A dressing device and polishing system for chemical mechanical polishing

Abstract

The application discloses a dressing device and a polishing system for chemical mechanical polishing, the dressing device comprises a swing arm, a base and a dressing head, the base is arranged at the end of the swing arm, and the dressing head is rotationally connected to the lower portion of the base through a guide shaft; the dressing head comprises a flange plate, a spherical hinge plate and a flexible film, the flange plate is fixed to the guide shaft, the spherical hinge plate is hingedly connected to the lower end of the guide shaft, and the flexible film is connected between the flange plate and the spherical hinge plate to form a pressure regulating chamber; the pressure regulating chamber can press a dressing disc below the spherical hinge plate against the surface of a polishing pad to apply a dressing load.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of chemical mechanical polishing, and particularly relates to a dressing device for chemical mechanical polishing and a polishing system. 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 the 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, cutting and packaging, and testing processes. Among them, chemical mechanical polishing is one of the five core processes in the wafer manufacturing process.

[0003] Chemical mechanical polishing (CMP) is a global planarization ultra-precision surface processing technology. Chemical mechanical polishing usually attracts the wafer to the bottom surface of the carrier head, the side of the wafer with the deposited layer abuts against 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 the chemical mechanical polishing of the wafer under the joint action of chemical and mechanical.

[0004] During the polishing process, in order to ensure that the polishing pad has good surface properties, the polishing pad surface groove can accommodate more polishing liquid, and the polishing material to be polished can be efficiently and stably removed, a dresser needs to be used to dress the surface of the polishing pad. The bottom of the dresser is configured with a dressing disk, and the bottom surface of the dressing disk is inlaid with diamond particles; the dresser gives the dressing disk a downward pressure and a rotary torque, and the dressing disk moves relative to the surface of the polishing pad to dress the surface of the polishing pad.

[0005] In the prior art, the inside of the dresser is configured with a metal spring plate, so that the dressing disk follows the ups and downs of the polishing pad to ensure the dressing effect; but when the dressing pressure is small, the metal spring plate meets the requirement of lateral force bearing, the bending stiffness is large, and the elastic deformation amount of the metal spring plate is small; this will cause one side of the dressing disk to adhere to the polishing pad, while the other side of the dressing disk is partially "suspended" above the polishing pad, that is, the entire dressing disk cannot completely adhere to the surface of the polishing pad.

[0006] Therefore, the existing dressing disk may be inclined, resulting in concentration of a part of the dressing downward pressure and no dressing downward pressure on the other part, causing uneven dressing of the surface of the polishing pad.

[0007] Usually, the flexible ring inside the dresser is used to transmit the dressing torque. However, the resistance of the existing flexible ring increases first and then decreases with its own downward movement, as shown in detail in Figure 1The flexible ring resistance-displacement curve shown; this will cause the flexible ring to be unable to fully balance the weight of the rotating body, so that the trimmer has a problem of insufficient control when a small trimming pressure is applied. In the above working condition, Figure 1 The curve inflection point and the end resistance difference restrict the lower limit of the trimming down pressure, making the application range of the trimmer relatively narrow. At the same time, the resistance-displacement curve corresponding to the existing flexible ring will make the pressure of the polishing pad on the polishing pad present: "the polishing pad high area corresponds to the low trimming down pressure, and the polishing pad low area corresponds to the large trimming down pressure", so that the polishing pad high area has less trimming removal, and the polishing pad low area has more trimming removal, causing the polishing pad to be more uneven after trimming. SUMMARY

[0008] The embodiments of the present application provide a trimming device and a polishing system for chemical mechanical polishing, aiming to at least solve one of the technical problems existing in the prior art.

[0009] The first aspect of the embodiments of the present application provides a trimming device for chemical mechanical polishing, which comprises a swing arm, a base and a trimming head, the base is arranged at the end of the swing arm, and the trimming head is rotationally connected to the lower side of the base through a guide shaft; the trimming head comprises a flange plate, a spherical hinge plate and a flexible film, the flange plate is fixed to the guide shaft, the spherical hinge plate is hinged to the lower end of the guide shaft, and the flexible film is connected between the flange plate and the spherical hinge plate to form a pressure regulating chamber; the pressure regulating chamber can press the polishing pad on the polishing pad surface to apply a trimming load.

