A carrier head for chemical mechanical polishing, a polishing system and a polishing method

Abstract

The application discloses a kind of for chemical mechanical polishing bearing head, polishing system and method method, the bearing head includes bearing disc, elastic film and retaining ring, the elastic film is set below bearing disc, the retaining ring is set at the outer circumferential side of elastic film and is located at the bottom of bearing disc;The elastic film includes bottom plate part, vertical part, horizontal part and wrinkle part, the bottom plate part is disc structure, vertical part extends vertically upward along the outer edge of the bottom plate part, the horizontal part extends horizontally inward from the top end of the vertical part, the wrinkle part is set above vertical part, and its edge is set between bearing disc and retaining ring;It also includes detection piece and adjusting piece, the detection piece and adjusting piece are adjacently arranged and located below the wrinkle part;The detection piece measures the stress information of the wrinkle part, the adjusting piece adjusts the stress of wrinkle part based on the measured value of detection piece, so that the deformation of cavity formed by wrinkle part is uniform in circumferential direction.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chemical mechanical polishing, and particularly relates to a carrier head for chemical mechanical polishing, a polishing system and a polishing method. BACKGROUND

[0002] The integrated circuit industry is the core of the information technology industry and plays a key role in promoting the transformation and upgrading of manufacturing industry to digitalization and intelligentization. Chips are the carriers of integrated circuits, and chip manufacturing involves integrated circuit design, wafer manufacturing, wafer processing, electrical measurement, packaging and testing, and other process flows. Among them, chemical mechanical polishing (CMP) is one of the five core processes in the wafer manufacturing process.

[0003] Chemical mechanical polishing usually attracts the wafer to the bottom surface of the carrier head, the side of the wafer with the deposition layer abuts the upper surface of the polishing pad, and the carrier head rotates with the polishing pad under the actuation of the drive assembly and gives the wafer a downward load; the polishing liquid is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the wafer completes chemical mechanical polishing under the joint action of chemical and mechanical.

[0004] In the production and manufacturing process of the carrier head, the consistency of the machining assembly of each device of the carrier head, especially the elastic membrane and the retaining ring, cannot be guaranteed, resulting in inconsistent material removal rate of the polished wafer in the same circumferential direction. In addition, the existing multi-zone pressure control technology is based on the assumption that the material removal rate in the same circumferential direction is uniform, and if the thickness of the wafer before polishing is not uniform in the same circumferential direction, the existing pressure control technology cannot improve the thickness uniformity in the same circumferential direction. SUMMARY

[0005] The present application provides a carrier head for chemical mechanical polishing, a polishing system and a polishing method, which aims to at least solve one of the technical problems existing in the prior art.

[0006] The first aspect of the present application provides a carrier head for chemical mechanical polishing, comprising a carrier disc, an elastic membrane and a retaining ring, the elastic membrane is arranged below the carrier disc, and the retaining ring is arranged on the outer circumferential side of the elastic membrane and located at the bottom of the carrier disc.

[0007] The elastic membrane comprises a bottom plate part, a vertical part, a horizontal part and a pleated part, the bottom plate part is a disc structure, the vertical part extends vertically upward along the outer edge of the bottom plate part, the horizontal part extends horizontally inward from the top end of the vertical part, and the pleated part is arranged above the vertical part, and the edges thereof are arranged between the carrier disc and the retaining ring.

[0008] The detection member and the adjusting member are arranged adjacently and below the pleat part; the detection member measures stress information of the pleat part, and the adjusting member adjusts the stress of the pleat part based on the measurement value of the detection member, so that the deformation of the cavity formed by the pleat part is uniform in the circumferential direction.

[0009] In some embodiments, the pleat part comprises vertical ribs and bending ribs; the vertical ribs are arranged upwardly from the upright part; the bending ribs are outwardly opened flange structures, and edges of the bending ribs are connected between the carrier disc and the retaining ring; the detection member and the adjusting member are arranged inside the vertical ribs.

[0010] In some embodiments, the detection member and the adjusting member are arranged below the bending ribs.

[0011] In some embodiments, the detection member and the adjusting member are arranged uniformly along the circumference of the pleat part and above the upright part.

