Grinding system and equipment and wafer cleaning method

Abstract

The invention discloses a grinding system, equipment and a wafer cleaning method.The grinding system comprises a first grinding device, a second grinding device and a pre-cleaning device, the first grinding device is used for conducting first grinding on a wafer, and the second grinding device is used for conducting second grinding on the wafer; the pre-cleaning device is used for pre-cleaning the wafer after the first grinding of the wafer is completed and before the second grinding is started. According to the grinding system, the possibility of pollutant residues and scratches caused by drying of the surface of the ground wafer can be reduced, the cleaning time of the cleaning system can be shortened, and the overall productivity of grinding equipment is improved.

Description

Technical Field

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

[0002] Chemical mechanical polishing (CMP) is a key process for planarizing wafer surfaces in integrated circuit manufacturing. As the integration level of integrated circuit manufacturing processes increases and critical dimensions shrink, CMP becomes increasingly important.

[0003] In CMP (Chemical Metal Processing), wafers are polished multiple times using a series of polishing units within a polishing machine. The cleaning system within the polishing machine then cleans the wafer surface to remove residues generated during the polishing process. However, if a subsequent polishing unit does not promptly perform a second polishing process after the previous unit has finished polishing the wafer, the wafer surface is susceptible to damage from contaminants such as chemicals and polishing byproducts left over from the previous unit, thus affecting wafer yield. Summary of the Invention

[0004] This application provides a grinding system, equipment, and wafer cleaning method to reduce the possibility of residual contaminants damaging the wafer surface during wafer processing using a grinding process with multiple grinding steps, thereby improving wafer yield.

[0005] In a first aspect, this application provides a polishing system, including a first polishing apparatus, a second polishing apparatus, and a pre-cleaning apparatus. The first polishing apparatus is used to perform a first polishing on a wafer, the second polishing apparatus is used to perform a second polishing on the wafer, and the pre-cleaning apparatus is used to pre-clean the wafer after the first polishing is completed and before the second polishing begins.

[0006] With the above technical solution, after the first grinding device grinds the wafer and before the second grinding device grinds the wafer a second time, the pre-cleaning device can clean the wafer that has completed the first grinding in a timely manner. Therefore, even if the second grinding device cannot grind the wafer that has completed the first grinding in a timely manner, the pre-cleaning device can pre-clean the chemical agents and by-products left on the wafer surface after the first grinding, reducing the possibility of the wafer surface being damaged by contaminants such as residual chemical agents and grinding by-products. In addition, when the subsequent grinding device continues to grind the pre-cleaned wafer surface, it can also reduce the possibility of wafer surface scratches caused by residual contaminants on the wafer surface, thereby improving the wafer yield.

[0007] Furthermore, the grinding system of this application adds a pre-cleaning device between the first grinding device and the second grinding device, so that the wafer surface is pre-cleaned during the grinding stage. Therefore, the grinding system of this application can alleviate the cleaning pressure of the cleaning system used for the final cleaning of the ground wafer in the grinding equipment. On the one hand, it can reduce the situation where the grinding process capacity is limited by the cleaning system when the load of the cleaning system is increasing. On the other hand, it can reduce the cleaning time of the cleaning system on the wafer, so that the cleaning system can complete the wafer cleaning in a shorter time and improve the overall capacity of the grinding equipment.

[0008] Furthermore, the polishing system provided in the first aspect of this application also includes a carrier device for carrying the wafer and pre-wetting the wafer. A pre-cleaning device is integrated above the carrier device, and when the wafer moves above the carrier device, it is pre-cleaned. Since the carrier device is an existing structure in related polishing systems, this arrangement allows the polishing system of this application to achieve dual functions of wafer pre-wetting and wafer pre-cleaning through the cooperation of the carrier device and the pre-cleaning device, thereby reducing the difficulty of modifying related polishing equipment.

[0009] Secondly, this application also provides a wafer cleaning method, comprising:

[0010] Provide wafers;

[0011] The wafer is first polished;

[0012] The wafer after the first grinding is pre-cleaned;

[0013] The pre-cleaned wafer is then subjected to a second grinding process.

[0014] The beneficial effects of the second aspect of this application can be referred to the beneficial effects of the first aspect, and will not be repeated here.

[0015] Furthermore, the wafer cleaning method utilizes the polishing system provided in the first aspect of this application. The polishing system includes a carrier device, a first polishing device, a second polishing device, and a pre-cleaning device, with the pre-cleaning device integrated above the carrier device. The wafer cleaning method includes:

[0016] A wafer is provided, which is placed above the carrier device;

[0017] The wafer is pre-cleaned using the carrier device.

[0018] The wafer is first polished using the first polishing device;

[0019] The pre-cleaning device is used to pre-clean the wafer after the first grinding.

[0020] The pre-cleaned wafer is then subjected to a second grinding process using the second grinding device.

[0021] Thirdly, this application also provides a grinding apparatus, including a cleaning system, a transfer system, and the grinding system described in the first aspect of this application.

[0022] The beneficial effects of the third aspect of this application can be referred to the beneficial effects of the first aspect, and will not be repeated here. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 A schematic diagram of the structure of the grinding equipment of the related technology is shown;

[0025] Figure 2 A schematic diagram of a grinding apparatus according to an embodiment of this application is shown;

[0026] Figure 3 A schematic diagram of abnormal scratches on the polished surface of a wafer is shown in the relevant technology;

[0027] Figure 4 A schematic diagram of the structure of a cleaning system according to an exemplary embodiment of this application is shown;

[0028] Figure 5 A schematic diagram illustrating the abnormal contaminant residue on the polished surface of a wafer in related technologies is shown.

[0029] Figure 6 A schematic diagram illustrating the structural principle of a grinding system according to an embodiment of this application is shown;

[0030] Figure 7 A schematic diagram of the basic structure of the pre-cleaning device according to an embodiment of this application is shown;

[0031] Figure 8 A schematic diagram of the honeycomb-shaped arrangement of nozzles according to an embodiment of this application is shown;

[0032] Figure 9 A schematic diagram of a possible structure of the pre-cleaning device according to an embodiment of this application is shown;

[0033] Figure 10A This diagram illustrates the usage state of the pre-cleaning device according to an embodiment of the present application in the first stage.

[0034] Figure 10BThis illustration shows a schematic diagram of the pre-cleaning device in the second stage of use according to an embodiment of this application.

[0035] Figure 10C This diagram illustrates the usage status of the pre-cleaning device according to an embodiment of this application in the third stage;

[0036] Figure 11 A schematic flowchart of a wafer cleaning method according to an embodiment of this application is shown;

[0037] Figure 12 A schematic diagram of another grinding system according to an embodiment of this application is shown;

[0038] Figures 13A-13D This paper illustrates four stages of the wafer cleaning process using a grinding system according to an embodiment of the present application.

[0039] Figure 14 A schematic diagram of a supporting device according to an embodiment of this application is shown;

[0040] Figure 15 A schematic diagram of the structure of another grinding system according to an embodiment of this application is shown;

[0041] Figure 16 A schematic flowchart of another wafer cleaning method according to an embodiment of this application is shown. Detailed Implementation

[0042] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0043] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0044] In the embodiments of this application, directional terms such as "up," "down," "left," and "right" may be defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms can be relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0045] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "electrical connection" can be a direct electrical connection or an indirect electrical connection through an intermediate medium. The term "contact" can be direct contact or indirect contact through an intermediate medium.

[0046] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0047] It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0048] This application provides a polishing apparatus that can not only polish the wafer surface but also reduce various defects caused by polishing byproducts (contaminants) remaining on the wafer surface, thereby ensuring wafer yield. It should be understood that the polishing apparatus in this application can be any polishing system implementing the technical solution of this application. The polishing principles of these apparatuses may be conventional mechanical polishing, chemical mechanical polishing, etc., but are not limited to these.

[0049] Figure 1 A schematic diagram of the structure of a grinding device related to the technology is shown. For example... Figure 1 As shown, the grinding apparatus 100 of the exemplary embodiments of this disclosure may include a grinding system 101 and a cleaning system 102. The grinding system 101 can grind the wafer surface to achieve planarization, while the cleaning system 102 can clean the ground wafer surface to remove grinding byproducts and other residues.

[0050] The polishing system of this application embodiment may include one polishing device or multiple polishing devices, which may be connected in series or in parallel. When multiple polishing devices are connected in series, they can polish the wafer surface in sequence; when multiple polishing devices are connected in parallel, they can polish different wafer surfaces in parallel, where each polishing device polishes a different wafer.