[0010] In some embodiments, the guide shaft and the spherical hinge plate are connected through a spherical hinge bearing to adaptively adjust the position and posture of the trimming disc below the spherical hinge plate.

[0011] In some embodiments, the flexible film is an annular structure, which comprises a first extension, a wrinkle part and a second extension, which are integrally formed; the wrinkle part is arranged between the first extension and the second extension and is bent towards the inside.

[0012] In some embodiments, the first extension is fixed to the flange plate by a first pressure ring, and the second extension is fixed to the spherical hinge plate by a second pressure ring.

[0013] In some embodiments, the wrinkle part extends downward and inward from the first extension, and then extends downward and outward; the wall thickness of the wrinkle part is greater than or equal to the wall thickness of the first extension and the second extension.

[0014] In some embodiments, the wall thickness of the wrinkle part is 1.1-1.5 times the wall thickness of the first extension or the second extension.

[0015] In some embodiments, the ball hinge plate is configured with an annular fixing groove to place the second extension, and the second compression ring is pressed on the second extension.

[0016] In some embodiments, the ball hinge plate is further configured with a limiting platform, a side wall of the limiting platform forms a side wall of the fixing groove; a vertical transition section is arranged between the second extension and the wrinkle part, and a height of the limiting platform is greater than a length of the transition section.

[0017] In some embodiments, a difference between the height of the limiting platform and the length of the transition section is 1-3 mm.

[0018] In some embodiments, the trimming head further comprises a limiting member which at least partially covers the first extension to inhibit the bulging of the upper part of the flexible film.

[0019] In some embodiments, the flexible film is made of an elastic material of silicone.

[0020] In some embodiments, the guide shaft is internally provided with a vent hole which is in communication with the pressure regulating chamber to introduce fluid into the pressure regulating chamber.

[0021] In some embodiments, the vent hole comprises a vertical hole arranged along the length direction of the guide shaft and a horizontal hole arranged along the radial direction of the guide shaft.

[0022] In some embodiments, the horizontal hole is arranged towards the wrinkle part of the flexible film.

[0023] A second aspect of the embodiments of the present application provides a polishing system comprising a polishing disc, a carrier head, a liquid supply device and the trimming device described above, the carrier head loads a wafer to be polished and abuts the wafer against a polishing pad above the polishing disc, the liquid supply device supplies a polishing liquid towards the polishing pad and the wafer, and the trimming device is used to trim the surface of the polishing pad.

[0024] The beneficial effects of the present application include:

[0025] a. The trimming device provided by the present application is configured with a ball hinge bearing between the guide shaft of the trimming head and the ball hinge plate, the inner and outer rings of the ball hinge bearing can freely slide; by using the mechanism that the gravity is always vertically downward, the horizontal pose of the trimming disc relative to the polishing pad can be adjusted by the self-weight of the trimming disc, the inclination of the bottom surface of the trimming disc relative to the polishing pad is avoided to affect the application of the trimming load, and the uneven application of the trimming load is prevented to cause the flatness of the polishing pad surface to be poor;

[0026] b. The flexible film of the trimming head is configured with a fold part inclined towards the inner side, so that the resistance-displacement curve of the flexible film is a monotonically increasing curve; such resistance-displacement curve makes the pressure of the trimming disc on the polishing pad present the rule that "the high area of the polishing pad corresponds to large trimming pressure, and the low area of the polishing pad corresponds to small trimming pressure", so as to reduce the height difference between the high and low areas of the polishing pad, and gradually weaken the unevenness of the polishing pad surface;

[0027] c. The configured spherical hinge bearing can reduce the gravity center of the trimming head, so that the operation of the trimming device is more stable, and then a good trimming effect is obtained;

