Cleaning device and double-sided grinding equipment

Abstract

The utility model provides a cleaning device and double-sided grinding equipment, the cleaning device comprises: a scraper which is used for being inserted into a groove of a grinding surface of a fixed disc of the double-sided grinding equipment and moving along the groove; and the nozzle is arranged at the downstream of the scraper in the moving direction of the scraper and is arranged to synchronously move along with the scraper, and the nozzle is used for spraying cleaning liquid into the groove. The cleaning device efficiently removes pollutants in the groove of the fixed disc through cooperative automatic operation of the scraper and the nozzle, the cost is reduced, the safety and the production efficiency are improved, and meanwhile the wafer grinding quality is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor wafer manufacturing, and in particular to a cleaning device and a double-sided grinding equipment. Background Technology

[0002] Double-sided wafer polishing is a crucial step in semiconductor manufacturing, primarily aimed at precisely planarizing the two surfaces of a wafer. This process is essential for improving wafer flatness and surface quality, directly impacting the accuracy of subsequent photolithography processes and chip performance. In double-sided polishing equipment, the upper and lower mounting pads are core components, their surfaces adorned with grooves that enhance the polishing effect. However, the accumulation of contaminants such as slurry and polishing debris in these grooves can cause blockages, consequently affecting polishing efficiency and quality.

[0003] Currently, the cleaning of the upper and lower mounting plates mainly relies on manual operation. Operators need to regularly clean the contaminants in the trenches to keep the trenches clear and the upper and lower mounting plates clean.

[0004] Although manual cleaning is currently the most common method, it has many problems and limitations. First, manual cleaning is time-consuming and labor-intensive, requiring operators to invest significant time and energy, which not only increases production costs but also reduces efficiency. Second, the effectiveness of manual cleaning is limited. Due to the complex shape of the trenches, manual operation cannot reach all areas, resulting in incomplete cleaning and persistent contaminant residue. Furthermore, long-term manual operation may lead to equipment damage or safety risks for operators. Therefore, existing cleaning methods can no longer meet the requirements of modern semiconductor manufacturing for high efficiency, high precision, and high reliability, and there is an urgent need for an automated and efficient cleaning solution. Utility Model Content

[0005] This invention provides a cleaning device and a double-sided grinding equipment, which can efficiently remove contaminants in the fixed plate groove through the coordinated and automated operation of scrapers and nozzles, reduce costs, improve safety and production efficiency, and at the same time ensure the quality of wafer grinding.

[0006] The technical solution of this utility model is implemented as follows:

[0007] In a first aspect, this utility model provides a cleaning device, the cleaning device comprising:

[0008] A scraper, which is used to insert into and move along the grooves of the grinding surface of the platen of the double-sided grinding equipment;

[0009] A nozzle is provided downstream of the scraper in the moving direction of the scraper and is arranged to move synchronously with the scraper, the nozzle being configured to spray cleaning liquid into the groove.

[0010] In some optional examples, the scraper has a profile that fits the inner wall of the groove, such that when the scraper is inserted into the groove, the scraper fits the inner wall of the groove.

[0011] In some optional examples, the cleaning device further comprises:

[0012] A booster is configured to boost the cleaning liquid;

[0013] A supply conduit is configured to communicate the booster with the nozzle;

[0014] A valve is provided on the supply conduit and is configured to adjust the flow rate of the cleaning liquid sprayed from the nozzle.

[0015] In some optional examples, the nozzle is configured to enable the cleaning liquid to be sprayed to any position in the circumference of the groove.

[0016] In a second aspect, the utility model provides a double-sided polishing equipment, the double-sided polishing equipment comprises:

[0017] A chuck plate, the polishing surface of the chuck plate is formed with a groove, the groove is distributed as a plurality of circular arcs with a common center, and the common center is located outside the chuck plate;

[0018] A telescopic rod is arranged in parallel with the polishing surface of the chuck plate;

[0019] The cleaning device according to the first aspect, the scraper and the nozzle are arranged on the telescopic rod;

[0020] A first driver is configured to rotate the telescopic rod around a rotation axis perpendicular to the polishing surface of the chuck plate and passing through the common center.

[0021] In some optional examples, the polishing surface of the chuck plate comprises a first half and a second half with the diameter of the polishing surface as a boundary, and a first common center of the plurality of circular arcs in which the groove of the first half is distributed and a second common center of the plurality of circular arcs in which the groove of the second half is distributed are symmetrical about the diameter.

