[0026] Reference numerals :

[0027] 100-polishing unit; 200-loading and unloading part; 400-retaining ring;

[0028] 10-carrying head; 20-polishing disc; 30-polishing pad; 40-dressing device; 41-dressing arm; 42-dressing head; 50-polishing liquid supply device; 60-liquid drop; 70-liquid

[0029] 300-existing lifting mechanism; 310-sleeve; 320-guide cylinder; 321-blocking block; 322-top surface of blocking block; 322a, 322b-first slope surface; 323, 324-side surface of blocking block; 323a, 324a-second slope surface; 325-bottom surface of blocking block; 325a, 325b-third slope surface; 326-front surface of blocking block; 327-upper surface of guide cylinder; 328-drainage groove; 329-spacer; 330-lifting rod;

[0030] 1000-Chemical mechanical polishing unit of the present application; 3000-Anti-drip lifting mechanism of the present application. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the embodiments of the present application should fall within the scope of protection of the embodiments of the present application.

[0032] In the description of the present application, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In addition, in the description of the present application, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0034] Figure 1 It is a schematic diagram of the positions of the polishing unit 100 and the loading and unloading part 200 in the prior art chemical mechanical polishing equipment. The loading and unloading part 200 is arranged adjacent to the polishing unit 100 to facilitate the transfer of wafers.

[0035] The polishing unit 100 includes a carrier head 10, a polishing disk 20, a polishing pad 30, a dressing device 40 and a polishing liquid supply device 50; the polishing pad 30 is arranged on the upper surface of the polishing disk 20 and rotates therewith; the horizontally movable carrier head 10 is arranged above the polishing pad 30, and the lower surface of the carrier head 10 attracts the wafer to be polished; the dressing device 40 includes a dressing arm 41 and a dressing head 42, and the dressing arm 41 drives the rotating dressing head 42 to swing to dress the surface of the polishing pad 30 to a state suitable for polishing; the polishing liquid supply device 50 spreads the polishing liquid on the surface of the polishing pad 30; during the polishing operation, the carrier head 10 presses the surface of the wafer to be polished to the surface of the polishing pad 30, and the polishing liquid is distributed between the polishing pad 30 and the wafer, and the removal of the wafer surface material is completed under the action of chemical machinery.

[0036] In chemical mechanical polishing, the operation process of each wafer mainly includes:

[0037] 1) Wafer suction process: the carrier head 10 is moved to the top of the loading and unloading part and then the wafer placed on the loading and unloading part is sucked to the bottom of the carrier head 10;

[0038] 2) Polishing process, the wafer is loaded onto the polishing pad by the carrier head 10 for polishing;

[0039] 3) Wafer unloading process: after polishing is completed, the wafer is transported back by the carrier head 10 and unloaded onto the loading and unloading part.

[0040] During the polishing operation, the liquid on the polishing disk is thrown out to the outside of the polishing disk by the centrifugal force generated by the rotation of moving parts such as the polishing head and the polishing disk. The thrown-out liquid includes not only polishing liquid and water containing a variety of chemical solutions and abrasive particles, but also impurities such as metal ions, silicon or silicon oxide particles generated in the polishing process. These impurities are highly corrosive and easily form crystals, making them difficult to clean and easily damaging the wafer.

[0041] In order to prevent the liquid thrown off the polishing disc from causing pollution, such as Figure 2As shown, the polishing unit 100 also includes a lifting mechanism 300 and a retaining ring 400 fixedly installed with the lifting mechanism 300. The lifting mechanism 300 is a columnar structure as a whole, and a plurality of lifting mechanisms 300 are evenly spaced and distributed on the outer side of the circumference of the polishing disc 20 to jointly support and drive the retaining ring 400 to rise and fall. During the film suction and unloading process, the lifting mechanism 300 drives the retaining ring 400 to be in a low position, as shown by the solid line. When in the low position, the upper end surface of the retaining ring 400 is not higher than the disc surface of the polishing disc 20, and will not interfere with the movement of the bearing head, etc.; during the polishing process, the lifting mechanism 300 drives the retaining ring 400 to be in a high position, as shown by the dotted line. When in the high position, the lower end surface of the retaining ring 400 is not higher than the disc surface of the polishing disc 20, forming a barrier to the liquid thrown out of the polishing disc.

