Chemical mechanical polishing equipment and chemical mechanical polishing method

Abstract

The present application relates to the field of semiconductor wafer processing technology, and provides a chemical mechanical polishing device and a chemical mechanical polishing method. The chemical mechanical polishing device includes: a polishing plate; a top plate, the lower surface of which is provided with a circular track; a head assembly, including a drive device and a carrier head, the upper end of the drive device being slidably mounted on the circular track to drive the head assembly to slide along the circular track; a side structure of the drive device having a protruding limit portion; a limit assembly provided on the lower surface of the top plate, including a first stopper, a second stopper, and a swing limiter movably limited between the first and second stopper, the swing limiter partially overlapping the limiter in the vertical direction, the limiter being limited by the first stopper in the clockwise direction and by the second stopper in the counterclockwise direction via the swing limiter, so that the sliding range of the head assembly along the circular track is 360 to 380 degrees, so that the head assembly can return to its initial position and interact with the interaction cup in both clockwise and counterclockwise directions.

Description

Technical Field

[0001] The present application relates to the field of semiconductor wafer processing technology, and in particular to a chemical mechanical polishing device and a chemical mechanical polishing method. Background Art

[0002] The production of large-scale integrated circuits (ICs) places extremely high demands on wafer flatness. Currently, wafer flattening is achieved through the chemical mechanical polishing (CMP) process, and CMP equipment is the primary equipment for this process. Key performance indicators for CMP equipment include machining accuracy, yield, and efficiency. Machining accuracy, or flatness, typically requires the overall flatness of the polished wafer to reach the nanometer or even atomic level. This requires high rigidity in all components of the CMP equipment to minimize deformation and offset, and precise positioning of all moving parts to ensure overall operational stability, reliability, and accuracy. Yield requires minimal wafer scrap, such as wafer fragments, scratches, and warpage. Efficiency, expressed as wafers per hour (WPH), requires efficient equipment operation.

[0003] Current circular track-type chemical mechanical polishing equipment usually hoists the head assembly used for wafer polishing onto the circular track, allowing the head assembly to slide along the circular track to switch between different polishing stations. Since the head assembly is usually connected to structures such as power cables and air pipes, it cannot achieve 360° unlimited single-direction free rotation. Fixed limit blocks are often set on the circular track to rigidly limit the head assembly to prevent the cables and air pipes from being entangled and broken when the twisting angle exceeds 360°.

[0004] However, since the fixed limit block itself occupies a certain angular space, the head assembly cannot achieve full 360° coverage of the entire circular track in both the clockwise and counterclockwise directions. In other words, the head assembly cannot slide back to its original position in one direction from its original position. For example, if the original position is on the left side of the fixed limit block, the head assembly cannot cross the fixed limit block and return to its original position after sliding from its original position along the circular track to the right side of the fixed limit block. This causes the head assembly to take the wafer from the loading and unloading cup at the original position and slide to the polishing disk for polishing. After that, it cannot continue to slide back to the same loading and unloading cup in the same direction to place the wafer, but must return to the same loading and unloading cup along the original path. As a result, the head assembly slides repeatedly only within a part of the circular track, causing serious local wear of the circular track, and the circular track is prone to local tilt or collapse, affecting the sliding smoothness of the head assembly and its positioning accuracy at the loading and unloading cup and polishing disk, thereby reducing the wafer processing accuracy and even causing wafer damage and reducing the yield rate. In addition, the movement path of the head assembly is limited and can only return to its original position from one side. Especially in embodiments with more than two head assemblies, it is difficult to efficiently coordinate the movement of multiple head assemblies. During the mutual avoidance process, ineffective movement movements are caused for wafer polishing, thereby reducing wafer processing efficiency. Summary of the Invention

[0005] The present application provides a chemical mechanical polishing apparatus and a chemical mechanical polishing method to solve or alleviate at least some of the above-mentioned problems.

[0006] According to one aspect of the present application, a chemical mechanical polishing device is provided for wafer processing, comprising:

[0007] polishing disc,

[0008] A top plate located above the polishing disc has a ring track on its lower surface;

[0009] A head assembly includes a driving device and a carrier head connected to the lower end of the driving device, the carrier head is used to carry the wafer to the polishing plate for polishing, the upper end of the driving device is slidably mounted on the annular track to drive the head assembly to slide along the annular track; a protruding limit portion is configured on the side of the driving device;

[0010] A limit assembly is provided on the lower surface of the top plate, and the limit assembly includes a first stop block and a second stop block arranged at intervals along an arc concentric with the annular track, and a swing limit member with a movable limit between the two. In the clockwise direction, the first stop block is located downstream of the second stop block, and the swing limit member partially overlaps with the limit portion in the vertical direction. The limit portion is limited by the first stop block in the clockwise direction and by the second stop block in the counterclockwise direction via the swing limit member, so that the sliding range of the head assembly along the annular track is 360 to 380 degrees, so that the head assembly can return to the initial position in the clockwise or counterclockwise direction and interact with the interaction cup at the initial position in an aligned manner.

[0011] Optionally, the first stop block and the second stop block are configured such that when the limiting portion is limited by the first stop block or the second stop block, the projections of the carrier head and the polishing disk on the horizontal plane do not overlap, so that contaminants on the carrier head fall outside the polishing disk when limiting, thereby preventing the contaminants from contaminating the polishing disk and then contaminating or scratching the wafer during polishing.

[0012] Optionally, the swing limiter includes an arc track concentric with the annular track and a movable limit block slidably mounted to the arc track, the first stop block and the second stop block are respectively arranged at both ends of the arc track, the movable limit block partially overlaps with the limiting portion in the vertical direction, and the limiting portion is limited by the first stop block in the clockwise direction and by the second stop block in the counterclockwise direction via the movable limit block.

[0013] Optionally, the movable limit block includes a first side toward the first stop block and a second side toward the second stop block; when the limiting portion moves clockwise, it can abut against the second side of the movable limit block and push the movable limit block to the first side of the movable limit block against the first stop block, so as to be limited by the first stop block; when the limiting portion moves counterclockwise, it can abut against the first side of the movable limit block and push the movable limit block to the second side of the movable limit block against the second stop block, so as to be limited by the second stop block.

[0014] Optionally, the plane where the first side and the second side of the movable limit block are located extends radially along the annular track; the sides of the first stop block and the second stop block facing each other extend radially along the annular track; the two side surfaces on which the limiting portion abuts against the movable limit block match the shape of the movable limit block to form surface contact between the limiting portion and the movable limit block when the two abut against each other.

[0015] Optionally, the swing limiter includes a limit rocker arm vertically arranged between the first stop block and the second stop block, the first end of the limit rocker arm swings around the swing axis so that the second end thereof swings and limits between the first stop block and the second stop block, the swing axis is not on the arc where the first stop block and the second stop block are located, and a downwardly protruding limit column is provided at a position of the limit rocker arm corresponding to the limit portion, the limit column and the limit portion partially overlap in the vertical direction, and the limit portion is limited by the first stop block in the clockwise direction and by the second stop block in the counterclockwise direction via the limit column.