[0022] In some optional examples, the double-sided polishing equipment further comprises a second driver configured to rotate the chuck plate by 180 DEG around its central axis.

[0023] In some optional examples, the double-sided polishing apparatus further comprises a position sensor for sensing a relative positional relationship between the groove and the rotation axis during rotation of the platen about its central axis, and issuing an instruction to stop rotation of the platen when the rotation axis passes the common center.

[0024] In some optional examples, the platen comprises an upper platen and a lower platen, the lower polishing surface of the upper platen is formed with the groove, the upper polishing surface of the lower platen is formed with the groove, and the double-sided polishing apparatus further comprises a third driver for rotating the telescopic rod by 180° about its longitudinal axis.

[0025] In some optional examples, the platen is formed with a discharge outlet for discharging the cleaned contaminants and the cleaning liquid, the discharge outlet is formed at the center and the end of each circular arc.

[0026] The utility model provides a kind of cleaning device and double-sided polishing apparatus, and cleaning device is effectively and rapidly removed the contaminants in the groove on platen by the cooperation of scraper and nozzle operation.It is responsible for scraping the contaminants in the groove by scraper, then nozzle sprays cleaning liquid to flush, ensure that groove is thoroughly cleaned.This synchronous operation mode not only ensures the comprehensive coverage of cleaning work, but also simplifies mechanical structure, reduces production and maintenance cost.The automated cleaning process reduces manual intervention, improves operational safety, and avoids equipment damage caused by operation failure.In addition, the cleaning device of continuous work improves production continuity, reduces production interruption.The high efficiency and high quality of cleaning work help to protect platen, prolong its service life, and ensure the efficiency of wafer polishing process and the quality of final product. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The utility model provides double-sided polishing apparatus and its cleaning device's front view section schematic view for embodiment of the utility model.

[0028] Figure 2 The utility model provides double-sided polishing apparatus and its cleaning device's front view section schematic view for embodiment of the utility model.

[0029] Figure 3 The utility model provides double-sided polishing apparatus and its cleaning device's front view section schematic view for embodiment of the utility model. DETAILED DESCRIPTION

[0030] The technical solutions of the utility model will be described clearly and completely in conjunction with the drawings in the utility model.

[0031] In the field of semiconductor manufacturing, double-side polishing of wafers plays a crucial role in ensuring the precision and quality of the wafers. This process involves planarizing both surfaces of the wafer to improve its flatness and surface quality. The accuracy of this step directly affects the precision of subsequent photolithography processes and the performance of the final chip. In this process, the upper platen and the lower platen of the double-side polishing equipment are key components that enable effective polishing. The grooves on their surfaces are designed to enhance polishing efficiency. However, these grooves tend to accumulate contaminants such as slurry and polishing debris during the polishing process, leading to clogging of the grooves and affecting the polishing efficiency and quality. Currently, the cleaning of the upper platen and the lower platen relies mainly on manual labor. Operators need to frequently remove contaminants from the grooves to maintain the openness of the grooves and the cleanliness of the platens. Although manual cleaning is the current common method, it has obvious shortcomings. First, manual cleaning is time-consuming and labor-intensive, increasing production costs and reducing production efficiency. Second, due to the complex structure of the grooves, manual cleaning cannot cover all areas thoroughly, resulting in incomplete cleaning and residual contaminants. In addition, long-term manual operation may cause damage to the equipment or pose a threat to the safety of the operators. Therefore, the existing cleaning method cannot meet the high standards of efficiency, precision, and reliability required by modern semiconductor manufacturing, and there is an urgent need for an automated and efficient cleaning solution.

[0032] To address the above problems, the present application provides a new technical solution aimed at improving cleaning efficiency and effectiveness through automated equipment.

[0033] Specifically, referring to Figure 1 and Figure 2 , the present application provides a cleaning device 10, which can include a scraper 11 and a nozzle 12. In the front view cross-sectional view in Figure 1 , the scraper 11 and the nozzle 12 are overlapped, and the scraper 11 is schematically shown by a box filled with dots, while the nozzle 12 is schematically shown by a box without filling.

[0034] The scraper 11 is used to be inserted into the grooves 20G of the polishing surface 20S of the platen 20 of the double-side polishing equipment 1 and move along the grooves 20G, and in the top view of Figure 2 , the grooves 20G on the platen 20 are schematically shown by curved arcs.