[0012] In some embodiments, the vertical ribs have a wall thickness smaller than that of the upright part; the detection member and the adjusting member are arranged below the bending ribs by flexible connecting members, and bottoms of the detection member and the adjusting member are arranged toward the upright part.

[0013] In some embodiments, the adjusting member comprises a housing, a piezoelectric actuator arranged in the housing, and a moving block arranged closely to the piezoelectric actuator and at least partially outside the housing; the moving block is arranged toward the upper surface of the upright part and can be pressed against the upright part to adjust the deformation of the pleat part.

[0014] In some embodiments, a vertical projection of the moving block overlaps with an outer ring part of the upright part.

[0015] In some embodiments, the detection member is provided with a signal transmitter, the adjusting member is provided with a signal receiver, and the signal transmitter and the signal receiver are signal-connected to a control unit arranged outside the carrier head in a wireless manner.

[0016] In some embodiments, the carrier head is internally provided with a power supply, which provides electric energy for operation of the detection member, the adjusting member, the signal transmitter and the signal receiver.

[0017] The second aspect of the embodiments of the present application provides a chemical mechanical polishing system, which comprises a polishing disc, a dresser, a liquid supply arm and the carrier head described above.

[0018] The third aspect of the embodiment of the present application provides a chemical mechanical polishing method, which uses the chemical mechanical polishing system described above to process a wafer, and the carrier head adjusts the displacement of the wrinkle part of the elastic film by the adjusting member based on the measurement value of the detecting member, so that the cavity formed by the wrinkle part is uniformly deformed in the circumferential direction.

[0019] The beneficial effects of the present application include:

[0020] a. The detecting member and the adjusting member are arranged inside the elastic film, which prevents the polishing particles from adhering to the surface of the detecting member and the adjusting member, so as to avoid the influence of the polishing particles on the detection accuracy of the detecting member and ensure the accuracy of the deformation adjustment of the adjusting member on the elastic film;

[0021] b. The adjusting member adjusts the stress of the wrinkle part based on the measurement value of the detecting member, so that the cavity formed by the wrinkle part is uniformly deformed in the circumferential direction, so as to reduce the influence of the processing assembly error of the elastic film on the polishing uniformity;

[0022] c. The adjusting member is arranged inside the vertical rib and below the bending rib, which can adjust the position of the moving block to apply a certain load to the edge position of the wafer through the upright part, so as to participate in the regulation of the polishing removal rate of the edge position of the wafer;

[0023] d. The adjusting member can act on the upright part through the moving block to adjust the vertical position of the elastic film installation, so as to weaken the influence of the wear of the retaining ring on the polishing uniformity. BRIEF DESCRIPTION OF DRAWINGS

[0024] The advantages of the present application will become more apparent and more easily understood from the following detailed description, which is only illustrative and not restrictive of the present application, and is best understood with reference to the following drawings, in which:

[0025] Figure 1 is a schematic view of a carrier head for chemical mechanical polishing provided by an embodiment of the present application;

[0026] Figure 2 is a schematic view of a carrier head for chemical mechanical polishing provided by an embodiment of the present application; Figure 1

[0027] Figure 3 is a schematic view of an elastic film provided by an embodiment of the present application;

[0028] Figure 4 is a schematic view of an elastic film provided by an embodiment of the present application; Figure 3

[0029] is a schematic view of an adjusting member provided by an embodiment of the present application; Figure 5

[0030] Figure 6 ​​is a simulation effect diagram of the displacement amount of the moving block moving downward and the stress change of the edge position of the elastic film provided by an embodiment of the present application;

[0031] Figure 7 is a schematic diagram of a bearing head provided by the present application;

[0032] Figure 8 is a signal transmission route diagram between the detection member and the adjusting member described in the present application;

[0033] Figure 9 is a schematic diagram of the removal rate in the same circumferential direction of a wafer polished by the bearing head provided by the present application;

[0034] Figure 10 is a schematic diagram of a chemical mechanical polishing system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be described in detail below with specific embodiments and their accompanying drawings. The embodiments described herein are specific specific embodiments of the present application, which are used to illustrate the concept of the present application; these descriptions are all explanatory and exemplary, and should not be understood as limiting the embodiments of the present application and the protection scope of the present application. In addition to the embodiments described herein, those skilled in the art can also employ other technical solutions that are obvious based on the content disclosed in the claims and the specification of the present application, which include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.

