Method for improving flatness of polishing pad and double-sided polishing equipment

Abstract

The invention relates to a method for improving the flatness of a polishing pad and a double-sided polishing device.The method for improving the flatness of the polishing pad is applied to the double-sided polishing device.The double-sided polishing device comprises an upper fixed disc and a lower fixed disc which are oppositely arranged, and an upper polishing pad is arranged on the side, facing the lower fixed disc, of the upper fixed disc; a lower polishing pad is arranged on the side, facing the upper fixed disc, of the lower fixed disc, a groove is formed in the upper polishing pad, and the method for improving the flatness of the polishing pad comprises the following steps that S1, when the upper polishing pad and the lower polishing pad are oppositely pressed and attached, the groove is formed in the upper polishing pad; and the upper polishing pad and the lower polishing pad are rolled and leveled through a rolling structure arranged between the upper polishing pad and the lower polishing pad. In the opposite pressing and attaching process of the upper polishing pad and the lower polishing pad, the rolling process is added, the problem that grid marks are generated on the lower polishing pad due to grooves in the upper polishing pad is solved, and the surface of the lower polishing pad is kept flat.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor product manufacturing, and particularly to a method for improving flatness of a polishing pad and a double-side polishing device. BACKGROUND

[0002] In the manufacturing process of semiconductor silicon wafers, global flatness is one of the key parameters for measuring the surface quality of the silicon wafers, and edge flatness ZDD is particularly important. ZDD (Z height double derivative) describes the average value of the curvature of the edge region (generally a region 2 mm away from the edge of the silicon wafer) of the surface of the semiconductor silicon wafer. In particular, ZDD directly and accurately reflects the edge flatness of the semiconductor silicon wafer. The physical meaning of ZDD is the rate of change of the tangent (slope) of the surface of the silicon wafer at a radial distance R (radial distance from the center of the silicon wafer). Therefore, when the ZDD value is positive (positive) at a certain point, the surface shape is convex downward at that point, and when the ZDD value is negative (negative) at a certain point, the surface shape is convex upward at that point.

[0003] ZDD is one of the important parameters for evaluating the flatness of the silicon wafer. The flatness of the silicon wafer has a direct impact on processes such as lithography, thin film deposition, and etching in the semiconductor manufacturing process. Insufficient flatness can lead to decreased lithography alignment accuracy, poor thin film uniformity, and unstable final device performance, among other issues. Good edge flatness can ensure that the entire surface of the silicon wafer maintains consistent performance during processing, reducing the occurrence of defects.

[0004] In the chemical mechanical polishing (CMP) or double-side polishing process, an upper pad (polishing pad) with grooves is usually used to ensure uniform flow of slurry. However, after the grooved upper polishing pad is pressed and bonded with the lower polishing pad, a corresponding "lattice mark" is left on the surface of the lower polishing pad, resulting in uneven distribution of polishing pressure and thus deteriorating the edge flatness ZDD of the polished silicon wafer. SUMMARY

[0005] To solve the above technical problems, the present application provides a method for improving flatness of a polishing pad and a double-side polishing device, which solves the problem of poor silicon wafer flatness caused by the setting of grooves on the upper polishing pad, which results in a lattice mark on the lower polishing pad after the upper and lower polishing pads are pressed and bonded.

[0006] In order to achieve the above object, the technical scheme adopted by the embodiment of the present application is as follows: a method for improving flatness of polishing pads is applied to a double-sided polishing device, the double-sided polishing device comprises oppositely arranged upper and lower chucks, the upper chuck is provided with an upper polishing pad on the side facing the lower chuck, the lower chuck is provided with a lower polishing pad on the side facing the upper chuck, and the method for improving flatness of polishing pads comprises the following steps:

[0007] Step S1: when the upper polishing pad and the lower polishing pad are pressed and attached, the upper polishing pad and the lower polishing pad are subjected to rolling flattening treatment by a rolling structure arranged between the upper polishing pad and the lower polishing pad.

[0008] Optionally, the step S1 specifically comprises:

[0009] Step S01: the upper chuck and the lower chuck are controlled to move towards each other, so that the upper polishing pad and the lower polishing pad are clamped on the opposite sides of the rolling structure with a preset pressure;

[0010] Step S02: the upper chuck and the lower chuck are controlled to rotate relative to each other to perform rolling flattening treatment on the upper polishing pad and the lower polishing pad.

[0011] Optionally, the preset pressure is 600-1200 DaN.

[0012] Optionally, the rolling structure comprises a plurality of rolling shafts uniformly distributed along the circumferential direction of the lower polishing pad, and the step S02 specifically comprises:

[0013] The upper chuck and the lower chuck are controlled to rotate relative to each other at a speed of 1-5 rpm / min to drive the rolling shafts to rotate and roll the surfaces of the upper polishing pad and the lower polishing pad.