[0016] Optionally, the first stop block and the second stop block are configured to be cylindrical in shape with the same size, and the limiting rocker arm is configured to have an inwardly recessed arc-shaped recess at the second end toward the first side of the first stop block and toward the second side of the second stop block, respectively, and the arc-shaped recess matches the radius of the cylinder. When the limiting portion moves clockwise, it can abut against the limiting column to push the limiting rocker arm to the arc-shaped recess on the first side of the limiting rocker arm against the first stop block, so as to be limited by the first stop block; when the limiting portion moves counterclockwise, it can abut against the limiting column to push the limiting rocker arm to the arc-shaped recess on the second side of the limiting rocker arm against the second stop block, so as to be limited by the second stop block.

[0017] Optionally, the distance between the first stopper and the second stopper is set so that the sliding range of the limiting portion from the position limited by the first stopper to the position limited by the second stopper in a counterclockwise direction is 360 degrees to 380 degrees.

[0018] Optionally, the sliding range of the head assembly on the annular track is 365 degrees to 375 degrees.

[0019] Optionally, the limiting portion is configured to magnetically repel the first stopper and the second stopper respectively to form a magnetic buffer limit.

[0020] Optionally, the driving device is configured to drive the head assembly to slide along the circular track and control the head assembly to stop at an initial position; when the head assembly is in the initial position, the limiting portion is located at the origin position between the first stop block and the second stop block, and the limiting portion is configured to be able to move 360 degrees along the circular track to return to the origin position, so that the head assembly slides 360 degrees along the circular track to return to the initial position.

[0021] Optionally, the chemical mechanical polishing apparatus comprises a loading and unloading cup located in the initial position and below the head assembly; the loading and unloading cup is configured to interact with the carrier head to provide wafers to the carrier head or receive wafers unloaded from the carrier head.

[0022] Optionally, the head assembly is configured to: take the wafer from the loading and unloading cup, slide along the annular track to carry the wafer to the polishing plate for polishing, and then continue to slide along the annular track in the same sliding direction back to the loading and unloading cup to unload the wafer.

[0023] Optionally, pressure sensors are provided on the sides of the first stop block and the second stop block facing each other, and the pressure sensors are communicatively connected to the driving device; the pressure sensors are configured to send a hard limit signal when the pressure applied by the swing limit member is detected, and the driving device drives the head assembly to slide to the initial position in the opposite direction and at a speed lower than the previous drive based on the receipt of the hard limit signal.

[0024] Optionally, a distance measuring sensor is provided on the side of one of the first stop block and the second stop block facing the swing limit member, and the distance measuring sensor is communicatively connected to the driving device; the distance measuring sensor is configured to detect a detection distance between the distance measuring sensor and the limit portion when the limit portion is limited between the first stop block and the second stop block, and to send an offset signal when the detection distance is greater than the distance between the distance measuring sensor and the limit portion when the limit portion is located at the origin position; the driving device drives the head assembly to slide to the initial position at a speed lower than the speed of the previous drive based on the offset signal.

[0025] Optionally, the chemical mechanical polishing apparatus includes more than two head assemblies, and the lower surface of the top plate is provided with limit assemblies corresponding to the head assemblies one by one; the horizontal position of the portion where the swing limiter of each limiter assembly overlaps with the limit portion matches the horizontal distance where the limit portion of the corresponding head assembly protrudes from the driving device, and the vertical position of the portion where the swing limiter of each limiter assembly overlaps with the limit portion matches the vertical distance between the limit portion of the corresponding head assembly and the upper end of the driving device;

[0026] The horizontal distance of the limiting portion of one head assembly protruding from the driving device and the vertical distance from the upper end of the driving device are respectively greater than or smaller than the horizontal distance of the limiting portion of another head assembly protruding from the driving device and the vertical distance from the upper end of the driving device, so that the head assembly is not interfered with by the limiting assembly of other head assemblies when sliding along the annular track.

[0027] Optionally, the chemical mechanical polishing equipment includes more than two head assemblies, and the lower surface of the top plate is provided with a limit assembly corresponding to the head assembly one by one; each limit assembly is the same size and is arranged at intervals on the same circumference; the limit portion of each head assembly is configured to be retractable inward and outward or movable up and down, so that when passing through a limit assembly that does not correspond to it, it can retract or move downward to avoid it, and when passing through a limit assembly that corresponds to it, it can extend or move upward to limit it.

[0028] Optionally, the chemical mechanical polishing equipment includes three head assemblies, two polishing discs, and three interactive cups; the three head assemblies are a first head assembly, a second head assembly, and a third head assembly, and the three are movable relative to each other; the two polishing discs are a rough polishing disc and a fine polishing disc; the three interactive cups are a first loading and unloading cup, a second loading and unloading cup, and a moisturizing cup located at the initial positions of the first head assembly, the second head assembly, and the third head assembly; each head assembly moves to the rough polishing disc and the fine polishing disc in sequence to polish the wafer;

[0029] Each head assembly is configured to be able to slide 360 degrees to 380 degrees along the circular track. During the process of sliding one circle along the circular track to polish the wafer, one or more of the three head assemblies slide back and forth within a local range of the circular track to cooperate with the sliding of other head assemblies.

[0030] According to another aspect of the present application, a chemical mechanical polishing method is provided, which is used in the chemical mechanical polishing apparatus according to the aforementioned aspect, and the method comprises:

[0031] Controlling the head assembly to take the wafer from the loading and unloading cup;

[0032] driving the head assembly to slide along the annular track to the polishing plate to polish the wafer at the polishing plate;

[0033] After polishing, the head assembly is driven to slide along the annular track back to the loading and unloading cup, and the head assembly is controlled to unload the polished wafer into the loading and unloading cup;

[0034] The direction in which the head assembly carries the current wafer and slides along the circular track is opposite to the direction in which the head assembly carries the previous wafer and slides along the circular track.

[0035] According to the chemical mechanical polishing equipment and chemical mechanical polishing method of the present application, the first stopper and the second stopper can provide a hard limit for the sliding of the head assembly along the circular track, preventing the sliding range of the head assembly from being too large, which may cause the cables and air pipes connected to the head assembly to twist excessively and become entangled or broken. In addition, through the swinging cooperation between the swinging limiter of the limiter assembly and the swinging of the first stopper and the second stopper, the swinging limit of the limiter between the first stopper and the second stopper is realized, so that the head assembly can slide at least 360 degrees along the circular track, so that it can return to the initial position after sliding one circle, ensuring that the circular track is evenly stressed and has high levelness, so that the head assembly slides smoothly and has high position accuracy, thereby improving the wafer polishing accuracy. In addition, the technical solution of the present application can also optimize the sliding route of the head assembly during operation, expand the sliding range of the head assembly, increase the selectivity of the route, significantly improve the operating efficiency of the chemical mechanical polishing equipment, and improve WPH. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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.

