Grinding device and chemical mechanical grinding equipment

Abstract

The utility model relates to a grinding device and chemical mechanical grinding equipment, and relates to the field of semiconductor manufacturing, and the grinding device comprises a stepless speed change mechanism which comprises a first end used for driving a grinding disc to rotate at a first angular speed and a second end used for driving a grinding head to rotate at a second angular speed; the grinding head is used for pressing the wafer on the grinding surface of the grinding pad; the motor is used for driving the first end to move and driving the grinding disc to move; the stepless speed change mechanism is used for transmitting power of the motor to the second end and driving the grinding head to rotate; the transmission speed ratio of the stepless speed change mechanism is related to the center distance between the wafer and the grinding pad, and the transmission speed ratio is the ratio of the second angular speed to the first angular speed. On the basis of existing CMP machine table equipment, the arrangement of a grinding head motor power source is omitted, and a closed loop control system is added for the rotating speed of a grinding disc, so that the uniform grinding linear speed is obtained, and the grinding quality of wafers is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a grinding device and a chemical mechanical grinding equipment. BACKGROUND

[0002] With the rapid development of the semiconductor industry, in many process, the wafer needs to be chemically mechanically ground (CMP), through chemical reaction and mechanical grinding, the wafer is planarized or polished, CMP is one of the most commonly used wafer surface planarization methods in the semiconductor manufacturing industry.

[0003] In the grinding process, the wafer needs to be moved to the top of the grinding disc by the grinding head first, then the grinding head is pressed downward to press the wafer to the grinding surface of the grinding pad. In order to avoid the area without speed in the center of the grinding pad, the wafer is usually offset to one side of the center of the grinding disc, finally, the relative motion of the grinding disc and the wafer is used to realize the grinding and polishing of the wafer surface.

[0004] However, in the general grinding process, if the grinding head is fixed, after long-term use, the grinding pad will be concentrated in the fixed area of the wafer and the grinding pad, reducing the utilization rate of the grinding pad, increasing the replacement frequency, and thus unable to reduce the CMP process cost. If the wafer is set to swing, it will affect the average grinding line speed of the wafer, cause the edge of the wafer to grind unstably, the grinding effect is poor or defects are generated, thereby affecting the quality of the wafer. Figure 1 Figure 2 Therefore, how to prolong the service life of the grinding pad while obtaining a stable grinding line speed and improving the grinding quality has become one of the technical problems to be solved.

[0005] Therefore, how to prolong the service life of the grinding pad while obtaining a stable grinding line speed and improving the grinding quality has become one of the technical problems to be solved. INVENTION CONTENTS

[0006] Therefore, how to prolong the service life of the grinding pad while obtaining a stable grinding line speed and improving the grinding quality has become one of the technical problems to be solved.

[0007] In a first aspect, the present application provides a grinding device, comprising: a stepless speed change mechanism, comprising a first end for driving the grinding disc to rotate at a first angular velocity, and a second end for driving the grinding head to rotate at a second angular velocity; the grinding head is used to press the wafer on the grinding surface of the grinding pad; the motor is used to drive the first end to move and drive the grinding disc to move; the stepless speed change mechanism is used to transmit the power of the motor to the second end to drive the grinding head to rotate; the transmission ratio of the stepless speed change mechanism is related to the center distance between the wafer and the grinding pad, and the transmission ratio is the ratio of the second angular velocity to the first angular velocity.​

[0008] In the polishing device in the above embodiments, a set of stepless speed change mechanisms can be designed on the basis of the existing CMP machine equipment, one end of which is connected with the motor and the polishing disc, and the other end of which is connected with the polishing head. The power of the polishing disc movement is transmitted to the polishing head through the stepless speed change mechanism. The speed ratio of the polishing disc transmitted to the polishing head is freely adjusted according to the swing position of the polishing head driving the wafer. In this way, no matter how the polishing head swings, the wafer can have a fixed and uniform polishing linear speed, which not only ensures the average polishing pad wear area, but also ensures the uniform polishing of the wafer surface, so as to achieve the purpose of obtaining better surface quality and more uniform film thickness and improving the polishing performance of the polishing device. Through the stepless speed change mechanism, the polishing disc and the polishing head share the same power source, reducing the power source setting.

[0009] Compared with the prior art, the polishing device of the present application can more accurately and reliably stabilize the polishing speed of the wafer, effectively improve the polishing quality of the wafer, and at the same time, realize power transmission by using a stepless speed change mechanism composed of a simple mechanical structure, eliminating the need for an additional polishing head motor.