[0014] Optionally, the lower chuck comprises an inner pin ring and an outer pin ring, the rolling shafts are arranged between the inner pin ring and the outer pin ring, and the rolling shafts comprise oppositely arranged first ends and second ends along the axial direction thereof, the first ends are in pressure connection with the inner pin ring, and the second ends are in pressure connection with the outer pin ring.

[0015] Optionally, the end face of the first end is a curved surface matched with the shape of the side face of the inner pin ring, and the end face of the second end is a curved surface matched with the shape of the side face of the outer pin ring.

[0016] Optionally, the method further comprises:

[0017] Step S2: the upper polishing pad and the lower polishing pad are cleaned under preset process conditions, and the preset process conditions comprise cleaning the upper polishing pad and the lower polishing pad by using a plurality of same nozzles.

[0018] Optionally, the preset process condition comprises: the spray angle of the nozzle is 35-90°; the spray pressure of the nozzle is 50-70 Bar; the distance between the nozzle outlet and the lower polishing pad surface or the lower polishing pad surface is 15-25 mm.

[0019] Optionally, the step S1 specifically comprises:

[0020] Step S011: control the upper platen and the lower platen to move towards each other, so that the upper polishing pad and the lower polishing pad are pressed and attached with a preset pressure;

[0021] Step S012: control the upper platen and the lower platen to move away from each other, and place the rolling structure between the upper polishing pad and the lower polishing pad;

[0022] Step S013: control the upper platen and the lower platen to move towards each other, so that the upper polishing pad and the lower polishing pad are clamped on opposite sides of the rolling structure with a preset pressure;

[0023] Step S014: control the upper platen and the lower platen to rotate relative to each other, so as to perform rolling flattening treatment on the upper polishing pad and the lower polishing pad.

[0024] The embodiment of the present application also provides a double-sided polishing equipment for realizing the method for improving the flatness of the polishing pad, the double-sided polishing equipment comprises an upper platen and a lower platen arranged oppositely, one side of the upper platen facing the lower platen is provided with an upper polishing pad, one side of the lower platen facing the upper platen is provided with a lower polishing pad, the upper polishing pad is provided with a groove, and the double-sided polishing equipment further comprises:

[0025] A rolling structure comprising a plurality of rolling shafts arranged between the upper polishing pad and the lower polishing pad, so as to perform rolling flattening treatment on the upper polishing pad and the lower polishing pad;

[0026] A first driving structure for driving at least one of the upper platen and the lower platen, so that the upper platen and the lower platen move towards or away from each other;

[0027] A second driving structure for driving at least one of the upper platen and the lower platen, so that the upper platen and the lower platen rotate relative to each other, to drive the rolling shafts in the rolling structure to rotate.

[0028] Optionally, the double-sided polishing equipment further comprises a cleaning structure for cleaning the upper polishing pad and / or the lower polishing pad, and the cleaning structure comprises:

[0029] A spray part comprising a plurality of same nozzles;

[0030] The distance control unit is used to control the distance between the multiple nozzles and the upper polishing pad or the lower polishing pad to be within a preset threshold.

[0031] The beneficial effects of the present invention are: the present invention provides a method for improving the flatness of polishing pads. In the pressing and bonding process of the upper polishing pad and the lower polishing pad, a rolling process is added to solve the problem of grid marks on the lower polishing pad caused by the grooves on the upper polishing pad, so that the surface of the lower polishing pad remains flat. Attached Figure Description

[0032] Figure 1 A schematic diagram showing the morphology of the upper polishing pad;

[0033] Figure 2 A schematic diagram showing the positional relationship between the upper polishing pad, the lower polishing pad, and the roller;

[0034] Figure 3 A schematic diagram showing the distribution of the rollers;

[0035] Figure 4 A schematic diagram showing the cleaning structure;

[0036] Figure 5 A schematic diagram showing the spraying state of the nozzle;

[0037] Figure 6 A schematic diagram showing the ZDD value of silicon wafers polished with polishing equipment without the added rolling process and the ZDD value of silicon wafers polished with polishing equipment with the added rolling process;

[0038] Figure 7 A flowchart illustrating a method for improving the flatness of a polishing pad;

[0039] Figure 8 A flowchart illustrating a method for improving the flatness of a polishing pad. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0041] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning as understood by a person having ordinary skill in the art to which the present disclosure pertains. The terms "first", "second", and similar terms are used herein to distinguish one element from another, but do not necessarily indicate an order of importance, a number or a quantity. Similarly, the terms "one", "a" or "the" are not limited to refer to one instance only, but are intended to cover at least one. The terms "comprises", "comprising", "includes", "including" and the like are inclusive of the elements listed thereafter and equivalents thereof, and do not preclude other elements or steps. The terms "connected", "coupled" or "linked" are not limited to physical or mechanical connections or couplings, but also include electrical connections or couplings, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positions, and can change accordingly when the absolute positions of the described objects change.