[0037] Figure 1 is a schematic diagram of a chemical mechanical polishing device;

[0038] Figure 2 is a partial schematic diagram of a chemical mechanical polishing device according to an embodiment of the present application;

[0039] Figure 3 for Figure 2 Schematic diagram of the top plate and head assembly in FIG;

[0040] Figure 4 Shown Figure 3 Bottom view of the top plate in;

[0041] Figure 5 Shown Figure 4 Enlarged view of point A in the middle;

[0042] Figure 6 A schematic diagram of a position limiting assembly according to another embodiment of the present application is shown;

[0043] Figure 7 Shown Figure 3 Cross-sectional view at the middle BB;

[0044] Figure 8 Shown Figure 3 A cross-sectional view at the middle BB, in which the other head assembly and its limit assembly are indicated by dotted lines;

[0045] Figure 9 Shown Figure 2 A schematic diagram of the first step of a polishing process of a chemical mechanical polishing device in FIG.

[0046] Figure 10 Shown Figure 9 Schematic diagram of the next step;

[0047] Figure 11 Shown Figure 10 Schematic diagram of the next step;

[0048] Figure 12 Shown Figure 11 Schematic diagram of the next step;

[0049] Figure 13 Shown Figure 12 Schematic diagram of the next step;

[0050] Figure 14 Shown Figure 13 Schematic diagram of the next step;

[0051] Figure 15 Shown Figure 14 Schematic diagram of the next step;

[0052] Figure 16 The figure is a flow chart of a chemical mechanical polishing method according to one embodiment of the present application.

[0053] Reference numerals:

[0054] 100, head assembly; 1001, first head assembly; 1002, second head assembly; 1003, third head assembly; 10, carrier head; 110, drive device; 111, stopper; 1101, first slider; 1102, second slider; 1103, third slider; 1104, fourth slider; 20, polishing disc; 201, first polishing disc; 202, second polishing disc; 30, polishing pad; 40, dressing device; 41, dressing arm; 42, dressing head; 50 , polishing liquid supply device; 60, loading and unloading cup; 601, first loading and unloading cup; 602, second loading and unloading cup; 603, moisturizing cup; 70, top plate; 71, circular track; 711, first loop; 712, second loop; 721, first stopper; 722, second stopper; 723, movable limit block; 7231, movable base; 7232, movable protrusion; 724, arc track; 725, limit rocker; 726, swing axis; 727, limit column; W, wafer. DETAILED DESCRIPTION

[0055] 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. Based on the embodiments in the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field should fall within the scope of protection of the embodiments of the present application.

[0056] In the description of this application, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this 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 cannot be understood as a limitation on this application.

[0057] In addition, in the description of this application, unless otherwise specified and limited, it should be noted that the terms "install", "connect" and "connect" 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.

[0058] Figure 1 The schematic diagram of a chemical mechanical polishing device includes a head assembly 100, a polishing plate 20, a polishing pad 30, a dressing device 40, a polishing liquid supply device 50, and an interactive cup located on the side of the polishing plate 20. Figure 1 In the embodiment, the interactive cup is a loading and unloading cup 60, and the head assembly 100 includes a carrier head 10. The polishing pad 30 is disposed on the upper surface of the polishing plate 20 and rotates therewith; the horizontally movable carrier head 10 is disposed above the polishing pad 30, and the wafer W to be polished is attracted to its lower surface; the dressing device 40 includes a dressing arm 41 and a dressing head 42. 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 W to be polished against the surface of the polishing pad 30, and the polishing liquid is distributed between the polishing pad 30 and the wafer W, completing the removal of material from the surface of the wafer W under the action of chemical machinery.

[0059] In chemical mechanical polishing, the operation process of each wafer W mainly includes: (1) the wafer suction process, in which the carrier head 10 moves to the top of the loading and unloading cup 60 and then adsorbs the wafer W placed on the loading and unloading cup 60 to the carrier head 10; (2) the polishing process, in which the wafer W is moved to the polishing pad by the carrier head 10 for polishing; (3) the wafer unloading process, in which the wafer W is transported back by the carrier head 10 after polishing and unloaded onto the loading and unloading cup 60.

[0060] In order to improve the moving efficiency and stability of the carrier head 10, the carrier head 10 is set to slide along the circular track 71. Figure 2 FIG2 shows a partial schematic diagram of a chemical mechanical polishing device according to an embodiment of the present application. Figure 2 The circular track 71 is indicated by a dotted line. Figure 3 for Figure 2 The top plate 70 and the head assembly 100 are shown in FIG. 1 . The chemical mechanical polishing equipment mainly includes a polishing plate 20, a top plate 70, a head assembly 100 and an interactive cup. The top plate 70 is located above the polishing plate 20. The lower surface of the top plate 70 is provided with an annular track 71. Figure 3 The head assembly 100 includes a driving device 110 and a carrier head 10 that is driven and connected to the lower end of the driving device 110. The carrier head 10 is used to carry the wafer W to the polishing disk 20 for polishing. The upper end of the driving device 110 is slidably mounted on the circular track 71 to drive the head assembly 100 to slide along the circular track 71. In a specific embodiment, the driving device 110 may include a first motor that drives the head assembly 100 to slide along the circular track 71 and a second motor that drives the carrier head 10 to rotate to polish the wafer W on the polishing disk 20. Preferably, the first motor may be a linear motion motor driven by electromagnetic force. For example, the circular track 71 may be provided with a magnetic track that generates an electromagnetic effect with the magnetic block of the linear motion motor to drive the head assembly 100 to slide along the magnetic track and start and stop.

[0061] Figure 2Two juxtaposed polishing discs 20 and three head assemblies 100 are shown in the figure, which are the first polishing disc 201, the second polishing disc 202, the first head assembly 1001, the second head assembly 1002, and the third head assembly 1003. Each head assembly 100 has a corresponding initial position, and an interactive cup is set at the initial position. The interactive cup is used to accurately align with the head assembly and then interact. "Interaction" includes the interactive cup providing wafers to the head assembly so that the head assembly can load wafers, the interactive cup receives wafers unloaded by the head assembly, and the head assembly is cleaned or cached and moisturized at the interactive cup. The initial position can be understood as the original position of the head assembly 100. When the head assembly 100 is not performing polishing work, it is cleaned at the original position or stopped at the original position for standby. The interactive cup at the initial position can be a loading and unloading cup 60. In the figure, the first loading and unloading cup 601 and the second loading and unloading cup 602 are respectively set at the initial positions of the first head assembly 1001 and the second head assembly 1002. The interactive cup at the initial position can also be a moisturizing cup 603, Figure 2 A moisturizing cup 603 is set at the initial position of the third head assembly 1003. The moisturizing cup 603 is used to cache and moisturize the head assembly 100 and / or the wafer W thereon. For example, in the process of a head assembly 100 carrying wafer W and running along the circular track 71, if both polishing discs 20 are performing polishing work, the head assembly 100 needs to wait. At this time, moisturizing can be performed at the moisturizing cup 603 to prevent the liquid on the surface of the wafer W from drying and crystallizing. In addition, the loading and unloading cup 60 can also spray moisturizing liquid toward the head assembly or wafer for moisturizing and cleaning. In an optional embodiment, the first polishing disc 201 is a rough polishing disc, and the second polishing disc 202 is a fine polishing disc. The head assembly 100 can carry the wafer W and perform two-stage polishing at the rough polishing disc and the fine polishing disc in sequence to achieve ultra-high polishing flatness close to the atomic level.

