A polishing device

Abstract

This invention relates to a polishing apparatus. The polishing apparatus includes: a polishing table with a polishing pad disposed thereon; a polishing assembly including a polishing head and a polishing drive, the polishing head being used to adsorb and fix a wafer, the polishing drive being driven to the polishing head to drive the polishing head to move the wafer along the surface of the polishing pad; and a dresser including a dresser head and a dresser drive, the dresser drive being driven to the dresser head to drive the dresser head to move along the surface of the polishing pad; wherein, during the movement of the polishing head and the dresser head along the surface of the polishing pad, the following condition is satisfied: the distance between the center positions of the polishing head and the dresser head is greater than the sum of the radii of the polishing head and the dresser head.

Description

Technical Field

[0001] This application relates to the field of semiconductor processing equipment technology, specifically a polishing apparatus. Background Technology

[0002] In semiconductor manufacturing processes, chemical mechanical polishing (CMP) is a superior process for achieving global planarization. Especially after semiconductor manufacturing processes entered the submicron level, CMP has become an indispensable process technology.

[0003] In chemical mechanical polishing (CMP), the wafer is adsorbed onto the polishing head and in contact with the polishing pad. The polishing platform drives the polishing pad to rotate around its center, while the polishing head drives the wafer in a reciprocating motion relative to the polishing pad, thus allowing the polishing pad to grind the polishing head. Simultaneously, a dresser is used to polish the polishing pad, removing grinding residue and restoring the morphology of the grooves on its surface. Because the movement range of both the polishing head and the dresser is limited to the edge to the center of the polishing pad, their movements overlap, making collisions prone to occur and negatively impacting production efficiency. Summary of the Invention

[0004] Therefore, it is necessary to provide a polishing device that can avoid collisions between the polishing head and the dressing tool, thereby improving production efficiency.

[0005] A polishing apparatus, comprising:

[0006] A polishing table, wherein a polishing pad is provided on the polishing table;

[0007] A polishing assembly includes a polishing head and a polishing drive unit. The polishing head is used to adsorb and fix a wafer, and the polishing drive unit is driven to the polishing head to drive the polishing head to move the wafer along the surface of the polishing pad.

[0008] A dressing device includes a dressing head and a dressing drive, wherein the dressing drive is driven to connect with the dressing head to drive the dressing head to move along the surface of the polishing pad.

[0009] During the movement of the polishing head and the dressing head along the surface of the polishing pad, the following condition is met: the distance between the center position of the polishing head and the center position of the dressing head is greater than the sum of the radius of the polishing head and the radius of the dressing head.

[0010] In some embodiments, the polishing head includes a first polishing head and a second polishing head. The first polishing head and the second polishing head move synchronously back and forth along a first preset straight line trajectory and a second preset straight line trajectory, respectively, under the drive of the polishing drive member. The first preset straight line trajectory and the second preset straight line trajectory both extend from the center of the polishing pad to the edge, and the first preset straight line trajectory and the second preset straight line trajectory are collinear.

[0011] In some embodiments, driven by the trimming drive, the trimming head oscillates back and forth about a fulcrum O between the center and the edge of the polishing pad.

[0012] In some embodiments, the first polishing head and the trimming head move along the surface of the polishing pad respectively, satisfying the following:

[0013] ;

[0014] Where R represents the distance between the fulcrum and the center position of the dressing head, t represents time, w(t) represents the angular velocity of the dressing head oscillating around the fulcrum, v1(t) represents the velocity of the first polishing head, and x head1 This represents the X-axis coordinate of the initial center position of the first polishing head in a coordinate system with the fulcrum as the origin, the X-axis parallel to the first preset straight line trajectory, and the Y-axis perpendicular to the first preset straight line trajectory. head1 This represents the Y-axis coordinate of the initial center position of the first polishing head in a coordinate system with the fulcrum as the origin, the X-axis parallel to the first preset straight line trajectory, and the Y-axis perpendicular to the first preset straight line trajectory. θ1 represents the angle between the line connecting the center position of the dressing head and the fulcrum when the dressing head moves to the center of the polishing pad and the X-axis. R pc R represents the radius of the trimming head. head1 This represents the radius of the first polishing head.