[0042] In a double-side polishing process, a double-side polishing apparatus includes an upper platen and a lower platen arranged oppositely, wherein the upper platen is provided with an upper polishing pad on the side facing the lower platen, and the lower platen is provided with a lower polishing pad on the side facing the upper platen. In order to ensure that the polishing liquid can be uniformly and sufficiently transported to the entire polishing area and timely take away the polishing by-products, the surface of the upper polishing pad is usually designed with a precise groove structure (such as XY grid, concentric circle or spiral). Although these grooves optimize the fluid dynamics, they also bring an inherent disadvantage: in the process of assembling the upper polishing pad and the lower polishing pad, the upper polishing pad is first bonded to the upper platen by a glue layer, and the lower polishing pad is bonded to the lower platen by a glue layer, then pressure is applied to the upper platen and the lower platen to make them move towards each other, the upper polishing pad and the lower polishing pad are tightly attached under pressure, and the protruding part of the upper polishing pad exerts concentrated pressure on the lower polishing pad, while the pressure in the area corresponding to the groove is almost zero. This uneven pressure distribution will form a concave topography corresponding to the groove pattern of the upper polishing pad on the surface of the lower polishing pad, i.e. "lattice printing". When the surface of the lower polishing pad has such microscopic unevenness, the pressure exerted on the wafer during the subsequent polishing process will also be uneven. Especially in the edge region of the wafer, which is inherently less rigid, it is more sensitive to such pressure fluctuations, resulting in microscopic fluctuations in the material removal rate (MRR) in this region, and finally forming a flatness defect related to "lattice printing" that is difficult to eliminate in the edge of the wafer, seriously deteriorating the ZDD value.

[0043] Reference Figures 1-3To solve the above problems, the embodiment provides a method for improving flatness of a polishing pad, which is applied to a double-sided polishing device, the double-sided polishing device comprising an upper chuck plate 1 and a lower chuck plate 2 arranged oppositely, wherein one side of the upper chuck plate 1 is provided with an upper polishing pad 11 facing the lower chuck plate 2, and one side of the lower chuck plate 2 is provided with a lower polishing pad 21 facing the upper chuck plate 1, and the method for improving flatness of the polishing pad comprises the following steps:

[0044] Step S1: when the upper polishing pad 11 and the lower polishing pad 21 are pressed and attached, the upper polishing pad 11 and the lower polishing pad 21 are subjected to a rolling flattening treatment through a rolling structure arranged between the upper polishing pad 11 and the lower polishing pad 21.

[0045] In the related art, in order to ensure that the polishing liquid can be uniformly and sufficiently transported to the entire polishing area and the polishing by-products can be removed in time, the surface of the upper polishing pad 11 is usually designed with precise grooves 101, and the existence of the grooves 101 will cause the grid printing on the lower polishing pad 21, which affects the polishing quality. In order to solve this problem, in the embodiment, a rolling process is added to perform a rolling flattening treatment on the upper polishing pad 11 and the lower polishing pad 21, so as to eliminate the grid printing on the lower polishing pad 21 caused by the grooves 101 on the upper polishing pad 11, improve the overall flatness of the lower polishing pad 21, and further improve the surface flatness in the silicon wafer polishing process.

[0046] It should be noted that the unevenness of the polishing pad is not only caused by the above-mentioned grooves 101, but also may be affected by other factors, which means that there are many factors that cause the unevenness of the polishing pad, especially the unevenness of the lower polishing pad. Through the rolling process added in the embodiment, these problems can be effectively solved.

[0047] Reference Figure 7 In an exemplary embodiment, the step S1 specifically comprises:

[0048] Step S01: controlling the upper chuck plate 1 and the lower chuck plate 2 to move oppositely, so that the upper polishing pad 11 and the lower polishing pad 21 are clamped on the opposite sides of the rolling structure with a preset pressure;

[0049] Step S02: controlling the upper chuck plate 1 and the lower chuck plate 2 to rotate oppositely, so as to perform a rolling flattening treatment on the upper polishing pad 11 and the lower polishing pad 21.