[0036] The drawings of the present specification are schematic diagrams that assist in illustrating the concept of the present application, and schematically represent the shape of each part and their mutual relationship. It should be understood that in order to clearly show the structure of each component of the embodiments of the present application, the drawings are not drawn according to the same scale, and the same reference signs are used to represent the same parts in the drawings.

[0037] In the present application, "Chemical Mechanical Polishing (CMP)" is also referred to as "Chemical Mechanical Planarization (CMP)", and "wafer (W)" is also referred to as "substrate", which have the same meaning and actual function.

[0038] Embodiments of the present application generally relate to a chemical mechanical polishing (CMP) system and a key component, a carrier head, used in the CMP process in the semiconductor device manufacturing industry. In the CMP process, a polishing liquid composed of sub-micron or nano abrasive particles and chemical solution is made to flow between a wafer and a polishing pad, and the polishing liquid is uniformly distributed by the transmission of the polishing pad and the centrifugal force of rotation to form a thin liquid film between the wafer and the polishing pad. The chemical components in the liquid chemically react with the wafer to convert insoluble substances into soluble substances, and then the chemical reaction products are removed from the wafer surface by the micro-mechanical friction of the abrasive particles and dissolved into the flowing liquid to be carried away, so that the surface planarization treatment is achieved by removing the surface material in the alternating process of chemical film formation and mechanical film removal, thereby achieving the purpose of global planarization.

[0039] Figure 1 Fig. 1 is a schematic view of a carrier head 100 for chemical mechanical polishing according to an embodiment of the present application. The carrier head 100 comprises a pivot base 10, a carrier disc 20, an elastic membrane 30 and a retaining ring 40. The pivot base 10 is connected to the carrier disc 20 through an annular membrane 50. The elastic membrane 30 is connected to the lower side of the carrier disc 20. The retaining ring 40 is arranged on the outer circumferential side of the elastic membrane 30 and below the carrier disc 20.

[0040] Further, the pivot base 10 is provided with a through hole in the middle part, and the carrier disc 20 is provided with a shaft part in the middle part. The shaft part of the carrier disc 20 is slidably inserted into the through hole of the pivot base 10 and can move in the vertical direction in the through hole. The pivot base 10 is connected to the carrier disc 20 through the annular membrane 50, so that the carrier disc 20 can rotate together with the pivot base 10 and / or move in the vertical direction.

[0041] The top of the pivot base 10 is provided with a connecting flange, which is connected to an external driving shaft. The rotating pivot base 10 drives the carrier disc 20 and the elastic membrane 30 thereon to rotate coaxially through the annular membrane 50. The elastic membrane 30 with the wafer sucked thereon presses against the rotating polishing pad. The polishing liquid is supplied between the wafer and the polishing pad, and the material on the bottom surface of the wafer is removed under the action of chemical and mechanical forces.

[0042] Figure 1 In the embodiment shown, the elastic membrane 30 is provided with six adjustable pressure chambers, which act on the central region and concentric annular regions of the wafer respectively to ensure the uniformity of wafer material removal and achieve global planarization of the wafer. It can be understood that the pivot base 10 and the carrier disc 20 are provided with fluid channels (not shown), and an external air source is connected to the chambers of the elastic membrane 30 to adjust the pressure of the chambers and optimize the polishing pressure.

[0043] Figure 2 Fig. 1 is a schematic view of a carrier head 100 for chemical mechanical polishing according to an embodiment of the present application. The carrier head 100 comprises a pivot base 10, a carrier disc 20, an elastic membrane 30 and a retaining ring 40. The pivot base 10 is connected to the carrier disc 20 through an annular membrane 50. The elastic membrane 30 is connected to the lower side of the carrier disc 20. The retaining ring 40 is arranged on the outer circumferential side of the elastic membrane 30 and below the carrier disc 20. Figure 1The local enlarged view of the middle A, the elastic film 30 includes a bottom plate part 31, an upright part 32, a horizontal part 33 and a pleat part 34. Among them, the bottom plate part 31 is a disc structure, the upright part 32 extends vertically upward along the outer edge of the bottom plate part 31, the horizontal part 33 extends horizontally inward from the top end of the upright part 32, and the pleat part 34 is arranged above the upright part 32, and the edge of the pleat part 34 is arranged between the carrier disc 20 and the retaining ring 40. The inner side of the upright part 32 is also configured with a concentric inner side rib plate to divide the cavity of the elastic film 30 into multiple concentric cavities to realize multi-zone pressure control according to the predetermined polishing process.