[0028] d. The fold part formed by bending towards the inner side of the flexible film can increase the torsional stiffness of the flexible film, and then improve the deformation of the flexible film under the action of the torsional moment, and improve the carrying capacity of the flexible film;

[0029] e. The circular arc transition structure is adopted between the fold part and the first extension part and between the fold part and the second extension part, so as to facilitate the polishing pollutants to slide off the surface of the flexible film, prevent the strong adhesion of the pollutants, and then inhibit the crystallization of the polishing pollutants on the surface of the flexible film, and prevent the wafers from being scratched by the falling crystals;

[0030] f. The limiting piece is combined with the first pressure ring to limit the deformation of the upper part of the flexible film, so that the upper part of the flexible film hardly deforms, and then the service life of the flexible film is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0031] The advantages of the present application will become more apparent and more readily appreciated when considered in connection with the following detailed description, taken in conjunction with the accompanying drawings, which are merely illustrative and not restrictive of the present application, wherein:

[0032] Figure 1 is the resistance-displacement curve corresponding to the flexible ring of the prior art;

[0033] Figure 2 is a schematic view of a trimming device for chemical mechanical polishing provided by an embodiment of the present application;

[0034] Figure 3 is a schematic view of a trimming head provided by an embodiment of the present application;

[0035] Figure 4 is a longitudinal sectional view of a flexible film provided by an embodiment of the present application;

[0036] Figure 5 is a resistance-displacement curve corresponding to the flexible film provided by an embodiment of the present application;

[0037] Figure 6 is a schematic view of a polishing system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0038] The technical solutions of the present application will be described in detail below with reference to specific embodiments and their accompanying drawings. The embodiments described herein are 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.

[0039] The drawings of the present specification are schematic drawings that assist in illustrating the concept of the present application, and schematically represent the shape of each part and the relationship between them. 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.

[0040] 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. The term "comprising" and similar terms are to be understood as open-ended, i.e., "including but not limited to". The term "based on" is to be understood as "based at least in part on". The term "one embodiment" or "the embodiment" is to be understood as "at least one embodiment". The terms "first", "second", etc. can refer to different or the same objects and are only used to distinguish the referred objects, and do not imply a specific spatial order, a time order, an importance order, etc. of the referred objects. In some embodiments, values, processes, selected items, determined items, devices, apparatuses, means, components, assemblies, etc. are referred to as "optimal", "lowest", "highest", "minimum", "maximum", etc. It should be understood that such descriptions are intended to indicate that a selection can be made among many available functional options, and such a selection does not need to be better, lower, higher, smaller, larger or otherwise preferred than other options in other aspects or all aspects.

[0041] Figure 2This is a schematic diagram of a dressing device 100 for chemical mechanical polishing according to an embodiment of the present invention. The dressing device 100 includes a swing arm 110, a base 120, and a dressing head 130. The base 120 is disposed at the end of the swing arm 110. The dressing head 130, also called a PC head (pad condition head), is guided by a guide shaft 10 (…). Figure 3 (As shown) It is rotatably connected to the lower part of the base 120. The fixed point of the swing arm 110 is located on the outside of the polishing pad. The swing arm 110 can rotate around the fixed point to drive the trimming head 130 at the end to swing periodically, thereby completing the trimming of the polishing pad surface.

[0042] Figure 3 yes Figure 2 The schematic diagram of the dressing head 130 in the embodiment shows that the dressing head 130 includes a flange plate 20 and a ball joint plate 30. The flange plate 20 is rotatably connected to the guide shaft 10, and the ball joint plate 30 is hinged to the lower end of the guide shaft 10. A dressing disc 40 is arranged below the ball joint plate 30, and a number of diamond particles are arranged below the dressing disc 40 to process the microporous structure on the surface of the polishing pad and dress the surface of the polishing pad.

[0043] Specifically, the base 120 has a rotating part inside, which is located on the outer periphery of the guide shaft 10 and rotates relative to the guide shaft 10. The flange plate 20 is connected to the rotating part, that is, the flange plate 20 and its connected components can rotate synchronously with the rotating part.