[0062] Figure 3 for Figure 2 Schematic diagram of the top plate 70 and head assembly 100 in FIG. Figure 2 The top plate 70 is generally square. Figure 3 Only a circular portion of the top plate 70 is shown. In actual implementations, the top plate 70 can be configured into a square, circular, annular, or other appropriate shapes according to the space design and overall equipment layout requirements. Figure 3 It can be seen that the side of the driving device 110 is constructed with a protruding limit portion 111. A limit assembly is provided on the lower surface of the top plate 70, which includes a first stopper 721 and a second stopper 722 arranged along an arc concentric with the annular track 71, and a swing limiter movably limited between the first stopper 721 and the second stopper 722. The swing limiter partially overlaps with the limit portion 111 in the vertical direction to be able to swing to stop the limit portion 111. Figure 3-Figure 5In the embodiment shown, the swing limiter includes an arc track 724 concentric with the annular track 71 and a movable limit block 723 slidably mounted to the arc track 724. The first stop block 721 and the second stop block 722 are respectively arranged at both ends of the arc track 724. Figure 3 In the clockwise direction indicated by the hollow arrow, the first stopper 721 is located downstream of the second stopper 722. The movable stopper 723 partially overlaps with the limiting portion 111 in the vertical direction, so that the movable stopper 723 can movably stop the limiting portion 111. The limiting portion 111 is limited in the clockwise direction by the first stopper 721 and in the counterclockwise direction by the second stopper 722 via the movable stopper 723, so that the sliding range of the head assembly 100 on the annular track 71 is 360 to 380 degrees, preferably 370 degrees.

[0063] It should be understood that the arc where the first stop block 721 and the second stop block 722 are located can be arranged on the inner side or the outer side of the circular track 71. If it is arranged on the inner side, the radius of the arc is smaller than the circular track 71. Correspondingly, the limit portion 111 is arranged on the side of the driving device 110 facing the center of the circular track 71; if the arc is arranged on the outer side, the radius is larger than the circular track 71. Correspondingly, the limit portion 111 is arranged on the side of the driving device 110 facing away from the center of the circular track 71; the positions of other related structures are also adaptively arranged.

[0064] According to the technical solution of the present application, whether the driving device 110 drives the head assembly 100 to slide along the circular track 71 during processing, or the head assembly 100 is manually pushed to slide for equipment debugging and maintenance during non-processing, the first stop block 721 and the second stop block 722 can provide hard limits for the sliding of the head assembly 100 along the circular track 71, preventing the head assembly 100 from sliding too far and causing the cables and air pipes connected to the head assembly 100 to twist too much and become entangled or broken. In addition, through the active cooperation between the swing limiter and the first stop block 721 and the second stop block 722, the swing limit of the limit part 111 between the first stop block 721 and the second stop block 722 is realized, so that the head assembly 100 can slide at least 360 degrees along the circular track 71, so that it can return to the initial position after sliding one circle, which enables the head assembly to return to the initial position from both sides of the limit assembly, that is, it can return to the initial position along the original path, and can also continue to slide a full 360 degrees in the same direction to return to the initial position, avoiding path redundancy and low wafer processing efficiency caused by having to return to the original position along the original path when the sliding range is less than 360 degrees, and avoiding long-term reciprocation on only a part of the circular track 71, resulting in local wear or deflection of the circular track 71. Therefore, the technical solution of the present application can ensure that the circular track 71 is evenly stressed and has high levelness, so that the head assembly slides smoothly and has high positioning accuracy, thereby ensuring wafer processing accuracy. In addition, especially when there are more than two head assemblies 100 on the circular track 71, the return along the original path may be blocked by other head assemblies 100, and the other head assemblies 100 must avoid it, thereby causing cumbersome avoidance actions, generating excessive redundant movements, and reducing the operating efficiency of the equipment. Therefore, the technical solution of the present application can optimize the sliding route of the head assembly 100 during operation, promote the coordination and cooperation of multiple head assemblies during relative movement, significantly improve the operating efficiency of the chemical mechanical polishing equipment, and improve WPH.

[0065] In a preferred embodiment, the first stop block 721 and the second stop block 722 are configured such that when the limiting portion 111 is limited by the first stop block 721 or the second stop block 722 via the swing limiter, the projections of the carrier head 10 and the polishing disk 20 on the horizontal plane do not overlap, so that when the limiting portion 111 indirectly hits the first stop block 721 or the second stop block 722 for hard limiting, the contaminants on the carrier head 10 fall outside the polishing disk 20 during the collision without contaminating the polishing disk and the wafer. Furthermore, in order to mitigate the impact when the limiting portion 111 is hard-limited by the first stop block 721 or the second stop block 722 through the swing limiter, it is desired to have a buffer limit structure. However, in the corrosive environment of chemical mechanical polishing filled with polishing liquid, if the swing limiter or the first stop block 721 and the second stop block 722 are made of elastic rubber material, the rubber may be corroded or carbonized and fail after a period of time. For this reason, the swing limiter (specifically, for example, the movable limit block 723) and the first stop block 721 and the second stop block 722 can be set to be magnetic, and the swing limiter is configured to magnetically repel the first stop block 721 and the second stop block 722 respectively to form a magnetic buffer limit without generating a strong impact, thereby increasing the stability of the head assembly 100 during movement, reducing the drop of contaminants caused by the impact, and ensuring the cleanliness of the polishing.

[0066] In a specific embodiment, the movable stopper 723 includes a first side facing the first stopper 721 and a second side facing the second stopper 722. For example, the first side is Figure 4 、 Figure 5 The right side of the movable limit block 723, the second side is Figure 4 、 Figure 5 The movable limit block 723 may include a movable base 7231 that is slidably engaged with the curved track 724 and a movable protrusion 7232 that extends downward from the movable base 7231. The movable base 7231 can slide along the curved track 724 and is used to contact the first stop block 721 or the second stop block 722 for movable limiting. The movable protrusion 7232 is used to contact the limiting portion 111 to stop the limiting portion 111. The width of the movable base 7231 can be wider than the movable protrusion 7232, and the movable protrusion 7232 is centered with respect to the movable base 7231, or the movable base 7231 and the movable protrusion 7232 can have the same width. The right side of the movable base 7231 and the right side of the movable protrusion 7232 can be collectively regarded as the first side of the movable limit block 723 , and the left side of the movable base 7231 and the left side of the movable protrusion 7232 can be collectively regarded as the second side of the movable limit block 723 .