[0010] In some embodiments, the polishing device further comprises a moving component for driving at least the polishing head to move closer to or away from the center of the polishing pad in the radial direction.

[0011] In some embodiments, the stepless speed change mechanism further comprises: a driving wheel arranged at the second end for driving the polishing head to rotate at a second angular speed; a driven wheel arranged at the first end for driving the polishing disc to rotate at a first angular speed; and the driving radius ratio of the driving wheel to the driven wheel is related to the transmission ratio.

[0012] In some embodiments, when the polishing head is close to the edge of the polishing pad, the driving radius of the driven wheel is greater than the driving radius of the driving wheel; and when the polishing head is close to the center of the polishing pad, the driving radius of the driven wheel is less than the driving radius of the driving wheel.

[0013] In some embodiments, the stepless speed change mechanism further comprises at least two driven wheels; the driven wheels are connected through a power transmission member; and among the at least two driven wheels, one driven wheel is connected with the motor, and the other driven wheel is connected with the driving wheel through a transmission belt.

[0014] In some embodiments, the moving component comprises a rocker arm; the rocker arm is connected with the polishing head for controlling the lifting of the polishing head and driving the polishing head to move horizontally on the polishing pad.

[0015] In some embodiments, the polishing head further comprises a position sensor for detecting the center distance value between the wafer and the polishing pad.

[0016] In some embodiments, the polishing device further comprises a controller connected to the position sensor and the continuously variable transmission, for receiving the center distance value and controlling the continuously variable transmission to adjust the transmission ratio.

[0017] In a second aspect, the present application provides a chemical mechanical polishing apparatus comprising the polishing device of any one of the above embodiments.

[0018] In some embodiments, the chemical mechanical polishing apparatus further comprises an adjustment mechanism connected to the motor for driving the polishing pad to move, a polishing liquid supply mechanism arranged on the adjustment mechanism for supplying the polishing pad with polishing liquid, and a polishing pad conditioner arranged on the adjustment mechanism for conditioning the polishing surface of the polishing pad.

[0019] In the chemical mechanical polishing apparatus of the above embodiments, thanks to the polishing device configured, a closed loop control system is added to the rotation speed of the polishing head on the basis of the existing CMP machine equipment, the optimal polishing linear speed is achieved, the service life of the polishing pad is increased, and the wafer polishing rate is stabilized, so that a better wafer topography / flatness is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings of other embodiments can also be obtained by those skilled in the art without creative labor.

[0021] Figure 1 A schematic diagram of the wear area of the polishing pad when the wafer is fixed during the polishing process;

[0022] Figure 2 A schematic diagram of the wear area of the polishing pad and the change of the polishing linear speed when the wafer is swinging during the polishing process;

[0023] Figure 3 A schematic diagram of the polishing device provided by an embodiment;

[0024] Figure 4 A top view structural schematic diagram of the polishing pad and the wafer in the polishing device provided by an embodiment;

[0025] Figure 5 A functional relationship diagram of the center distance between the wafer and the polishing pad and the second angular velocity in the polishing device provided by an embodiment;

[0026] Figure 6 A schematic diagram of the change of the driving radius of the driving wheel and the driven wheel when the wafer is close to the edge of the polishing pad in the polishing device provided by an embodiment;

[0027] Figure 7 Fig. 6 is a schematic diagram of a change in driving radius of the driving wheel and the driven wheel when the wafer is close to the center of the polishing pad in the polishing apparatus according to an embodiment;

[0028] Figure 8 Fig. 7 is a schematic diagram of an electrical connection relationship in the polishing apparatus according to an embodiment;

[0029] Figure 9 Fig. 8 is a schematic diagram of a conventional polishing apparatus;

[0030] Figure 10 Fig. 9 is a schematic diagram of a cross-sectional profile of a wafer polished by a conventional polishing apparatus;

[0031] Figure 11 Fig. 10 is a schematic diagram of a cross-sectional profile of a wafer polished by the polishing apparatus according to an embodiment.