[0050] That is, before the upper polishing pad 11 and the lower polishing pad 21 are pressed and fitted, the rolling structure (specifically, the plurality of rolling shafts 5 included in the rolling structure) is first placed between the upper polishing pad 11 and the lower polishing pad 21, and then the upper fixed disc 1 and the lower fixed disc 2 are controlled to move towards each other by a motor or the like driving structure, and the upper polishing pad 11 and the lower polishing pad 21 are stably clamped at a preset pressure on opposite sides of the rolling structure, so as to ensure the clamping stability and the uniformity of the subsequent rolling process; then the upper fixed disc 1 and the lower fixed disc 2 are controlled to rotate relatively by a motor or the like driving structure, so as to roll and flatten the upper polishing pad 11 and the lower polishing pad 21. During the relative rotation of the upper fixed disc 1 and the lower fixed disc 2, the friction generated between the upper polishing pad 11, the lower polishing pad 21 and the rolling shafts 5 of the rolling structure can drive the rolling shafts 5 in the rolling structure to rotate. In order to achieve the ideal rolling and flattening effect, the process needs to be maintained for a certain period of time (for example, 1-3 hours, but not limited thereto), until the process requirements are met.

[0051] It should be noted that when the upper fixed disc 1 and the lower fixed disc 2 rotate relatively, the rotation directions of the upper fixed disc 1 and the lower fixed disc 2 can be the same or opposite, as long as relative rotation is generated between the two. In some specific embodiments, in order to effectively drive the rotation of the rolling shafts 5 located between the upper polishing pad 11 and the lower polishing pad 21, the rotation directions of the upper fixed disc 1 and the lower fixed disc 2 are opposite.

[0052] In an exemplary embodiment, the preset pressure is 600-1200 DaN, but not limited thereto. The use of the above-mentioned preset pressure range can ensure the rolling effect, guarantee the flatness of the lower polishing pad 21, and avoid adverse effects on the grooves 101 on the upper polishing pad 11.

[0053] In an exemplary embodiment, the duration of the rolling process is 1-3 hours, so as to ensure the rolling effect, guarantee the fitting stability of the upper polishing pad 11 and the lower polishing pad 21, and guarantee the flatness of the lower polishing pad 21.

[0054] In an exemplary embodiment, the rolling structure includes a plurality of rolling shafts 5 uniformly distributed along the circumferential direction of the lower polishing pad 21, the axial direction of the rolling shafts 5 is parallel to the radial direction of the lower polishing pad 21, and the step S02 specifically includes:

[0055] The upper fixed disc 1 and the lower fixed disc 2 are controlled to rotate relatively at a speed of 1-5 rpm / min, so as to drive the rolling shafts 5 to rotate, and roll and flatten the surfaces of the upper polishing pad 11 and the lower polishing pad 21.

[0056] It should be noted that the number of the roller 5, the diameter of the roller 5 and other parameters can be flexibly set according to actual needs, for example, 3-5 rollers 5 can be provided (the number of the roller 5 is not limited to 4) Figure 3 The four rollers 5 are provided in the embodiment, but the number of the rollers 5 is not limited to four), and 3-5 rollers 5 are uniformly arranged between the upper polishing pad 11 and the lower polishing pad 21 along the circumferential direction of the lower polishing pad 21, so that the upper polishing pad 11 and the lower polishing pad 21 can be uniformly stressed when being pressed and attached on both sides of the roller 5, and the uniformity of the rolling process can be improved.

[0057] Referring to Figure 2 and Figure 3 In an exemplary embodiment, the lower platen 2 includes an inner pin ring 1001 and an outer pin ring 1002, the roller 5 is arranged between the inner pin ring 1001 and the outer pin ring 1002, and the roller 5 includes a first end and a second end arranged oppositely along the axial direction of the roller 5, the first end is in pressure connection with the inner pin ring 1001, and the second end is in pressure connection with the outer pin ring 1002.

[0058] It should be noted that Figure 3 The positional relationship between the roller 5 and the inner pin ring 1001 and the outer pin ring 1002 is shown in the embodiment, which is only a schematic diagram and is not a specific limitation on the structure of the inner pin ring 1001 and the outer pin ring 1002.

[0059] In order to ensure the flatness of the lower polishing pad 21, the rolling range of the roller 5 needs to completely cover the lower polishing pad 21, therefore, the length of the roller 5 can be determined according to the radial distance between the inner pin ring 1001 and the outer pin ring 1002, in the embodiment, the roller 5 includes a first end and a second end arranged oppositely along the axial direction of the roller 5, the first end is in pressure connection with the inner pin ring 1001, and the second end is in pressure connection with the outer pin ring 1002, which not only ensures that the roller 5 can roll and flatten the whole lower polishing pad 21, but also prevents the axial deviation of the roller 5, and plays a limiting and guiding role in the rolling path of the roller 5. In addition, the above technical solution also helps to improve the stability of the rolling process, reduce the risk of deformation of the polishing pad caused by uneven local pressure, improve the flatness of the lower polishing pad 21, and thus enhance the uniformity and consistency in the process of polishing the silicon wafer, thereby improving the overall quality of the polished surface of the silicon wafer.

