Polishing device, polishing system and polishing method

Abstract

The invention discloses a polishing device, a polishing system and a polishing method, and relates to the technical field of semiconductor manufacturing. The outer side of the polishing shaft is provided with a polishing sleeve, and the lower end of the polishing shaft is provided with a polishing head; the driving assembly comprises a fixing base and a motor rotor, and the motor rotor is arranged on the peripheral side of the polishing sleeve; a driven block on the lifting assembly is arranged on a moving seat of the polishing shaft and arranged on one side of the polishing shaft in an offset mode, and the polishing shaft synchronously moves along with the moving seat so as to change the vertical position of the polishing head; the adjusting assembly is arranged on the peripheral side of the polishing shaft and located above the motor rotor. The adjusting assembly comprises a supporting bearing, an adjusting seat and an adjusting pin, the supporting bearing and the adjusting seat are arranged on the peripheral side of the polishing sleeve from inside to outside, and the adjusting pin is located on the peripheral side of the adjusting seat; the adjusting pin is of an eccentric structure and abuts against the peripheral wall of the adjusting base so as to adjust the coaxiality of the polishing shaft relative to the fixing base.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a polishing apparatus, polishing system and polishing method. Background Technology

[0002] The integrated circuit industry is the core of the information technology industry, playing a crucial role in promoting the digital and intelligent transformation and upgrading of the manufacturing industry. Chips are the carriers of integrated circuits, and chip manufacturing involves processes such as integrated circuit design, wafer fabrication, wafer processing, electrical measurement, dicing, packaging, and testing. Among these, chemical mechanical polishing (CMP) is one of the five core processes in wafer fabrication.

[0003] Chemical mechanical polishing (CMP) is an ultra-precision surface finishing technique that achieves global planarization, implemented in a CMP system. Specifically, the wafer to be polished is mounted on the bottom surface of a polishing head, with the side of the wafer having the deposited layer abutting against the upper surface of a polishing pad. The polishing head, actuated by a drive assembly, rotates in the same direction as the polishing pad and applies a downward load to the wafer. Polishing fluid is supplied to the upper surface of the polishing pad and distributed between the wafer and the pad, allowing the wafer to undergo chemical mechanical polishing through a combination of chemical and mechanical processes.

[0004] The polishing head interacts with the load cup of the CMP system to load or unload wafers. During this interaction, the elastic membrane of the polishing head stretches and extends vertically to prevent the adsorbed wafers from interfering with other components of the CMP system and breaking. Because the vertical stretching range of the elastic membrane is limited, it restricts the structural design of the CMP system to some extent.

[0005] With the further development of wafer fabrication processes, the requirements for various performance aspects of CMP systems, such as polishing stability, internal layout rationality, and equipment footprint, are becoming increasingly stringent. Therefore, there is an urgent need to design a polishing device that breaks through the bottleneck of relying solely on elastic membrane stretching for vertical extension, thereby improving the overall performance of the CMP system. Summary of the Invention

[0006] In view of this, embodiments of this application provide a polishing apparatus, a polishing system, and a polishing method to at least partially solve the above-mentioned problems.

[0007] According to a first aspect of the embodiments of this application, a polishing apparatus is provided for chemical mechanical polishing of wafers, comprising: A polishing shaft with a polishing sleeve on its outer side and a polishing head at its lower end; The drive assembly includes a fixed base and a motor mover, the motor mover being disposed on the outer peripheral side of the polishing sleeve; The lifting assembly has a driven block disposed on the movable seat of the polishing shaft and biased to one side of the polishing shaft. The polishing shaft moves synchronously with the movable seat to change the vertical position of the polishing head. An adjustment assembly is disposed on the outer periphery of the polishing shaft and above the motor mover; the adjustment assembly includes a support bearing, an adjustment seat, and an adjustment pin, the support bearing and the adjustment seat are disposed from the inside to the outside on the outer periphery of the polishing sleeve, and the adjustment pin is located on the outer periphery of the adjustment seat; the adjustment pin has an eccentric structure and abuts against the outer peripheral wall of the adjustment seat to adjust the coaxiality of the polishing shaft relative to the fixed seat.

[0008] In some embodiments, the adjusting seat is concentrically disposed on the outer ring of the supporting bearing, and a plurality of adjusting pins are spaced apart on the outer peripheral side of the adjusting seat.

[0009] In some embodiments, the adjusting pin includes a pin shaft and a roller, the pin shaft being eccentrically disposed below the roller; the pin shaft being disposed above the fixed base, and the outer side wall of the roller abutting against the outer peripheral wall of the adjusting base.

[0010] In some embodiments, the adjustment assembly further includes a retaining ring disposed on the outer peripheral wall of the polishing shaft and abutting against the inner ring of the support bearing.