[0032] BRIEF DESCRIPTION OF DRAWINGS

[0033] 10 motor; 20 polishing disk; 21 polishing pad; 30 polishing head; 31 wafer; 40 continuously variable transmission mechanism; 41 driven wheel; 411 first driven wheel; 412 second driven wheel; 413 third driven wheel; 42 driving wheel; 50 power transmission member; 51 connecting rod; 52 transmission belt; 521 first transmission belt; 522 second transmission belt; 60 controller; 70 position sensor. DETAILED DESCRIPTION

[0034] For the purposes of promoting an understanding of the principles of the application, reference will now be made to the embodiments illustrated in the drawings. It is expressly understood that the drawings are for illustration only and that the application can be embodied in many different forms. In the drawings:

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0036] In the case of using "include", "have", and "contain" described herein, unless an explicit limiting term is used, such as "only", "consisting of", and the like, another component can be added. Unless otherwise mentioned, the singular form of the term can include the plural form, and it cannot be understood as one in number.

[0037] It should be understood that, although the terms "first", "second" and the like can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present application.

[0038] In the present application, unless specifically defined otherwise and limited, the terms "mount", "connect", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection, it can be direct connection, or indirect connection through intermediate medium, it can be the internal communication of two elements, and for those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0039] If you want to prolong the service life of the polishing pad while ensuring the polishing effect of the wafer, you need to reasonably design the rotation speed and polishing position of the polishing disc and the wafer to obtain a uniform and stable polishing rate, so as to ensure the uniform removal of the wafer surface material and improve the surface quality and the uniformity of the film thickness.

[0040] Based on this, please refer to Figure 3 The present application provides a kind of polishing device, comprising: stepless speed change mechanism 40, including for driving polishing disc 20 to rotate with first angular velocity first end, and for driving polishing head 30 to rotate with second angular velocity second end;Polishing head 30 is used to press down wafer 31 on the polishing surface of polishing pad 21;Motor 10 is used to drive the first end movement and drive polishing disc 20 movement;Stepless speed change mechanism 40 is used to transmit the power of motor 10 to second end, drive polishing head 30 to rotate;The transmission ratio of stepless speed change mechanism 40 is related to the center distance between wafer 31 and polishing pad 21, and the transmission ratio is the ratio of second angular velocity and first angular velocity.

[0041] Wherein, polishing pad 21 is arranged on the upper surface of polishing disc 20, and the polishing surface is the top surface of polishing pad 21. The size and type of polishing pad 21 can be set according to the size of wafer and polishing disc 20 or demand, it needs to be explained that the size of polishing disc 20 and wafer 31 mentioned in the present application is consistent, that is, the diameter of polishing disc 20 is 762 millimeters, and the diameter of wafer 31 is 300 millimeters.

[0042] Please continue to refer to Figure 3In an alternative embodiment, the continuously variable transmission 40 further comprises: a driving wheel 42 disposed at the second end for driving the grinding head 30 to rotate at the second angular velocity; a driven wheel 41 disposed at the first end for driving the grinding disc 20 to rotate at the first angular velocity; the driving radius ratio of the driving wheel 42 to the driven wheel 41 is associated with the transmission ratio.

[0043] Please continue to see Figure 3 In an alternative embodiment, the continuously variable transmission 40 further comprises at least two driven wheels 41; the driven wheels 41 are connected by a power transmission member 50; among the at least two driven wheels 41, one driven wheel is connected with the motor 10, and the other driven wheel is connected with the driving wheel 42 through a transmission belt 52.

[0044] Specifically, the driven wheel 41 comprises: a first driven wheel 411, a second driven wheel 412, and a third driven wheel 413; the power transmission member 50 comprises: a connecting rod 51 and a transmission belt 52; the transmission belt 52 comprises: a first transmission belt 521 and a second transmission belt 522.

[0045] Among them, the first driven wheel 411 is disposed at the second end of the continuously variable transmission 40, one end of which is connected with the motor 10 and the other end of which is connected with the grinding disc 20.

[0046] Among them, the second driven wheel 412 is connected with the first driven wheel 411 through the first transmission belt 521.

[0047] Among them, the third driven wheel 413 is connected with the second driven wheel 412 through the connecting rod 51, and the connecting rod 51 is used to adjust the distance between the second driven wheel 412 and the third driven wheel 413.

[0048] Among them, the driving wheel 42 is connected with the third driven wheel 413 through the second transmission belt 522.

[0049] Here, the first transmission belt 521 and the second transmission belt 522 are both fixed in length, and the first driven wheel 411, the second driven wheel 412, and the third driven wheel 413 maintain the same driving radius.