[0067] When the limiting portion 111 moves clockwise, it can abut against the second side of the movable limiting block 723 and push the movable limiting block 723 to the first side of the movable limiting block 723 to abut against the first stopper 721, so that the limiting portion 111 is stopped and limited by the first stopper 721 via the movable limiting block 723. When the limiting portion 111 moves counterclockwise, it can abut against the first side of the movable limiting block 723 and push the movable limiting block 723 to the second side of the movable limiting block 723 to abut against the second stopper 722, so that the limiting portion 111 is stopped and limited by the second stopper 722 via the movable limiting block 723. The distance between the first stop block 721 and the second stop block 722 is set so that the sliding range of the limit part 111 from moving counterclockwise from the limit position of the first stop block 721 to the limit position of the second stop block 722 is 360 degrees to 380 degrees, thereby allowing the head assembly 100 to slide 360 degrees along the circular track 71 to return to its original position under the control of the drive device 110, optimizing the sliding route of the head assembly 100 and improving the operating efficiency of the equipment. At the same time, it can also ensure that the cables, air pipes, etc. connected to the head assembly 100 will not be entangled or twisted, thereby ensuring the reliability and service life of related components. When the sliding range is exactly 360 degrees, if the head assembly 100 rebounds by hitting the first stop block 721 or the second stop block 722 through the movable limit block 723, it is difficult to ensure that the head assembly 100 can slide a full circle. Therefore, preferably, the sliding range is 365 degrees to 375 degrees, and more preferably 370 degrees. The range beyond 360 degrees can provide rebound space when the head assembly 100 rebounds by hitting the first stop block 721 or the second stop block 722, or provide overshoot space when it stops beyond the initial position due to inertia, thereby reducing continuous vibration caused by rigid devices.

[0068] Figure 6 FIG2 shows a schematic diagram of a position limiting assembly according to another embodiment of the present application. Figure 3-Figure 5 The limiting assembly may further include a limiting rocker arm 725 disposed longitudinally between the first stopper 721 and the second stopper 722, and a curved track 724 and a movable limiting block 723 as shown in the figure. The limiting assembly may further include a limiting rocker arm 725 disposed longitudinally between the first stopper 721 and the second stopper 722. The first end of the limiting rocker arm 725 swings about a swing axis 726 that is not on the arc where the first stopper 721 and the second stopper 722 are located, so that the second end of the limiting rocker arm 725 swings and limits between the first stopper 721 and the second stopper 722. A downwardly protruding limiting post 727 is provided at a position of the limiting rocker arm 725 corresponding to the limiting portion 111. The limiting post 727 partially overlaps with the limiting portion 111 in the vertical direction to stop the limiting portion 111. The limiting portion 111 is limited in the clockwise direction by the first stopper 721 and in the counterclockwise direction by the second stopper 722 via the limiting post 727.

[0069] Specifically, if Figure 6The first stop block 721 and the second stop block 722 are constructed to be cylindrical with the same size. The limiting rocker arm 725 is respectively constructed with an inwardly recessed arc-shaped recess at its second end toward the first side of the first stop block 721 and the second side toward the second stop block 722. The arc-shaped recess matches the radius of the cylinder. When the limiting portion 111 moves clockwise, it can abut against the limiting column 727 to push the limiting rocker arm 725 to the arc-shaped recess on the first side of the limiting rocker arm 725 and abut against the first stop block 721, so as to be limited by the first stop block 721; when the limiting portion 111 moves counterclockwise, it can abut against the limiting column 727 to push the limiting rocker arm 725 to the arc-shaped recess on the second side of the limiting rocker arm 725 and abut against the second stop block 722, so as to be limited by the second stop block 722.

[0070] Similar to the above, the limit rocker 725 can be configured to magnetically repel the first stopper 721 and the second stopper 722 respectively to form a magnetic buffer limit.

[0071] The swing limiter in the form of a limit rocker 725 can replace the arc track 724 and the movable limit block 723 with the limit rocker 725, which simplifies the structure and reduces the probability of motion jamming. Other beneficial effects are similar to those mentioned above.

[0072] During the polishing process of wafer W, precise alignment of the head assembly 100 and the loading and unloading cup 60 is a prerequisite for ensuring smooth loading and unloading of wafer W, accurate positioning, and no fragmentation. The drive device 110 is configured to drive the head assembly 100 to slide along the circular track 71 and control the head assembly 100 to stop at the initial position. In the initial position, the center of the carrier head 10 of the head assembly 100 is aligned with the center of the loading and unloading cup 60 below it to ensure precise loading and unloading of wafer W, thereby preventing the wafer W from hitting the carrier head 10 or the edge of the loading and unloading cup 60 due to misalignment between the two centers and causing fragmentation. When the head assembly 100 is in the initial position, the limiter 111 is located at the origin position between the first stop 721 and the second stop 722. The origin position can be the midpoint between the first stop 721 and the second stop 722, so that there is an equal amount of overshoot space on both sides of the origin position. The limiter 111 is configured to move 360 degrees along the circular track 71 to return to the origin position, so that the head assembly 100 slides 360 degrees along the circular track 71 and returns to the initial position. During the polishing operation, the head assembly 100 takes the wafer W from the loading and unloading cup 60, slides along the circular track 71 to carry the wafer W to the polishing plate 20 for polishing, and then continues to slide along the circular track 71 in the same sliding direction to return to the loading and unloading cup 60 to unload the wafer W. In this way, the head assembly 100 can move 360 degrees in one direction to complete a wafer W polishing process, without having to move to the polishing plate 20 in one direction and then repeat the same path in the opposite direction during the polishing process of a wafer W. In the case of only one head assembly 100, this technical solution of the present application can avoid the head assembly 100 from moving back and forth for a long time on only a section of the circular track 71, resulting in severe local wear or deflection of the circular track 71; in the case of multiple head assemblies 100, it can facilitate the coordination of multiple head assemblies 100, avoiding the ineffective and redundant movement caused by one head assembly 100 having to return along the original path and forcing other head assemblies 100 to avoid, which can significantly improve the overall operating efficiency of the chemical mechanical polishing equipment. An embodiment of multiple head assemblies 100 is described in detail below.

[0073] To further ensure precise alignment of the head assembly 100 and the loading and unloading cup 60 during processing, in a preferred embodiment, pressure sensors are provided on the mutually facing sides of the first and second stoppers 721, 722. The pressure sensors are in communication with the drive device 110. The pressure sensors are configured to issue a hard limit signal upon detecting pressure applied by a swing limit member (e.g., a movable limit block 723 or a limit rocker 725). Upon receiving the hard limit signal, the drive device 110 drives the head assembly 100 to slide to its initial position in the opposite direction and at a lower speed than the previous drive. Thus, if the head assembly 100 exceeds the initial position due to inertia or other factors, the drive device 110 can fine-tune it back to the initial position. Fine-tune at a lower speed during fine-tuning to ensure that the head assembly 100 stops smoothly and accurately at the initial position.

[0074] In another embodiment, a distance sensor is provided on the side of one of the first and second stops 721 and 722 facing the swing limiter (e.g., the movable stopper 723 or the limit rocker 725). The distance sensor is in communication with the drive device 110. The distance sensor is configured to detect the distance between the distance sensor and the limiter 111 when the limiter 111 is limited between the first and second stops 721 and 722, and to generate an offset signal when the detected distance is greater than the distance between the distance sensor and the limiter 111 when the limiter 111 is at the origin. Based on the offset signal, the drive device 110 drives the head assembly 100 to slide to the initial position at a speed lower than the previous drive speed. In this embodiment, even if no hard limit occurs, the limiter 111 can be controlled to return to the origin when there is offset, thereby returning the head assembly 100 to the initial position and ensuring precise alignment between the head assembly 100 and the loading and unloading cup 60.