[0011] In some embodiments, the lifting assembly further includes a lifting motor and a lead screw, the output shaft of the lifting motor is connected to the lead screw, and the driven block is connected to the outer periphery of the lead screw.

[0012] In some embodiments, the lifting assembly further includes a pair of support rods, which are vertically arranged and located on both sides of the lead screw; one end of the support rod is connected to the lifting motor fixing plate, and the other end is connected to the fixing base.

[0013] In some embodiments, the lead screw is located above the fixed base, and a gap is provided between its lower end and the fixed base.

[0014] According to a second aspect of the embodiments of this application, a polishing system is provided, which includes a polishing disc, a liquid supply device, a trimming device, and the polishing device described above. The polishing head presses the wafer to be polished against a polishing pad above the polishing disc. The liquid supply device supplies polishing liquid between the polishing pad and the wafer. The trimming device is used to trim the surface of the polishing pad.

[0015] In some embodiments, there are multiple polishing devices, which are mounted on slide rails above polishing pads. The polishing devices move between adjacent polishing pads via the slide rails. The polishing shaft of the polishing device moves vertically at the wafer loading / unloading position on the side of the polishing pad so that the polishing head can load or unload wafers.

[0016] In some embodiments, the slide rail spans at least two polishing discs, and the number of polishing devices is three, which are spaced apart along the slide rail.

[0017] In some embodiments, the center line connecting the lead screw and the polishing shaft of the polishing device is collinear with the linear velocity of the polishing device along the slide rail.

[0018] In some embodiments, the slide rail is a circular structure, with the center line connecting it to the center of the polishing shaft of the polishing device being L1, and the center line connecting the lead screw and the center of the polishing shaft of the polishing device being L2, and the included angle between L1 and L2 being 75°~100°.

[0019] In some embodiments, as the polishing device moves along the slide rail, the polishing head moves upward to a high position.

[0020] In some embodiments, before the polishing apparatus is operated, the coaxiality of the polishing shaft relative to the fixed base is adjusted by adjusting the adjustment component.

[0021] According to a third aspect of the embodiments of this application, a polishing method is provided, which uses the polishing system described above to perform chemical mechanical polishing on a wafer.