[0044] Further, the carrier head 100 further comprises a detection piece 60 and an adjusting piece 70, wherein the detection piece 60 and the adjusting piece 70 are arranged adjacent to each other, and the detection piece 60 and the adjusting piece 70 are located below the pleat part 34 to detect and adjust the deformation state of the cavity C1 under pressure or decompression. In the present application, the cavity C1 is formed by the horizontal part 33, the pleat part 34 and the carrier disc 20, and the load formed by the cavity C1 is transmitted downward along the upright part 32 to the edge of the wafer to participate in the regulation of the polishing removal rate of the wafer edge position.

[0045] Specifically, the detection piece 60 measures the stress information of the pleat part 34, and the adjusting piece 70 adjusts the stress of the pleat part 34 based on the measurement value of the detection piece 60, so that the deformation of the cavity C1 formed by the pleat part 34 is uniform in the circumferential direction. That is, the detection piece 60 is used to detect the deformation of the pleat part 34 in real time to obtain whether the deformation of the pleat part 34 in the circumferential direction is uniform. If the deformation of a certain phase is greater than or less than the deformation of other phases, the adjusting piece 70 will adjust the deformation of the corresponding phase of the pleat part 34, so that the deformation of the edge position of the elastic film 30 is uniform, so as to solve the problem that the polishing load in the same circumferential direction is not consistent due to the uneven deformation of the elastic film.

[0046] Figure 2 Among them, the pleat part 34 includes a vertical rib 34a and a bent rib 34b, wherein the vertical rib 34a extends upward from the upright part 32, and the bent rib 34b is arranged above the vertical rib 34a. The bent rib 34b is a folded edge structure with an outward opening, and the edge of the bent rib 34b is connected between the carrier disc 20 and the retaining ring 40.

[0047] Further, the bent rib 34b extends horizontally inward from the top end of the vertical rib 34a, and then extends horizontally outward through an arc transition. That is, the bent rib 34b includes a horizontally inward extending rib, a transition rib and a horizontally outward extending rib, wherein the length of the horizontally inward extending rib is greater than or equal to the width of the upright part 32 to provide space for the arrangement of the detection piece 60 and the adjusting piece 70.

[0048] Figure 2In the embodiment shown, the detection member 60 and the adjustment member 70 arranged in the chamber C1 are arranged inside the vertical rib 34a to accurately detect and adjust the deformation state of the pleat 34. Meanwhile, the detection member 60 and the adjustment member 70 are arranged in the chamber C1, and thus arranged, the attachment of the polishing particles to the surface of the detection member 60 and the adjustment member 70 can be reduced, so as to avoid the influence of the polishing particles on the detection accuracy of the detection member 60 and ensure the accuracy of the deformation adjustment of the elastic film 30 by the adjustment member 70.

[0049] As an embodiment of the present application, the detection member 60 and the adjustment member 70 are located below the bent rib 34b. Specifically, the detection member 60 and the adjustment member 70 are located below the horizontally inwardly extending rib.

[0050] Figure 3 is a schematic view of the elastic film 30 provided by an embodiment of the present application, Figure 4 is Figure 3 is a partial enlarged view at B in FIG. 6. The detection member 60 and the adjustment member 70 are arranged in a matching manner with a quantity ratio of 1:1. Figure 3 In the embodiment shown, the detection member 60 and the adjustment member 70 are arranged in a matching manner with a quantity ratio of 1:1.

[0051] It can be understood that in some embodiments, the quantity ratio of the detection member 60 and the adjustment member 70 can also be other values, such as 1:2, 1:3, etc. In some embodiments, the number of the detection member 60 can also be greater than the number of the adjustment member 70, that is, a plurality of detection members 60 detect the deformation of the pleat 34, and one or more adjustment members 70 adjust the position state of the pleat 34.