[0051] When multiple grinding devices are connected in series, their arrangement can be customized according to the actual situation, for example: Figure 1 As shown, the grinding system 101 includes four grinding units connected in series, arranged in a 2×2 configuration. It should be understood that... Figure 1 The layout of the four grinding devices shown is not limited to... Figure 1 As shown, other possible methods can also be used. For example, when the four grinding devices are the first grinding device 101A, the second grinding device 101B, the third grinding device 101C, and the fourth grinding device 101D, they can be arranged in a 2×2 manner.

[0052] Figure 2 A schematic diagram of a grinding apparatus according to an embodiment of this application is shown. Figure 2 As shown, the polishing apparatus 200 of this application embodiment may include a polishing disc 201, a polishing head 202, and a load cup 203, etc. The load cup 203 may be located on one side of the polishing disc 201 and is used to support the wafer. The polishing disc 201 may include a turntable and a polishing pad disposed on the turntable. The end face of the polishing head 202 may fix the wafer by snapping, adsorption, or other means, and ensure that the surface of the wafer is opposite to the surface of the polishing pad.

[0053] like Figure 2 As shown, when the polishing apparatus 200 polishes a wafer, the wafer can first be placed on the bearing surface of the carrier 203, ensuring that the wafer surface is opposite to the bearing surface of the carrier 203. In this case, the carrier 203 can also spray a wetting liquid onto the wafer surface to facilitate the polishing operation of the polishing pad on the wafer surface. After the wafer surface is wetted, the wafer can be fixed on the end face of the polishing head 202. The polishing head 202 can move in both horizontal and vertical directions. Therefore, the end face of the polishing head 202 can be used to transfer the wafer above the polishing pad and perform a descent operation, so that the wafer surface contacts the surface of the polishing pad. The polishing head 202 also has a rotation function. When the turntable drives the polishing pad to rotate and polish the wafer surface, the polishing head 202 can also drive the wafer to rotate and move, so that the wafer and the polishing pad rotate and move relative to each other, thereby using the polishing pad to polish the wafer surface.

[0054] like Figure 2As shown, the polishing apparatus 200 of this embodiment may further include a polishing slurry nozzle 204. The polishing slurry nozzle 204 can introduce polishing slurry into the polishing pad, so that while the polishing pad polishes the wafer surface, the polishing slurry can contact the wafer surface through the polishing pad, allowing the polishing slurry to chemically react with the wafer surface material, thereby forming an easily removable surface layer on the wafer surface. This surface layer is then removed by polishing with the polishing pad. Additionally, the polishing apparatus 200 of this embodiment may further include a dresser 205, which can be used to maintain a certain roughness on the surface of the polishing pad to ensure the polishing effect on the wafer.

[0055] To facilitate wafer transfer, such as Figure 1 As shown, the grinding apparatus 100 in this application embodiment may further include a transfer system, which can be used to transfer the wafers ground by the grinding apparatus from the grinding system 101 to the cleaning system 102, or, in the case of multiple grinding apparatuses connected in series, transfer the wafers between different grinding apparatuses.

[0056] like Figure 1 As shown, the transfer system of this exemplary embodiment includes a transfer rail 1031, a grinding transfer robot, and a cleaning transfer robot (not shown). The number of grinding transfer robots can be one or more. When the grinding system 101 includes four grinding devices, if the four grinding devices are connected in parallel, the number of grinding transfer robots can be two, namely a first grinding transfer robot 1032A and a second grinding transfer robot 1032B.

[0057] like Figure 1 As shown, the first grinding and transfer robot 1032A can be disposed between the first grinding device 101A and the second grinding device 101B, for transferring the wafers ground by the first grinding device 101A to the second grinding device 101B, and transferring the wafers ground by the second grinding device 101B to the transfer guide rail 1031. The first grinding device 101A and the second grinding device 101B are disposed on the first side of the transfer guide rail 1031, while the third grinding device 101C and the fourth grinding device 101D are disposed on the second side of the transfer guide rail 1031.

[0058] like Figure 1As shown, the second grinding transfer robot 1032B can be located between the third grinding device 101C and the fourth grinding device 101D. It is used to transfer the wafers ground by the second grinding device 101B from the transfer rail 1031 to the third grinding device 101C, and can also transfer the wafers ground by the third grinding device 101C to the fourth grinding device 101D, and can also transfer the wafers ground by the fourth grinding device 101D to the transfer rail 1031, so that the transfer rail 1031 can transfer the wafers ground by the fourth grinding device 101D to the cleaning system 102.

[0059] After the current grinding device completes wafer grinding, the grinding head can transfer the wafer to the carrier device, and then the grinding transfer robot will transfer the wafer to the carrier device of the next grinding device or to the transfer guide 1031. For example: Figure 1 As shown, after the first grinding device 101A completes grinding the wafer, the grinding head of the first grinding device 101A can place the wafer on the carrier included in the first grinding device 101A. The first grinding transfer robot 1032A can pick up the wafer from the carrier included in the first grinding device 101A and then transfer it to the carrier surface of the carrier included in the second grinding device 101B. For example, after the second grinding device 101B completes grinding the wafer, the wafer can be placed on the carrier included in the second grinding device 101B. The second grinding transfer robot 1032B can pick up the wafer from the carrier included in the second grinding device 101B and then transfer it to the transfer guide rail 1031.

[0060] In some polishing processes, the same wafer needs to undergo multiple polishing processes. These processes can be performed on different polishing machines or on multiple polishing units within a single polishing machine. When a wafer needs to undergo multiple polishing processes within a single machine, it first completes the first polishing process on one polishing unit before moving on to the next unit for the second polishing process. When multiple polishing units are used in series, if the next polishing unit is busy or experiencing other abnormalities while the current unit is finishing polishing the wafer (e.g., uneven polishing time distribution between polishing pads, with the current unit's polishing time being shorter and the next unit's polishing time being longer), the next polishing unit may be unable to properly perform the next polishing operation on the wafer held by the polishing head of the current unit. In this situation, the grinding head and the wafer it is fixed to in the current grinding apparatus spin idly, and the moisture (or other liquid) on the wafer surface gradually evaporates until it dries out. This results in chemical agents and grinding byproducts remaining on the wafer surface. Therefore, when the next grinding apparatus grinds the wafer currently being ground, the grinding byproducts and other contaminants remaining on the wafer surface can easily cause damage during the grinding process of the grinding disc in the next grinding apparatus. Figure 3 The scratches and other abnormalities indicated by the middle arrow affect the wafer yield. Figure 4 A schematic diagram of the cleaning system according to an exemplary embodiment of this application is shown. Figure 4 As shown, the cleaning system 400 of this application embodiment may include an ultrasonic cleaning device 401, a brushing device 402, a drying device 403, and a film output device 404. It should be understood that the number of these devices may be one or two. Figure 4 The brushing device 402 shown includes two pairs of roller brushes 402A and 402B, but it can also be one pair or more pairs of roller brushes, which is not further limited here.

[0061] As integrated circuit manufacturing nodes advance, the requirements for defects after CMP (Chemical Mechanical Polishing) become increasingly stringent, placing a greater burden on the cleaning systems of polishing equipment. This leads to CMP capacity being limited by the cleaning process. For example, after the polishing system completes wafer polishing, the wafer needs to be cleaned in the cleaning system. However, due to the high load on the cleaning system, it may not be able to clean the wafer in time. Therefore, the wafer may need to wait for a period of time before being cleaned by the cleaning system. During this waiting period, the moisture (or other liquids) on the wafer surface gradually evaporates until it dries, leaving chemical agents and polishing byproducts on the wafer surface. In this situation, when the cleaning system cleans the wafer under the original conditions, it cannot achieve the expected cleaning effect, resulting in defects such as… Figure 5The arrows indicate contaminant residues (mainly organic matter and other grinding byproducts) and other defects that affect wafer yield.

[0062] To overcome the above problems, this application provides a grinding system that can pre-clean the wafer after grinding, thereby reducing the problem of residual contaminants such as chemical agents and grinding by-products caused by the drying of the wafer surface, reducing the possibility of defects in the wafer in the next grinding process, thereby improving the wafer yield, and also reducing the situation where the grinding process capacity is limited by the cleaning system, thus improving the overall capacity of the grinding equipment.

[0063] Figure 6 A schematic diagram illustrating the structural principle of a grinding system according to an embodiment of this application is shown. Figure 6 As shown, the polishing system 600 of this application embodiment may include a first polishing device 601A, a second polishing device 601B, and a pre-cleaning device 602. The first polishing device 601A is used to perform a first polishing on the wafer, the second polishing device 601B is used to perform a second polishing on the wafer, and the pre-cleaning device 602 is used to pre-clean the wafer after the first polishing is completed and before the second polishing begins.