[0015] In some embodiments, the second polishing head and the trimming head move along the surface of the polishing pad, satisfying the following:

[0016] ;

[0017] Where R represents the distance between the fulcrum and the center position of the dressing head, t represents time, w(t) represents the angular velocity of the dressing head oscillating around the fulcrum, v2(t) represents the velocity of the second polishing head, and x head2 This represents the initial X-axis coordinate of the center position of the second polishing head in a coordinate system with the fulcrum as the origin, the X-axis parallel to the second preset straight line trajectory, and the Y-axis perpendicular to the second preset straight line trajectory. head2This represents the Y-axis coordinate of the initial center position of the second polishing head in a coordinate system with the fulcrum as the origin, the X-axis parallel to the second preset straight line trajectory, and the Y-axis perpendicular to the second preset straight line trajectory. θ1 represents the angle between the line connecting the center position of the dressing head and the fulcrum when the dressing head moves to the center of the polishing pad and the X-axis. R pc R represents the radius of the trimming head. head2 This indicates the radius of the second polishing head.

[0018] In some embodiments, as the trimming head oscillates from the edge of the polishing pad to the center, the angular velocity of the trimming head accelerates to a positive maximum value Wmax, and then decelerates from the positive maximum value Wmax to 0.

[0019] During the process of the trimming head oscillating from the center to the edge of the polishing pad, the angular velocity of the trimming head accelerates from 0 to a negative maximum value -Wmax, and then decelerates from the negative maximum value -Wmax back to 0.

[0020] In some embodiments, the angular velocity of the trimming head during the first oscillation cycle of the reciprocating oscillation motion satisfies:

[0021] , Where T1 represents the time point of 1 / 2 cycle, T2 represents the time point of one cycle, and θ represents the angle value of the trimming head swinging from the edge of the polishing pad to the center.

[0022] In some embodiments, as the first polishing head moves from the edge of the polishing pad to the center, the speed of the first polishing head accelerates from 0 to a positive maximum value Vmax, and then decelerates from the positive maximum value Vmax back to 0.

[0023] During the process of the first polishing head moving from the center to the edge of the polishing pad, the speed of the first polishing head accelerates from 0 to a negative maximum value -Vmax, and then decelerates from the negative maximum value -Vmax back to 0.

[0024] In some embodiments, the speed of the first polishing head during the first reciprocating movement cycle satisfies:

[0025] , , , Wherein, when the first polishing head is in the initial position, the center position of the first polishing head is located at the midpoint of the first preset straight line trajectory, t1 represents the time point of 1 / 4 cycle, t2 represents the time point of 1 / 2 cycle, t3 represents the time point of 3 / 4 cycle, t4 represents the time point of one cycle, and a represents the minimum distance between the first polishing head and the center of the polishing pad when the first polishing head is in the initial position.

[0026] In some embodiments, as the second polishing head moves from the edge of the polishing pad to the center, the speed of the second polishing head accelerates from 0 to a negative maximum value -Vmax, and then decelerates from the negative maximum value -Vmax back to 0.

[0027] As the second polishing head moves from the center to the edge of the polishing pad, its speed increases from 0 to a positive maximum value Vmax, and then decreases from the positive maximum value Vmax back to 0.

[0028] In one embodiment, the speed of the second polishing head during the first movement cycle of the reciprocating motion satisfies:

[0029] , , , Wherein, when the second polishing head is in the initial position, the center point of the second polishing head is located at the midpoint of the second preset straight line trajectory, t1 represents the time point of 1 / 4 cycle, t2 represents the time point of 1 / 2 cycle, t3 represents the time point of 3 / 4 cycle, t4 represents the time point of one cycle, and a represents the minimum distance between the second polishing head and the center of the polishing pad when the second polishing head is in the initial position.