[0052] Further, the detection member 60 and the adjustment member 70 are arranged above the upright portion 32, as shown in Figure 2 When the chamber C1 is pressurized or depressurized, the detection member 60 and the adjustment member 70 can abut against the upper surface of the upright portion 32 to detect and adjust the deformation state of the pleat 34 located above the upright portion 32.

[0053] Figure 2 In the embodiment shown, the wall thickness of the vertical rib 34a is smaller than the wall thickness of the upright portion 33, and the detection member 60 and the adjustment member 70 are arranged below the bent rib 34b and inside the vertical rib 34a.

[0054] Figure 4 In the embodiment shown, the detection member 60 and the adjustment member 70 are arranged below the bent rib 34b through the flexible connecting member 36, and the bottom surface of the detection member 60 and the adjustment member 70 is arranged to face the upper surface of the upright portion 32 to detect and adjust the deformation state of the pleat 34.

[0055] Figure 4 In the embodiment shown, the elastic modulus of the flexible connector 36 is consistent with that of the elastic membrane 30 to reduce the impact of material differences on the accuracy of deformation state detection.

[0056] Figure 5 This is a schematic diagram of an adjusting member 70 provided in an embodiment of the present invention. The adjusting member 70 contains a piezoelectric actuator, which abuts against the upright portion 32 of the elastic membrane 30 based on the inverse piezoelectric effect to adjust the deformation state of the wrinkled portion 34.

[0057] Figure 5 In the middle, the adjusting member 70 includes a housing 71, a piezoelectric actuator 72 and a moving block 73. The piezoelectric actuator 72 is disposed in the housing 71, and the moving block 73 is close to the piezoelectric actuator 72 and is disposed downward.

[0058] Furthermore, the upper part of the movable block 73 is disposed close to the piezoelectric actuator 72, and its lower part is disposed on the outside of the housing 71. The movable block 73 located on the outside of the housing 71 is disposed facing the upper surface of the upright part 32. The movable block 73 can move in the vertical direction to exert a pressing force on the upright part 32, thereby adjusting the deformation state of the wrinkled part 34.

[0059] As Figure 5 In one aspect of the embodiment, the vertical projection of the movable block 73 is aligned with the outer ring 35 of the upright portion 32. Figure 2 (As shown) the partial overlap allows the downward movement of the moving block 73 to generate a certain load. This load can be transmitted downwards along the assembly formed by the upright portion 32 and the outer ring 35 to participate in the adjustment of the polishing removal rate at the wafer edge, thereby improving the uniformity of the polishing removal rate at the wafer edge. Specifically, in the circumferential direction of the elastic film 30, the adjustment members 70 of each phase can accurately apply different displacements to the upright portion 32 according to the thickness distribution of the wafer in the circumferential direction, thereby controlling the uniformity of wafer polishing.

[0060] Figure 6 This is a simulation diagram showing the downward displacement of the moving block 73 and the stress change at the edge of the elastic membrane 30 according to an embodiment of the present invention. Figure 6 The curves in the diagram are multiple, representing different displacement changes of the moving block 73. Figure 6 As can be seen from the simulation results, as the displacement of the moving block 73 of the adjusting component 70 increases, the stress at the edge of the elastic membrane 30 also increases, so as to adjust the polishing removal rate of the wafer edge region, especially the region 145-147mm away from the center of the wafer, in order to weaken the influence of the edge effect on the polishing removal rate.

[0061] Figure 7is a schematic view of the bearing head 100 provided by an embodiment of the present application, wherein the detection member 60 and the adjusting member 70 are arranged inside the elastic film 30. The detection member 60 is configured with a signal transmitter 81, and the adjusting member 70 is configured with a signal receiver 82. The signal transmitter 81 and the signal receiver 82 are signal-connected with a control unit 83 arranged outside the bearing head 100 in a wireless manner. The control unit 83 can send a control instruction to the adjusting member 70 according to the measurement result of the detection member 60, so as to adjust the deformation of the wrinkle part 34, and make the deformation of the edge part of the elastic film 30 relatively uniform.