[0022] The beneficial effects of this invention include: a. The provided polishing device is equipped with a lifting component, which can drive the polishing shaft and polishing head to move vertically to load and unload wafers in conjunction with the polishing head. This breaks through the bottleneck of relying solely on the expansion and contraction of the elastic membrane of the polishing head to achieve vertical movement and improves the flexibility of CMP system configuration. b. The lead screw of the lifting assembly is located above the fixed seat, and there is a gap between its lower end and the fixed seat; the range of the driven block moving downward cannot exceed the gap, so as to prevent the lower end face of the driven block from abutting against the top surface of the fixed seat and causing interference, thereby avoiding the driven block moving beyond the limit and affecting the stable operation of the polishing device. c. The polishing device is equipped with an adjustment component, which is located on the outer periphery of the polishing shaft and above the motor mover. The adjustment component can limit the upper position of the polishing shaft, which is beneficial to control the end floating range of the polishing shaft, and thus control the end runout of the polishing head. The adjustment seat of the adjustment component is concentrically set on the outer ring of the support bearing, so that the adjustment seat can move in the horizontal direction, which can change the position of the support bearing set on the outside of the polishing shaft, thereby efficiently adjusting the installation state of the polishing shaft. d. The adjusting assembly is equipped with a locking bolt, which is arranged adjacent to the adjusting pin, so that the adjusting point and the locking point are very close in space; when the locking bolt is tightened, the locking force applied and the resulting clamping deformation mainly occur in the local area enclosed by the two points, thereby controlling the effect of the locking bolt's locking force on the adjusting seat and suppressing the effect of the locking bolt's tightening on the coaxiality of the polishing shaft; e. The provided polishing system includes multiple polishing devices mounted on slide rails above polishing discs. These devices move between adjacent discs via the slide rails to perform different polishing processes, thereby enhancing the flexibility of the polishing system. The center line connecting the lead screw and polishing shaft of each polishing device is collinear with the linear velocity of the device along the slide rail. The center line connecting the lead screw and polishing shaft of the lifting assembly forms the principal stiffness direction of the lifting assembly, which is aligned with the instantaneous movement direction of the polishing device along the slide rail. This means the strongest support direction of the lifting assembly faces the front of the polishing device's movement. This configuration ensures that the inertial forces generated during the starting and braking of the polishing device primarily act along this principal stiffness direction, thus suppressing the impact of bending or torsional loads generated by inertial forces on the operational stability of the polishing device. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0024] Figure 1 This is a schematic diagram of a polishing apparatus provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a polishing apparatus provided in another embodiment of the present invention; Figure 3 yes Figure 2 A perspective view of the polishing apparatus in the embodiment; Figure 4 yes Figure 3 Top view of the corresponding polishing device; Figure 5 This is a cross-sectional view of an adjustment component provided in an embodiment of the present invention; Figure 6 yes Figure 5 Top view of the corresponding adjustment component; Figure 7 This is a schematic diagram of an adjusting pin provided in an embodiment of the present invention; Figure 8 This is a schematic diagram of a polishing system provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of a polishing system provided in another embodiment of the present invention; Figure 10 This is a schematic diagram of a polishing device provided in an embodiment of the present invention mounted on a slide rail; Figure 11 yes Figure 10 Top view of the corresponding scheme in the embodiment. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0026] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0027] It should be understood that although the terms "first," "second," "third," etc., may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0028] Figure 1 This is a schematic diagram of a polishing apparatus 100 provided in an embodiment of the present invention. The polishing apparatus 100 is used for chemical mechanical polishing of wafers and includes: The polishing shaft 10 has a polishing head 11 at its lower end, which is used to load the wafer to be polished. A polishing sleeve 14 is arranged on the outer periphery of the polishing shaft 10. The polishing sleeve 14 rotates synchronously with the polishing shaft 10, and the polishing shaft 10 can move vertically relative to the polishing sleeve 14. The drive assembly 20 includes a fixed base 21 and a motor mover 22, wherein the motor mover 22 is disposed on the outer periphery of the polishing sleeve 14 to drive the polishing shaft 10 and the polishing head 11 connected thereto to rotate around the axis, thereby driving the wafer to rotate around the axis. The lifting assembly 30 has a driven block 31 offsetly disposed on one side of the polishing shaft 10, and the driven block 31 is connected to the moving seat 12 of the polishing shaft 10; the polishing shaft 10 moves synchronously with the moving seat 12 to change the vertical position of the polishing head 11 at the lower end of the polishing shaft 10. Furthermore, the lifting assembly 30 also includes a lifting motor 32 and a lead screw 33, such as Figure 1 As shown, the output shaft of the lifting motor 32 is connected to the lead screw 33, and the driven block 31 is connected to the outer periphery of the lead screw 33. The lifting motor 32 drives the lead screw 33 to rotate, and the driven block 31 can move along the axis of the lead screw 33 to drive the moving seat 12 connected to the driven block 31 to move, thereby driving the polishing shaft 10 connected to the moving seat 12 to move vertically and change the position of the polishing head 11. It can be understood that the driven block 31 is matched with the lead screw 33 to convert the rotational motion into linear motion. The driven block 31 can be a lead screw nut to ensure the accuracy of the linear movement of the driven block 31.

[0029] Furthermore, the lifting assembly 30 also includes a pair of support rods 34, which are arranged vertically and located on both sides of the lead screw 33, as shown below. Figure 3 and 4 As shown, a pair of support rods 34 are located on both sides of the vertically arranged lead screw 33 to reliably support the lifting motor fixing plate 35 and the lifting motor 32 on it.

[0030] Furthermore, one end of the support rod 34 is connected to the lifting motor fixing plate 35, and the other end of the support rod 34 is connected to the fixing seat 21; at the same time, a gap is provided between the support rod 34 and the moving seat 12 of the polishing shaft 10 to avoid interference between the support rod 34 and the moving seat 12 during the vertical movement of the polishing shaft 10.

[0031] In this invention, the lead screw 33 is located above the fixed base 21, and a gap G is provided between its lower end and the fixed base 21, such as... Figure 1 As shown. The range of downward movement of the driven block 31 cannot exceed the gap G, so as to prevent the lower end face of the driven block 31 from abutting against the top surface of the fixed seat 21 and causing interference, thereby avoiding the driven block 31 moving beyond the limit and affecting the stable operation of the lifting assembly 30.

[0032] In some embodiments, the gap G between the lower end face of the lead screw 33 and the top surface of the mounting base 21 is 5mm-10mm. It should be noted that this gap G is related to the vertical height of the polishing unit in the CMP system; to ensure structural compactness, the vertical height of the polishing unit needs to be minimized to control the overall size of the CMP system. It can be understood that the top surface of the mounting base 21 refers to the highest point of the mounting base 21 (including the upper mounting components) below the lead screw 33.

[0033] Figure 1 In the illustrated embodiment, the movable seat 12 is connected to the upper end of the polishing shaft 10 via a retaining assembly 13. The retaining assembly 13 includes a retaining bearing 131, which is sleeved on the upper end of the polishing shaft 10 to reliably and stably fix the movable seat 12 to the upper end of the polishing shaft 10. Specifically, the retaining bearing 131 is located in a through hole of the movable seat 12. To ensure the reliability of the retaining assembly 13's operation, an upper retaining ring 132 and a lower retaining ring 133 are respectively disposed above and below the retaining bearing 131.