[0042] The lifting mechanism 300 includes a sleeve 310, a guide sleeve 320, a lifting rod 330 and a cylinder 340 (not shown). The sleeve 310 is fixedly connected to the retaining ring 400. The guide sleeve 320 and the cylinder 340 are fixedly installed on the machine platform where the polishing unit 100 is located. The guide sleeve 320 has a hollow structure to accommodate the lifting rod 330. The lifting rod 330 passes through the hollow structure of the guide sleeve 320 and is fixedly connected to the top surface of the sleeve 310. Under the action of the cylinder 340, the lifting rod 330 is extended and retracted along the hollow structure of the guide sleeve 320, driving the sleeve 310 to rise and fall. The sleeves 310 of multiple lifting mechanisms 300 rise synchronously to jointly drive the retaining ring 400 to be in a high position, and the sleeves 310 of multiple lifting mechanisms 300 fall synchronously to jointly drive the retaining ring 400 to be in a low position.

[0043] like Figure 3 As shown, when the sleeve 310 of the lifting mechanism 300 rises, the guide cylinder 320 is exposed to the outside. On the one hand, the liquid thrown out will splash around after colliding with the surface of the guide cylinder 320. Some of the droplets splashed upward may directly enter the upper surface of the guide cylinder 320 from the gap between the sleeve 310 and the guide cylinder 320 and form adhesion; on the other hand, due to the viscosity of the chemical solution and the force between impurities, the small droplets splashed on the surface of the guide cylinder 320 are likely to remain on the surface of the guide cylinder 320 and form droplets 60 with strong adhesion. Figures 4 to 5 As shown, during the repeated lifting and lowering of the sleeve 310, the droplets attached to the surface of the guide cylinder 320 will adhere to the inner wall of the sleeve 310, and as the sleeve 310 rises, the liquid 70 will be gathered on the upper surface of the guide cylinder 320, and then enter the hollow structure of the guide cylinder 320 along the direction of the arrow. Once the liquid 70 flows into the cylinder through the hollow structure of the guide cylinder 320 and the lifting rod 330, the lifting rod 330 will not be able to be lifted smoothly, and even damage the cylinder. In addition, the liquid that enters the upper surface of the guide cylinder 320 is not easy to clean, and crystals will form on the upper surface of the guide cylinder 320, the surface of the hollow structure, and the surface of the lifting rod, affecting the normal lifting and lowering of the sleeve, and may even collapse onto the polishing pad, causing scratches on the surface of the wafer, reducing the wafer yield.

[0044] In order to solve the above technical problems, Figures 6 to 9 As shown, the anti-droplet lifting mechanism 3000 disclosed in the present application includes a sleeve 310, a guide cylinder 320, a lifting rod 330, and a cylinder 340 (not shown) which are arranged in sequence from the outside to the inside. The sleeve 310 is sleeved on the outside of the guide cylinder 320. The guide cylinder 320 has a hollow structure to accommodate the lifting rod 330. The upper end of the lifting rod 330 extends out of the upper surface of the guide cylinder 320 and is fixedly connected to the top surface of the sleeve 310. The guide cylinder 320 and the cylinder 340 are fixedly installed on the machine platform where the lifting mechanism 3000 is located. Under the action of the cylinder 340, the lifting rod 330 is extended and retracted along the hollow structure of the guide cylinder 320, driving the sleeve 310 to rise and fall.