[0050] Here, the power transmission direction through the continuously variable transmission 40 is as shown in Figure 3 When the motor 10 drives the grinding disc 20 to rotate around the axis at the first angular velocity, the first driven wheel 411 rotates at the same angular velocity in the same direction, the first transmission belt 521 drives the connected second driven wheel 412 to rotate, the connecting rod 51 transmits power to the third driven wheel 413, and the second transmission belt 522 drives the driving wheel 42 to rotate.

[0051] In the power transmission process, the linear speed of the transmission belt 52 on the passive wheel 41 and the driving wheel 42 at all points is equal. Therefore, the rotation angular velocity of the polishing pad 20 and the passive wheel 41 is consistent in direction, and the rotation direction of the polishing pad 20 and the driving wheel 42 and the polishing head 30 is the same, but since the transmission ratio of the stepless speed change mechanism 40 is related to the driving radius ratio of the driving wheel 42 and the passive wheel 41, the polishing head 30 connected below the driving wheel 42 rotates at a second angular velocity determined by the transmission ratio.

[0052] Referring to Figure 4 In an optional embodiment, the polishing device further comprises a moving component (not shown) for driving the polishing head 30 to move at least radially along the polishing pad 21 to approach or move away from the center.

[0053] For example, Figure 4 The polishing device provided in an embodiment is shown in a top view of the polishing pad 21 and the wafer 31. The center distance between the wafer 31 and the polishing pad 21 is set as d. V1 represents the first angular velocity, and V2 represents the second angular velocity.

[0054] In this way, the radially oscillating polishing head 30 can increase the contact area between the polishing pad 21 and the wafer 31, average the polishing pad wear area, prolong the service life, and reduce the process cost of CMP. Here, the polishing head 30 is controlled to reciprocate along the radial direction of the polishing pad 21 while being controlled by the stepless speed change mechanism 40 to keep rotating.

[0055] For example, referring to Figure 5 , Figure 5 The functional relationship between the center distance d between the wafer 31 and the polishing pad 21 and the second angular velocity V2 in the polishing device provided in an embodiment is shown in a graph.

[0056] Wherein, d+ represents the movement of the wafer 31 in the direction away from the center of the polishing pad 21, and d- represents the movement of the wafer 31 in the direction approaching the center of the polishing pad 21.

[0057] Specifically, the stepless speed change mechanism 40 adjusts the second angular velocity of the polishing head 30 in real time as the d distance oscillates, so that a fixed and average polishing linear speed can be obtained. When d→d+, the wafer 31 approaches the edge of the polishing pad 21, the first angular velocity V1 increases (linear speed ∝ radius), so the second angular velocity V2 of the wafer 31 is increased; when d→d-, the wafer 31 approaches the center of the polishing pad 21, the first angular velocity V1 decreases, so the second angular velocity V2 of the wafer 31 is decreased.

[0058] Thus, according to the fitting function relationship between the center distance value d and the second angular velocity V2, a program is written to establish a feedback mechanism, to monitor and analyze data in real time, to feed back the center distance value and the second angular velocity V2 data to the control system, and to timely adjust the rotation speed of the wafer 31 to ensure the matching of the center distance value and the second angular velocity V2.

[0059] Referring to Figure 6 and Figure 7 In an optional embodiment, when the polishing head 30 is close to the edge of the polishing pad 21, the driving radius of the passive wheel 41 is greater than that of the driving wheel 42; when the polishing head 30 is close to the center of the polishing pad 21, the driving radius of the passive wheel 41 is smaller than that of the driving wheel 42.

[0060] For example, Figure 6 The driving radius change diagram of the driving wheel 42 and the passive wheel 41 in the polishing device provided for an embodiment when the wafer 31 is close to the edge of the polishing pad 21; Figure 7 The driving radius change diagram of the driving wheel 42 and the passive wheel 41 in the polishing device provided for an embodiment when the wafer 31 is close to the center of the polishing pad 21.

[0061] Specifically, when the driving wheel 42 expands (the driving radius increases), the passive wheel 41 shrinks (the driving radius decreases); when the driving wheel 42 shrinks (the driving radius decreases), the passive wheel 41 expands (the driving radius increases). As described above, the angular velocity and the rotation direction of the polishing disc 20 and the passive wheel 41 are consistent, the third passive wheel 413 rotates at the first angular velocity V1, and the transmission ratio of the stepless speed change mechanism 40 is related to the driving radius ratio of the passive wheel 41 and the driving wheel 42. Since the length of the transmission belt 52 is fixed, by adjusting the driving radius ratio of the passive wheel 41 and the driving wheel 42, the transmission ratio of the stepless speed change mechanism can be changed, and the second angular velocity V2 can be controlled in real time.