[0064] In practical applications, after the first polishing device 601A polishes the wafer and before the second polishing device 601B polishes it a second time, the pre-cleaning device 602 can promptly pre-clean the wafer that has completed the first polishing. Therefore, if the second polishing device 601B is unable to clean the wafer that has completed the first polishing in time due to polishing other wafers or other reasons, the pre-cleaning device 602 can pre-clean the wafer surface, reducing the possibility of the wafer surface being damaged by contaminants such as residual chemicals and polishing byproducts. In this case, if the second polishing device 601B continues to polish the pre-cleaned wafer surface, it can also reduce the possibility of wafer surface scratches caused by residual contaminants, thereby improving wafer yield.

[0065] For example, such as Figure 6 As shown, the first grinding apparatus 601A and the second grinding apparatus 601B of this application embodiment can be referred to Figure 2 The described grinding apparatus. After the first grinding apparatus 601A performs a first grinding on the wafer, the grinding head included in the first grinding apparatus 601A ( Figure 6 (Not shown) The wafer can be moved to the area where the pre-cleaning device 602 is located, and then the pre-cleaning device 602 pre-cleans the wafer that has completed the first grinding. Then, the grinding transfer robot transfers the wafer that has completed the first grinding to the carrier device included in the second grinding device 601B, so that the second grinding device 601B begins to perform the second grinding on the wafer that has completed the first grinding.

[0066] Moreover, such as Figure 6 As shown, the polishing system 600 of this application embodiment adds a pre-cleaning device 602 between the first polishing apparatus 601A and the second polishing apparatus 601B, so that the wafer surface is pre-cleaned during the polishing stage. Therefore, the polishing system 600 of this application embodiment can alleviate the cleaning pressure of the cleaning system used for the final cleaning of the polished wafer in the polishing equipment. On the one hand, it can reduce the situation where the cleaning system is limited by the polishing process capacity when the load of the cleaning system is increasing. On the other hand, it can reduce the cleaning time of the cleaning system on the wafer, so that the cleaning system can complete the wafer cleaning in a shorter time and improve the overall capacity of the polishing equipment.

[0067] As one possible implementation, such as Figure 6 As shown, the pre-cleaning device 602 of this application embodiment may include a mechanical swing arm 6021 and a cleaning component 6022. The cleaning component 6022 is disposed at one end of the mechanical swing arm 6021, which is used to move the cleaning component 6022 to the wafer surface. When it is necessary to clean the wafer surface after the first grinding, the mechanical swing arm 6021 can move the cleaning component 6022 until the cleaning component 6022 contacts the wafer surface. At this time, the mechanical swing arm 6021 can swing the cleaning component 6022 along the wafer surface to clean the wafer surface, thereby reducing the possibility of contaminants such as chemical agents and grinding byproducts remaining on the wafer surface.

[0068] Figure 7 A schematic diagram of the basic structure of the pre-cleaning device according to an embodiment of this application is shown. Figure 7 As shown, the cleaning component 6022 in this embodiment may include a base 6022A and an elastic portion 6022B and a first nozzle 6022C respectively disposed on the base 6022A. At this time, during the process of the mechanical swing arm 6021 driving the base 6022A to swing along the wafer surface, the elastic portion 6022B and the first nozzle 6022C may also be driven to swing along the wafer surface.

[0069] like Figure 7As shown, the first nozzle 6022C is used to spray the first cleaning fluid onto the wafer. The elastic part 6022B is used to contact the wafer surface to pre-clean it. In this case, when the mechanical arm 6021 drives the first nozzle 6022C to swing along the wafer surface, the first nozzle 6022C can spray the first cleaning fluid onto the wafer surface to rinse and wet various areas of the wafer surface, making it easier to remove contaminants such as chemicals and grinding byproducts from the wafer surface. In this case, when the mechanical arm 6021 drives the elastic part 6022B, which is in contact with the wafer surface, to swing along the wafer surface, the elastic part 6022B can more easily remove contaminants such as chemicals and grinding byproducts from the wafer surface by friction, thereby shortening the cleaning time of the elastic part 6022B on the wafer surface and reducing the wafer surface scratches that may be caused by excessive friction time between the elastic part 6022B and the wafer surface.

[0070] Moreover, such as Figure 7 As shown, when the elastic portion 6022B of this embodiment comes into contact with the wafer surface, the elastic portion 6022B can utilize its own elasticity to ensure that the friction between the elastic portion 6022B and the wafer surface exists in the form of soft friction, thereby reducing the possibility of scratches caused to the wafer surface during the friction process. For example, the elastic portion 6022B of this embodiment includes brush bristles or a sponge block. When the elastic portion 6022B is a sponge block, the sponge block is densely covered with tiny pores, which have extremely strong adsorption properties. During the friction process between the elastic portion 6022B and the wafer surface, contaminants such as chemical agents and grinding byproducts that detach from the wafer surface can be quickly captured and adsorbed by the elastic portion 6022B, thereby improving the cleaning ability of the elastic portion 6022B.

[0071] And, as Figure 7 As shown, the wafer surface exerts a certain squeezing effect on the cleaning component 6022, causing the cleaning component 6022 to contract under its own elasticity, thereby quickly discharging the first cleaning fluid contaminated with pollutants from the porous structure. Then, it falls off under the action of gravity, thereby achieving the purpose of fluid discharge, reducing the accumulation of the first cleaning fluid contaminated with pollutants in the cleaning component 6022, and reducing secondary contamination of the wafer surface.

[0072] In practical applications, the shape of the elastic part in the embodiments of this application can be various regular shapes, such as cuboids, cubes, cylinders, etc., or it can be an irregular shape. The material of the elastic part is not limited to polyurethane, rubber, fiber, etc., but can also be other materials with cleaning function.

[0073] like Figure 7As shown, the aforementioned elastic part 6022B is a consumable and can be installed on the base 6022A by snap-fitting, adhesive, or other methods. For example, the base 6022A can be on a mechanical mounting bracket. Of course, the elastic part 6022B can also be attached to the base 6022A using various adhesives such as self-adhesive. When it is necessary to replace the elastic part 6022B, it can be directly removed from the mechanical swing arm 6021, and a new elastic part 6022B can be installed on the base 6022A.

[0074] In some embodiments, such as Figure 7 As shown, the elastic part 6022B of this application embodiment has a fluid diffusion cavity and a plurality of nozzles for ejecting cleaning fluid. The fluid diffusion cavity is connected to each nozzle, and the orifice of each nozzle can be located on the surface of the elastic part for contacting the wafer.

[0075] like Figure 7 As shown, the fluid diffusion chamber and each nozzle constitute the first nozzle 6022C. In this case, the fluid diffusion chamber can be regarded as the main channel of the first cleaning fluid, which is used to distribute the first cleaning fluid to each nozzle, so that the first cleaning fluid can be sprayed out from the cleaning surface of the cleaning member 6022 through multiple paths. Here, the orifice 6022D of the multiple nozzles of the elastic part 6022B in this embodiment can be adopted Figure 8 The honeycomb arrangement shown can also be a dot matrix arrangement, but it is not limited to this.

[0076] In some embodiments, such as Figure 7 As shown, the elastic part 6022B also has a fluid discharge structure. Figure 7 (Not shown), this fluid outlet structure is used to outlet the first cleaning fluid that enters the elastic part 6022B. For example, the elastic part 6022B has a porous structure, which can be used as a fluid outlet structure. When the first cleaning fluid contaminated with contaminants falls onto the cleaning component 6022 under the action of gravity, the first cleaning fluid contaminated with contaminants can enter the porous structure of the elastic part 6022B. When the elastic part 6022B cleans the wafer surface, the elastic part 6022B rubs against the wafer surface. On the one hand, chemical agents and grinding byproducts that detach from the wafer surface can be quickly captured and adsorbed by the elastic part 6022B, thereby improving the cleaning ability of the elastic part 6022B. On the other hand, the wafer surface has a certain squeezing effect on the cleaning component 6022, causing the cleaning component 6022 to contract under its own elasticity, thereby quickly discharging the first cleaning fluid contaminated with contaminants from the porous structure. Then, it falls under the action of gravity, thereby achieving the purpose of fluid outlet, reducing the accumulation of the first cleaning fluid contaminated with contaminants in the cleaning component 6022, and reducing secondary contamination of the wafer surface.

[0077] In some embodiments, such as Figure 7As shown, the elastic part 6022B has at least one through hole ( Figure 7 (Not shown in the image), the angle between the axial direction of each through-hole and the cleaning surface of the cleaning component 6022 is greater than a first preset angle and less than or equal to 90°. When the first cleaning fluid contaminated with contaminants falls onto the cleaning component 6022 under the action of gravity, the first cleaning fluid contaminated with contaminants can enter the through-hole from one end and then be easily discharged from the other end under the action of gravity, thereby achieving the purpose of discharging the first cleaning fluid contaminated with contaminants, reducing the accumulation of the first cleaning fluid contaminated with contaminants in the cleaning component 6022, and reducing secondary contamination of the wafer surface.