[0075] Figure 7 Shown Figure 3 Cross-sectional view at the middle BB, combined with Figure 5 and Figure 7 , it can be seen that the annular track 71 includes a first loop 711 and a second loop 712 that are concentric and have different radii. Setting two loops can increase the stability of the head assembly 100. The arc track 724 is set radially outside the annular track 71 and has a radius larger than the second loop 712. The upper end of the driving device 110 is provided with a first slider 1101, a second slider 1102, a third slider 1103, and a fourth slider 1104. The first slider 1101 and the second slider 1102 are slidably connected to the first loop 711, and the third slider 1103 and the fourth slider 1104 are slidably connected to the second loop 712. Figure 7 It can be seen that the limiting portion 111 protrudes from the driving device 110, and the protruding direction is radially outward along the annular track 71. The movable limiting block 723 is slidably connected to the arc track 724. The movable limiting block 723 extends downward to partially overlap with the limiting portion 111 in the vertical direction, thereby being able to movably limit the limiting portion 111.

[0076] In the case where the chemical mechanical polishing equipment includes more than two head assemblies 100, the lower surface of the top plate 70 is provided with a limit assembly corresponding to the head assembly 100 one by one; the horizontal position of the portion where the swing limiter of each limit assembly overlaps with the limit portion 111 matches the horizontal distance that the limit portion 111 of the corresponding head assembly 100 protrudes from the driving device 110, and the vertical position of the portion where the swing limiter of each limit assembly overlaps with the limit portion 111 matches the vertical distance between the limit portion 111 of the corresponding head assembly 100 and the upper end of the driving device 110. The "overlapping portion" is the portion that contacts the limit portion 111 for stopping, and the "overlapping portion where the swing limiter overlaps with the limit portion 111" is in Figure 3-Figure 5 In the embodiment shown, it refers to the portion where the movable limit block 723 and the limit portion 111 overlap in the vertical direction. Figure 6 In the illustrated embodiment, this refers to the portion where the limiting post 727 vertically overlaps the limiting portion 111. The horizontal distance that the limiting portion 111 of one head assembly 100 protrudes from the drive device 110 and the vertical distance from the top of the drive device 110 are both greater or smaller than the horizontal distance that the limiting portion 111 of another head assembly protrudes from the drive device 110 and the vertical distance from the top of the drive device 110, respectively, so that the head assembly 100 is not interfered with by the limiting assembly of the other head assembly 100 when sliding along the annular track 71.

[0077] Figure 8 The plurality of head assemblies 100 are shown in FIG. Figure 3-Figure 5 The limiting assembly shown is arranged in a manner in which the drive devices 110 and the carrier heads 10 of the two head assemblies 100 are placed in an overlapping position to facilitate observation of the dimensions of the limiting assemblies and other structures. The lower surface of the top plate 70 is provided with limiting assemblies corresponding to the head assemblies 100 one by one; the radius of the arc-shaped track 724 of each limiting assembly matches the horizontal distance that the limiting portion 111 of its corresponding head assembly 100 protrudes from the drive device 110, and the length of the movable limiting block 723 of each limiting assembly extending downward matches the vertical position of the limiting portion 111 of its corresponding head assembly 100. In this embodiment, the radius of the arc-shaped track 724 corresponds to the horizontal position of the movable limiting block 723. The limiting assembly of the head assembly 100 and the limiting portion 111 of the driving device 110 that are blocked in the figure are shown with dotted lines. It can be seen that the horizontal distance of the limiting portion 111 shown by the dotted line protruding from the driving device 110 and the downward extending length of the movable limiting block 723 of the corresponding limiting assembly are respectively greater than the horizontal distance of the limiting portion 111 of the head assembly 100 protruding from the driving device 110 and the downward extending length of the movable limiting block 723 of the corresponding limiting assembly shown by the solid line. As a result, one head assembly 100 can slide along the annular track 71 without being interfered with by the limiting assemblies of other head assemblies 100. Optionally, in order to avoid interference and simplify the structure, the limiting portion of each head assembly is configured to be retractable inward and outward or movable up and down. Specifically, in an embodiment in which the chemical mechanical polishing apparatus includes more than two head assemblies, the lower surface of the top plate 70 is provided with limiting assemblies corresponding to the head assemblies 100 one by one, each limiting assembly having the same size and spaced apart on the same circumference. The limiting portion 111 of each head assembly 100 is configured to be retractable inward and outward or movable up and down, so that when passing through a limiting assembly that does not correspond to it, it can retract inward or move downward to avoid it, and when passing through a limiting assembly that corresponds to it, it can extend outward or move upward to limit it. The head assembly 100 and the limiting assembly corresponding to it can be communicated with or provided with other mutually inductive devices so that when they are close to each other, they can sense each other to promote the extension or movement of the limiting portion 111.

[0078] In multiple head assemblies 100, Figure 6 In the illustrated limiting assembly, the portion where the swing limiting member overlaps the limiting portion 111 is the portion where the limiting post 727 contacts and overlaps the limiting portion 111. Since the position of the limiting post 727 can be varied along the length of the limiting rocker 725, it no longer has to be located between the first and second stops 721, 722. Therefore, the position of the limiting post 727 is decoupled from the positions of the first and second stops 721, 722. Consequently, the first and second stops 721, 722 of the limiting assemblies corresponding to multiple head assemblies 100 can be located at the same distance from the center of the annular track 71, i.e., positioned on different arcs of a circle with the same radius. The limiting rockers 725 of the corresponding limiting assemblies can also be designed to have the same dimensions, with the swing shafts 726 positioned at the same radial position. The limiting post 727 can be matched to the limiting portions 111 of different head assemblies 100 solely through the position of the limiting post 727 on the limiting rocker 725 and the downward projection distance of the limiting post 727, thereby forming a swing limiting mechanism. In this way, except for the limiting column 727, the other structures of the limiting components corresponding to the multiple head components can be of the same size and evenly distributed on a circle concentric with the annular track 71, so that the distribution of gravity of the limiting components on the top plate 70 is more uniform, avoiding the uneven force on the top plate caused by the arrangement of different limiting components at different radial positions, resulting in deformation and deflection, which affects the horizontality of the annular track and further affects the sliding or processing feed accuracy of the head component 100 during the polishing operation.