[0045] In one embodiment, the outer surface of the guide tube 320 is provided with a plurality of blocking blocks 321, which are arranged at intervals and staggered along the outer surface of the guide tube 320 to prevent liquid droplets from entering the upper surface of the guide tube 320 along the gap between the sleeve 310 and the guide tube 320. Specifically, the plurality of blocking blocks 321 are distributed in two directions, the first part of the blocking blocks 321 are arranged at intervals in a direction around the outer surface of the guide tube 320, and the second part of the blocking blocks 321 are arranged higher or lower than the first part of the blocking blocks 321 in the vertical direction, and are arranged at intervals corresponding to the gaps between the first part of the blocking blocks 321, so that the two parts of the blocking blocks 321 form an interval and staggered maze structure. Preferably, the blocking blocks 321 are also arranged to have a shape or structure that is conducive to the liquid droplets attached to the surface of the blocking blocks 321 to flow down.

[0046] like Figure 7 and Fig.11As shown, when the sleeve 310 rises, the guide cylinder 320 is exposed to the outside, and the liquid thrown out splashes around after colliding with the surface of the guide cylinder 320. The upward splashing droplets will be blocked by the spaced and staggered blocking blocks 321, and cannot continue to enter the gap between the sleeve 310 and the guide cylinder 320. At the same time, the liquid thrown out will directly collide with the spaced and staggered blocking blocks 321. Compared with the droplets splashing around after colliding with the surface of the guide cylinder 320, the splashing direction of the droplets after colliding with the blocking blocks 321 will be more random and dispersed, and it is difficult to form droplets 60 with strong adhesion on the surface of the blocking blocks 321. The experimental results show that most of the droplets either fall on the machine platform where the lifting mechanism 3000 is located after splashing, or flow down along the surface of the blocking blocks 321 and the gaps between them or along the surface of the guide cylinder 320 to the machine platform where the lifting mechanism 3000 is located, so as to be guided and collected; the remaining small part of the droplets mainly adhere to the surface of the guide cylinder 320 in the gaps between the blocking blocks 321. Due to the existence of the blocking block 321, the distance between the inner wall of the sleeve 310 and the surface of the guide tube 320 at the gap between the blocking block 321 is relatively large, and during the repeated descent and ascent of the sleeve 310, the droplets are not easily adhered to the inner wall of the sleeve 310. In other words, compared with the prior art, the present embodiment can not only directly block the droplets splashing upward, but also work together from two aspects: accelerating the downward discharge of the droplets and reducing the "contact" area between the inner wall of the sleeve 310 and the surface of the guide tube 320, thereby reducing the possibility of droplets adhering to the side wall of the sleeve 310 during the ascent and descent, and effectively blocking the droplets from entering the upper surface of the guide tube 320 as the sleeve 310 rises.

[0047] In one embodiment, multiple layers of blocking blocks 321 are evenly spaced along the vertical direction on the surface of the guide cylinder 320, and the blocking blocks 321 of each layer are at the same height and are spaced around the outer surface of the guide cylinder 320, and the blocking blocks 321 of two adjacent layers are staggered along the outer surface of the guide cylinder 320. Preferably, as Figures 6 to 8 As shown, four layers of blocking blocks 321 are arranged on the surface of the guide cylinder 320 in the vertical direction, and the blocking blocks 321 of each layer are at the same height and are arranged at intervals around the outer surface of the guide cylinder 320. The positions of the first layer of blocking blocks 321 and the third layer of blocking blocks 321 are completely consistent in the direction along the outer surface of the guide cylinder 320, and the positions of the second layer of blocking blocks 321 and the fourth layer of blocking blocks 321 are completely consistent in the direction along the outer surface of the guide cylinder 320. The second layer of blocking blocks 321 are aligned with and completely cover the gaps between the first layer of blocking blocks 321 in the direction along the outer surface of the guide cylinder 320, so that the four layers of blocking blocks 321 together form a staggered maze structure, which has a better blocking effect on the upward splashing droplets.