[0060] In an exemplary embodiment, the end face of the first end is a curved surface matching the shape of the side face of the inner pin ring 1001, and the end face of the second end is a curved surface matching the shape of the side face of the outer pin ring 1002.

[0061] The technical scheme makes the contact between the first end of the roller 5 and the inner pin ring 1001 be surface contact, and the contact between the second end of the roller 5 and the outer pin ring 1002 be surface contact, ensures that the rolling path of the roller 5 is always accurately limited between the inner pin ring 1001 and the outer pin ring 1002, prevents deviation, and thus guarantees the consistency and repeatability of the rolling of the entire polishing pad surface. The curvature of the end face of the first end of the roller 5 matches the curvature of the side face of the inner pin ring 1001, and the curvature of the end face of the second end matches the curvature of the side face of the outer pin ring 1002, which increases the effective contact area between the roller 5 and the outer pin ring 1002 and the inner pin ring 1001, significantly reduces the local contact stress (pressure) in the rolling process, and thus reduces the wear of the inner pin ring 1001, the outer pin ring 1002 and the roller 5 itself, and improves the service life of the equipment.

[0062] In an exemplary embodiment, the length of the roller 5 is 70 cm, the diameter is 4 cm, and the contact area between the upper polishing pad 11 or the lower polishing pad 21 and the roller 5 is 70 cm 2 The upper platen 1 and the lower platen 2 rotate at a speed of 1-5 rpm / min to drive the roller 5 to rotate to roll the surface of the upper polishing pad 11 and the lower polishing pad 21. This ensures that the "lattice mark" of the lower polishing pad 21 is effectively eliminated while avoiding adverse effects on the groove 101 of the upper polishing pad 11.

[0063] In the above technical scheme, the method for improving the flatness of the polishing pad is to control the relative movement of the upper platen 1 and the lower platen 2, so that the roller 5 of the rolling structure is arranged between the upper polishing pad 11 and the lower polishing pad 21 before the upper polishing pad 11 and the lower polishing pad 21 are pressed and fitted with a predetermined pressure, and then the rolling process is performed, but it is not limited thereto. The roller 5 is detachably arranged between the upper polishing pad 11 and the lower polishing pad 21, that is, the roller 5 is detachable, especially after the upper polishing pad 11 and the lower polishing pad 21 are assembled, the roller 5 needs to be detached to avoid affecting the subsequent polishing process. The arrangement of the rolling structure including the roller 5 is to eliminate the lattice mark generated by the groove 101 on the upper polishing pad 11 on the lower polishing pad 21, so the roller 5 can be arranged between the upper polishing pad 11 and the lower polishing pad 21 according to actual needs in the corresponding process, as long as it does not affect the fitting and assembly of the upper polishing pad 11 and the lower polishing pad 21, and can achieve the effect of eliminating the lattice mark on the lower polishing pad 21 and improving the flatness of the lower polishing pad 21.

[0064] Reference Figure 8 In an exemplary embodiment, the step S1 specifically comprises:

[0065] Step S011: control the upper platen 1 and the lower platen 2 to move towards each other, so that the upper polishing pad 11 and the lower polishing pad 21 are pressed and attached with a preset pressure;

[0066] Step S012: control the upper platen 1 and the lower platen 2 to move away from each other, and place the rolling structure between the upper polishing pad 11 and the lower polishing pad 21;

[0067] Step S013: control the upper platen 1 and the lower platen 2 to move towards each other, so that the upper polishing pad 11 and the lower polishing pad 21 are clamped on opposite sides of the rolling structure with a preset pressure;

[0068] Step S014: control the upper platen 1 and the lower platen 2 to rotate relative to each other, so as to perform rolling flattening treatment on the upper polishing pad 11 and the lower polishing pad 21.

[0069] With the above scheme, after the upper polishing pad 11 and the lower polishing pad 21 are pressed and attached, and the lower polishing pad 21 produces a grid mark, the rolling process is used to perform rolling flattening treatment on the lower polishing pad 21 to eliminate the grid mark on the lower polishing pad 21.

[0070] In order to maintain the stability and repeatability of the polishing process, it is crucial to regularly clean the polishing pad online or offline to remove the polishing by-products and failed abrasive particles clogged in the pores of the polishing pad. High-pressure micro jet (HPMJ) is the current mainstream polishing pad cleaning technology. It sprays extremely high-pressure fine water columns through multiple nozzles 7 installed on the support rod 6, which impact the polishing pad surface to achieve physical cleaning. However, in the HPMJ process, the nozzle 7 model and the distance between it and the polishing pad are two key parameters that affect the impact force. The difference in impact force will directly act on the polishing pad, causing uneven micro-thickness on its surface under long-term action. This pad thickness difference will further be transmitted to the wafer, ultimately resulting in deterioration of the edge flatness index.