[0079] For Figure 2 In the embodiment shown in FIG. 1 , there are two polishing plates 20 and three head assemblies 100. An exemplary polishing process is performed in FIG. Figures 9-15 , wherein small circles with numbers 1, 2, and 3 represent the first head assembly 1001, the second head assembly 1002, and the third head assembly 1003. The figure also marks the first polishing plate 201, the second polishing plate 202, the first loading and unloading cup 601, the second loading and unloading cup 602, and the moisturizing cup 603. The arrow in the figure indicates the direction in which the first head assembly 1001 will move next. Specifically, an exemplary polishing process can be: (1) as Figure 9 , the first head assembly 1001, the second head assembly 1002, and the third head assembly 1003 are respectively in their initial positions, i.e., the first loading and unloading cup 601, the second loading and unloading cup 602, and the moisturizing cup 603, the first head assembly 1001 takes the wafer W from the first loading and unloading cup 601, and simultaneously or subsequently the second head assembly 1002 takes the wafer W from the second loading and unloading cup 602; (2) Figure 10 , the first head assembly 1001 moves clockwise to the first polishing plate 201 to perform rough polishing of the wafer W; (3) Figure 11After the rough polishing, the first head assembly 1001 further moves clockwise to the second polishing plate 202 to perform fine polishing on the wafer W. At the same time, the second head assembly 1002 can move clockwise to the first polishing plate 201 to perform rough polishing, and the third head assembly 1003 can move clockwise to the second loading and unloading cup 602 to load the wafer W; (4) Figure 12 After the first head assembly 1001 finishes fine polishing on the second polishing plate 202, it continues to move clockwise back to the first loading and unloading cup 601 to unload the wafer W. After the second head assembly 1002 carries the wafer W, it can continue to move clockwise to the second polishing plate 202 for fine polishing of the wafer W. The third head assembly 1003 can carry the wafer W and move clockwise to the first polishing plate 201 for rough polishing; (5) Figure 13 After the fine polishing is completed, the second head assembly 1002 moves clockwise back to the second loading and unloading cup 602 to unload the wafer W. At this point, the first head assembly 1001 and the second head assembly 1002 have completed the polishing of a wafer W after sliding one circle clockwise along the circular track 71. The first head assembly 1001 and the second head assembly 1002 take their respective next wafer W at the first loading and unloading cup 601 and the second loading and unloading cup 602 respectively; (6) Figure 14 , the third head assembly 1003 moves counterclockwise to the second polishing disc 202 for fine polishing, the second head assembly 1002 moves counterclockwise to the first polishing disc 201 for rough polishing, and the first head assembly 1001 moves to the moisturizing cup 603 for buffering and moisturizing, waiting for polishing; (7) Figure 15 , the third head assembly 1003 then moves clockwise to the second loading and unloading cup 602 to unload the wafer W. At this point, the third head assembly 1003 completes the polishing of one wafer W. The subsequent polishing process will not be described in detail. It should be understood that the above polishing process is only a simple possible embodiment. In actual implementation, due to differences in the processing time of rough polishing and fine polishing, the coordination process of multiple polishing heads will be more complicated. Each head assembly 100 may have one or more clockwise and counterclockwise reciprocating movements like the third head assembly 1003 described above to coordinate with the movement path of other head assemblies 100 to achieve overall efficient operation. By setting a limit component, the present application enables the head component 100 to slide 360 degrees along the circular track 71 to return to its original position while ensuring the hard limit of the head component 100 and the non-entanglement of related cables and air pipes, thereby reducing the invalid movement of the head component 100, providing convenient, efficient and rich path selection for the polishing of the head component 100, especially multiple head components 100, greatly promoting the efficient progress of the polishing process, and significantly improving the wafer W processing efficiency of the chemical mechanical polishing equipment as a whole.

[0080] In addition, in the existing circular track type chemical mechanical polishing equipment, the multiple head assemblies on the circular track are usually relatively fixed in position and slide together along the circular track, while the multiple head assemblies of the present application are arranged to be relatively movable, thereby improving the flexibility of the movement of the multiple head assemblies and providing convenience for the multiple head assemblies to perform efficient processing at multiple polishing disks.

[0081] It should be understood that the first loading and unloading cup 601 is located at the initial position of the first head assembly 1001, but it does not mean that the first loading and unloading cup 601 and the first head assembly 1001 can only interact one-to-one. The first loading and unloading cup 601 can also interact with the second head assembly 1002 and the third head assembly 1003, and the first head assembly 1001 can also interact with the second loading and unloading cup 602 and the moisturizing cup 603; the same is true for other loading and unloading cups 60 or moisturizing cups 603 and head assembly 100.

[0082] like Figure 16 The following is a flow chart of a chemical mechanical polishing method according to one embodiment of the present application. The method includes the following steps:

[0083] S1: Control the head assembly 100 to take the wafer W from the loading and unloading cup 60;

[0084] S2: The driving head assembly 100 slides along the annular track 71 to the polishing plate 20 to polish the wafer W on the polishing plate 20;

[0085] S3: After polishing, the head assembly 100 is driven to slide along the annular track 71 back to the loading and unloading cup 60 , and the head assembly 100 is controlled to unload the polished wafer W into the loading and unloading cup 60 ;

[0086] In which, the direction in which the head assembly 100 carries the current wafer W to slide along the circular track 71 is opposite to the direction in which it carries the previous wafer W to slide along the circular track 71. It should be understood that for the case of multiple head assemblies 100, the overall movement direction is referred to here. In order to cooperate with each other, the head assembly 100 can slide back and forth within a local range of the circular track 71.

[0087] When the chemical mechanical polishing equipment includes a first polishing pad 201 and a second polishing pad 202 , step S2 includes driving the head assembly 100 along the annular track 71 to sequentially slide to the first polishing pad 201 and the second polishing pad 202 to perform primary rough polishing and secondary fine polishing.

[0088] When the chemical mechanical polishing equipment includes multiple head assemblies 100, step S2 may also include one of the multiple head assemblies 100 carrying the wafer W moving to the loading and unloading cup 60 or the moisturizing cup 603 for caching and moisturizing to wait for other head assemblies 100 to complete polishing and release the polishing disk 20.

[0089] The above implementation methods are only used to illustrate the embodiments of the present application, and are not intended to limit 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 fall within the scope of the embodiments of the present application, and the scope of patent protection of the embodiments of the present application should be defined by the claims.

Claims

1. A chemical mechanical polishing device for wafer processing, characterized in that: include: The first head assembly, the second head assembly and the third head assembly are movable relative to each other; Two polishing discs, including a rough polishing disc and a fine polishing disc; Three interactive cups, including a first loading and unloading cup, a second loading and unloading cup, and a moisturizing cup, which are located at the initial positions of the first head assembly, the second head assembly, and the third head assembly respectively; each head assembly loads and unloads wafers at the first loading and unloading cup or the second loading and unloading cup or moisturizes wafers while waiting for polishing, or moisturizes wafers at the moisturizing cup while waiting for polishing; A top plate located above the polishing disc has a ring track on its lower surface; The head assembly includes a driving device and a carrier head connected to the lower end of the driving device, the carrier head is used to carry the wafer to the polishing plate for polishing, the upper end of the driving device is slidably mounted on the annular track to drive the head assembly to slide along the annular track, and the side of the driving device has a protruding limit portion; A limit assembly corresponding to the head assembly is provided on the lower surface of the top plate, which includes a first stopper and a second stopper arranged at intervals along an arc concentric with the annular track, and a swing limiter movably limited between the first stopper and the second stopper. In the clockwise direction, the first stopper is located downstream of the second stopper. The swing limiter and the limiter partially overlap in the vertical direction. The limiter is limited by the first stopper in the clockwise direction and by the second stopper in the counterclockwise direction via the swing limiter, so that the sliding range of the head assembly along the annular track is 360 to 380 degrees, so that the head assembly can return to the initial position in the clockwise or counterclockwise direction and interact with the interaction cup at the initial position in an aligned manner. Each limiting assembly has the same size and is spaced apart and arranged on the same circumference; the limiting portion of each head assembly is configured to be telescopic inward and outward or movable up and down; the head assembly and its corresponding limiting assembly are in communication with each other so as to sense each other when approaching each other, thereby causing the limiting portion to telescope or move, so as to retract or move downward to avoid when passing through a limiting assembly that does not correspond to it, and to extend or move upward to limit when passing through a limiting assembly that corresponds to it; the swing limiting member is configured to magnetically repel the first stop block and the second stop block, respectively, to form a magnetic buffer limit; One or more of the three head assemblies are configured to slide back and forth within a local range of the circular track to cooperate with the sliding of other head assemblies during the process of sliding one circle along the circular track to polish the wafer, including: during the process of the first head assembly and the second head assembly sliding one circle clockwise to perform rough polishing and fine polishing, the third head assembly moves clockwise to the second loading and unloading cup to load the wafer and to the rough polishing disk for rough polishing; during the process of the first head assembly and the second head assembly sliding counterclockwise to perform the next polishing, the third head assembly returns counterclockwise to the fine polishing disk for fine polishing, and then returns clockwise to the second loading and unloading cup to unload the wafer.