[0034] It should be noted that, in order to supply multiple gas streams to the polishing head 11 below the polishing shaft 10, a rotary joint assembly is also provided above the polishing shaft 10; since the rotary joint assembly is not closely related to the inventive point of this application, a specific component number is not given for the time being.

[0035] In this invention, the polishing shaft 10 rotates around its axis under the action of the driving component 20, thereby driving the polishing head 11 below it to rotate. Simultaneously, the polishing shaft 10 needs to move vertically under the drive of the lifting component 30 to adapt to changing the vertical position of the polishing head 11. Considering the above requirements, the mating section between the polishing shaft 10 and the polishing sleeve 14 can be a spline shaft, and correspondingly, the polishing sleeve 14 is a spline sleeve, to achieve axial sliding and torque transmission of the polishing shaft 10. It should be noted that the polishing shaft 10 and the polishing sleeve 14 can also adopt other structural forms, as long as the axial sliding and torque transmission of the polishing shaft 10 are considered.

[0036] In this invention, the lifting component 30 configured in the polishing device 100 can drive the polishing shaft 10 and the polishing head 11 to move in the vertical direction, so as to cooperate with the polishing head 11 to load and unload wafers, thereby breaking through the bottleneck of relying solely on the expansion and contraction of the elastic membrane of the polishing head 11 to achieve vertical movement, and improving the flexibility of CMP system configuration.

[0037] Figure 1 In the illustrated embodiment, the lifting assembly 30 is offset to one side of the polishing shaft 10. This offset design is a result of spatial layout optimization, but it also has an adverse effect on the polishing shaft: the lifting assembly 30 inevitably exerts a continuous lateral bending moment on the polishing shaft 10 when transmitting vertical power. The polishing shaft 10 is fixed to the lower end of the motor mover 22, and a small gap is provided between the polishing sleeve 14 and the motor mover 22, which is located above the fixing point of the two. Since the lower end of the polishing sleeve 14 is fixed, while its upper end is relatively floating, the upper end of the polishing shaft 10 will swing slightly during the operation of the polishing device 100. Figure 1 In the process, the slight oscillation of the polishing shaft 10 is represented by the oscillation of the central axis. The oscillation of the polishing shaft 10 will have an adverse effect on the stability of polishing.

[0038] Furthermore, during the vertical movement of the lifting assembly 30, while transmitting vertical power, it generates an additional bending moment on the polishing shaft 10. This causes changes in the end runout of the polishing shaft 10, increasing the end runout of the polishing head 11, and causing the bottom of the polishing head 11 to come into contact with the polishing pad 200. Figure 8 and Figure 10 The increased friction between the wafers (as shown in the diagram) affects the polishing effect of the wafer.

[0039] Therefore, the core contradiction faced by this invention is that while the offset lifting component is needed to achieve a large stroke and optimized layout, the harmful bending moment it introduces must be eliminated to ensure ultra-precision polishing coaxiality. To solve the above-mentioned technical problem, the polishing device 100 is also equipped with an adjustment component 40, such as... Figure 2 As shown, it is located on the outer periphery of the polishing sleeve 14 and above the motor mover 22. This position is the "critical point" where the polishing shaft 10 is most affected by the bending moment of the offset lifting assembly, is most prone to swaying, and therefore requires the most precise constraint. The adjustment assembly 40 can limit the upper position of the polishing shaft 10, which helps control the end floating range of the polishing shaft 10, and thus control the end jump at the bottom of the polishing head 11. The adjustment assembly 40 and the lifting assembly 30 form a synergistic relationship of "problem generation" and "problem compensation" in function. Both are indispensable and together achieve the improvement of overall performance.

[0040] Furthermore, the adjusting assembly 40 includes a support bearing 41, an adjusting seat 42, and an adjusting pin 43, such as Figures 2 to 4 As shown, the support bearing 41 and the adjusting seat 42 are arranged from the inside to the outside on the outer periphery of the polishing shaft 10, while the adjusting pin 43 is located on the outer periphery of the adjusting seat 42. During installation and commissioning of the polishing device 100, the installation state of the polishing shaft 10 can be adjusted by adjusting the adjusting pin 43 to control the end runout of the lower end of the polishing shaft 10, suppress the negative impact of the bending moment generated by the offset lifting assembly 30 on the end runout of the polishing head 11, and improve the stability of the operation of the polishing device 100 in order to obtain a good polishing effect.