[0078] In one alternative approach, such as Figure 7 As shown, the pre-cleaning device in this embodiment further includes a second nozzle 6023 disposed on the mechanical arm 6021. The number of second nozzles 6023 can be one or more. The second nozzle 6023 is used to spray a second cleaning fluid onto the mechanical arm 6021. Considering that when the first nozzle 6022C sprays the first cleaning fluid onto the wafer surface, the first cleaning fluid, contaminated with chemical agents and grinding byproducts, falls downwards under gravity, causing the mechanical arm 6021 to become contaminated with the first cleaning fluid containing chemical agents, grinding byproducts, and even grinding fluid, the second nozzle 6023 can be used to spray the second cleaning fluid onto the mechanical arm 6021 to clean the mechanical arm 6021, reducing secondary contamination of the wafer surface caused by contaminants on the mechanical arm 6021.

[0079] like Figure 7 As shown, the second nozzle 6023 in this embodiment can also spray a second cleaning solution onto the wafer surface. In this case, the second cleaning solution sprayed from the second nozzle 6023 can also achieve the purpose of wetting and cleaning the wafer surface, thereby further improving the pre-cleaning capability of the pre-cleaning device.

[0080] like Figure 7 As shown, when the swing plane of the mechanical arm 6021 is parallel to the wafer surface, multiple second nozzles 6023 are positioned on the mechanical arm 6021 along its arm direction. In this case, the multiple second nozzles 6023 are essentially distributed along the radial direction of the wafer surface. During the swinging process of the mechanical arm 6021, the multiple second nozzles 6023 can not only clean the mechanical arm 6021, but also simultaneously rinse and wet different areas of the wafer surface, thereby improving the pre-cleaning quality.

[0081] In practical applications, such as Figure 7As shown, in this embodiment of the application, the nozzle of each second nozzle 6023 can be located on the mechanical arm 6021 near the cleaning surface of the cleaning component 6022. For example, each second nozzle 6023 and the cleaning component 6022 are located on the same side of the mechanical arm 6021. In this case, the second cleaning fluid sprayed by each second nozzle 6023 can not only clean the mechanical arm 6021 and reduce secondary contamination of the wafer surface by the mechanical arm 6021, but also further rinse and wet the wafer surface, thereby further improving the pre-cleaning capability of the subsequent cleaning component 6022 on the wafer surface and ensuring wafer yield.

[0082] like Figure 7 As shown, to facilitate the supply of cleaning fluid to the first nozzle 6022C and the second nozzle 6023, the pre-cleaning device in this embodiment further includes a fluid supply pipe 6024, through which both the first nozzle 6022C and the second nozzle 6023 are connected. In this case, the fluid supply pipe 6024 can simultaneously supply cleaning fluid to both the first nozzle 6022C and the second nozzle 6023, making the first cleaning fluid ejected from the first nozzle 6022C and the second cleaning fluid ejected from the second nozzle 6023 the same. In other embodiments, the fluid supply pipes 6024 can also be independently configured, communicating with both the first nozzle 6022C and the second nozzle 6023 respectively, making the first cleaning fluid ejected from the first nozzle 6022C and the second cleaning fluid ejected from the second nozzle 6023 different.

[0083] like Figure 7 As shown, when the first nozzle 6022C sprays the first cleaning fluid onto the wafer surface, the first cleaning fluid falls onto the mechanical arm 6021 under the influence of gravity, thus contaminating the mechanical arm 6021. Therefore, while the first nozzle 6022C sprays the first cleaning fluid onto the wafer surface, the second nozzle 6023 can also simultaneously spray clean second cleaning fluid. This allows the clean second cleaning fluid to promptly clean the mechanical arm 6021, reducing the degree of contamination on the mechanical arm 6021 and minimizing secondary contamination of the wafer surface caused by excessive contamination of the mechanical arm 6021.

[0084] It can be seen that, as Figure 7 As shown in the embodiment of this application, when the first cleaning fluid is sprayed onto the wafer surface by the first nozzle 6022C, the mechanical arm 6021 can be sprayed with the second cleaning fluid sprayed by the second nozzle 6023, so that the mechanical arm 6021 has a self-cleaning function, thereby reducing the contamination of the mechanical arm 6021 by contaminants and avoiding unnecessary secondary contamination of the wafer surface.

[0085] Figure 9 A schematic diagram of a possible structure of the pre-cleaning device according to an embodiment of this application is shown. Figure 9As shown, the pre-cleaning device in this embodiment further includes a cleaning tank 6025 and a third nozzle 6026. The third nozzle 6026 is disposed on the cleaning tank 6025 and is used to spray a third cleaning fluid onto the wafer during pre-cleaning. The cleaning tank 6025 is disposed below the mechanical swing arm 6021.

[0086] like Figure 9 As shown, when the first nozzle 6022C sprays the first cleaning fluid onto the wafer surface and the second nozzle 6023 sprays the second cleaning fluid onto the mechanical arm 6021, the cleaning tank 6025 can be used as a container to collect the contaminated first and second cleaning fluids, thereby reducing the contaminated area of ​​the first and second cleaning fluids.

[0087] like Figure 7 and Figure 9 As shown, the cleaning fluid sprayed by the first nozzle 6022C, the second nozzle 6023, and the third nozzle 6026 in this embodiment may include water (deionized water) or chemicals (such as alkaline chemical solutions like ammonia). When these cleaning fluids rinse and wet the wafer surface, they can loosen and wet contaminants on the wafer surface, facilitating subsequent pre-cleaning by the pre-cleaning device. Furthermore, they can react chemically with various residual contaminants on the wafer surface, such as chemical agents and grinding byproducts, generating soluble or removable reactants. This makes the pre-cleaning of the wafer surface more thorough, thereby reducing the possibility of residual contaminants on the wafer surface.

[0088] To facilitate the description of the use of the pre-cleaning device in different stages of the pre-cleaning process according to embodiments of this application, the use process of the pre-cleaning device according to embodiments of this application is described below with reference to the accompanying drawings. It should be understood that the following is only for explaining the use process of the pre-cleaning device and is not intended to be limiting.

[0089] Figure 10A A schematic diagram illustrating the usage state of the pre-cleaning device according to an embodiment of this application in the first stage is shown. Figure 10A As shown, considering that the grinding head has translational and lifting functions, the grinding head 6010A included in the first grinding device can be used to move the wafer that has completed the first grinding to above the cleaning tank 6025. The lifting function of the grinding head 6010A controls the distance between the surface of the wafer 603 fixed by the grinding head 6010A and the cleaning tank 6025, thereby ensuring a distance between the surface of the wafer 603 and the cleaning tank 6025. Figure 10A The gap is shown. In this case, a third cleaning solution can be sprayed onto the surface of wafer 603 through the third nozzle 6026 to rinse and wet the surface of wafer 603.

[0090] Figure 10BA schematic diagram illustrating the usage state of the pre-cleaning device according to an embodiment of this application in the second stage is shown. Figure 10B As shown in the embodiment of this application, the distance between the surface of the wafer 603 fixed by the grinding head 6010A and the cleaning component 6022 can also be controlled by the lifting function of the grinding head 6010A, thereby ensuring that there is a distance between the surface of the wafer 603 and the cleaning component 6022 as shown in the figure. Figure 10B The gap shown. In this case, as Figure 10A and Figure 10B As shown, after the third nozzle 6026 sprays the third cleaning fluid onto the surface of the wafer 603, the mechanical swing arm 6021 can swing along a swing plane parallel to the surface of the wafer 603. This allows the mechanical swing arm 6021 to drive the cleaning component 6022 to swing relative to the surface of the wafer 603 to be cleaned (i.e., the wafer surface). This allows the first nozzle included in the cleaning component 6022 to spray the first cleaning fluid onto different parts of the surface of the wafer 603. Furthermore, to ensure that the first cleaning fluid has sufficient diffusion space, when the mechanical swing arm 6021 moves the cleaning component 6022 between the cleaning tank 6025 and the polishing head 6010A, a certain gap is maintained between the cleaning surface of the cleaning component 6022 and the surface of the wafer 603. This allows the first cleaning fluid sprayed from the first nozzle 6022C to have sufficient diffusion space to spread to the surface of the wafer 603, thereby ensuring that the first cleaning fluid can cover all areas of the surface of the wafer 603.