[0044] Furthermore, the guide shaft 10 and the ball joint plate 30 are connected by a ball joint bearing 50. Specifically, the inner ring of the ball joint bearing 50 is fixed to the outer periphery of the guide shaft 10, and the outer ring of the ball joint bearing 50 is connected to the groove 31 on the top surface of the ball joint plate 30.

[0045] The inner and outer rings of the ball bearing 50 can slide freely within a certain range with minimal friction. When the surface morphology of the polishing pad is uneven, the inner and outer rings of the ball bearing 50 tilt slightly, and the dressing disc 40 and the guide shaft 10 have a small tilt angle. The dressing disc 40 and the polishing pad can always be in contact, thereby achieving uniform application of the dressing load to the surface of the polishing pad to obtain a good dressing effect.

[0046] Furthermore, in order to limit the vertical position of the ball joint bearing 50, the dressing head 130 also includes a pressure cap 60. The bottom of the pressure cap 60 is provided with a placement groove. The pressure cap 60 is located on the outer periphery of the guide shaft 10 and is sleeved on the ball joint bearing 50 to prevent the ball joint bearing 50 from moving up and down during the dressing process, which would affect the adaptive adjustment of the dressing disk 40's position and thus ensure that the dressing disk 40 always fits against the surface of the polishing pad.

[0047] Meanwhile, the arrangement of the spherical hinge bearing 50 can lower the gravity center of the dressing head 130, so that the gravity center of the dressing head 130 is located below the spherical hinge bearing 50, and is closer to the surface of the polishing pad, thereby ensuring the stability of the dressing operation.

[0048] Figure 3 In some embodiments, the dressing head 130 further comprises a flexible film 70, one end of which is connected to the flange plate 20, and the other end of which is connected to the spherical hinge plate 30, so as to form a pressure regulating chamber C1, and the dressing load of the dressing disc 40 acting on the polishing pad is changed by changing the internal pressure of the pressure regulating chamber C1.

[0049] Further, the flexible film 70 has a ring structure, which comprises a first extension part 71, a pleat part 73 and a second extension part 72, which are integrally formed, as shown in Figure 4 The pleat part 73 is arranged between the first extension part 71 and the second extension part 72, and the pleat part 73 is bent towards the inner side of the dressing head 130.

[0050] In this way, when the pressure regulating chamber C1 of the flexible film 70 is in positive pressure, i.e. when the pressure regulating chamber C1 is pressurized and expanded, the dressing head 130 rises vertically; when the pressure regulating chamber C1 of the flexible film 70 is in negative pressure, i.e. when the pressure regulating chamber C1 is evacuated and contracted, the dressing head 130 descends vertically. During the rising and descending of the dressing head 130, the flexible film 70 is in a contracted state and an extended state respectively, thereby optimizing the resistance-displacement curve of the flexible film 70.

[0051] Meanwhile, the pleat part 73 extends downward and inward from the first extension part 71, and then extends downward and outward. The arrangement of the pleat part 73 extending towards the inner side of the flexible film 70 can increase the torsional stiffness of the flexible film 70, thereby improving the deformation of the flexible film 70 under the action of the torsional moment, and improving the load-carrying capacity of the flexible film 70.

[0052] Figure 3 In the embodiment shown, the wall thickness of the pleat part 73 is the same as that of the first extension part 71 and the second extension part 72, and the corresponding wall thickness of the pleat part 73 is 2-5 mm, so as to ensure that the pleat part 73 has a certain strength. In some embodiments, the wall thickness of the pleat part 73 can be slightly greater than that of the first extension part 71 and the second extension part 72. For example, the wall thickness of the pleat part 73 is 1.1-1.5 times the wall thickness of the first extension part 71 or the second extension part 72, so as to increase the strength of the pleat part 73 under the condition of maintaining good flexibility of the pleat part 73, and ensure the torsional stiffness of the pleat part 73 of the flexible film 70.