[0048] In one embodiment, Fig.10As shown, the blocking block 321 includes a top surface 322, two side surfaces 323 and 324, a bottom surface 325 and a front surface 326. The top surface 322 includes a first slope surface 322a and a first slope surface 322b which are downwardly oriented from the middle to the two side surfaces 323 and 324 at a certain arc or a certain angle. When the splashing droplets adhere to or flow to the top surface 322, the shape of the top surface 322 is conducive to guiding the droplets to flow down along the first slope surfaces 322a and 322b. Preferably, the first slope surface 322a is connected to the side surface 323, the first slope surface 322b is connected to the side surface 324, and the first slope surfaces 322a and 322b include a section of arc-shaped surface which is high in the middle and low on both sides.

[0049] In one embodiment, the side surface 323 and the side surface 324 both include second slope surfaces 323a and 324a that are downwardly directed at a certain arc or a certain angle toward the middle direction of the bottom surface 326. When the splashing droplets adhere to or flow to the side surface 323 or the side surface 324, their shapes are conducive to guiding the droplets to flow down obliquely along the second slope surface 323a or 324a. Preferably, the second slope surface 323a is connected to the first slope surface 322a through a section of arc surface, and the second slope surface 324a is connected to the first slope surface 322b through a section of arc surface, and the droplets flowing down obliquely along the first slope surfaces 322a and 322b are further guided by the second slope surfaces 323a and 324a and flow down obliquely along the second slope surfaces 323a and 324a.

[0050] In one embodiment, the bottom surface 325 includes third slope surfaces 325a and 325b that are downwardly oriented at a certain arc or angle from the middle to the two side surfaces 323 and 324, respectively. When the splashing droplets adhere to the bottom surface 325, the shape of the bottom surface 325 is conducive to guiding the droplets to flow down along the third slope surfaces 325a and 325b. Preferably, the third slope surface 325a is connected to the second slope surface 323a, and the third slope surface 325b is connected to the second slope surface 324a. The third slope surfaces 325a and 325b include a section of arc-shaped surface with a high middle and low sides, and the droplets flowing down along the second slope surface or the third slope surface are gathered at the junction of the second slope surface and the third slope surface.

[0051] In one embodiment, for two adjacent layers of blocking blocks 321, the droplets attached to the blocking block 321 of the upper layer and flowing obliquely along the first slope surface 322a, the first slope surface 322b, the second slope surface 323a, the second slope surface 324a, the third slope surface 325a or the third slope surface 325b are gathered at the junction of the second slope surface and the third slope surface, and then drip downward under the action of gravity. The blocking block 321 of the lower layer is configured to face and receive the droplets dripping from the blocking block 321 of the upper layer with its first slope surface 322a or the first slope surface 322b, and guide the droplets to continue to flow obliquely downward. This configuration makes it difficult for the dripping droplets to splash upward again, and can better guide the flow downward.

[0052] In one embodiment, the upper surface 327 of the guide cylinder is tilted downward at a certain arc or angle from the center to the outside, so as to guide the droplets attached to or flowing to the upper surface 327 of the guide cylinder to flow downward obliquely. At the same time, a plurality of drainage grooves 328 are arranged at intervals on the edge of the upper surface 327 of the guide cylinder, and the bottom surface of the drainage grooves 328 is vertically consistent with the outer surface of the guide cylinder 320; the spacing parts 329 between the drainage grooves 328 are higher than the bottom surface of the drainage grooves 328. Preferably, the drainage grooves 328 are opposite to the topmost layer of blocking blocks 321, the spacing parts are opposite to the gaps between the topmost layer of blocking blocks 321, and the distance between the spacing parts 329 and the topmost layer of blocking blocks 321 is smaller than the distance between the two layers of blocking blocks 321, which makes the spacing parts 329 play the equivalent effect of a layer of blocking blocks. In addition, as Fig. 9 As shown, the distance between the side surface of the spacer 329 and the inner wall of the sleeve 310 is set to be greater than the distance between the front surface 326 of the blocking block 321 and the inner wall of the sleeve 310, that is, the surface of the spacer 329 is farther from the inner wall of the sleeve 310 than the front surface 326 of the blocking block 321 is from the inner wall of the sleeve 310, which makes it easy for droplets to flow down obliquely once they adhere to the spacer 329.