[0062] Referring to Figure 6 When the wafer 31 moves along the polishing pad 21 radially close to the edge thereof, the driving radius of the driving wheel 42 shrinks, and the driving radius of the passive wheel 41 increases. Since the linear velocity is equal, the smaller the driving radius is, the greater the angular velocity is, i.e. the transmission ratio of the stepless speed change mechanism 40 (the ratio of the first angular velocity V1 to the second angular velocity V2) is equal to the inverse of the driving radius ratio of the passive wheel 41 and the driving wheel 42. Therefore, the second angular velocity V2 of the driving wheel 42 increases accordingly.

[0063] Referring to Figure 7 When the wafer 31 moves along the polishing pad 21 radially close to the center thereof, the driving radius of the driving wheel 42 expands, and the driving radius of the passive wheel 41 shrinks. At this time, the second angular velocity V2 of the driving wheel 42 decreases accordingly.

[0064] In the above embodiment, the stepless speed change mechanism 40 shares the same motor 10 with the polishing disc 20, the speed change intervals of the speed-up and speed-down are the same, that is, the maximum transmission ratio is equal to the inverse of the minimum transmission ratio, the continuous change of the transmission ratio is realized according to the real-time response of the wafer 31 polishing swing feedback, thereby providing a smooth and continuous speed change effect.

[0065] In an optional embodiment, the moving component comprises a rocker arm (not shown) connected with the polishing head 30 for controlling the lifting of the polishing head 30 and driving the polishing head 30 to move horizontally on the polishing pad 21. The moving component is a known technology in the art, which will not be described in detail in the present embodiment.

[0066] In an optional embodiment, the polishing head 30 further comprises a position sensor 70 (not shown) for detecting the center distance value d between the wafer 31 and the polishing pad 21. Of course, the position sensor 70 can comprise a plurality of types of distance measuring sensors without limitation.

[0067] Referring to Figure 8 In an optional embodiment, the polishing device further comprises a controller 60 electrically connected with the position sensor 70 and the stepless speed change mechanism 40, for receiving the center distance value d and controlling the stepless speed change mechanism 40 to adjust the transmission ratio.

[0068] For example, Figure 8 The schematic diagram of the electrical connection relationship in the polishing device provided in an embodiment is shown in the figure. Specifically, the motor 10 is arranged to rotate at a constant speed with a preset first angular velocity, thereby driving the polishing head 30 to rotate synchronously. At this time, the moving component pressurizes the polishing head 30, thereby pressing the wafer 31 to the polishing surface of the polishing pad 21 for the polishing process. The position sensor 70 is arranged on the polishing head 30, thereby detecting the center distance value d of the wafer 31 on the polishing pad 21 in real time and transmitting the center distance value d to the controller 60. The controller 60 is connected with the stepless speed change mechanism 40, for adjusting the transmission ratio of the stepless speed change mechanism 40 according to the center distance value d provided by the position sensor 70, thereby dynamically adjusting the second angular velocity of the polishing head 30 and avoiding the unstable polishing of the edge of the wafer 31.

[0069] Referring to Figure 9 , Figure 9As a schematic diagram of the prior art grinding device, compared with the grinding device provided in the present application, the prior art grinding device is usually provided with at least two motors, one motor is configured to be connected with the grinding disc 20 and is used to drive the grinding disc 20 to rotate at a first angular velocity, and the other motor is configured to be connected with the grinding head 30 and is used to drive the grinding head 30 to rotate at a second angular velocity. Therefore, compared with the prior art, on the basis of the original device, a set of stepless speed change mechanism 40 is designed, and the rotational speed of the wafer 31 can be adjusted in real time through the stepless speed change mechanism 40. In addition, the grinding device provided in the present application abolishes the motor used to drive the grinding head 30 in the traditional grinding device, reduces the power supply setting, and is energy-saving and environment-friendly.