[0041] Figure 5 This is a cross-sectional view of the adjustment component 40 provided in an embodiment of the present invention. The adjustment seat 42 is concentrically disposed on the outer ring of the support bearing 41, so that the adjustment seat 42 moves in the horizontal direction, thereby changing the position of the support bearing 41 disposed on the outside of the polishing shaft 10, and realizing the adjustment of the installation state of the polishing shaft 10.

[0042] Furthermore, multiple adjusting pins 43 are spaced apart on the outer periphery of the adjusting seat 42 to adjust the position of the adjusting seat 42 from various directions, thereby improving the adjustment accuracy of the adjusting assembly 40. Figure 6In the illustrated embodiment, there are four adjusting pins 43, which are distributed approximately evenly around the outer periphery of the adjusting seat 42. It is understood that the number of adjusting pins 43 can also be other, such as five, six, or seven.

[0043] In some embodiments, the adjusting pin 43 is an eccentric structure that abuts against the outer peripheral wall of the adjusting seat 42 to adjust the coaxiality of the polishing shaft 10 relative to the fixed seat 21 by limiting the bearing 41. In particular, the structure of the eccentric pin and roller has significant advantages over traditional adjustment methods such as adding or removing shims or tightening set screws: rotating the adjusting pin can achieve continuous, smooth, and stepless radial position adjustment, avoiding the inconvenience and inaccuracy of step adjustment; after adjustment, the roller and the outer peripheral wall of the adjusting seat 42 form a stable line contact, rather than point contact or surface pressing, which provides reliable limiting while reducing local stress and allowing slight self-adaptation, making it more suitable for high-precision, long-term operation conditions.

[0044] The operator rotates the adjusting pin 43 to change the position of the adjusting seat 42 and the support bearing 41. After the end runout of the adjusted polishing shaft 10 is within the process requirement range, the adjusting seat 42 is installed on the fixed seat 21 by tightening the locking bolt 44 to fix the adjusting assembly 40 in the through hole between the polishing shaft 10 and the fixed seat 21.

[0045] In this invention, the locking bolt 44 is positioned approximately adjacent to the adjusting pin 43, making the adjusting point and the locking point very close in space. This design is crucial, as it solves a typical problem in precision mechanical assembly: the adjusted position is prone to shifting when a locking force is applied. When the locking bolt 44 is tightened, the applied locking force and the resulting clamping deformation mainly occur within the local area enclosed by the adjusting point and the locking point, thus minimizing and predicting the impact range of the locking deformation. This effectively controls the influence of the locking force of the locking bolt 44 on the adjusted position of the adjusting seat 42, thereby suppressing secondary damage to the coaxiality of the polishing shaft 10 caused by the locking action itself, and ensuring high repeatability and long-term stability of the adjustment accuracy.

[0046] Figure 6 In the illustrated embodiment, the adjusting pin 43 and the locking bolt 44 are located in the same radial plane. This radial plane is a plane passing through the center of the adjusting seat 42, and the influence range of the locking force generated by the locking bolt 44 is strictly limited to the vicinity of the adjusting point, making the locking deformation predictable and repeatable, thereby improving the convenience of adjusting the coaxiality of the polishing shaft 10.

[0047] In some embodiments, the angle between the center line connecting the adjusting pin 43 and the center line connecting the locking bolt 44 and the center line connecting the adjusting seat 42 is less than or equal to 5°~10°, so that the influence range of the locking bolt 44 is localized, so as to efficiently adjust the polishing device 100 and make the end runout of the polishing shaft 10 meet the process requirements.

[0048] Figure 7 This is a schematic diagram of an adjusting pin 43 provided in an embodiment of the present invention. The adjusting pin 43 includes a pin shaft 431 and a roller 432. The pin shaft 431 is eccentrically disposed below the roller 432.

[0049] Furthermore, the pin 431 of the adjusting pin 43 is positioned above the fixed base 21, and the outer wall of the roller 432 abuts against the outer peripheral wall of the adjusting base 42. Rotating the adjusting pin 43 causes it to rotate along the axis of the pin 431, thereby driving the roller 432 to rotate. Since the roller 432 and the pin 431 are not concentric, the roller 432 can generate a certain thrust on the outer peripheral wall of the adjusting base 42, thereby adjusting the position of the adjusting base 42 and the support bearing 41, and realizing the adjustment of the installation state of the polishing shaft 10.

[0050] In this invention, the adjusting component 40 also includes a retaining ring 45, such as... Figure 2 As shown, it is disposed on the outer peripheral wall of the polishing shaft 10 and abuts against the inner ring of the support bearing 41 to limit the position of the support bearing 41 along the length direction of the polishing shaft 10, and to prevent or suppress the axial movement of the support bearing 41 from affecting the setting position of the adjusting seat 42 and the support bearing 41.