[0062] Figure 8 is a signal transmission route map between the detection member and the adjusting member. When the elastic film 30 is pressurized to expand or is reduced in pressure to shrink, the detection member 60 can obtain a voltage signal reflecting the stress change of the wrinkle part 34, and transmit the voltage signal to the control unit 83. Then, the control unit 83 converts the voltage signal into a digital signal, and transmits the digital signal to a processing unit through the signal transmitter 81. The processing unit mainly performs filtering processing on the signal, so as to eliminate the interference of external environment and other factors on the digital signal, and ensure the accuracy of signal detection. At the same time, the processing unit calculates the adjustment displacement of the adjusting member 70 according to the detection result of the detection member 60. Then, the processing unit transmits the digital signal to the control unit 83 through the signal receiver 82. Then, the control unit 83 converts the adjustment displacement into a voltage signal, and acts on the piezoelectric actuator 72 in the adjusting member 70, so as to realize the displacement adjustment of the moving block 73, adjust the deformation of the wrinkle part 34 of the elastic film 30, and make the deformation of the wrinkle part 34 of the elastic film 30 in the circumferential direction relatively uniform.

[0063] Further, the inside of the bearing head 100 is configured with an unshown power supply, so as to provide electric energy for the operation of the detection member 60, the adjusting member 70, the signal transmitter 81 and the signal receiver 82. In some embodiments, the power supply inside the bearing head 100 can be a button cell, so as to be replaced as needed when the bearing head 100 is developed for regular maintenance. It can be understood that the electric energy of the bearing head 100 can also be directly or indirectly generated based on the principles of the Seebeck effect, electromagnetic induction and the like, so as to provide electric energy for the operation of the electric components inside the bearing head 100.

[0064] Figure 9 is a schematic view of the removal rate of a wafer polished by using the bearing head 100 provided by the present application in the same circumferential direction. In the view, the abscissa represents the phase of the wafer in the same circumferential direction, and the ordinate represents the removal rate of the wafer in the same circumferential direction. In the embodiment, 18 sets of detection members 60 and adjusting members 70 are arranged along the circumference of the elastic film 30, and the detection members 60 and the adjusting members 70 are uniformly distributed along the circumference of the elastic film 30. The corresponding numbers are used to represent the phases of the wafer.

[0065] Figure 9In the diagram, the dashed line represents the removal rate without the addition of the detection element 60 and the adjustment element 70, while the solid line represents the removal rate with the addition of the detection element 60 and the adjustment element 70.

[0066] Depend on Figure 9 It can be seen that after the elastic membrane 30 of the bearing head 100 is equipped with the detection component 60 and the adjustment component 70, the non-uniformity of the removal rate of the wafer in the same circumferential direction is significantly improved. That is, the fluctuation of the removal rate of the wafer in the same circumferential direction is smaller, which is beneficial to accurately adjust the polishing load of each area of ​​the wafer according to the actual working conditions, so as to improve the uniformity of wafer polishing.

[0067] Figure 10 This is a schematic diagram of a chemical mechanical polishing system 1000 provided in an embodiment of the present invention. The chemical mechanical polishing system 1000 includes the above-mentioned bearing head 100, polishing disc 300, dressing device 400 and liquid supply arm 500, wherein the polishing pad 200 is disposed on the upper surface of the polishing disc 300.

[0068] During chemical mechanical polishing, the polishing pad 200 and the polishing disk 300 rotate together; the horizontally movable support head 100 is positioned above the polishing pad 200, and the bottom of the support head 100 holds the wafer to be polished; the dresser 400 oscillates around a fixed point, and the dressing disk on it rotates itself and applies a downward load to dress the surface of the polishing pad 200; the liquid supply unit 500 is positioned above the polishing pad 200 to distribute the polishing liquid onto the surface of the polishing pad 200.

[0069] During the polishing operation, the carrier head 100 presses the surface of the wafer to be polished against the surface of the polishing pad 200. The carrier head 100 rotates and reciprocates radially along 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 unit 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 carrier head 100 and the polishing disk 300 causes the wafer to rub against the polishing pad 200 for polishing.