[0053] During chemical mechanical polishing, polishing liquid and polishing formed particles and other polishing pollutants may splash to the surface of the pleat portion 73 of the flexible membrane 70; to inhibit or avoid the polishing pollutants from adhering to the area with sharp corners (such as right angle), the pleat portion 73 and the first extending portion 71 and the pleat portion 73 and the second extending portion 72 adopt a circular arc transition structure. In this way, the polishing pollutants are facilitated to slide off the surface of the flexible membrane 70, the strong adhesion of the pollutants is prevented, and the crystallization of the polishing pollutants on the surface of the flexible membrane 70 is prevented, thereby preventing the wafer from being scratched.

[0054] In the present application, the dressing head 130 further comprises a limiting member 21 arranged at the upper portion of the flexible membrane 70. The limiting member 21 can at least partially cover the upper portion of the flexible membrane 70 to inhibit the flexible membrane 70 from bulging upward. Specifically, the limiting member 21 is a ring-shaped member which covers the upper portion of the first extending portion 71 to prevent the polishing pollutants from crystallizing on the surface of the first extending portion 71.

[0055] In order to enhance the crystallization resistance of the surface of the limiting member 21 and reduce the adhesion of the solid-liquid mixture to the surface of the limiting member 21, the limiting member 21 can be made of a hydrophobic material or a super-hydrophobic material, such as polyformaldehyde, or a hydrophobic coating layer can be arranged on the surface of the limiting member 21.

[0056] In some embodiments, the surface of the limiting member 21 is smoothly transitioned, especially the structure corner portion, to avoid the structure edges and corners, so as to ensure that the solid-liquid pollutants can smoothly move on the surface of the limiting member 21, thereby inhibiting the polishing pollutants from crystallizing on the surface of the limiting member 21.

[0057] Figure 3 In the illustrated embodiment, the first extending portion 71 comprises a horizontal extending segment and a vertical extending segment which are integrally formed. The limiting member 21 can cover the whole horizontal extending segment of the first extending portion 71 and partially cover the vertical extending segment, so as to inhibit the bulging of the upper portion of the flexible membrane 70. That is, the unnecessary bulging of the flexible membrane 70 is reduced, the use characteristics of the flexible membrane 70 are maintained, and the service life of the flexible membrane 70 is prolonged.

[0058] Figure 5 is the resistance-displacement curve of the flexible membrane 70 according to an embodiment of the present application, wherein the abscissa is the displacement of the flexible membrane 70 along the vertical direction, and the displacement of the flexible membrane 70 is zero when the flexible membrane 70 is in the initial state; the ordinate is the resistance received by the flexible membrane 70, and the direction of the force is upward, that is, opposite to the direction of the dressing downward pressure.

[0059] The greater the downward stroke of the flexible film 70, the greater the resistance received by the flexible film 70, and the smaller the trimming down pressure applied; the smaller the downward stroke of the flexible film 70, the smaller the resistance received by the flexible film 70, and the greater the trimming down pressure applied, thereby enhancing the trimming effect and weakening the unevenness of the surface of the polishing pad. That is, the trimming down pressure of the trimming disc 40 on the polishing pad presents the following rule: "the trimming down pressure corresponding to the high area of the polishing pad is large, and the trimming down pressure corresponding to the low area of the polishing pad is small", so as to reduce the height difference between the high and low areas of the polishing pad, gradually weaken the unevenness of the surface of the polishing pad, and make the surface of the polishing pad more flat.

[0060] As an aspect of the embodiment, the flexible film 70 is made of an elastic material of silicone resin, so that the hardness of the flexible film 70 is moderate, thereby balancing the self-weight of the ball hinge plate 30 and the trimming disc 40, adjusting the lower limit of the down pressure of the trimming head 130 to 0N, expanding the adjustment range of the trimming down pressure, and improving the adaptability of the trimming device 100 claimed in the application.