[0091] like Figure 10A and Figure 10BAs shown, when the mechanical arm 6021 drives the first nozzle 6022C to swing above the cleaning tank 6025, the distance between the third nozzle 6026 and the surface of the wafer 603 is greater than the distance between the first nozzle 6022C and the surface of the wafer 603. Therefore, the third cleaning fluid sprayed by the third nozzle 6026 has a smaller impact force on the surface of the wafer 603, while the first cleaning fluid sprayed by the first nozzle 6022C has a larger impact force on the surface of the wafer 603. In this scenario, a third cleaning solution can first be sprayed onto the surface of the wafer 603 with a smaller impact force through the third nozzle 6026. This allows the third cleaning solution to rinse and wet the surface of the wafer 603, facilitating the removal of chemicals, grinding byproducts, and other contaminants from the wafer 603 surface. Then, a first cleaning solution is sprayed onto the surface of the wafer 603 with a larger impact force through the first nozzle 6022C. This allows the first cleaning solution to rinse and wet the surface of the wafer 603, while its larger impact force also helps to remove chemicals, grinding byproducts, and other contaminants from the surface, thereby indirectly reducing the cleaning time required by the subsequent elastic part 6022B. Additionally, while the first nozzle 6022C is spraying the first cleaning solution onto the surface of the wafer 603, the second nozzle 6023 can also spray the second cleaning solution to clean the mechanical arm 6021, reducing the possibility of secondary contamination on the surface of the wafer 603.

[0092] like Figure 7 , Figure 9 and Figure 10B As shown, the first, second, and third cleaning solutions in this embodiment can be the same or different cleaning solutions, depending on the actual situation. When the first, second, and third cleaning solutions are the same, the fluid supply pipe 6024 can be connected not only to the first nozzle 6022C and the second nozzle 6023, but also to the third nozzle 6026 (the specific connection method is not shown in the figure), and a controllable valve can be installed on the fluid supply pipe 6024. Figure 7 , Figure 9 and Figure 10B (Not shown in the image). When the third nozzle 6026 needs to spray the third cleaning fluid, a controllable valve is used to supply the cleaning fluid to the third nozzle 6026. When the first nozzle 6022C sprays the first cleaning fluid and the second nozzle 6023 needs to spray the second cleaning fluid, a controllable valve can be used to supply the cleaning fluid to the first nozzle 6022C and the second nozzle 6023, so that the first nozzle 6022C and the second nozzle 6023 spray the cleaning fluid simultaneously.

[0093] For example: Figure 7 , Figure 9 , Figure 10A and Figure 10BAs shown, when the first cleaning solution, the second cleaning solution, and the third cleaning solution are all deionized water, the first nozzle 6022C, the second nozzle 6023, and the third nozzle 6026 can spray deionized water onto the wafer surface at a flow rate of 10 mL / min to 3000 mL / min, so that the deionized water can rinse and wet the wafer surface.

[0094] Figure 10C A schematic diagram illustrating the usage state of the pre-cleaning device according to an embodiment of this application in the third stage is shown. Figure 10C As shown, after the first nozzle 6022C completes rinsing and wetting the wafer surface, the cleaning surface of the cleaning component 6022 can be brought into contact with the wafer 603 surface. Then, the mechanical swing arm 6021 drives the cleaning component 6022 to swing along a swing plane parallel to the wafer 603 surface, allowing the cleaning component 6022 to clean the wafer 603 surface. In an optional embodiment, such as... Figure 7 , Figure 9 , Figure 10B and Figure 10C As shown, the mechanical swing arm 6021 in this embodiment may include a rotary motor 6021A and a swing arm 6021B disposed on the rotation shaft of the rotary motor 6021A. A fluid supply pipe 6024 may be disposed on the swing arm 6021B and extend along the arm direction of the swing arm 6021B.

[0095] like Figure 7 , Figure 9 , Figure 10B and Figure 10C As shown, the cleaning component 6022 in this embodiment of the application includes a base 6022A, which can be a controllable universal joint. When the elastic part 6022B and the first nozzle 6022C are disposed on the base 6022A, the controllable universal joint can control the friction angle between the elastic part 6022B and the surface of the wafer 603, as well as the spray direction of the first nozzle 6022C spraying the first cleaning liquid, thereby better pre-cleaning the surface of the wafer 603 and reducing the adverse effects of contaminants remaining on the surface of the wafer 603 on the wafer during the second grinding process.

[0096] In some embodiments, such as Figure 7 , Figure 9 , Figure 10B and Figure 10CAs shown, when the cleaning component 6022 cleans the surface of the wafer 603 in this embodiment, it is sufficient to ensure that there is a certain relative movement between the cleaning component 6022 and the wafer 603. Here, the swing arm 6021B, driven by the rotary motor 6021A, can swing from 0° to 180° in angle and from 0 to 200 times / min in frequency. When the grinding head 6010A of the first grinding device fixes the wafer 603, if the elastic part 6022B cleans the surface of the wafer 603, the wafer can be rotated by the rotation function of the grinding head 6010A, thereby improving the cleaning efficiency. For example, the grinding head 6010A can rotate the wafer at a speed of 0 RPM to 150 RPM, participating in the cleaning process of the elastic part 6022B on the surface of the wafer 603. For example, when the swing frequency of the swing arm 6021B is 0 times / min, the rotation speed of the grinding head 6010A can be greater than 0 RPM. When the swing frequency of the swing arm 6021B is greater than 0 times / min, the rotation speed of the grinding head 6010A can be arbitrarily selected within the range of 0 RPM to 150 RPM.

[0097] like Figure 10B As shown, when the controllable universal joint drives the cleaning component 6022 to rotate, the pre-cleaning device sprays cleaning fluid using the first nozzle 6022C and the second nozzle 6023 in the second stage. The controllable universal joint drives the first nozzle 6022C and the second nozzle 6023 to rotate. Under centrifugal force, the cleaning fluid sprayed by the first nozzle 6022C and the second nozzle 6023 can cover a larger area. This not only improves the cleaning effect on the mechanical swing arm 6021, but also increases the rinsing and wetting range of the wafer surface.

[0098] In another alternative approach, such as Figure 10C As shown, in the third stage of operation of the pre-cleaning device in this embodiment, that is, when the cleaning element 6022 contacts the surface of the wafer 603, and the cleaning surface of the cleaning element 6022 is driven by the mechanical swing arm 6021 to swing along a swing plane parallel to the surface of the wafer 603 to clean the surface of the wafer 603, the first nozzle 6022C and the second nozzle 6023 of the cleaning element 6022 can also spray cleaning fluid at the same time to help chemical agents, grinding by-products, etc., detach from the surface of the wafer 603, thereby shortening the pre-cleaning time and enabling the mechanical swing arm 6021 to maintain self-cleaning during the cleaning process of the wafer 603 surface. In some optional embodiments, such as Figure 7 , Figure 9 , Figures 10A-10CAs shown, the cleaning tank 6025 of this embodiment is also used to pre-wet the wafer 603 before the first polishing. The pre-cleaning device further includes a fourth nozzle (not shown) disposed in the cleaning tank 6025, which is used to spray wetting liquid onto the wafer 603 during pre-wetting. Here, the cleaning tank 6025 of this embodiment has a fluid discharge channel (not shown). This fluid discharge channel can discharge not only the contaminated first and second cleaning liquids, but also the wetting liquid.

[0099] In some alternative embodiments, the cleaning tank can be a support device included in the grinding apparatus of the related art. As mentioned above, the support device included in the grinding apparatus of the related art at least has the function of supporting the wafer. In some grinding apparatuses of the related art, the support device also has the function of pre-wetting the wafer before grinding, and has a fourth nozzle for spraying wetting liquid onto the wafer during pre-wetting and a fluid discharge channel. Improving the original support device as the cleaning tank of the pre-cleaning device in the embodiments of this application can reduce the difficulty of modifying the grinding equipment of the related art. Figure 7 , Figure 9 and Figures 10A-10C As shown, when the first nozzle 6022C, the second nozzle 6023, and the third nozzle 6026 spray cleaning fluid, or the fourth nozzle sprays wetting fluid, regardless of whether these liquids are used to clean the surface of the wafer 603 fixed to the polishing head 6010A, they may fall to the support device under gravity and then be discharged through the fluid discharge channel opened in the support device. Therefore, the support device in this embodiment not only serves as a wafer support but also collects and discharges waste liquid, alleviating the contamination problem of the polishing system caused by the pre-cleaning device on the wafer surface.

[0100] Figure 11 A schematic flowchart of a wafer cleaning method according to an embodiment of this application is shown. Figure 11 As shown, the wafer cleaning method in this application embodiment may include:

[0101] Step 1101: Provide a wafer. The wafer may be a wafer to be subjected to at least two grinding processes.

[0102] Step 1102: Perform the first grinding on the wafer. This first grinding can be performed by the first grinding device mentioned above. The execution method can refer to the wafer grinding process of the grinding device in the related technology mentioned above, or refer to other wafer grinding methods in the related technology to perform the first grinding on the wafer.

[0103] In practical applications, the method of this application embodiment can also pre-wet the wafer before performing the first grinding, so as to improve the grinding effect of the first grinding of the wafer.