[0051] It should be noted that before the polishing device 100 is operated, the coaxiality of the polishing shaft 10 relative to the fixed seat 21 is adjusted by adjusting the component 40 to control the end runout of the polishing shaft 10 within the process requirements range, so as to avoid excessive runout of the polishing head 11 end, which would affect the processing quality of the wafer.

[0052] Figure 8 This is a schematic diagram of a polishing system provided in an embodiment of the present invention. The polishing system includes a polishing disc 300, a dressing device 400, a liquid supply device 500, and... Figure 2 The polishing apparatus 100 is shown.

[0053] The polishing pad 200 is disposed on the upper surface of the polishing disk 300 and rotates together with it along the axis Ax; the reciprocating polishing head 11 is disposed above the polishing pad 200, and the wafer to be polished is loaded on its lower surface; the dressing device 400 includes a dressing arm and a dressing head, which is disposed on one side of the polishing disk 300, and the dressing arm drives the rotating dressing head to swing to dress the surface of the polishing pad 200; the liquid supply device 500 is disposed on the upper side of the polishing pad 200 to distribute the polishing liquid on the surface of the polishing pad 200.

[0054] During the polishing operation, the polishing head 11 presses the surface of the wafer to be polished against the surface of the polishing pad 200. The polishing head 11 rotates and reciprocates relative to the polishing disk 300, gradually removing the surface of the wafer in contact with the polishing pad 200. Simultaneously, the polishing disk 300 rotates, and the liquid supply device 500 sprays polishing liquid onto the surface of the polishing pad 200. Under the chemical action of the polishing liquid, the relative movement between the polishing head 11 and the polishing disk 300 causes the wafer to rub against the polishing pad 200 for polishing.

[0055] Figure 9 This is a schematic diagram of a polishing system provided in another embodiment of the present invention. The polishing system includes three polishing devices 100, which are mounted on slide rails 600 above polishing discs 300. The polishing devices 100 can move between adjacent polishing discs 300 via the slide rails 600. That is, the polishing devices 100 can move between adjacent polishing discs 300 to perform different or the same polishing processes on different polishing discs 300.

[0056] The polishing system is also equipped with a load cup 700, which is located on the side of the polishing disk 300 to form a wafer loading and unloading position. The polishing device 100 can move along the slide rail 600 from the polishing disk 300 (polishing position) to the wafer loading and unloading position. The polishing shaft 10 on it moves vertically under the drive of the lifting assembly 30 to facilitate the loading or unloading of wafers by the polishing head 11.

[0057] Furthermore, the slide rail 600 spans at least two polishing discs 300, and the three polishing devices 100 mounted on the slide rail 600 are arranged at intervals. The polishing devices 100 can move along the slide rail 600 to switch between polishing positions and wafer loading / unloading positions.

[0058] The line connecting the center of the lead screw 33 and the center of the polishing shaft 10 of the polishing device 100 is collinear with the linear velocity of the polishing device 100 along the slide rail 600. A moving seat 12 is horizontally connected above the polishing shaft 10, and the lead screw 33 is connected to the driven block 31 on the moving seat 12. Therefore, the line connecting the center of the lead screw 33 and the center of the polishing shaft 10 of the lifting assembly 30 is the main stiffness direction of the lifting assembly 30, which is aligned with the instantaneous movement direction of the polishing device 100 along the slide rail 600. That is, the strongest support direction of the lifting assembly 30 is facing the front of the movement of the polishing device 100.

[0059] When the polishing device 100 moves along the slide rail 600, especially during startup, shutdown, or speed change, an inertial force is generated, which acts on the center of mass of the polishing device 100. Since the lifting assembly 30 is offset to one side of the polishing shaft 10, the center of mass of the polishing device 100 is located outside the axis of the polishing shaft 10 and biased towards the lifting assembly 30. If the line connecting the center of the lead screw 33 and the center of the polishing shaft 10 is not collinear with the linear velocity of the polishing device 100 along the slide rail 600, such as when there is an angle between them (e.g., perpendicular to each other), the inertial force during startup will generate a large torsional torque on the polishing shaft 10, causing the polishing head 11 fixed to the lower end of the polishing shaft 10 to swing horizontally, reducing the stability of wafer polishing.

[0060] The present invention adopts a collinear design, which makes the inertial force generated by the start-up and braking of the polishing device 100 mainly act along this "principal stiffness direction", thereby suppressing the influence of the bending or torsional load generated by the inertial force on the operational stability of the polishing device 100.

[0061] Furthermore, in the collinear design, the moving module on the slide rail 600 mainly provides constraints perpendicular to the tangential direction of the slide rail 600, effectively preventing the polishing device 100 from deviating from the track; moreover, the mass of the offset lifting component 30 is directly supported by the moving module of the slide rail 600, which will not generate additional torques of "jamming" and "rail biting", effectively suppressing the vibration and deformation caused by the movement of the polishing device 100, which is conducive to ensuring the stability of the polishing system operation.