[0061] Figure 3 In the illustrated embodiment, the first extension 71 is fixed to the flange plate 20 by the first pressing ring 81. Specifically, the first pressing ring 81 is arranged inside the flexible film 70, and in combination with the limiting piece 21, the first pressing ring 81 fixes the first extension 71 of the flexible film 70.

[0062] In the application, the first pressing ring 81 is in a ring structure, which is arranged to extend in the horizontal direction, i.e. the first pressing ring 81 is pressed below the first extension 71. The first pressing ring 81 is combined with the limiting piece 21 to limit the deformation of the upper part of the flexible film 70, so that the upper part of the flexible film 70 hardly deforms, which is beneficial to prolong the service life of the flexible film 70.

[0063] Further, the second extension 72 is fixed to the ball hinge plate 30 by the second pressing ring 82. Specifically, the surface of the ball hinge plate 30 is provided with a fixing groove 32 to place the second extension 72, as shown. Figure 3 The fixing groove 32 is configured with a limiting table 33 towards the center of the ball hinge plate 30 to limit the transition section 74 between the wrinkle part 73 and the second extension 72 (as shown), so that the transition section 74 is in a substantially vertical state to achieve the fixation of the second extension 72 of the flexible film 70. Figure 4

[0064] ​In some embodiments, the vertical height of the transition section 74 is 3-8 mm, so as to prevent the limiting platform 33 from contacting the wrinkle section 73 of the flexible film 70 and affecting the normal inflation and expansion of the flexible film 70. It should be noted that the vertical height of the limiting platform 33 matches the vertical height of the transition section 74, and the top of the transition section 74 of the flexible film 70 installed on the spherical hinge plate 30 is slightly higher than the limiting platform 33, so as to avoid the hard contact between the limiting platform 33 and the wrinkle section 73 of the flexible film 70 and affect the deformation of the flexible film 70.

[0065] In some embodiments, the difference between the height of the limiting platform 33 and the length of the transition section 74 is 1-3 mm, so as to avoid the hard contact between the limiting platform 33 and the wrinkle section 73 of the flexible film 70. As an aspect of the present embodiment, the top edge of the limiting platform 33 is rounded, so as to ensure the flexibility of the wrinkle section 73 under the condition of limiting the lower part of the flexible film 70.

[0066] In the present application, the vertical height of the transition section 74 is smaller than the length of the vertical extension section of the first extension section 71, so that the spherical hinge plate 30 connected with the lower part of the flexible film 70 can be adaptively adjusted with a small amplitude by the spherical hinge bearing 50, so as to prevent the spherical hinge plate 30 from being adjusted with a large amplitude and causing the trimming head 130 to be tilted.

[0067] The limiting platform 33 can make the connection position of the flexible film 70 and the spherical hinge plate 30 relatively uniform, so as to ensure the use performance of the flexible film 70, and further present Figure 5 the resistance-displacement characteristics of the flexible film.

[0068] It should be noted that, in order to reduce or inhibit the contact between the flexible film 70 and the chemical liquid in the polishing process, a protective cover plate (not shown) can be further arranged on the outer peripheral side of the flexible film 70, and the protective cover plate is connected between the flange plate 20 and the spherical hinge plate 30, so as to prevent the chemical agents such as polishing liquid from crystallizing on the outer peripheral side of the flexible film 70.

[0069] It can be understood that the protective cover plate can be integrally formed with the limiting member 21 mentioned above, that is, the functions of protection and limiting are integrated on one component, so as to simplify the structure of the trimming head 130 and ensure the convenience of use of the trimming device 100.

[0070] Further, the inside of the guide shaft 10 is provided with a vent hole, and the vent hole is in communication with the pressure regulating chamber C1. Specifically, the vent hole includes a vertical hole 91 and a horizontal hole 92, wherein the vertical hole 91 is arranged along the length direction of the guide shaft 10, and the horizontal hole 92 is arranged along the radial direction of the guide shaft 10. An external gas source (not shown) is in communication with the pressure regulating chamber C1 through the vent hole of the guide shaft 10, so that the gas can be transmitted to the pressure regulating chamber C1 through the vertical hole 91 and the horizontal hole 92 in sequence, so as to change the pressure of the pressure regulating chamber C1.