[0104] Step 1103: Pre-clean the wafer after the first grinding. This pre-cleaning can be performed by the pre-cleaning device described above; for example, refer to... Figures 10A-10C The wafer cleaning process pre-cleans the wafer after the first grinding.

[0105] Step 1104: Perform a second polishing on the pre-cleaned wafer. This second polishing can be performed by the second polishing apparatus described above. The execution method can refer to the wafer polishing process of the polishing equipment in the embodiments of the previous application, or refer to other wafer polishing methods in the embodiments of this application to perform the first polishing on the wafer.

[0106] The wafer polishing method of this application embodiment further includes pre-wetting the wafer before polishing the first wafer. This pre-wetting can be performed by the pre-cleaning device described above. In some embodiments, the pre-cleaning device can be modified from a carrier device of a polishing apparatus in the related art; in these embodiments, pre-wetting can be performed by the carrier device. Furthermore, the wafer cleaning method of this application embodiment may also include:

[0107] The operating status of the second grinding device is detected. When the second grinding device is in a busy state, it is determined to pre-clean the wafer after the first grinding. When the second grinding device is in an idle state, it is determined to perform a second grinding on the wafer.

[0108] In practical applications, embodiments of this application may include a first sensor in a first grinding apparatus and a second sensor in a second grinding apparatus, along with a controller that receives signals from both the first and second sensors and controls the operation of the grinding system. Here, the first and second sensors can be various applicable sensors, such as various types of photoelectric sensors.

[0109] Taking an image sensor as an example, the first sensor can be used to acquire images of the operating status of the first grinding device, and the second sensor can acquire images of the operating status of the second grinding device. The first sensor can transmit the images of the operating status of the first grinding device to the controller, and the second sensor can transmit the images of the operating status of the second grinding device to the controller. The controller can analyze the images of the operating status of the first grinding device based on image analysis technology to determine whether the first grinding device has completed the first grinding of the wafer. At the same time, it can also analyze the images of the operating status of the second grinding device based on image analysis technology to determine whether the second grinding device is in an idle state.

[0110] If the controller detects that the first grinding unit has completed the first grinding of the wafer, while the second grinding unit is busy due to grinding another wafer or a malfunction, it can send a command to the grinding system to pre-clean the wafer after the first grinding. Therefore, the pre-cleaning device can be directly activated. For example, the grinding head can be controlled to move the wafer to the area where the pre-cleaning device is located, and then the pre-cleaning device can be controlled to pre-clean the wafer to prevent residual chemicals and grinding byproducts from affecting wafer yield due to the wafer surface drying during the second grinding process. If the controller detects that the first grinding unit has completed the first grinding of the wafer, while the second grinding unit is functioning correctly and has not ground any wafers, it indicates that the second grinding unit is idle. The controller can then send a command to the grinding system to perform the second grinding of the wafer. Therefore, the grinding transfer robot can be controlled to transfer the wafer after the first grinding to the carrier device included in the second grinding unit.

[0111] Considering the cost of modifying grinding equipment, this application provides another grinding system that can introduce the grinding head and carrier device included in the grinding system of related technologies into the wafer pre-cleaning process. Through the cooperation of the carrier device, grinding head and pre-cleaning device, the wafer is pre-cleaned during the grinding stage. This can not only reduce the possibility of contaminant residue and scratches on the wafer surface, improve wafer yield, and increase the overall production capacity of the grinding equipment, but also reduce the difficulty of modifying grinding equipment of related technologies.

[0112] Figure 12 A schematic diagram of another grinding system according to an embodiment of this application is shown. Figure 12 As shown, the polishing system 1200 of this application embodiment may include: a polishing device, which may include a carrier device 1201 and a polishing head 1202; the carrier device 1201 may be used to carry a wafer 1204, and in some embodiments, the carrier device 1201 may also be used to pre-wet the wafer 1204; the polishing head 1202 is used to fix the wafer 1204 and move the wafer 1204 above the carrier surface of the carrier device 1201.

[0113] like Figure 12 As shown, the polishing system 1200 of this application embodiment may further include a pre-cleaning device 1203. The pre-cleaning device 1203 is used to pre-clean the surface of the wafer 1204 fixed to the polishing head 1202 when the polishing head 1202 is located above the bearing surface of the bearing device 1201 after the polishing head 1202 has completed the polishing operation of the wafer 1204.

[0114] In practical applications, such as Figure 12As shown, in this embodiment of the application, after the grinding head 1202 grinds the wafer 1204, the pre-cleaning device 1203 pre-cleans the surface of the wafer 1204 fixed to the grinding head 1202 when the grinding head 1202 is located above the bearing surface of the bearing device 1201. For example, after the grinding head 1202 of the grinding system 1200 has completed the grinding operation on the wafer 1204, the grinding head 1202 uses its own translation function to transfer the wafer 1204 fixed to the grinding head 1202 to above the bearing device 1201, and then the pre-cleaning device 1203 pre-cleans the surface of the wafer 1204.

[0115] When multiple polishing systems are used in series, if the next polishing unit is unable to polish the wafer surface due to being busy or experiencing other abnormalities after the current polishing unit has finished polishing it, the pre-cleaning unit included in the current polishing system can be used to pre-clean the wafer surface in the manner described above. This reduces the amount of residual chemicals, polishing byproducts, and other contaminants on the wafer surface during the waiting period. In this case, when the next polishing unit polishes the wafer surface, the possibility of scratching the wafer surface is reduced, thereby improving wafer yield.

[0116] It can be seen that, as Figure 12 As shown, the polishing system 1200 of this application embodiment can cooperate with the support device 1201, polishing head 1202 and pre-cleaning device 1203 to achieve pre-cleaning of the surface of wafer 1204 during the polishing stage. This can not only reduce the difficulty of modifying polishing equipment in related technologies, but also reduce the possibility of residual contaminants and scratches on the wafer surface and improve wafer yield.

[0117] Moreover, such as Figure 12 As shown, the polishing system 1200 of this application embodiment adds a pre-cleaning device 1203 to the polishing apparatus of related technologies, so that the surface of the wafer 1204 is pre-cleaned during the polishing stage. Therefore, the polishing system 1200 of this application embodiment can alleviate the cleaning pressure of the cleaning system used for the final cleaning of the polished wafer in the polishing equipment. On the one hand, it can reduce the situation where the cleaning system is limited by the polishing process capacity when the load of the cleaning system is increasing. On the other hand, it can reduce the cleaning time of the cleaning system on the wafer, so that the cleaning system can complete the wafer cleaning in a shorter time and improve the overall capacity of the polishing equipment.

[0118] As one possible implementation, such as Figure 12As shown, the pre-cleaning device 1203 in this embodiment is actually a movable cleaning device, and its structure can be referenced from the pre-cleaning device 1203 described above. For example, the pre-cleaning device 1203 may also include a mechanical swing arm 1203A and a cleaning component 1203B. The cleaning component 1203B includes a base and an elastic part and a first nozzle respectively disposed on the base. The base is disposed at one end of the mechanical swing arm. The first nozzle is used to spray a first cleaning liquid onto the wafer. The elastic part is used to contact the wafer surface to pre-clean the wafer surface. The difference between the pre-cleaning device 1203 in this embodiment and the pre-cleaning device 602 described above is that the pre-cleaning device 1203 in this embodiment can replace the cleaning tank function of the pre-cleaning device 602 described above with a support device 1201.

[0119] In practical applications, such as Figure 12 As shown, in this embodiment of the application, the mechanical swing arm 1203A can move the cleaning component 1203B between the bearing surface of the bearing device 1201 and the surface of the wafer 1204, and ensure that there is a certain gap between the surface of the cleaning component 1203B and the surface of the wafer 1204. Then, the first nozzle can swing along the swing plane parallel to the wafer surface under the drive of the mechanical swing arm 1203A, spraying the first cleaning liquid on different areas of the wafer 1204 surface, so that the chemical agents, grinding by-products and other contaminants remaining on the wafer 1204 surface can be easily removed from the wafer surface.

[0120] In some embodiments, the elastic part of this application can refer to the foregoing description. For example, the shape of the elastic part can be various regular shapes, such as cuboids, cubes, cylinders, etc., or it can be an irregular shape. The material of the elastic part is not limited to polyurethane, rubber, fiber, etc., but can also be other materials with cleaning function. This elastic part is a consumable and can be installed on the base by snap-fit, adhesive, or other methods. For example, the base can be a mechanical mounting bracket. Of course, the elastic part can also be attached to the base with various adhesives such as self-adhesive. When it is necessary to replace the elastic part, the elastic part can be directly removed from the mechanical swing arm, and the new elastic part can be installed on the base.