[0030] In the aforementioned polishing apparatus, during actual use, the polishing table drives the polishing pad to rotate around its own center. The wafer is loaded onto the polishing head, and the polishing drive moves the polishing head until the wafer contacts the polishing pad, causing the wafer to move along the surface of the polishing pad, thus enabling the polishing pad to perform chemical mechanical polishing on the wafer. Simultaneously, the dressing drive moves the dressing head along the surface of the polishing pad, thus dressing the surface of the polishing pad. Because the distance between the center positions of the polishing head and the dressing head (i.e., the center-to-center distance between the polishing head and the dressing head) is always greater than the sum of the radii of the polishing head and the dressing head during their respective movements along the polishing pad surface, it is ensured that the polishing head and the dressing head will never collide, thus preventing collision accidents and avoiding adverse effects on production efficiency. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the polishing apparatus in one embodiment of this application;

[0032] Figure 2 for Figure 1 A diagram illustrating the movement of the dressing head, the first polishing head, and the second polishing head in the polishing apparatus shown.

[0033] Figure 3 for Figure 2 The curve showing the change of the angular velocity w(t) of the trimming head over time is shown.

[0034] Figure 4 for Figure 2 The curve showing the change of the moving speed v1(t) of the first polishing head over time is shown.

[0035] Figure 5 for Figure 2 The curve showing the change of the moving speed v2(t) of the second polishing head over time is shown. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0037] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, 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, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0042] Please see Figure 1 This application provides a polishing apparatus, including a polishing table 10, a polishing assembly 20, and a dresser 30. The polishing table 10 has a polishing pad 11 mounted on it, and the polishing table 10 can drive the polishing pad 11 to rotate around its center. The polishing assembly 20 includes a polishing head and a polishing drive. The polishing head is used to hold and fix a wafer, and the polishing drive is driven to the polishing head to move relative to the polishing pad 11, thereby causing the wafer to move along the surface of the polishing pad 11, so that the polishing pad 11 performs chemical mechanical polishing on the wafer on the polishing head. The dresser 30 includes a dressing head 31 and a dressing drive, and the dressing drive is driven to the dressing head 31 to move along the surface of the polishing pad 11, so that the dressing head 31 dresses the surface of the polishing pad 11. During the movement of the polishing head and the dressing head 31 along the surface of the polishing pad 11, the following condition is met: the distance between the center position of the polishing head and the center position of the dressing head 31 is greater than the sum of the radius of the polishing head and the radius of the dressing head 31.

[0043] Thus, in actual use, the polishing device described above involves the polishing table 10 rotating the polishing pad 11 around its own center. The wafer is fed onto the polishing head, and the polishing drive moves the polishing head until the wafer abuts against the polishing pad 11, causing the wafer to move along the surface of the polishing pad 11, thereby enabling the polishing pad 11 to perform chemical mechanical polishing on the wafer. Simultaneously, the dressing drive, the dressing head 31, also moves along the surface of the polishing pad 11, thus dressing the surface of the polishing pad 11. Because the distance between the center positions of the polishing head and the dressing head 31 (i.e., the center-to-center distance between the polishing head and the dressing head 31) is always greater than the sum of the radii of the polishing head and the dressing head 31 during their respective movements along the surface of the polishing pad 11, it is ensured that the polishing head and the dressing head 31 will never collide, thus preventing collision accidents and avoiding adverse effects on production efficiency.

[0044] In the embodiments of this application, there are two polishing heads, namely a first polishing head 21 and a second polishing head 22. Driven by a polishing drive, the first polishing head 21 and the second polishing head 22 reciprocate synchronously along a first preset straight line trajectory and a second preset straight line trajectory, respectively. Both the first and second preset straight line trajectories extend from the center of the polishing pad 11 to its edge, and are collinear. Specifically... Figure 2 In the embodiment shown, the first polishing head 21 and the second polishing head 22 are respectively arranged on the left and right sides of the center of the polishing pad 11, and move synchronously in the left and right direction. That is, when the first polishing head 21 moves to the center of the polishing pad 11, the second polishing head 22 moves to the right edge of the polishing pad 11; when the first polishing head 21 moves to the left edge of the polishing pad 11, the second polishing head 22 moves to the center of the polishing pad 11.