[0035] The nozzle 12 is arranged downstream of the scraper 11 in the moving direction of the scraper 11 and is arranged to move synchronously with the scraper 11, and the nozzle 12 is used to spray cleaning liquid CL, which is schematically shown by a dashed line segment in Figure 1 , into the grooves 20G. As shown in Figure 1 and Figure 2As shown in the figure, when the telescopic rod 30 rotates in the counterclockwise direction to move the scraper 11 and the nozzle 12 as described in more detail below, the scraper 11 is located in front of the counterclockwise direction and the nozzle 12 is located in the rear of the counterclockwise direction.

[0036] The cleaning device 10 can quickly remove contaminants in the groove 20G of the chuck 20 through the cooperation of the scraper 11 and the nozzle 12. The scraper 11 first scrapes the contaminants out of the groove 20G, and then the nozzle 12 sprays the cleaning liquid CL to flush the groove 20G, effectively removing residual contaminants and ensuring thorough cleaning of the chuck 20. Due to the synchronous movement design of the scraper 11 and the nozzle 12, it can be ensured that every part of the groove 20G can be continuously and thoroughly cleaned without dead angles, thereby improving the thoroughness of cleaning. By setting the scraper 11 and the nozzle 12 to move synchronously, the number of driving components required by the cleaning device 10 is reduced, thereby reducing manufacturing and maintenance costs. At the same time, this design simplifies the operation process, making it easier to automate the control of the cleaning device 10. The automated cleaning process reduces manual operation and reduces the risk of equipment damage caused by improper manual operation, while also improving the safety of the operator. Improve production efficiency: The automated cleaning device 10 can work continuously, reducing production interruptions caused by manual cleaning, thereby improving overall production efficiency. Timely and thorough cleaning can prevent potential damage to the chuck 20 caused by contaminants, prolong the service life of the equipment, and reduce maintenance costs. A clean chuck 20 can ensure that the groove 20G is unobstructed during the grinding process, thereby improving grinding efficiency and grinding quality and ensuring the flatness and quality of the wafer surface.

[0037] In some embodiments of the present application, referring to Figure 1 The scraper 11 can have a profile structure that is adapted to the inner wall 20W of the groove 20G, so that when the scraper 11 is inserted into the groove 20G, the scraper 11 is in close contact with the inner wall 20W of the groove 20G.

[0038] By designing the scraper 11 to be in close contact with the inner wall 20W of the groove 20G, the mortar and grinding debris in the groove can be more effectively scraped off. This design allows the scraper 11 to more thoroughly remove contaminants during movement, reducing residue and thereby improving cleaning efficiency. The close contact design of the scraper 11 and the inner wall 20W ensures that all areas within the groove 20G are accessible during movement of the scraper 11, which facilitates subsequent cleaning work by the nozzle 12, allowing the cleaning liquid CL to more effectively act on every corner of the groove 20G for thorough cleaning. Since the scraper 11 can scrape out as much mortar and grinding debris as possible, it reduces residue in the groove 20G, providing more favorable working conditions for the nozzle 12, which encounters less residue in the groove 20G, improving the efficiency and cleaning effect of the cleaning liquid CL.

[0039] In some embodiments of this utility model, see Figure 1 The cleaning device 10 may also include a booster 13, a supply pipe 14 schematically shown by thick solid lines, and a valve 15. The booster 13 is used to pressurize the cleaning fluid CL, thereby serving as a supply source for the cleaning fluid CL, or providing the power to make the cleaning fluid CL flow. The supply pipe 14 connects the booster 13 to the nozzle 12, so that the cleaning fluid CL flows from the booster 13 to the nozzle 12 under the power provided by the booster 13. The valve 15 is provided on the supply pipe 14 and is used to adjust the flow rate of the cleaning fluid CL ejected from the nozzle 12.

[0040] By utilizing the booster 13, supply pipe 14, and valve 15, the cleaning device 10 can flexibly adjust the flow rate of the cleaning fluid CL according to the amount and difficulty of removing residual contaminants in the trench 20G. When there are many contaminants or they are difficult to remove, the flow rate is increased to improve cleaning efficiency; when there are few contaminants or they are easy to remove, the flow rate is decreased to save cleaning fluid. This adjustment mechanism makes the cleaning process more efficient and economical. The valve 15 allows the flow rate of the cleaning fluid CL to be adjusted according to the actual situation, enhancing the adaptability of the cleaning device 10 to different contamination conditions and ensuring optimal cleaning results under various working conditions. The simple operation of the valve 15 allows for adjustment of the cleaning fluid CL flow rate, enabling operators to react quickly to actual conditions and enhancing the user experience.