[0121] In some embodiments, the elastic portion of this application has a fluid diffusion chamber and a plurality of nozzles for ejecting cleaning fluid. The fluid diffusion chamber is in communication with each nozzle, and the fluid diffusion chamber and each nozzle constitute a first nozzle.

[0122] In some embodiments, the elastic portion of this application further has a fluid outlet structure for outleting a first cleaning fluid that enters the elastic portion.

[0123] In some embodiments, the elastic portion has at least one outlet through hole, and the angle between the axial direction of each outlet through hole and the cleaning surface of the cleaning member is greater than a first preset angle and less than or equal to 90°.

[0124] In some embodiments, the angle between the arm direction of the mechanical swing arm and the bearing surface of the bearing device is less than or equal to a second preset angle. When the second preset angle is equal to 10° to 30°, when the mechanical swing arm drives the cleaning component to move between the bearing surface of the bearing device and the end face of the grinding head, it can achieve active avoidance of the bearing device and the grinding head, reducing the probability of the mechanical swing arm colliding with the bearing device and the grinding head.

[0125] For example, when the angle between the arm direction of the mechanical swing arm and the bearing surface of the bearing device can be 0° or approximately 0°, the mechanical swing can swing along the direction parallel to the end face of the grinding head, thereby effectively avoiding mutual interference between the mechanical swing arm, the bearing device and the grinding head, and ensuring the stability of wafer pre-cleaning.

[0126] In some embodiments, the pre-cleaning device of this application may further include a plurality of second nozzles disposed on a mechanical arm. The second nozzles are used to spray a second cleaning fluid onto the mechanical arm, thereby reducing secondary contamination of the wafer surface by the mechanical arm. Simultaneously, the second nozzles may be disposed on the side of the mechanical arm close to the cleaning surface of the cleaning component, so that the second cleaning fluid sprayed by the second nozzles can further rinse and wet the wafer surface.

[0127] For example, embodiments of this application also include a fluid supply pipe, and the mechanical swing arm has a plurality of second nozzles for spraying cleaning fluid. The first nozzle and the second nozzle are both connected to the fluid supply pipe or are respectively connected to the plurality of fluid supply pipes, so that the fluid supply pipe can simultaneously deliver cleaning fluid to the first nozzle and the second nozzle.

[0128] In some embodiments, such as Figure 13A-13DAs shown, the carrier surface of the carrier device 1201 in this embodiment has at least one third nozzle 1205 for spraying cleaning fluid. Since the carrier surface of the carrier device 1201 has at least one third nozzle 1205, the number of third nozzles 1205 can be one or more. Each third nozzle 1205 can spray third cleaning fluid towards the grinding head 1202. Therefore, when the grinding head 1202 moves the wafer 1204 above the carrier surface of the carrier device 1201, the surface of the wafer 1204 fixed by the grinding head 1202 can be cleaned using the third cleaning fluid sprayed from each third nozzle 1205. In this case, the third cleaning fluid can rinse and wet the surface of the wafer 1204, making it easier for the cleaning component on the mechanical arm to clean the surface of the wafer 1204, thereby reducing the possibility of contaminant residue on the surface of the wafer 1204. The process of the first and third nozzles spraying cleaning fluid sequentially by the first and third nozzles in this embodiment can be referred to the previous description and will not be detailed here.

[0129] Figures 13A-13D The diagram illustrates four stages of wafer cleaning using the grinding system according to an embodiment of this application, which are described below in sequence. It should be understood that these stages are designed for easy observation of the wafer. Figure 13A The grinding head is not shown.

[0130] like Figure 13A As shown, since the carrier device 1201 of this embodiment is used to carry the wafer 1204, and the grinding head (not shown) is used to fix the wafer 1204, before grinding the wafer 1204 or after grinding the wafer 1204 with the grinding disc 1206, the grinding head can be used to move the wafer 1204 above the carrier surface of the carrier device 1201. In this case, the surface of the wafer 1204 is opposite to the carrier surface of the carrier device 1201. Therefore, the third nozzle 1205 (in this drawing, for the convenience of showing the position of the third nozzle 1205, in the actual top view, the third nozzle 1205 is located below the wafer 1204, the third nozzle 1205 ( Figure 13A Although the third nozzle 1205 shown is visible, it is actually blocked by the wafer 1204, making the third nozzle 1205 not actually visible. It can spray deionized water onto the surface of the wafer 1204, so that the deionized water can rinse and wet the surface of the wafer 1204.

[0131] like Figure 13B and Figure 13CAs shown, after the deionized water sprayed from the third nozzle 1205 rinses and wets the surface of the wafer 1204, the pre-cleaning device 1203 can be controlled to move between the bearing surface of the bearing device 1201 and the end face of the polishing head 1202, so that the pre-cleaning device 1203 can pre-clean the surface of the wafer 1204 fixed to the end face of the polishing head 1202. Since the deionized water has already wetted and rinsed the surface of the wafer 1204 in advance, the pre-cleaning device 1203 can clean the surface of the wafer 1204 more easily, thereby reducing the possibility of contaminant residue on the surface of the wafer 1204.

[0132] like Figure 13D and Figure 12 As shown, after the pre-cleaning device 1203 cleans the surface of the wafer 1204, if the wafer 1204 is ready for the next grinding operation, the grinding transfer robot 1207 can pick up the wafer 1204 and transfer it to the carrier device included in the next grinding device.

[0133] When multiple polishing systems consist of polishing units connected in series, if the polishing time of the current polishing unit is relatively short while that of the next polishing unit is relatively long, the next polishing unit may still be busy or unable to operate due to other abnormalities when the current unit finishes polishing the wafer. This prevents the next polishing unit from properly polishing the wafer. In such cases, a pre-cleaning device included in the current polishing system can be used to pre-clean the wafer as described above, reducing the amount of contaminants remaining on the wafer surface. In this situation, when the next polishing unit polishes the wafer surface, the possibility of scratches on the wafer surface can be reduced, thereby improving wafer yield.

[0134] In one alternative embodiment, the grinding head of this application may have a rotation function, a lifting function, and a translation function, for example: Figures 13A-13D as well as Figure 12 As shown, the grinding head 1202 can be moved above the support device 1201 by translation function, and the distance between the surface of the wafer 1204 fixed by the grinding head 1202 and the cleaning surface of the cleaning component 1203B can be controlled by lifting function, so that there is a gap or contact between the surface of the wafer 1204 and the cleaning surface of the cleaning component 1203B.

[0135] like Figure 14 As shown, when the first cleaning fluid is sprayed from the first nozzle, if the spraying distance of the first cleaning fluid is insufficient, the grinding head 1202 can be raised and lowered to move the wafer 1204 toward the bearing surface of the bearing device 1201 until the first cleaning fluid can rinse and wet the surface of the wafer 1204.

[0136] As can be seen, the grinding head in this embodiment not only has the function of fixing the wafer and cooperating with the wafer to perform grinding operations, but can also participate in the pre-cleaning operation of the wafer surface by utilizing its own rotation, lifting and translation functions. Thus, with minimal modifications to the grinding device, the wafer can be pre-cleaned before the cleaning stage, thereby reducing the possibility of residual contaminants and scratches on the wafer surface, improving wafer yield, and reducing the bottleneck of grinding process capacity being limited by the cleaning system.

[0137] In one alternative approach, Figure 14 A schematic diagram of a supporting device according to an embodiment of this application is shown. Figure 12 As shown, the carrier device 1201 of this application embodiment may include a carrier container 1201A and a plurality of third nozzles 1205. Each third nozzle 1205 is disposed inside the carrier container 1201A and is used to spray a third cleaning fluid to rinse and wet the wafer surface. The carrier container 1201A has at least one fluid discharge channel (not shown in the figure). For example, the discharge channel may be an opening provided at the bottom of the carrier container. It should be understood that the carrier device may also include a support 1201B, the support surface of which is used to support the wafer 1204.

[0138] like Figure 14 and Figure 12 As shown, when the polishing head 1202 is positioned above the bearing surface of the bearing device 1201, the first nozzle, the second nozzle, and the third nozzle spray cleaning fluid. Regardless of whether this cleaning fluid is used to clean the wafer 1204 fixed to the polishing head 1202, it may fall into the bearing container 1201A under the influence of gravity and then be discharged through the fluid discharge channel provided in the bearing container 1201A. Therefore, the bearing device 1201 of this application not only serves to support the wafer 1204 but also to collect and discharge the cleaning fluid, mitigating the contamination problem of the polishing device caused by cleaning the surface of the wafer 1204.

[0139] It should be noted that, as Figure 14 and Figure 15 As shown, the carrier device 1201 in this embodiment may further include multiple sets of fourth nozzles (not shown) disposed at the bottom of the carrier container 1201A for spraying out wetting liquid to pre-wet the wafer 1204.