2. The chemical mechanical polishing equipment according to claim 1, wherein The first stop block and the second stop block are arranged so that when the limiting portion is limited by the first stop block or the second stop block, the projections of the carrier head and the polishing disk on the horizontal plane do not overlap, so that the contaminants on the carrier head fall outside the polishing disk when limiting.

3. The chemical mechanical polishing equipment according to claim 2, wherein The swing limiter includes an arc track concentric with the annular track and a movable limit block slidably mounted to the arc track, the first stop block and the second stop block are respectively arranged at both ends of the arc track, the movable limit block partially overlaps with the limit portion in the vertical direction, and the limit portion is limited by the first stop block in the clockwise direction and by the second stop block in the counterclockwise direction via the movable limit block.

4. The chemical mechanical polishing equipment according to claim 3, wherein The movable limit block includes a first side toward the first stop block and a second side toward the second stop block; when the limiting portion moves clockwise, it can abut against the second side of the movable limit block and push the movable limit block to the first side of the movable limit block against the first stop block, so as to be limited by the first stop block; when the limiting portion moves counterclockwise, it can abut against the first side of the movable limit block and push the movable limit block to the second side of the movable limit block against the second stop block, so as to be limited by the second stop block.

5. The chemical mechanical polishing equipment according to claim 4, wherein The plane where the first side and the second side of the movable limit block are located extends radially along the annular track; the sides of the first stop block and the second stop block facing each other extend radially along the annular track; the two side surfaces of the limiting portion abutting against the movable limit block match the shape of the movable limit block to form surface contact between the limiting portion and the movable limit block when the two abut against each other.

6. The chemical mechanical polishing equipment according to claim 1, wherein The swing limiter includes a limit rocker arm vertically arranged between the first stop block and the second stop block, the first end of the limit rocker arm swings around the swing axis so that the second end thereof swings and limits between the first stop block and the second stop block, the swing axis is not on the arc where the first stop block and the second stop block are located, and a downwardly protruding limit column is provided at a position of the limit rocker arm corresponding to the limit portion, the limit column and the limit portion partially overlap in the vertical direction, and the limit portion is limited by the first stop block in the clockwise direction and by the second stop block in the counterclockwise direction via the limit column.

7. The chemical mechanical polishing equipment according to claim 1, wherein The distance between the first stopper and the second stopper is set so that the sliding range of the limiting portion from the position limited by the first stopper to the position limited by the second stopper in a counterclockwise direction is 360 degrees to 380 degrees.

8. The chemical mechanical polishing apparatus according to any one of claims 1 to 7, wherein: The driving device is configured to drive the head assembly to slide along the circular track and control the head assembly to stop at an initial position; when the head assembly is in the initial position, the limiting portion is located at the origin position between the first stop block and the second stop block, and the limiting portion is configured to be able to move 360 degrees along the circular track to return to the origin position, so that the head assembly can slide 360 degrees along the circular track to return to the initial position.

9. The chemical mechanical polishing equipment according to claim 8, wherein The interaction cup includes a loading and unloading cup located below the head assembly; the loading and unloading cup is used to interact with the carrier head to provide wafers to the carrier head or receive wafers unloaded from the carrier head.

10. The chemical mechanical polishing equipment according to claim 9, wherein The head assembly is configured to take a wafer from the loading and unloading cup, slide along the annular track to carry the wafer to the polishing plate for polishing, and then continue to slide along the annular track in the same sliding direction back to the loading and unloading cup to unload the wafer.

11. The chemical mechanical polishing equipment according to claim 8, wherein The sides of the first stop block and the second stop block facing each other are both provided with pressure sensors, and the pressure sensors are communicatively connected to the driving device; the pressure sensors are configured to send a hard limit signal when the pressure applied by the swing limit member is detected, and the driving device drives the head assembly to slide to the initial position in the opposite direction and at a speed lower than the speed of the previous drive based on the receipt of the hard limit signal.

12. The chemical mechanical polishing equipment according to claim 8, wherein A distance measuring sensor is provided on the side of one of the first stop block and the second stop block facing the swing limit member, and the distance measuring sensor is communicatively connected to the driving device; the distance measuring sensor is configured to detect a detection distance between the distance measuring sensor and the limit portion when the limit portion is limited between the first stop block and the second stop block, and to send an offset signal when the detection distance is greater than the distance between the distance measuring sensor and the limit portion when the limit portion is located at the origin position; the driving device drives the head assembly to slide to the initial position at a speed lower than the speed of the previous drive based on the offset signal.

13. A chemical mechanical polishing method, used in the chemical mechanical polishing apparatus according to any one of claims 1 to 12, characterized in that: The method comprises: Control the first head assembly and the second head assembly to take wafers from the first loading and unloading cup and the second loading and unloading cup respectively, and the third head assembly is located at the moisturizing cup; Driving the first head assembly to slide clockwise along the annular track to the rough polishing disk to perform rough polishing of the wafer; After the first head assembly completes the rough polishing, the first head assembly is driven to slide clockwise to the fine polishing plate for wafer fine polishing, and at the same time, the second head assembly is driven to slide clockwise to the rough polishing plate for rough polishing, and the third head assembly is driven to slide clockwise to the second loading and unloading cup to load the wafer; After the first head assembly finishes fine polishing, the first head assembly is driven to move clockwise back to the first loading and unloading cup to unload the wafer. After the second head assembly finishes rough polishing, the second head assembly is driven to move clockwise to the second polishing plate for wafer fine polishing. Then the third head assembly is moved clockwise to the first polishing plate for rough polishing. After the second head assembly finishes fine polishing, the second head assembly is driven to move clockwise back to the second loading and unloading cup to unload the wafer; Controlling the first head assembly and the second head assembly to take the next wafer from the first loading and unloading cup and the second loading and unloading cup respectively; Drive the third head assembly counterclockwise to move to the fine polishing disc for fine polishing, the second head assembly counterclockwise moves to the first polishing disc for rough polishing, and the first head assembly moves to the moisturizing cup for buffering and moisturizing, waiting for polishing; The third head assembly is driven to move clockwise to the second loading and unloading cup to unload the wafer.

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