[0071] Figure 6 A comparison diagram of the ZDD value of a silicon wafer polished by a polishing equipment without a rolling process and the ZDD value of a silicon wafer polished by a polishing equipment with a rolling process. Figure 6The ZDD value of the silicon wafer polished by the polishing apparatus without the additional rolling process is -25.17, and the ZDD value of the silicon wafer polished by the polishing apparatus with the additional rolling process is -12.69. The ZDD value is obviously improved. After the additional rolling process, the flatness of the silicon wafer during polishing is improved.

[0072] Reference Figure 4 and Figure 5 To solve the above problems, the method for improving the flatness of the polishing pad in the embodiment further comprises:

[0073] S2: cleaning the upper polishing pad 11 and the lower polishing pad 21 by using a preset process condition, wherein the preset process condition comprises cleaning the upper polishing pad 11 and the lower polishing pad 21 by using a plurality of same nozzles 7.

[0074] In the embodiment, the plurality of nozzles 7 are used to clean the upper polishing pad 11 and the lower polishing pad 21, the types of the plurality of nozzles 7 are unified, that is, the difference in the impact force of the cleaning liquid sprayed by the different nozzles 7 on the polishing pad is reduced, thereby improving the flatness of the polishing pad and the flatness of the silicon wafer during polishing.

[0075] In an exemplary embodiment, in order to improve the consistency of the impact force of the plurality of nozzles 7 on the polishing pad during cleaning of the polishing pad, the plurality of nozzles 7 are of the same type, and the related parameters of the cleaning liquid sprayed by the plurality of nozzles 7 are set to be the same. The related parameters of the cleaning liquid sprayed by the plurality of nozzles 7 include the spraying angle of the nozzles 7, the spraying pressure of the nozzles 7, the distance between the outlet of the nozzles 7 and the surface of the lower polishing pad 21, and the like. In some embodiments, the preset process condition comprises that the spraying angle of the nozzles 7 is 35°-90°, the spraying pressure of the nozzles 7 is 50-70 Bar, and the distance between the outlet of the nozzles 7 and the surface of the lower polishing pad 21 is 15-25 mm.

[0076] In some specific embodiments, the spraying angle of the nozzles 7 can be 35 degrees, 45 degrees, 70 degrees, or 90 degrees, the spraying pressure of the nozzles 7 is 50 Bar, 60 Bar, or 70 Bar, and the distance between the outlet of the nozzles 7 and the surface of the lower polishing pad 21 is 15 cm, 20 cm, or 25 mm.

[0077] In the exemplary embodiment, the cleaning structure for cleaning the polishing pad includes a plurality of nozzles 7 of the same parameters arranged at equal intervals along the extension direction of a support rod 6, and when cleaning is performed, the polishing pad rotates and the support rod 6 moves to a preset position along the radial direction of the polishing pad to perform the cleaning work. Figure 4 In the exemplary embodiment, the rotating arrow 2001 represents the rotating direction of the polishing pad, and the straight arrow 2002 represents the moving direction of the support rod 6. The area of the cleaning liquid sprayed by the nozzles 7 presents a trapezoidal shape (refer to the trapezoidal shape 3001 in Figure 5 In the exemplary embodiment, the rotating arrow 2001 represents the rotating direction of the polishing pad, and the straight arrow 2002 represents the moving direction of the support rod 6. The area of the cleaning liquid sprayed by the nozzles 7 presents a trapezoidal shape (refer to the trapezoidal shape 3001 in

[0078] In the exemplary embodiment, the spraying coverage area of the nozzles 7 on the lower polishing pad 21 includes a middle area and an edge area located at the periphery of the middle area, and the edge area of adjacent nozzles 7 partially overlaps.

[0079] It should be noted that the method for improving the flatness of the polishing pad provided in the embodiment is executed by a control unit included in the polishing device and / or a control unit connected to the polishing device.

[0080] Reference Figure 2 The embodiment of the present application also provides a double-sided polishing device for implementing the method for improving the flatness of the polishing pad, and the double-sided polishing device includes oppositely arranged upper and lower platens 1 and 2, the upper platen 1 is provided with an upper polishing pad 11 on the side facing the lower platen 2, the lower platen 2 is provided with a lower polishing pad 21 on the side facing the upper platen 1, the upper polishing pad 11 is provided with a groove 101, and the double-sided polishing device further includes:

[0081] A rolling structure including a plurality of rollers 5 arranged between the upper polishing pad 11 and the lower polishing pad 21 to perform rolling flattening treatment on the upper polishing pad 11 and the lower polishing pad 21.

[0082] A first driving structure for driving at least one of the upper platen 1 and the lower platen 2 so that the upper platen 1 and the lower platen 2 move towards or away from each other.