[0041] In some embodiments of this utility model, see Figure 1 The nozzle 12 can be configured to spray the cleaning fluid CL to any position in the circumferential direction of the trench 20G. For example, as in Figure 1 When the horizontally placed plate 20 shown is cut by a vertical section, the beam formed by the cleaning fluid CL can directly reach any position on the intersection line between the inner wall 20W defining the groove 20G and the section, or in other words, can directly reach the entire intersection line.

[0042] The special configuration of the nozzle 12 enables the cleaning liquid CL to be sprayed to any position on the circumference of the groove 20G, which ensures direct flushing on the entire inner wall 20W without omission, thereby achieving a thorough cleaning effect. Since the cleaning liquid CL can reach any position of the inner wall 20W of the groove 20G, this comprehensive flushing mode improves the uniformity of cleaning and avoids poor grinding quality caused by uneven cleaning. The comprehensive contact of the cleaning liquid CL sprayed by the nozzle 12 with the inner wall 20W of the groove 20G enables the cleaning liquid CL to quickly remove residual mortar and grinding debris, improves the cleaning efficiency, and reduces the time required for cleaning. The comprehensive cleaning capacity of the nozzle 12 reduces the need for manual intervention in cleaning, reduces the risk of operators contacting hazardous substances, and improves the safety of operation.

[0043] Referring to Figure 1 and Figure 2 , the utility model embodiment still provides a double-sided grinding equipment 1, this double-sided grinding equipment 1 can include according to the cleaning device 10, fixed disc 20, telescopic rod 30 and first driver 40 of preceding each embodiment of the utility model.

[0044] The grinding surface 20S of the fixed disc 20 is formed with a groove 20G, and the groove 20G is distributed as a plurality of circular arcs with a common center C, and the common center C is located outside the fixed disc 20, Figure 1 and Figure 2 The common center C is schematically shown by a cross intersection symbol. The telescopic rod 30 is arranged parallel to the grinding surface 20S of the fixed disc 20, as more intuitively seen in Figure 1 The scraper 11 and the nozzle 12 are arranged on the telescopic rod 30. The first driver 40 is used to rotate the telescopic rod 30 around a rotation axis RX perpendicular to the grinding surface 20S of the fixed disc 20 and passing through the common center C.

[0045] The groove 20G is designed in a circular arc shape, which is more conducive to the discharge of contaminants such as mortar and grinding debris. The circular arc shape of the groove 20G reduces the retention of contaminants in the groove, making it easier for contaminants to flow out with the grinding liquid, thereby improving cleaning efficiency. The telescopic rod 30 allows the scraper 11 and the nozzle 12 to move radially along the diameter of the disc 20 and align with each circular arc-shaped groove 20G. This alignment mechanism ensures that the scraper 11 and the nozzle 12 can accurately act on each groove 20G, improving the targeting and effectiveness of cleaning. The first driver 40 moves the scraper 11 and the nozzle 12 along the circular arc-shaped groove 20G, in combination with the radial movement described above, to achieve cleaning of all grooves 20G. This movement mechanism ensures the continuity and comprehensiveness of the cleaning process, ensuring that each groove is thoroughly cleaned. Since the scraper 11 and the nozzle 12 can align with and move along each circular arc-shaped groove 20G, the cleaning process is more uniform, avoiding differences in grinding quality caused by uneven cleaning. Comprehensive and uniform cleaning reduces the need for equipment maintenance due to incomplete cleaning, reduces equipment failure rate, and extends equipment service life. The precise alignment and movement of the scraper 11 and the nozzle 12 reduce the need for manual intervention in cleaning, reducing the risk of operators coming into contact with hazardous substances and improving operational safety.

[0046] In some embodiments of the present application, referring to Figure 2 The grinding surface 20S of the disc 20 can include a first half 20S1 and a second half 20S2, with the diameter D of the grinding surface 20S as the dividing line. The first common center C1 of the plurality of circular arcs formed by the grooves 20G in the first half 20S1 can be symmetrical about the diameter D with the second common center C2 of the plurality of circular arcs formed by the grooves 20G in the second half 20S2.