[0045] It should be noted that when the first polishing head 21 moves to the center of the polishing pad 11, it means that the right edge of the first polishing head 21 reaches the center of the polishing pad 11. Similarly, when the second polishing head 22 moves to the center of the polishing pad 11, it means that the left edge of the second polishing head 22 reaches the center of the polishing pad 11.

[0046] The first polishing head 21 moving to the edge of the polishing pad 11 means that the left edge of the first polishing head 21 reaches the left edge of the polishing end; similarly, the second polishing head 22 moving to the edge of the polishing pad 11 means that the right edge of the second polishing head 22 reaches the right edge of the polishing pad 11.

[0047] In a specific embodiment, the polishing drive can be a moving motor, which drives the first polishing head 21 and the second polishing head 22 to move synchronously. The polishing device also includes a controller, which is communicatively connected to the moving motor, so that the controller controls the movement of the first polishing head 21 and the second polishing head 22 through the moving motor, that is, the controller controls the acceleration, deceleration and maximum speed of the first polishing head 21 and the second polishing head 22 through the moving motor. Optionally, the controller can be an industrial computer or the like.

[0048] In some embodiments, driven by the trimming drive, the trimming head 31 oscillates back and forth around a fulcrum O between the center and the edge of the polishing pad 11, thereby trimming the entire surface of the polishing pad 11.

[0049] Specifically Figure 2 In the illustrated embodiment, the trimming head 31 oscillates back and forth about the fulcrum O between the upper left edge and the center of the polishing pad 11. The trimming head 31 reaching the edge of the polishing pad 11 means that the upper left edge of the trimming head 31 reaches the upper left edge of the polishing pad 11. The trimming head 31 reaching the center of the polishing pad 11 means that the lower edge of the trimming head 31 reaches the center of the polishing pad 11.

[0050] In a specific embodiment, the trimming drive can be a rotary motor, that is, the rotary motor drives the trimming head 31 to swing around the fulcrum O. The controller is communicatively connected to the rotary motor, so that the controller controls the swing of the trimming head 31 around the fulcrum O through the rotary motor, that is, the controller controls the acceleration, deceleration and maximum angular velocity of the trimming head 31 through the rotary motor.

[0051] Specifically, in this embodiment, a coordinate system is established with the aforementioned fulcrum O as the center, the X-axis parallel to the aforementioned first preset straight line trajectory, and the Y-axis perpendicular to the aforementioned first preset straight line trajectory. The coordinates of the center position of the trimming head 31 are (x... pc ,y pc The coordinates of the center position of the first polishing head 21 are (x1, y1). head1 The coordinates of the center position of the second polishing head 22 are (x2, y2). head2 Please see ). Figure 2 As shown, x pc = y pc = x1= y head1 Keeping constant, x2= y head2 It remains unchanged.

[0052] It is understandable that the distance between the center position of the dressing head 31 and the center position of the first polishing head 21 (i.e., the center distance between the two) is:

[0053]

[0054] Where R represents the distance between the fulcrum O and the center position of the dressing head 31, t represents time, w(t) represents the angular velocity of the dressing head 31 oscillating around the fulcrum O, v1(t) represents the moving speed of the first polishing head 21, and x head1 The x-axis coordinate of the initial center position of the first polishing head 21 is represented by the y-axis coordinate. head1 θ1 represents the Y-axis coordinate of the initial center position of the first polishing head 21, and θ1 represents the angle between the line connecting the center position of the dressing head 31 and the fulcrum O when the dressing head 31 moves to the center of the polishing pad 11 and the X-axis.

[0055] To ensure that the dressing head 31 and the first polishing head 21 do not collide as they move along the surface of the polishing pad 11, the center distance between the dressing head 31 and the first polishing head 21 must be greater than the sum of their radii, which means satisfying the following formula:

[0056] ;

[0057] Among them, R pc R represents the radius of the trimmer head 31. head1 This indicates the radius of the first polishing head 21.