[0062] Figure 10 This is a schematic diagram of a polishing device 100 provided in an embodiment of the present invention, which is mounted on a slide rail 600. In this embodiment, the slide rail 600 is a circular structure and is located below the sliding drive module. The polishing device 100 is located below the slide rail 600. The polishing head 11 of the polishing device 100 is loaded with a wafer (not shown) and abuts against the upper surface of the polishing pad 200 to perform chemical mechanical polishing on the wafer.

[0063] Figure 11 yes Figure 10In the top view of the corresponding embodiment, the center line connecting the slide rail 600 and the polishing shaft 10 of the polishing device 100 is L1, and the center line connecting the lead screw 33 of the polishing device 100 and the polishing shaft 10 is L2. The included angle θ between L1 and L2 is 75°~100°. This angle range setting embodies profound mechanical optimization principles. Through the analysis of the system's motion dynamics, it can be seen that when the included angle between L1 and L2 is close to 90° (especially in the preferred range of 85°~95°), the inertial force generated by the movement of the device can be optimally decomposed: its component along the L1 direction (radial) is effectively borne by the moving module of the slide rail 600, while the component along the L2 direction (axial) is borne by the lead screw 33 of the lifting assembly 30 with its strongest axial stiffness. This force decomposition path design minimizes the harmful lateral bending moment or torsional load generated by the inertial force on the polishing shaft. This configuration helps to suppress swaying and vibration caused by inertial forces, ensuring that the polishing head 11 can maintain a high degree of horizontal stability during movement, especially when changing between workstations, so as to stably load or unload wafers at the wafer loading and unloading positions and ensure the reliability of the polishing system operation.

[0064] Figure 11 The provided technical solution helps extend the service life of the equipment. The moving module of the sliding drive module no longer needs to overcome additional torsional torque, and its load is more stable, which helps reduce the wear of the sliding drive module; at the same time, the lead screw 33 and driven block 31 of the lifting assembly 30 are precision transmission components, which mainly bear axial loads, avoiding damage from lateral bending moment and torque, and significantly extending their precision life and fatigue life.

[0065] The center line connecting the slide rail 600 and the polishing shaft 10 of the polishing device 100 is perpendicular to the center line connecting the lead screw 33 of the polishing device 100 and the polishing shaft 10. Harmful vibrations are effectively suppressed, which helps to shorten the movement time of the polishing device 100 between the polishing position and the wafer loading and unloading position, and improve the production cycle and efficiency of the whole machine.

[0066] Preferably, the included angle θ between L1 and L2 is 85°~95°, that is, the included angle between the two is close to 90°. This setting is an optimized choice after dynamic analysis and verification, which can most effectively suppress the sway and vibration caused by inertial force and ensure the reliable operation of the polishing system. In addition, the above scheme can also effectively weaken the influence of the torque generated during the polishing process on the lifting component 30, so that the force on the lifting component 30 is in the vertical direction, effectively preventing or suppressing the driven block 31 from eccentric wear or jamming, thereby ensuring the accuracy and long-term stability of the polishing head 11 moving in the vertical direction.

[0067] In this invention, to avoid interference between the polishing head 11 and the loaded wafer of the polishing device 100 and other components in the polishing system, during the movement of the polishing device 100 along the slide rail 600, the polishing shaft 10 and the polishing head 11 below it move vertically upwards to a high position under the drive of the lifting assembly 30. When the polishing head 11 moves to the polishing position and the wafer loading / unloading position, the lifting assembly 30 then controls the polishing head 11 to move downwards to facilitate the loading or unloading of the wafer.

[0068] Furthermore, the present invention also provides a polishing method, which uses Figure 8 and Figure 9 The polishing system shown is used to perform chemical mechanical polishing on wafers. The polishing method generally includes the following steps: The wafer is transferred from the front-end unit (EFEM) to the loading cup 700, and the polishing head 11 of the polishing device 100 loads the wafer from the loading cup 700. During the wafer loading process, the lifting assembly 30 controls the polishing shaft 10 to move vertically to flexibly adjust the position of the polishing head 11 so that the elastic film on the polishing head 11 can accurately adsorb the wafer. The polishing head 11, which is loaded with wafers, moves along the slide rail 600 toward one of the polishing disks 300 to perform chemical mechanical polishing above the polishing disk 300; Next, the polishing device 100 continues to move along the slide rail 600, and the polishing head 11 picks up the wafer that has completed one polishing and moves it to the adjacent polishing disk 300 to perform chemical mechanical polishing on the wafer again, thereby completing the "dual disk" polishing process. Next, the wafer that has completed the "dual-disc" polishing is moved above the loading cup 700 to unload the polished wafer; during the wafer unloading process, the lifting assembly 30 controls the polishing shaft 10 to move vertically to flexibly adjust the position of the polishing head 11; finally, the polished wafer is transferred by the transfer mechanism to the next process to continue the surface treatment of the wafer.