[0053] In one embodiment, the sleeve 310 and the guide tube 320 are made of corrosion-resistant plastic, such as PP, PVDF, PTFE, PEEK, etc. The sleeve 310 and the guide tube 320 are polished, and the smooth lower surface is conducive to guiding water flow. Optionally, the surface of the sleeve 310 and the guide tube 320 is covered with a hydrophilic material layer to further improve the water guiding effect.

[0054] Another embodiment of the present application provides a chemical mechanical polishing unit 1000, including a carrier head 10, a polishing disc 20, a polishing pad 30, a dressing device 40, a polishing liquid supply device 50, and the anti-drip lifting mechanism 3000 in any of the above embodiments. The chemical mechanical polishing unit 1000 performs a polishing operation on a wafer, including: the polishing pad 30 is arranged on the upper surface of the polishing disc 20 and rotates with it; the carrier head 10 that can move horizontally is arranged above the polishing pad 30, and the lower surface of the carrier head 10 attracts the wafer to be polished; the dressing device 40 includes a dressing arm 41 and a dressing head 42, and the dressing arm 41 drives the rotating dressing head 42 to swing to dress the surface of the polishing pad 30 to a state suitable for polishing; the polishing liquid supply device 50 spreads the polishing liquid on the surface of the polishing pad 30; during the polishing operation, the carrier head 10 presses the surface of the wafer to be polished to the surface of the polishing pad 30, and the polishing liquid is distributed between the polishing pad 30 and the wafer, and the material on the wafer surface is removed under the action of chemical machinery. The chemical mechanical polishing unit 1000 also performs a cleaning operation on the wafer, the polishing head 10, and the polishing pad 20, including: after the wafer is polished, a high-pressure nozzle sprays a large amount of deionized water to rinse the wafer, the polishing head 10, and the polishing pad 20 to remove impurities on their respective surfaces. Typical polishing operations and cleaning operations require tens of seconds or even longer, especially during cleaning operations, in order to ensure the cleaning effect, the water flow rate is as high as tens of liters per minute. Whether it is a polishing operation or a cleaning operation, the liquid on the polishing disk is continuously thrown out to the periphery of the polishing disk by the centrifugal force generated by the rotation of moving parts such as the polishing head and the polishing disk.

[0055] A plurality of anti-drip lifting mechanisms 3000 are arranged at equal intervals on the outer circumference of the polishing disc 20, and a retaining ring 400 surrounding the polishing disc 20 is commonly installed on a plurality of sleeves 310 of the plurality of anti-drip lifting mechanisms 3000. When the chemical mechanical polishing unit 1000 performs polishing and cleaning operations, the lifting rods 330 of the plurality of anti-drip lifting mechanisms 3000 rise synchronously, pushing the sleeves 310 and the retaining ring 400 to rise, so that the retaining ring 400 is higher than the polishing disc 20, and is used to prevent the liquid on the polishing disc 20 from splashing around.