[0070] Please refer to Figures 10-11 , Figure 10 As a schematic diagram of the cross-sectional profile of the wafer ground by the traditional grinding device. Figure 11 As a schematic diagram of the cross-sectional profile of the wafer ground by the grinding device provided in the present application. Four curves of wafers at the same position in the same grinding batch are selected, wherein the abscissa is used to represent the diameter of the wafer 31, and the unit is millimeter (mm), and the ordinate is used to represent the height of the wafer after grinding, and the unit is angstrom (A). According to the cross-sectional profile of the wafer 31 after the grinding process, compared with the traditional grinding device, the edge topography of the wafer 31 processed by the grinding device provided in the present application is relatively flat, and the peak-to-valley depth is obviously smaller. This indicates that the real-time control system of the grinding head 30 is used, and after the fixed grinding linear speed is obtained, the wear of the grinding pad 21 is more stable, the grinding rate and the flatness of the wafer 31 surface are better, and the wafer edge topography is better controlled.

[0071] In a second aspect, the present application provides a chemical mechanical grinding equipment, comprising the grinding device in any one of the above embodiments. The closed loop control system is arranged on the grinding head 30, and the second angular velocity of the grinding head 30 is dynamically adjusted in real time, so that the grinding rate of the wafer 31 is stably maintained, and the grinding effect is improved.

[0072] In an optional embodiment, the chemical mechanical grinding equipment further comprises: an adjusting mechanism connected with the motor 10 and used to drive the grinding disc 20 to move; a grinding liquid supply mechanism arranged on the adjusting mechanism and used to supply the grinding liquid to the grinding pad 21; and a grinding pad trimmer arranged on the adjusting mechanism and used to trim the grinding surface of the grinding pad 21. The adjusting mechanism, the grinding liquid supply mechanism and the grinding pad trimmer mentioned in the present embodiment are the known technologies in the art, and will not be described in detail in the present embodiment.

[0073] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A grinding device, characterized by, Comprising: a continuously variable transmission mechanism, comprising a first end for driving a polishing pad to rotate at a first angular velocity, and a second end for driving a polishing head to rotate at a second angular velocity; the polishing head for pressing a wafer against a polishing surface of a polishing pad; a motor for driving the first end to move and in turn driving the polishing pad to move; the continuously variable transmission mechanism for transmitting power from the motor to the second end to drive the polishing head to rotate; a transmission ratio of the continuously variable transmission mechanism is associated with a center distance between the wafer and the polishing pad, the transmission ratio being a ratio of the second angular velocity to the first angular velocity.

2. The polishing apparatus according to claim 1, wherein Further comprising: a moving component for moving the polishing head at least radially towards or away from the center of the polishing pad.

3. The polishing apparatus according to claim 1, wherein The continuously variable transmission mechanism further comprises: a driving pulley disposed at the second end for driving the polishing head to rotate at the second angular velocity; a driven pulley disposed at the first end for driving the polishing pad to rotate at the first angular velocity; a driving radius ratio of the driving pulley to the driven pulley is associated with the transmission ratio.

4. The abrading device of claim 3, wherein, When the polishing head is close to an edge of the polishing pad, the driving radius of the driven pulley is greater than the driving radius of the driving pulley; When the polishing head is close to the center of the polishing pad, the driving radius of the driven pulley is less than the driving radius of the driving pulley.

5. The abrading device of claim 3, wherein, The continuously variable transmission mechanism further comprises: at least two driven pulleys; the driven pulleys are connected through a power transmission component; of the at least two driven pulleys, one driven pulley is connected to the motor, and the other driven pulley is connected to the driving pulley through a transmission belt.

6. The abrading device of claim 2, wherein, The moving component comprises a rocker arm; the rocker arm is connected to the polishing head for controlling the polishing head to move up and down and to move horizontally on the polishing pad.

7. The grinding device according to any one of claims 1 to 6, characterized in that The polishing head further comprises: a position sensor for detecting a center distance value between the wafer and the polishing pad.

8. The abrading device of claim 7, wherein, Further comprising: a controller connected to the position sensor and the continuously variable transmission mechanism for receiving the center distance value and controlling the continuously variable transmission mechanism to adjust the transmission ratio.

9. A chemical mechanical polishing apparatus characterized by comprising: The polishing apparatus of any one of claims 1-8.

10. The chemical mechanical polishing apparatus of claim 9, wherein Further comprising: an adjustment mechanism connected to the motor for moving the polishing pad; a polishing liquid supply mechanism disposed at the adjustment mechanism for supplying a polishing liquid to the polishing pad; a polishing pad conditioner disposed at the adjustment mechanism for conditioning a polishing surface of the polishing pad.

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