[0058] It can also be understood that the distance between the center position of the dressing head 31 and the center position of the second polishing head 22 (i.e., the center distance between the two) is:

[0059]

[0060] Where R represents the distance between the fulcrum O and the center position of the dressing head 31, t represents time, w(t) represents the angular velocity of the dressing head 31 oscillating around the fulcrum O, v2(t) represents the moving speed of the second polishing head 22, and x head2 The x-axis coordinate represents the initial center position of the second polishing head 22, and the y-axis coordinate represents the center position of the second polishing head 22. head2 θ1 represents the Y-axis coordinate of the initial center position of the second polishing head 22, and θ1 represents the angle between the line connecting the center position of the dressing head 31 and the fulcrum O when the dressing head 31 moves to the center of the polishing pad 11 and the X-axis.

[0061] To ensure that the dressing head 31 and the second polishing head 22 do not collide as they move along the surface of the polishing pad 11, the center distance between the dressing head 31 and the second polishing head 22 must be greater than the sum of their radii, which means satisfying the following formula:

[0062] ;

[0063] Among them, Rpc R represents the radius of the trimmer head 31. head2 This indicates the radius of the second polishing head 22.

[0064] Please see Figure 3 As shown, in some embodiments, during the process of the trimming head 31 swinging from the edge of the polishing pad 11 to the center, the angular velocity of the trimming head 31 accelerates from 0 to a positive maximum value Wmax, swings at the positive maximum value Wmax for a certain period of time, and then decelerates from the positive maximum value Wmax back to 0.

[0065] During the oscillation of the trimming head 31 from the center to the edge of the polishing pad 11, the angular velocity of the trimming head 31 accelerates from 0 to a negative maximum value -Wmax, oscillates at the negative maximum value -Wmax for a period of time, and then decelerates back to 0. Specifically, the angular velocity of the trimming head 31 is 0 when it oscillates to the edge of the polishing pad 11, and the angular velocity of the trimming head 31 is 0 when it oscillates to the center of the polishing pad 11.

[0066] Furthermore, the angular velocity w(t) of the trimmer head 31 during the first oscillation cycle of its reciprocating oscillation motion satisfies:

[0067] , Where T1 represents the time point of 1 / 2 cycle, T2 represents the time point of one cycle, and θ represents the angle value of the trimming head 31 swinging from the edge of the polishing pad 11 to the center.

[0068] Please see Figure 4 As shown, in some embodiments, during the process of the first polishing head 21 moving from the edge of the polishing pad 11 to the center, the speed of the first polishing head 21 is accelerated from 0 to a positive maximum value Vmax, and after moving at the positive maximum value Vmax for a certain period of time, it is decelerated from the positive maximum value Vmax back to 0.

[0069] As the first polishing head 21 moves from the center to the edge of the polishing pad 11, its speed accelerates from 0 to a negative maximum value -Vmax, moves at the negative maximum value -Vmax for a certain period of time, and then decelerates back to 0. Specifically, the speed of the first polishing head 21 is 0 when it reaches the edge of the polishing pad 11, and the speed of the first polishing head 21 is 0 when it reaches the center of the polishing pad 11.

[0070] Furthermore, the velocity v1(t) of the first polishing head 21 during the first reciprocating movement cycle satisfies:

[0071] , , , Wherein, when the first polishing head 21 is in its initial position, its center is located at the midpoint of the aforementioned first preset straight line trajectory; t1 represents the time point of 1 / 4 cycle; t2 represents the time point of 1 / 2 cycle; t3 represents the time point of 3 / 4 cycle; t4 represents the time point of one cycle; and 'a' represents the minimum distance between the first polishing head 21 and the center of the polishing pad 11 when in its initial position. It should be noted that the minimum distance between the first polishing head 21 and the center of the polishing pad 11 when in its initial position refers to the distance between the right edge of the first polishing head 21 and the center of the polishing pad 11 when in its initial position.