[0140] Figure 15 A schematic diagram of another grinding system according to an embodiment of this application is shown. Figure 15As shown, the polishing system 1500 of this embodiment also includes a polishing head 1502, a polishing disc 1504, a polishing slurry nozzle 1505, and a dresser 1506, etc. The polishing disc 1504 also has a polishing pad (not shown). At the same time, the bearing surface of the bearing device 1501 may also have a nozzle 1507 for rinsing and wetting the wafer surface, so as to facilitate the pre-cleaning device 1503 to pre-clean the wafer surface and reduce the contaminant residue caused by the drying of the wafer surface.

[0141] like Figure 15 As shown, the aforementioned support device 1501, dressing device 1506, and polishing fluid nozzle 1505 can be disposed around the polishing disc 1504, and the dressing device 1506 and polishing fluid nozzle 1505 can swing, while the polishing head 1502 has lifting, horizontal movement, and rotation functions. It should be understood that the polishing system 1500 of this application embodiment may also include a housing 1500A and a lifting retaining ring 1500B. The polishing head 1502, support device 1501, pre-cleaning device 1503, polishing fluid nozzle 1505, and dressing device 1506 are all disposed within the housing 1500A, while the polishing disc 1504 may be disposed within the lifting retaining ring 1500B.

[0142] like Figure 15 As shown, when the grinding and transfer robot places the wafer on the support included in the carrier device 1501, the grinding head 1502 can move above the carrier device 1501. The grinding head 1502 can fix the wafer on the end face of the grinding head 1502 by adsorption or other means. Of course, if the carrier device 1501 has a lifting function, the carrier device 1501 can also drive the wafer placed on the support to rise and send the wafer into the end face of the grinding head 1502, so that the wafer is stuck on the end face of the grinding head 1502 or adsorbed on the end face of the grinding head 1502.

[0143] In one embodiment, such as Figure 15 As shown, when a wafer completes the previous grinding process and is about to undergo the current grinding process in the current grinding apparatus, it needs to be pre-cleaned before starting the current grinding process. With the wafer fixed on the end face of the grinding head 1502, the carrier device 1501, the pre-cleaning device 1503, and the grinding head 1502 can cooperate as described above to pre-clean the wafer surface. Then, the grinding head 1502 moves the wafer onto the grinding disk 1504, and the grinding operation is started. In this case, if the pre-cleaned wafer surface is already wetted, and the cleaning solution will not affect the grinding, it is not necessary for the carrier device 1501 to pre-wet the wafer again; the wafer can be directly fixed on the end face of the grinding head for grinding.

[0144] In another embodiment, such as Figure 15As shown, after the current polishing apparatus polishes the wafer, the end face of the polishing head 1502 included in the current polishing apparatus fixes the wafer. In this case, the carrier device 1501, the pre-cleaning device 1503, and the polishing head 1502 can cooperate with each other as described above to pre-clean the wafer surface in the current polishing apparatus, and then the polishing head 1502 moves the wafer onto the carrier device 1501, waiting for the transfer system to move the wafer to the next position.

[0145] like Figure 12 As shown, during the grinding process of the grinding disc 1504 grinding the wafer fixed on the end face of the grinding head 1502, the grinding fluid nozzle 1505 can move above the grinding disc 1504 and spray grinding fluid onto the grinding disc 1504 to react with the wafer surface material fixed on the end face of the grinding head 1502, generating an easily removable surface layer. Then, the wafer surface is mechanically and chemically ground by the grinding disc 1504. After the wafer grinding is completed, the grinding head 1502 drives the wafer to rise and detach from the contact with the grinding disc 1504. At this time, the dresser 1506 can move above the grinding disc 1504 and contact the grinding disc 1504 to dress the grinding disc 1504 and ensure the grinding capability of the grinding disc.

[0146] This application also provides another wafer cleaning method, which can be applied to a polishing system having a first polishing device and a second polishing device. The first polishing device has a polishing head, a carrier device, and a pre-cleaning device. For example, the first polishing device can be... Figure 12 Or based on Figure 16 The described grinding system can be adapted to various possible variations of the grinding system. The second grinding apparatus can be a grinding system of related art, or it can be the grinding system described above in this application.

[0147] Figure 16 A schematic flowchart of another wafer cleaning method according to an embodiment of this application is shown. ​ As shown, the cleaning method in this application embodiment may include:

[0148] Step 1601: Provide a wafer. The wafer is placed above the carrier device, with the wafer surface (i.e., the polished surface of the wafer) facing the carrier surface of the carrier device. The carrier device serves to support the wafer and has a nozzle for spraying a wetting solution.

[0149] Step 1602: Use the nozzle of the carrier device to spray wetting liquid to pre-wet the wafer.

[0150] Step 1603: Fix the wafer using the grinding head of the first grinding device and move the wafer to the first grinding device for grinding. Here, the horizontal movement function of the grinding head can be used to move the wafer above the bearing surface of the carrier device. Since the wafer surface faces away from the end face of the grinding head, the wafer surface is opposite to the bearing surface of the carrier device.

[0151] Step 1604: Determine if the second polishing device is busy. If busy, proceed to step 1605; otherwise, proceed to step 1606. The determination method here can be found in the previous text and will not be repeated here. With this setup, when the wafer finishes the first polishing and the second polishing device is idle, the possibility of the wafer surface drying or becoming damaged due to waiting for idle time is reduced. Therefore, the wafer can be directly polished a second time, saving the overall polishing process time, increasing efficiency, and improving production capacity.

[0152] Step 1605: Pre-clean the wafer surface using a pre-cleaning device. After pre-cleaning the wafer surface, step 1606 can be performed while the second polishing device is idle. In this case, even if the second polishing device cannot perform a second polishing on the wafer after the first polishing in a timely manner, no chemical agents, polishing byproducts, or other contaminants will remain on the wafer surface, thereby reducing the generation of wafer defects, reducing the cleaning pressure of the cleaning system, and improving the polishing efficiency of the polishing equipment.

[0153] Step 1606: Use the second grinding device to perform a second grinding on the wafer after the first grinding.

[0154] The wafer cleaning method of this application embodiment can alleviate the cleaning pressure on the cleaning system. On the one hand, it can reduce the situation where the cleaning system is limited by the grinding process capacity when the load on the cleaning system is increasing. On the other hand, it can reduce the cleaning time of the wafer by the cleaning system, so that the cleaning system can complete the wafer cleaning in a shorter time and improve the overall capacity of the grinding equipment.

[0155] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0156] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A grinding system, characterized in that, It includes a first grinding device, a second grinding device, and a pre-cleaning device; The first grinding device is used to perform a first grinding on the wafer; The second grinding device is used to perform a second grinding on the wafer; The pre-cleaning device is used to pre-clean the wafer after the first grinding is completed and before the second grinding begins.

2. The grinding system according to claim 1, characterized in that, The pre-cleaning device includes a mechanical swing arm and a cleaning component, wherein the mechanical swing arm is used to drive the cleaning component to move. The cleaning component includes a base and an elastic part and a first nozzle respectively disposed on the base. The base is located at one end of the mechanical swing arm. The first nozzle is used to spray a first cleaning liquid onto the wafer. The elastic part is used to contact the wafer surface to pre-clean the wafer surface.

3. The grinding system according to claim 2, characterized in that, The elastic part includes bristles or sponge blocks.

4. The grinding system according to claim 2, characterized in that, The pre-cleaning device further includes a second nozzle disposed on the mechanical swing arm, the second nozzle being used to spray a second cleaning fluid onto the mechanical swing arm.

5. The grinding system according to claim 4, characterized in that, The pre-cleaning device also includes a fluid supply pipe, and both the first nozzle and the second nozzle are connected to the fluid supply pipe.

6. The grinding system according to claim 2, characterized in that, The pre-cleaning device also includes a cleaning tank and a third nozzle, the cleaning tank being located below the mechanical swing arm; The third nozzle is disposed on the cleaning tank and is used to spray a third cleaning solution onto the wafer during pre-cleaning.

7. The grinding system according to claim 6, characterized in that, The cleaning tank is also used to pre-wet the wafer before the first grinding. The pre-cleaning device also includes a fourth nozzle provided in the cleaning tank, which is used to spray wetting liquid onto the wafer during the pre-wetting process.

8. The grinding system according to claim 6, characterized in that, The cleaning tank has a fluid discharge channel.

9. A grinding apparatus, characterized in that, It includes a cleaning system, a transfer system, and a grinding system as described in any one of claims 1 to 8.

10. A wafer cleaning method, characterized in that, include: Provide wafers; The wafer is first polished; The wafer after the first grinding is pre-cleaned; The pre-cleaned wafer is then subjected to a second grinding process.

11. The wafer cleaning method according to claim 10, characterized in that, The wafer cleaning method further includes: pre-wetting the wafer before performing the first grinding.

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