[0070] Furthermore, the present invention also provides a chemical mechanical polishing method, which uses Figure 10 The chemical mechanical polishing system 1000 shown processes wafers, wherein the elastic membrane 30 of the carrier head 100 is internally configured with a detection element 60 and an adjustment element 70, and the control unit 83 of the carrier head 100 ( Figure 7 (As shown) The adjusting member 70 can adjust the pleats 34 of the elastic membrane 30 based on the measured values ​​of the detection member 60. Figure 2The displacement of the straight portion 32 of the elastic film 30 is shown in the figure, so that the deformation of the cavity formed by the wrinkle portion 34 is uniform in the circumferential direction. In this way, the influence of the processing error and the installation error of the elastic film 30 on the non-uniform circumferential deformation of the edge portion of the elastic film 30 can be eliminated, so as to improve the uniformity of the wafer polishing.

[0071] At the same time, the cooperation of the detection member 60 and the adjusting member 70 arranged on the elastic film 30 can also properly adjust the wear of the retaining ring 40, that is, by the downward abutment of the moving block 73 of the adjusting member 70 to the top surface of the upright portion 32, the downward movement of the upright portion 32 of the elastic film 30 can be realized to compensate for the wear of the retaining ring 30, so as to ensure the consistency of the running state of the carrier head 100, so that the running state of the carrier head 100 in processing each wafer is relatively stable, which is conducive to improving the uniformity of the wafer polishing.

[0072] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0073] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A carrier head for chemical mechanical polishing, characterized by, The carrier head comprises a carrier disc, an elastic film and a retaining ring, the elastic film is arranged below the carrier disc, and the retaining ring is arranged at the outer circumferential side of the elastic film and at the bottom of the carrier disc. The elastic film comprises a bottom plate part, a vertical part, a horizontal part and a pleat part, the bottom plate part is a disc structure, the vertical part extends vertically upward along the outer edge of the bottom plate part, the horizontal part extends horizontally inward from the top end of the vertical part, and the pleat part is arranged above the vertical part and has edges arranged between the carrier disc and the retaining ring. The carrier head further comprises a detection member and an adjusting member, the detection member and the adjusting member are arranged adjacently and below the pleat part, are uniformly arranged along the circumferential direction of the pleat part and above the vertical part, the detection member measures stress information of the pleat part, and the adjusting member adjusts the stress of the pleat part based on the measurement value of the detection member, so that the deformation of the cavity formed by the pleat part is uniform along the circumferential direction. The pleat part comprises vertical ribs and bent ribs, the vertical ribs are arranged upward from the vertical part, the bent ribs are open outward, and the edges of the bent ribs are connected between the carrier disc and the retaining ring; the detection member and the adjusting member are arranged inside the vertical ribs and below the bent ribs; the wall thickness of the vertical ribs is smaller than that of the vertical part, the detection member and the adjusting member are arranged below the bent ribs through flexible connecting members, and the bottoms of the detection member and the adjusting member are arranged toward the vertical part.

2. The load head of claim 1 wherein, The adjusting member comprises a housing, a piezoelectric actuator and a moving block, the piezoelectric actuator is arranged in the housing, the moving block is arranged close to the piezoelectric actuator and at least partially outside the housing, the moving block is arranged toward the upper surface of the vertical part and can press against the vertical part to adjust the deformation of the pleat part.

3. The load head of claim 2 wherein, The vertical projection of the moving block overlaps with the outer ring part of the vertical part.

4. The load head of claim 1 wherein, The detection member is provided with a signal transmitter, the adjusting member is provided with a signal receiver, and the signal transmitter and the signal receiver are signal-connected to a control unit arranged outside the carrier head in a wireless manner.

5. The load head of claim 4 wherein, The inside of the carrier head is provided with a power supply, which provides electric energy for the operation of the detection member, the adjusting member, the signal transmitter and the signal receiver.

6. A chemical mechanical polishing system characterized by comprising: The chemical mechanical polishing system comprises a polishing disc, a trimmer, a liquid supply arm and the carrier head according to any one of claims 1 to 5.

7. A chemical mechanical polishing method characterized by, The wafer is processed by the chemical mechanical polishing system according to claim 6, and the carrier head adjusts the displacement of the pleat part of the elastic film by the adjusting member based on the measurement value of the detection member, so that the deformation of the cavity formed by the pleat part is uniform along the circumferential direction.

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