[0056] In addition, the retaining ring 400 is configured to not affect the polishing operation and the cleaning operation after it rises. During the polishing operation and the cleaning operation, not only the dressing arm 41 of the dressing device 40 drives the dressing head 42 to swing, but the carrier head 10 also swings under the drive of a connecting arm; the polishing liquid supply device 50 is installed on another connecting arm, but the connecting arm of the polishing liquid supply device 50 may not swing, but remain in a fixed position. The position to which the retaining ring 400 rises cannot affect the swinging of the connecting arm 41 and the carrier head 10 during the polishing operation and the cleaning operation, nor can it interfere with the connecting arm of the polishing liquid supply device 50. In one embodiment, the upper surface of the retaining ring 400 is provided with openings at the position where the dressing arm 41 and the connecting arm of the carrier head 10 swing and at the position of the connecting arm of the polishing liquid supply device 50. The retaining ring 400 of the chemical mechanical polishing unit 1000 of the present application does not affect the polishing and cleaning operations, and effectively prevents the liquid during the polishing and cleaning operations from splashing into the entire working environment to cause pollution; at the same time, the anti-droplet lifting mechanism 3000 of the present application is used to block and drain downward a large number of droplets splashed onto the surface of the guide cylinder 320, preventing the droplets from entering the interior of the lifting mechanism, reducing maintenance and cleaning costs, avoiding losses caused by downtime for maintenance, and effectively reducing the risk of damaging the wafer due to droplets crystallizing and then collapsing in the lifting mechanism.

[0057] Another embodiment of the present application provides a chemical mechanical polishing device, including the chemical mechanical polishing unit 1000 provided in the above embodiment, the chemical mechanical polishing unit 1000 is used to perform chemical mechanical polishing on a wafer. The chemical mechanical polishing device also includes a wafer post-processing unit to perform post-processing on the wafer after chemical mechanical polishing, and the post-processing includes but is not limited to cleaning and drying.

[0058] In one embodiment, the chemical mechanical polishing device further includes a loading and unloading part 200. In the chemical mechanical polishing device, the carrier head 10 of the chemical mechanical polishing unit 1000 needs to be constantly moved between a polishing position and an interaction position. The polishing position is a position for performing polishing and cleaning operations, and the polishing position is above the polishing disc 20; the interaction position is a position for interacting with the loading and unloading part 300 for wafers, and preferably, the interaction position is outside the retaining ring 400. This can effectively prevent the loading and unloading part 200 from being attached by liquid on the polishing disc, thereby contaminating the wafer or even forming crystals to damage the wafer.

[0059] The process of the loading and unloading part 200 and the chemical mechanical polishing unit 1000 in the chemical mechanical polishing equipment includes:

[0060] 1) During wafer suction operation, after the retaining ring 400 of the anti-drip lifting mechanism 3000 is lowered to a low position, the carrier head 10 moves to the interactive position to absorb the wafer from the loading and unloading portion 200. When the retaining ring 400 is at the low position, the upper end surface of the retaining ring 400 is not higher than the surface of the polishing plate 20, and does not interfere with the movement of the carrier head 10;

[0061] 2) Polishing and cleaning operations: the carrier head 10 moves to the polishing position, and the retaining ring 400 of the anti-drip lifting mechanism 3000 rises to a high position, and then the wafer is polished and cleaned. When in the high position, the lower end surface of the retaining ring 400 is not higher than the surface of the polishing plate 20, thereby blocking the liquid thrown out of the polishing plate;

[0062] 3) Wafer unloading operation: after the polishing operation and cleaning are completed, the retaining ring 400 of the anti-drip lifting mechanism 3000 is lowered to a low position, and the carrier head 10 moves to the interactive position and unloads the wafer to the loading and unloading part 200.

[0063] The chemical mechanical polishing equipment of the present application does not require changing the process flow. The anti-droplet lifting mechanism 3000 of the present application is used to block and drain downward a large number of droplets sputtered onto the surface of the guide tube 320, thereby preventing downtime for maintenance caused by damage to the lifting mechanism, thereby improving wafer production efficiency and yield.

[0064] The above implementation methods are only used to illustrate the embodiments of the present application, and are not limitations on the embodiments of the present application. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present application. The scope of patent protection of the embodiments of the present application should be limited by the claims.