[0071] In the present application, the plurality of transverse holes 92 are substantially uniformly distributed along the circumference of the guide shaft 10, so that the fluid entering through the vertical hole 91 can quickly fill the pressure regulating chamber C1, thereby ensuring the pressure response speed of the pressure regulating chamber C1. Further, the transverse holes 92 can be spaced along the length direction of the guide shaft 10 to ensure the quickness of fluid transmission.

[0072] In some embodiments, the transverse holes 92 are arranged towards the wrinkle portion 73 of the flexible film 70, and the vertical arrangement position of the transverse holes 92 is substantially flush with the inward convex point of the wrinkle portion 73, so that the fluid entering the pressure regulating chamber C1 through the vent hole of the guide shaft 10 can change the deformation of the wrinkle portion 73, improving the quickness of deformation of the flexible film 70.

[0073] Figure 3 In the illustrated embodiment, the lower end of the guide shaft 10 is configured with a nut not shown to block the vertical hole 91. That is, for the convenience of processing, the vertical hole 91 needs to be processed through along the length direction of the guide shaft 10, and then blocked with a nut to prevent the fluid from being transmitted to the groove 31 of the spherical hinge plate 30 through the vertical hole 91, thereby interfering with the pressure adjustment of the pressure regulating chamber C1, avoiding the problem of local overpressure or underpressure, so that the deviation of the actual trimming load from the set value is within the control range, thereby ensuring the trimming effect of the polishing pad.

[0074] Figure 6 is a schematic view of a polishing system 1000 provided by an embodiment of the present application, the polishing system 1000 comprising a polishing disc 200, a carrier head 300, a liquid supply device 400 and the above-mentioned trimming device 100, the carrier head 300 loading a wafer to be polished and abutting the polishing pad above the polishing disc 200, the liquid supply device 400 supplying polishing liquid towards the polishing pad and the wafer, and the trimming device 100 being used for trimming the surface of the polishing pad so that the polishing pad has good polishing properties.

[0075] The polishing pad is arranged on the upper surface of the polishing disc 200, and the polishing pad rotates together with the polishing disc 200; the horizontally movable carrier head 300 is arranged above the polishing pad, and the bottom of the carrier head 300 attracts the wafer to be polished; the trimming device 100 swings around a fixed point, and the trimming head 130 arranged thereon rotates itself and applies a downward load to trim the surface of the polishing pad; and the liquid supply device 400 is arranged above the polishing pad to spread the polishing liquid on the surface of the polishing pad.

[0076] During the polishing operation, the carrier head 300 abuts the polishing pad surface with the wafer surface to be polished, and the carrier head 300 rotates and reciprocates along the radial direction of the polishing disc 200 so that the wafer surface in contact with the polishing pad is gradually polished; at the same time, the polishing disc 200 rotates, and the liquid supply device 400 sprays the polishing liquid to the polishing pad surface. Under the chemical action of the polishing liquid, the wafer is rubbed with the polishing pad through the relative motion of the carrier head 300 and the polishing disc 200 to perform polishing.

[0077] The dressing device 100 is used for dressing and activating the polishing pad surface, and the dressing device 100 can be used to remove impurity particles remaining on the polishing pad surface, such as abrasive particles in the polishing liquid and waste materials falling from the wafer surface, to dress and activate the polishing pad surface.

[0078] In the dressing device 100 provided by the application, the ball hinge bearing 50 is arranged between the guide shaft 10 and the ball hinge plate 30, the inner ring and the outer ring of the ball hinge bearing 50 can slide freely; by using the principle of always vertical downward by gravity, the horizontal of the dressing disc 40 relative to the polishing pad can be adjusted by the self-weight of the dressing disc 40, so as to avoid the bottom surface of the dressing disc 40 relative to the polishing pad from being inclined to affect the application of the dressing load, and prevent the polishing pad surface from being uneven due to uneven application of the dressing load.