[0069] Understandably, the polishing system can also perform polishing processes such as "single disk" and "three disks" to meet the needs of different wafer fabrication processes.

[0070] Those skilled in the art will recognize that the units and method steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this application.

[0071] The above embodiments are only used to illustrate the embodiments of this application, and are not intended to limit the embodiments of this application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of this application. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of this application, and the patent protection scope of the embodiments of this application should be defined by the claims.

Claims

1. A polishing apparatus for chemical mechanical polishing of wafers, characterized in that, include: A polishing shaft with a polishing sleeve on its outer side and a polishing head at its lower end; The drive assembly includes a fixed base and a motor mover, the motor mover being disposed on the outer peripheral side of the polishing sleeve; The lifting assembly has a driven block disposed on the movable seat of the polishing shaft and biased to one side of the polishing shaft. The polishing shaft moves synchronously with the movable seat to change the vertical position of the polishing head. An adjustment assembly is disposed on the outer periphery of the polishing shaft and above the motor mover; the adjustment assembly includes a support bearing, an adjustment seat, and an adjustment pin, the support bearing and the adjustment seat are disposed from the inside to the outside on the outer periphery of the polishing sleeve, and the adjustment pin is located on the outer periphery of the adjustment seat; the adjustment pin has an eccentric structure and abuts against the outer peripheral wall of the adjustment seat to adjust the coaxiality of the polishing shaft relative to the fixed seat.

2. The polishing apparatus according to claim 1, characterized in that, The adjusting seat is concentrically arranged on the outer ring of the supporting bearing, and multiple adjusting pins are spaced apart on the outer periphery of the adjusting seat.

3. The polishing apparatus according to claim 2, characterized in that, The adjusting pin includes a pin shaft and a roller. The pin shaft is eccentrically positioned below the roller. The pin shaft is positioned above the fixed base, and the outer side wall of the roller abuts against the outer peripheral wall of the adjusting base.

4. The polishing apparatus according to claim 1, characterized in that, The adjustment assembly also includes a retaining ring disposed on the outer peripheral wall of the polishing shaft and abutting against the inner ring of the support bearing.

5. The polishing apparatus according to claim 1, characterized in that, The lifting assembly also includes a lifting motor and a lead screw, the output shaft of the lifting motor is connected to the lead screw, and the driven block is connected to the outer periphery of the lead screw.

6. The polishing apparatus according to claim 5, characterized in that, The lifting assembly also includes a pair of support rods, which are vertically arranged and located on both sides of the lead screw; one end of the support rod is connected to the lifting motor fixing plate, and the other end is connected to the fixing base.

7. The polishing apparatus according to claim 5, characterized in that, The lead screw is located above the fixed base, and there is a gap between its lower end and the fixed base.

8. A polishing system, characterized in that, The device includes a polishing pad, a liquid supply device, a trimming device, and a polishing apparatus as described in any one of claims 1 to 7, wherein the polishing head presses the wafer to be polished against a polishing pad above the polishing pad, the liquid supply device supplies polishing liquid between the polishing pad and the wafer, and the trimming device is used to trim the surface of the polishing pad.

9. The polishing system according to claim 8, characterized in that, The polishing device comprises multiple units, each mounted on a slide rail above a polishing pad. The polishing device moves between adjacent polishing pads via the slide rail. The polishing shaft of the polishing device moves vertically at the wafer loading / unloading position on the side of the polishing pad to load or unload the wafer with the polishing head.

10. The polishing system according to claim 9, characterized in that, The slide rail spans at least two polishing discs, and the number of polishing devices is three, which are spaced apart along the slide rail.

11. The polishing system according to claim 9, characterized in that, The center line connecting the lead screw and the polishing shaft of the polishing device is collinear with the linear velocity of the polishing device along the slide rail.

12. The polishing system according to claim 9, characterized in that, The slide rail has a circular structure, and the center line connecting it to the polishing shaft of the polishing device is L1. The center line connecting the lead screw of the polishing device and the polishing shaft is L2. The included angle between L1 and L2 is 75°~100°.

13. The polishing system according to claim 9, characterized in that, As the polishing device moves along the slide rail, the polishing head moves upward to a high position.

14. The polishing system according to claim 9, characterized in that, Before the polishing device is operated, the coaxiality of the polishing shaft relative to the fixed base is adjusted by adjusting the components.

15. A polishing method, characterized in that, The polishing system of claim 8 is used to perform chemical mechanical polishing on the wafer.

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