[0047] Since the telescopic rod 30 does not need to be greatly extended, the scraper 11 and the nozzle 12 only move within the radius of the disc 20, avoiding deformation caused by the telescopic rod 30 greatly extending outward, reducing the risk of mechanical failure, and ensuring the stability and reliability of the cleaning device 10. The telescopic rod 30 does not need to be greatly extended, making the movement of the scraper 11 and the nozzle 12 within the radius of the disc 20 more precise, ensuring accurate cleaning of each groove 20G and improving cleaning efficiency. Avoiding the telescopic rod 30 greatly extending outward reduces the possibility of rod deformation caused by external forces, enhancing the structural stability of the entire cleaning device 10. Since there is no need to design and manufacture a complex structure that can withstand great extension, the manufacturing cost of the telescopic rod 30 is reduced, and the overall cost of the cleaning device 10 is also reduced. Reducing the telescopic rod 30's large extension action reduces the safety risks caused by mechanical failure during operation, improving operational safety.

[0048] In the case of the foregoing embodiment, in some embodiments of the utility model, refer to Figure 1 The double-sided polishing equipment 1 can further include a second driver 50 for rotating the chuck 20 by 180° about its central axis 20X.

[0049] By rotating the chuck 20 by 180° through the second driver 50, the cleaning device 10 can sequentially clean the grooves 20G of the first half 20S1 and the second half 20S2. This design avoids the movement of the cleaning device 10 relative to the chuck 20, simplifies the mechanical structure and operation process, and improves the cleaning efficiency. Without the need for a complex movement mechanism to move the cleaning device 10, the cleaning of all grooves 20G is achieved through the rotation of the chuck 20. This design simplifies the mechanical structure, reduces the manufacturing and maintenance costs. Since the moving parts of the cleaning device 10 are reduced, the possibility of failure caused by the movement mechanism is reduced, and the reliability and stability of the equipment are improved. The simplified operation process reduces the safety risk of the operator during the adjustment and movement of the equipment, improving the safety of the operation.

[0050] In some embodiments of the utility model, refer to Figure 1 The double-sided polishing equipment 1 can further include a position sensor 60 for sensing the relative positional relationship between the groove 20G and the rotation axis RX during the rotation of the chuck 20 about its central axis 20X, and issuing a command to stop the rotation of the chuck 20 when the rotation axis RX passes through the common center C.

[0051] The use of the position sensor 60 enables the cleaning device 10 to accurately position the groove 20G relative to itself, ensuring that the groove 20G is in the optimal cleaning position when performing the cleaning operation, thereby improving the cleaning efficiency and effect. By sensing the relative positional relationship between the groove 20G and the rotation axis RX through the position sensor 60 and issuing a stop rotation command at the appropriate time, the cleaning process is automated, reducing manual intervention and improving production efficiency. The position sensor 60 ensures that the chuck 20 is rotated to an accurate position suitable for the cleaning device 10 to perform the cleaning operation, improving the cleaning accuracy and avoiding incomplete cleaning due to inaccurate positioning. Precise control of the rotation and stopping of the chuck 20 reduces equipment wear and tear caused by frequent or inaccurate positioning, prolonging the service life of the equipment. The automated cleaning process reduces the safety risk of the operator during the adjustment and movement of the equipment, improving the safety of the operation.

[0052] In some embodiments of the utility model, refer to Figure 3, the upper platen 21 can be formed with a lower grinding surface 21S, the lower platen 22 can be formed with an upper grinding surface 22S, and the double-sided polishing apparatus 1 can further include a third driver 70 configured to rotate the telescopic rod 30 by 180° about a longitudinal axis 30X of the telescopic rod 30.

[0053] By rotating the telescopic rod 30 with the third driver 70, the cleaning device 10 can clean not only the grooves 20G of the upper platen 21 but also the grooves 20G of the lower platen 22, which improves the flexibility and efficiency of the cleaning work. By controlling the rotation of the telescopic rod 30 with the third driver 70, the operation process is simplified, the operation of the apparatus is facilitated, and the cleaning work is more convenient. The cleaning device 10 can serve both the upper platen 21 and the lower platen 22 at the same time, which improves the utilization rate and cleaning efficiency of the apparatus. No additional apparatus or device is needed to clean the upper platen 21 and the lower platen 22 separately, which reduces the investment cost of the apparatus.