[0083] A second driving structure for driving at least one of the upper platen 1 and the lower platen 2 so that the upper platen 1 and the lower platen 2 rotate relative to each other to drive the rollers 5 in the rolling structure to rotate.

[0084] The first driving structure can include a motor or a pneumatic structure. The upper platen 1 is connected with a first rotating shaft 3, and the lower platen 2 is connected with a second rotating shaft 4. The first driving structure controls the independent movement of the upper platen 1 and the lower platen 2. Figure 2 The yellow arrow 100 in FIG. 1 indicates the direction of the pressure applied to the upper platen 1 or the lower platen 2. The first driving structure can further include a pressure monitoring structure for monitoring the pressure received by the upper polishing pad 11, the lower polishing pad 21, or the roller 5, thereby avoiding adverse effects on the grooves 101 on the upper polishing pad 11 while ensuring the rolling effect.

[0085] The second driving structure can include a motor. The first driving structure controls the independent rotational movement of the upper platen 1 and the lower platen 2. The second driving structure can further include a speed adjusting structure to control the relative rotational speed of the upper platen 1 and the lower platen 2, so that the upper platen 1 and the lower platen 2 rotate relative to each other at a preset speed, thereby ensuring the rolling effect.

[0086] In an exemplary embodiment, a cleaning structure for cleaning the upper polishing pad 11 and / or the lower polishing pad 21 is further included, and the cleaning structure includes:

[0087] a spraying part including a plurality of identical nozzles 7;

[0088] a distance control part for controlling the distance between the plurality of nozzles 7 and the upper polishing pad 11 or the lower polishing pad 21 to be within a preset threshold.

[0089] The cleaning structure further includes a support rod 6, and a plurality of nozzles 7 identical in parameters are arranged at equal intervals on the support rod 6.

[0090] The cleaning structure further includes a third driving structure for driving the movement of the support rod 6 to control the movement of the support rod 6 to a preset position to clean the corresponding conductive polishing pad.

[0091] The cleaning structure further includes a liquid storage part for storing a cleaning liquid, which can be ultrapure water but is not limited thereto.

[0092] The cleaning structure can further include a connecting pipe arranged between the nozzles 7 and the liquid storage part, and a valve is arranged on the connecting pipe to control the flow rate of the corresponding nozzles 7.

[0093] The cleaning structure further includes a pump arranged between the nozzles 7 and the liquid storage part to adjust the pressure of the cleaning liquid sprayed by the nozzles 7.

[0094] The electronic device includes a memory, a processor, and one or more programs stored in the memory and executable on the processor. When the one or more programs are executed by the processor, the electronic device performs the method for improving flatness of a polishing pad.

[0095] The computer readable storage medium stores a computer program. When the computer program is executed by a processor, the steps in the method embodiments described above are implemented.

[0096] The display device can be a liquid crystal television, a liquid crystal display, a digital photo frame, a mobile phone, a tablet computer, or any product or component with a display function. The display device further includes a flexible circuit board, a printed circuit board, and a back plate.

[0097] The computer readable storage medium stores a computer program. When the computer program is executed by a processor, the steps in the method embodiments described above are implemented.

[0098] A person of ordinary skill in the art can understand that all or part of the processes in the above method embodiments can be completed through a computer program instructing related hardware. The computer program can be stored in a non-volatile computer readable storage medium. When the computer program is executed, the processes of the above method embodiments can be included. Any reference to a memory, storage, database, or other medium in the embodiments provided in the present application can include at least one of a non-volatile and volatile memory. The non-volatile memory can include a read-only memory (ROM), a magnetic tape, a floppy disk, a flash memory, or an optical memory. The volatile memory can include a random access memory (RAM) or an external cache memory. As an illustration but not limitation, the RAM can be in various forms, such as a static random access memory (SRAM) or a dynamic random access memory (DRAM).

[0099] The following points need to be explained:

[0100] (1) The drawings of the embodiments of the present disclosure only involve the structures related to the embodiments of the present disclosure, and other structures can be referred to the general design.

[0101] (2) In the drawings used to describe and identify embodiments of the present disclosure, the thickness and / or size of the layers, regions, or elements can be exaggerated or reduced for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "under" another element, it can be "directly" on or under the other element or intervening elements can also be present.

[0102] (3) Embodiments of the present disclosure and features in embodiments can be combined if they do not conflict with each other.