[0079] At the same time, the arranged ball hinge bearing 50 can reduce the gravity center of the dressing head 130, so that the operation of the dressing device 100 is more stable, and a good dressing effect is obtained.

[0080] At the same time, the flexible film 70 is provided with the inwardly inclined wrinkle part 73, so that the resistance-displacement curve of the flexible film 70 is monotonously increasing; such resistance-displacement curve makes the pressure of the dressing disc 40 on the polishing pad present the following rule: the dressing down pressure of the high area of the polishing pad is large, and the dressing down pressure of the low area of the polishing pad is small, so as to reduce the height difference between the high and low areas of the polishing pad, and gradually weaken the unevenness of the polishing pad surface.

[0081] Although the embodiments of the 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 application, and the scope of the application is defined by the claims and their equivalents.

Claims

1. A dressing device for chemical mechanical polishing, characterized in that, The device includes a swing arm, a base, and a trimming head. The base is located at the end of the swing arm, and the trimming head is rotatably connected to the lower part of the base via a guide shaft. The trimming head includes a flange plate, a ball joint plate, and a flexible membrane. The flange plate is fixed to the guide shaft, the ball joint plate is hinged to the lower end of the guide shaft, and the flexible membrane is connected between the flange plate and the ball joint plate to form a pressure regulating chamber. The pressure regulating chamber can press the trimming disc below the ball joint plate against the surface of the polishing pad to apply a trimming load. The flexible membrane has an annular structure, including a first extension, a pleated portion, and a second extension, all three being integrally formed. The pleated portion is located between the first extension and the second extension. The two extensions are bent inwards; the first extension is fixed to the flange plate by the first pressure ring, and the second extension is fixed to the ball joint plate by the second pressure ring; the pleated part extends downwards and inwards from the first extension, and then downwards and outwards; the wall thickness of the pleated part is greater than or equal to the wall thickness of the first extension and the second extension; the guide shaft is provided with a vent hole, which is connected to the pressure regulating chamber to introduce fluid into the pressure regulating chamber; the vent hole includes a vertical hole and a horizontal hole, the vertical hole is arranged along the length of the guide shaft, and the horizontal hole is arranged along the radial direction of the guide shaft and is arranged towards the pleated part of the flexible membrane.

2. The trimming device as described in claim 1, characterized in that, The guide shaft is connected to the ball joint plate via a ball joint bearing to adaptively adjust the position and orientation of the trimming disc below the ball joint plate.

3. The trimming device as described in claim 1, characterized in that, The wall thickness of the folded portion is 1.1 to 1.5 times the wall thickness of the first extension or the second extension.

4. The trimming device as described in claim 1, characterized in that, The ball joint plate is provided with an annular fixing groove for placing the second extension, and the second pressure ring presses against the top of the second extension.

5. The trimming device as described in claim 4, characterized in that, The ball joint plate is also equipped with a limiting platform, the side wall of which forms the side wall of the fixing groove; a vertical transition section is provided between the second extension and the pleated part, and the height of the limiting platform is greater than the length of the transition section.

6. The trimming device as described in claim 5, characterized in that, The difference between the height of the limiting platform and the length of the transition section is 1-3mm.

7. The trimming device as claimed in claim 1, characterized in that, The trimming head also includes a limiting member that at least partially covers the first extension to suppress bulging of the upper part of the flexible membrane.

8. The trimming device as claimed in claim 1, characterized in that, The flexible membrane is made of an elastic material of silicone resin.

9. A polishing system, characterized in that, The device includes a polishing pad, a support head, a liquid supply device, and a dressing device as described in any one of claims 1 to 8, wherein the support head loads a wafer to be polished and abuts it against a polishing pad above the polishing pad, the liquid supply device supplies polishing liquid between the polishing pad and the wafer, and the dressing device is used to dress the surface of the polishing pad.

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