[0054] In some embodiments of the present application, referring to Figure 3 , the platen 20 can be formed with discharge outlets 20E for discharging the contaminants and the cleaning liquid CL, and the discharge outlets 20E can be formed at the center and the end of each circular arc. Figure 3 For the purpose of clarity of the drawings, only the discharge outlets 20E at the center and the end of a single circular arc of the lower platen 22 are shown.

[0055] The formation of the discharge outlets 20E at the center and the end of each circular arc enables the contaminants and the cleaning liquid CL to be discharged more quickly and directly from the grooves 20G, which improves the efficiency of the discharge of the contaminants. The provision of the discharge outlets 20E helps to reduce the residue of the contaminants in the grooves 20G, because the contaminants can be discharged more quickly, reducing the residence time in the grooves. The position design of the discharge outlets 20E enables the cleaning device 10 to more thoroughly remove the contaminants in the grooves 20G during the cleaning process, enhancing the overall cleaning effect. The reduction of the residue of the contaminants in the grooves 20G reduces the need for equipment maintenance due to clogging or accumulation of the contaminants, prolonging the service life of the apparatus. The discharge outlets 20E help to reduce the risk of operators contacting the contaminants, because the contaminants can be quickly discharged and collected during the cleaning process, improving the safety of the operation. The design of the discharge outlets 20E helps to reduce the additional energy consumption required during the cleaning process, because the contaminants and the cleaning liquid CL can be discharged more quickly.

[0056] It should be noted that the technical solutions described in the present application can be combined arbitrarily without conflict.

[0057] The above merely describes a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A cleaning device, characterized in that, The cleaning device comprises: a scraper for being inserted into and moving along a groove of a polishing surface of a chuck plate of a double-sided polishing apparatus; a nozzle disposed downstream of the scraper in a moving direction of the scraper and configured to move synchronously with the scraper, the nozzle for spraying a cleaning liquid into the groove.

2. The cleaning device of claim 1, wherein, The scraper has a profile structure adapted to an inner wall of the groove, such that when the scraper is inserted into the groove, the scraper fits the inner wall of the groove.

3. A cleaning device according to claim 1 or 2, characterised in that, The cleaning device further comprises: a pressure booster for pressurizing the cleaning liquid; a supply conduit communicating the pressure booster with the nozzle; a valve disposed on the supply conduit and for adjusting a flow rate of the cleaning liquid sprayed from the nozzle.

4. The cleaning device of claim 1 or 2, wherein The nozzle is configured to enable the cleaning liquid to be sprayed at any position in a circumferential direction of the groove.

5. A double-sided polishing apparatus characterized by comprising: The double-sided polishing apparatus comprises: a chuck plate, a polishing surface of the chuck plate being formed with a groove, the groove being distributed as a plurality of circular arcs having a common center, the common center being located outside the chuck plate; an extendable rod disposed in parallel with the polishing surface of the chuck plate; the cleaning device according to any one of claims 1 to 4, the scraper and the nozzle being disposed on the extendable rod; a first driver for rotating the extendable rod about a rotation axis perpendicular to the polishing surface of the chuck plate and passing through the common center.

6. The double-sided polishing apparatus according to claim 5, wherein The polishing surface of the chuck plate comprises a first half and a second half divided by a diameter of the polishing surface, a first common center of the plurality of circular arcs of the groove of the first half being symmetric to a second common center of the plurality of circular arcs of the groove of the second half about the diameter.

7. The double-sided polishing apparatus according to claim 6, wherein The double-sided polishing apparatus further comprises a second driver for rotating the chuck plate about a central axis thereof by 180°.

8. The double-sided polishing apparatus according to any one of claims 5 to 7, wherein The double-sided polishing apparatus further comprises a position sensor for sensing a relative positional relationship between the groove and the rotation axis during rotation of the chuck plate about the central axis thereof, and issuing an instruction for stopping rotation of the chuck plate when the rotation axis passes through the common center.

9. The double-sided polishing apparatus according to any one of claims 5 to 7, wherein The chuck plate comprises an upper chuck plate and a lower chuck plate, a lower polishing surface of the upper chuck plate being formed with the groove, an upper polishing surface of the lower chuck plate being formed with the groove, and the double-sided polishing apparatus further comprises a third driver for rotating the extendable rod about a longitudinal axis thereof by 180°.

10. The double-sided polishing apparatus according to any one of claims 5 to 7, wherein The chuck plate is formed with a discharge outlet for discharging the cleaned contaminants and the cleaning liquid, the discharge outlet being formed at a center and an end of each circular arc.

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