[0103] It can be understood that the above implementation is only an exemplary implementation adopted for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. A method for improving the flatness of a polishing pad, applied to a double-sided polishing device, the double-sided polishing device comprising an upper fixed plate and a lower fixed plate disposed opposite to each other, an upper polishing pad being disposed on the side of the upper fixed plate facing the lower fixed plate, and a lower polishing pad being disposed on the side of the lower fixed plate facing the upper fixed plate, characterized in that, The method for improving the flatness of the polishing pad includes the following steps: Step S1: When the upper polishing pad and the lower polishing pad are pressed together, the upper polishing pad and the lower polishing pad are rolled and leveled by a rolling structure disposed between the upper polishing pad and the lower polishing pad.

2. The method for improving the flatness of a polishing pad according to claim 1, characterized in that, Step S1 specifically includes: Step S01: Control the upper fixed plate and the lower fixed plate to move towards each other, so that the upper polishing pad and the lower polishing pad are clamped on opposite sides of the rolling structure with a preset pressure; Step S02: Control the upper fixed plate and the lower fixed plate to rotate relative to each other, so as to perform rolling and leveling treatment on the upper polishing pad and the lower polishing pad.

3. The method for improving the flatness of a polishing pad according to claim 2, characterized in that, The preset pressure is 600-1200 DaN.

4. The method for improving the flatness of a polishing pad according to claim 2, characterized in that, The rolling structure includes a plurality of rollers evenly distributed along the circumferential direction of the lower polishing pad, and step S02 specifically includes: The upper and lower fixed plates are controlled to rotate relative to each other at a speed of 1-5 rpm / min, so as to drive the roller to rotate and roll the surfaces of the upper and lower polishing pads.

5. The method for improving the flatness of a polishing pad according to claim 4, characterized in that, The lower plate includes an inner pin ring and an outer pin ring. The roller is disposed between the inner pin ring and the outer pin ring, and the roller includes a first end and a second end disposed opposite to each other along its axial direction. The first end is pressed against the inner pin ring, and the second end is pressed against the outer pin ring.

6. The method for improving the flatness of a polishing pad according to claim 5, characterized in that, The end face of the first end is a curved surface that matches the shape of the side surface of the inner pin ring, and the end face of the second end is a curved surface that matches the shape of the side surface of the outer pin ring.

7. The method for improving the flatness of a polishing pad according to claim 1, characterized in that, Also includes: Step S2: Clean the upper polishing pad and the lower polishing pad using preset process conditions, the preset process conditions including using multiple identical nozzles to clean the upper polishing pad and the lower polishing pad.

8. The method for improving the flatness of a polishing pad according to claim 7, characterized in that, The preset process conditions include: the spray angle of the nozzle is 35°-90°; the spray pressure of the nozzle is 50-70 Bar; and the vertical distance between the nozzle outlet and the surface of the lower polishing pad or the surface of the lower polishing pad is 15-25 mm.

9. The method for improving the flatness of a polishing pad according to claim 1, characterized in that, Step S1 specifically includes: Step S011: Control the upper fixed plate and the lower fixed plate to move towards each other, so that the upper polishing pad and the lower polishing pad are pressed together with a preset pressure; Step S012: Control the upper fixed plate and the lower fixed plate to move in opposite directions, and place the rolling structure between the upper polishing pad and the lower polishing pad; Step S013: Control the upper fixed plate and the lower fixed plate to move towards each other, so that the upper polishing pad and the lower polishing pad are clamped on opposite sides of the rolling structure with a preset pressure; Step S014: Control the upper fixed plate and the lower fixed plate to rotate relative to each other, so as to perform rolling and leveling treatment on the upper polishing pad and the lower polishing pad.

10. A double-sided polishing apparatus for implementing the method for improving the flatness of a polishing pad as described in any one of claims 1-9, the double-sided polishing apparatus comprising an upper fixed plate and a lower fixed plate disposed opposite to each other, an upper polishing pad being disposed on the side of the upper fixed plate facing the lower fixed plate, and a lower polishing pad being disposed on the side of the lower fixed plate facing the upper fixed plate, the upper polishing pad being provided with grooves, characterized in that, Also includes: The rolling structure includes a plurality of rollers disposed between the upper polishing pad and the lower polishing pad to perform rolling and leveling treatment on the upper polishing pad and the lower polishing pad; A first driving structure is used to drive at least one of the upper fixed plate and the lower fixed plate, so that the upper fixed plate and the lower fixed plate move towards each other or away from each other; The second driving structure is used to drive at least one of the upper fixed plate and the lower fixed plate, so that the upper fixed plate and the lower fixed plate rotate relative to each other, thereby driving the roller in the rolling structure to rotate.

11. The double-sided polishing equipment according to claim 10, characterized in that, It also includes a cleaning structure for cleaning the upper polishing pad and / or the lower polishing pad, the cleaning structure comprising: The injection section includes multiple identical nozzles; The distance control unit is used to control the distance between the multiple nozzles and the upper polishing pad or the lower polishing pad to be within a preset threshold.

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