[0072] Please see Figure 5 As shown, in some embodiments, during the process of the second polishing head 22 moving from the edge of the polishing pad 11 to the center, the speed of the second polishing head 22 is accelerated from 0 to a negative maximum value -Vmax, and after moving at the negative maximum value -Vmax for a certain period of time, it is decelerated from the negative maximum value -Vmax back to 0.

[0073] As the second polishing head 22 moves from the center to the edge of the polishing pad 11, its speed increases from 0 to a positive maximum value Vmax. After moving at the positive maximum value Vmax for a certain period of time, its speed decreases back to 0. Specifically, the speed of the second polishing head 22 is 0 when it reaches the edge of the polishing pad 11, and the speed of the second polishing head 22 is 0 when it reaches the center of the polishing pad 11.

[0074] Furthermore, the velocity v2(t) of the second polishing head 22 during the first reciprocating movement cycle satisfies:

[0075] , , , Wherein, when the second polishing head 22 is in its initial position, its center position is located at the midpoint of the aforementioned second preset straight line trajectory; t1 represents the time point of 1 / 4 cycle; t2 represents the time point of 1 / 2 cycle; t3 represents the time point of 3 / 4 cycle; t4 represents the time point of one cycle; and 'a' represents the minimum distance between the second polishing head 22 and the center of the polishing pad 11 when in its initial position. It should be noted that the minimum distance between the second polishing head 22 and the center of the polishing pad 11 when in its initial position refers to the distance between the left edge of the second polishing head 22 and the center of the polishing pad 11 when in its initial position.

[0076] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A polishing apparatus, characterized in that, include: A polishing table (10) is provided with a polishing pad (11). The polishing assembly (20) includes a polishing head and a polishing drive. The polishing head is used to adsorb and fix the wafer, and the polishing drive is driven to the polishing head to drive the polishing head to move the wafer along the surface of the polishing pad (11). The trimmer (30) includes a trimming head (31) and a trimming drive, wherein the trimming drive is driven to connect with the trimming head (31) to drive the trimming head (31) to move along the surface of the polishing pad (11). During the movement of the polishing head and the trimming head (31) along the surface of the polishing pad (11), the following conditions are met: the distance between the center position of the polishing head and the center position of the trimming head (31) is greater than the sum of the radius of the polishing head and the radius of the trimming head (31); The polishing head includes a first polishing head (21) and a second polishing head (22). Under the drive of the polishing drive, the first polishing head (21) and the second polishing head (22) move synchronously along a first preset straight line trajectory and a second preset straight line trajectory, respectively. The first preset straight line trajectory and the second preset straight line trajectory both extend from the center of the polishing pad (11) to the edge, and the first preset straight line trajectory and the second preset straight line trajectory are collinear. Driven by the trimming drive, the trimming head (31) oscillates back and forth around a fulcrum (O) between the center and the edge of the polishing pad (11); When the first polishing head (21) and the trimming head (31) move along the surface of the polishing pad (11), they satisfy the following: ； Where R represents the distance between the fulcrum (O) and the center position of the dressing head (31), t represents time, w(t) represents the angular velocity of the dressing head (31) oscillating around the fulcrum (O), v1(t) represents the velocity of the first polishing head (21), and x head1 This represents the X-axis coordinate of the initial center position of the first polishing head (21) in a coordinate system with the fulcrum (O) as the origin, the X-axis parallel to the first preset straight line trajectory, and the Y-axis perpendicular to the first preset straight line trajectory. head1 R represents the Y-axis coordinate of the initial center position of the first polishing head (21) in a coordinate system with the fulcrum (O) as the origin, the X-axis parallel to the first preset straight line trajectory, and the Y-axis perpendicular to the first preset straight line trajectory. θ1 represents the angle between the line connecting the center position of the dressing head (31) and the fulcrum (O) and the X-axis when the dressing head (31) moves to the center of the polishing pad (11). pc R represents the radius of the trimming head (31). head1 This indicates the radius of the first polishing head (21); When the second polishing head (22) and the trimming head (31) move along the surface of the polishing pad (11), they satisfy the following: ； Where R represents the distance between the fulcrum (O) and the center position of the dressing head (31), t represents time, w(t) represents the angular velocity of the dressing head (31) oscillating around the fulcrum (O), v2(t) represents the velocity of the second polishing head (22), and x head2 This represents the initial X-axis coordinate of the center position of the second polishing head (22) in a coordinate system with the fulcrum (O) as the origin, the X-axis parallel to the second preset straight line trajectory, and the Y-axis perpendicular to the second preset straight line trajectory. head2 R represents the initial Y-axis coordinate of the center position of the second polishing head (22) in a coordinate system with the fulcrum (O) as the origin, the X-axis parallel to the second preset straight line trajectory, and the Y-axis perpendicular to the second preset straight line trajectory. θ1 represents the angle between the line connecting the center position of the dressing head (31) and the fulcrum (O) and the X-axis when the dressing head (31) moves to the center of the polishing pad (11). pc R represents the radius of the trimming head (31). head2 This indicates the radius of the second polishing head (22).