Claims

1. A droplet-proof lifting mechanism, characterized in that: It includes a sleeve, a guide sleeve and a lifting rod which are arranged in sequence from the outside to the inside. The upper end of the lifting rod is fixedly connected to the top surface of the sleeve to drive the sleeve to rise and fall synchronously. The outer surface of the guide sleeve is provided with a plurality of blocking blocks which are spaced and staggered to block droplets from entering the upper surface of the guide sleeve along the gap between the sleeve and the guide sleeve and guide the droplets to flow down along at least one surface of the blocking blocks.

2. The anti-drip lifting mechanism according to claim 1, characterized in that: The blocking blocks are arranged in multiple layers, the blocking blocks in each layer are at the same height, and the blocking blocks in two adjacent layers are staggered in a direction along the outer surface of the guide cylinder.

3. The anti-drip lifting mechanism according to claim 2, characterized in that: The blocking block comprises a top surface, two side surfaces, a bottom surface and a front surface, wherein the top surface comprises a first downward slope surface with a certain arc or angle from the middle to the two side surfaces, respectively, for guiding the droplets on the top surface to flow downward obliquely.

4. The anti-drip lifting mechanism according to claim 3, characterized in that: Each of the two side surfaces comprises a second slope surface which is downwardly sloping at a certain arc or angle toward the middle direction of the bottom surface, and is used for guiding the liquid droplets on the two side surfaces to flow downward obliquely.

5. The anti-drip lifting mechanism according to claim 4, characterized in that: The bottom surface comprises a third downward slope surface which is formed from the middle to the two side surfaces at a certain arc or angle, and is used for guiding the liquid droplets on the lower surface to flow downward obliquely.

6. The anti-drip lifting mechanism according to claim 5, characterized in that: The staggering in the direction along the outer surface of the guide tube includes that the droplets flowing obliquely along the second slope surface or the third slope surface of the blocking block of the upper layer gather at the junction of the second slope surface and the third slope surface and then drip downward onto the first slope surface of the blocking block of the next layer.

7. The anti-drip lifting mechanism according to any one of claims 1 to 6, characterized in that: The upper surface of the guide tube includes a fourth downward slope surface with a certain arc or angle from the center to the outer surface, which is used to guide the droplets on the upper surface of the guide tube to flow down obliquely; The edge of the upper surface of the guide cylinder includes a plurality of drainage grooves arranged at intervals, the bottom surface of the drainage grooves is vertically consistent with the outer surface of the guide cylinder, and the distance between the surface of the spacing portion between the plurality of drainage grooves and the inner wall of the sleeve is greater than the distance between the front face of the blocking block and the inner wall of the sleeve.

8. A chemical mechanical polishing unit, characterized in that: The invention comprises a carrier head, a polishing disc, a polishing pad, a dressing device, a polishing liquid supply device and a plurality of anti-drip lifting mechanisms according to any one of claims 1 to 8, wherein the plurality of anti-drip lifting mechanisms are arranged at equal intervals on the periphery of the circumference of the polishing disc, and a retaining ring surrounding the polishing disc is commonly installed on the sleeves of the plurality of anti-drip lifting mechanisms; When the chemical mechanical polishing unit uses the carrier head, the polishing disc, the polishing pad, the dressing device and the polishing liquid supply device to perform polishing and cleaning operations, the lifting rods of the plurality of anti-drip lifting mechanisms rise synchronously, so that the retaining ring is higher than the polishing disc, so as to prevent the liquid on the polishing disc from splashing around; The retaining ring is configured not to affect the polishing and cleaning operations.

9. A chemical mechanical polishing device, characterized in that: The method comprises the chemical mechanical polishing unit as claimed in claim 9, wherein the chemical mechanical polishing unit is used to perform chemical mechanical polishing on a wafer.

10. The chemical mechanical polishing equipment according to claim 9, characterized in that: It also includes a loading and unloading part, and the carrying head moves between a polishing position and an interactive position. The polishing position is a position for performing polishing and cleaning operations, and the polishing position is above the polishing disk; the interactive position is a position for exchanging wafers with the loading and unloading part, and the interactive position is outside the retaining ring.

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