2. The polishing apparatus according to claim 1, characterized in that, During the process of the trimming head (31) swinging from the edge of the polishing pad (11) to the center, the angular velocity of the trimming head (31) accelerates from 0 to a positive maximum value Wmax, and then decelerates from the positive maximum value Wmax back to 0. During the process of the trimming head (31) swinging from the center to the edge of the polishing pad (11), the angular velocity of the trimming head (31) accelerates from 0 to a negative maximum value -Wmax, and then decelerates from the negative maximum value -Wmax back to 0.

3. The polishing apparatus according to claim 2, characterized in that, The angular velocity of the trimming head (31) during the first oscillation cycle of the reciprocating oscillation motion satisfies: , Where T1 represents the time point of 1 / 2 cycle, T2 represents the time point of one cycle, and θ represents the angle value of the trimming head (31) swinging from the edge of the polishing pad (11) to the center.

4. The polishing apparatus according to claim 1, characterized in that, During the process of the first polishing head (21) moving from the edge of the polishing pad (11) to the center, the speed of the first polishing head (21) is accelerated from 0 to a positive maximum value Vmax, and then decelerated from the positive maximum value Vmax back to 0. During the process of the first polishing head (21) moving from the center to the edge of the polishing pad (11), the speed of the first polishing head (21) is accelerated from 0 to a negative maximum value -Vmax, and then decelerated from the negative maximum value -Vmax back to 0.

5. The polishing apparatus according to claim 4, characterized in that, The speed of the first polishing head (21) during the first reciprocating movement cycle satisfies: , , , Wherein, when the first polishing head (21) is in the initial position, the center position of the first polishing head (21) is located at the midpoint of the first preset straight line trajectory, t1 represents the time point of 1 / 4 cycle, t2 represents the time point of 1 / 2 cycle, t3 represents the time point of 3 / 4 cycle, t4 represents the time point of one cycle, and a represents the minimum distance value between the first polishing head (21) and the center of the polishing pad (11) when the first polishing head (21) is in the initial position.

6. The polishing apparatus according to claim 1, characterized in that, During the process of the second polishing head (22) moving from the edge of the polishing pad (11) to the center, the speed of the second polishing head (22) is accelerated from 0 to a negative maximum value -Vmax, and then decelerated from the negative maximum value -Vmax back to 0. During the process of the second polishing head (22) moving from the center to the edge of the polishing pad (11), the speed of the second polishing head (22) is accelerated from 0 to a positive maximum value Vmax, and then decelerated from the positive maximum value Vmax back to 0.

7. The polishing apparatus according to claim 6, characterized in that, The second polishing head (22) has the following speed during the first moving cycle of its reciprocating motion: , , , ; wherein, when the second polishing head (22) is in the initial position, the center point of the second polishing head (22) is located at the midpoint of the second preset straight line trajectory, t1 represents the time point of 1 / 4 cycle, t2 represents the time point of 1 / 2 cycle, t3 represents the time point of 3 / 4 cycle, t4 represents the time point of one cycle, and a represents the minimum distance between the second polishing head (22) and the center of the polishing pad (11) when the second polishing head (22) is in the initial position.

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