Polishing pad cleaning apparatus and polishing pad cleaning method

Abstract

The application provides a polishing pad cleaning device and a polishing pad cleaning method, and relates to the technical field of semiconductors.The polishing pad cleaning device comprises a fixing support, a cleaning nozzle connected with the fixing support through a connecting arm, the cleaning nozzle being capable of rotating around the fixing support, the cleaning nozzle being used for spraying cleaning liquid to the upper polishing pad and the lower polishing pad when the cleaning nozzle rotates to between the upper polishing pad and the lower polishing pad, a detection assembly fixedly connected with the cleaning nozzle, the detection assembly comprising an emitting assembly and a receiving assembly, the emitting assembly being used for emitting a detection signal to the lower polishing pad, and the receiving assembly being used for receiving the detection signal reflected by the lower polishing pad or a silicon wafer carrier, and a processor used for obtaining a reflection result of the detection signal and determining whether the detection signal is reflected by the lower polishing pad or the silicon wafer carrier according to the reflection result.The application can ensure that the cleaning liquid is completely sprayed onto the upper polishing pad and the lower polishing pad, and the cleaning effect is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to a polishing pad cleaning apparatus and a polishing pad cleaning method. Background Technology

[0002] In existing double-sided polishing processes, a double-sided polishing device rotates the silicon wafer, and alkaline additives in the polishing slurry etch silicates onto the wafer surface. The silicates are then removed through friction between the polishing pad and SiO2 particles in the polishing slurry, thus removing the damaged surface layer and achieving a highly flat, mirror-like finish. However, after each polishing cycle, silicates generated during the process, tiny debris falling from the wafer surface, and SiO2 particles from the polishing slurry easily form aggregates and remain on the polishing pad.

[0003] After each polishing process, the surface of the polishing pad is sprayed or high-pressure cleaned with high-purity water. During the spraying or high-pressure cleaning, the polishing pad rotates, and the residue flushed out by the high-purity water is thrown out by centrifugal motion, ensuring that there is no residue left on the surface of the polishing pad before the next polishing process.

[0004] However, since the carrier tray used to place silicon wafers in the double-sided polishing equipment is placed on the polishing pad manually by the operator, the technique of each operator is slightly different, which leads to deviations in the position of the carrier tray on the polishing pad. Alternatively, the rotation of the carrier tray caused by the inner and outer pin rings can also cause the carrier tray to shift in position on the polishing pad. In summary, due to the shift in the position of the carrier tray on the polishing pad, the water jet sprayed from the cleaning nozzle hits the carrier tray, and a ring-shaped glaze layer appears in the polishing pad area blocked by the carrier tray, causing scratches and defects in the products processed later. Summary of the Invention

[0005] This invention provides a polishing pad cleaning device and a polishing pad cleaning method to solve the problem in the prior art where the high-purity water is blocked by the support plate when cleaning the polishing pad, resulting in poor cleaning effect.

[0006] To address the aforementioned technical problems, embodiments of the present invention provide the following technical solutions:

[0007] In a first aspect, embodiments of the present invention provide a polishing pad cleaning device applied to a double-sided polishing equipment. The double-sided polishing equipment includes an upper fixed plate and a lower fixed plate disposed opposite to each other. An upper polishing pad is disposed on the side of the upper fixed plate facing the lower fixed plate, and a lower polishing pad is disposed on the side of the lower fixed plate facing the upper fixed plate. A plurality of silicon wafer carriers are disposed on the lower polishing pad. The polishing pad cleaning device includes:

[0008] A fixing bracket is provided on one side of the lower polishing pad;

[0009] The cleaning nozzle, connected to the fixed bracket via a connecting arm, is rotatable around the fixed bracket. When the cleaning nozzle rotates between the upper polishing pad and the lower polishing pad, it is used to spray cleaning liquid onto the upper polishing pad and the lower polishing pad.

[0010] A detection assembly fixedly connected to the cleaning nozzle, the detection assembly including a transmitting assembly and a receiving assembly, the transmitting assembly being used to transmit a detection signal to the lower polishing pad, and the receiving assembly being used to receive a detection signal reflected by the lower polishing pad or the silicon wafer carrier.

[0011] The processor is configured to acquire the reflection result of the detection signal and determine, based on the reflection result, whether the detection signal is reflected by the lower polishing pad or by the silicon wafer carrier.

[0012] In some embodiments, the connecting arm is connected to the side of the cleaning nozzle;

[0013] The detection components are disposed on the side of the cleaning nozzle, and there are two detection components;

[0014] The first detection component of the two detection components is located on the side of the cleaning nozzle at the position furthest from the connecting arm, and the second detection component of the two detection components is located between the connecting arm and the first detection component.

[0015] In some embodiments, the distance between the second detection component and the connecting arm is equal to the distance between the second detection component and the first detection component.

[0016] In some embodiments, the first detection component and the second detection component are located at the same horizontal level.

[0017] In some embodiments, the transmitting component includes at least one of the following:

[0018] Radar signal transmitter;

[0019] Ultrasonic signal transmitter;

[0020] Laser signal transmitter;

[0021] The receiving component includes at least one of the following:

[0022] Radar signal receiver;

[0023] Ultrasonic signal receiver;

[0024] Laser signal receiver.

[0025] In a second aspect, embodiments of the present invention also provide a double-sided polishing device, including a polishing pad cleaning device as described in any one of the first aspects.

[0026] Thirdly, embodiments of the present invention also provide a polishing pad cleaning method, applied to the polishing pad cleaning apparatus as described in any one of the first aspects, the method comprising:

[0027] When the cleaning nozzle rotates between the upper polishing pad and the lower polishing pad, a detection signal is emitted to the lower polishing pad via the transmitting component, and a detection signal reflected by the lower polishing pad or silicon wafer carrier is received via the receiving component.

[0028] Obtain the reflection result of the detected signal;

[0029] Based on the reflection result, control the cleaning nozzle to stop or start spraying cleaning fluid;

[0030] The reflection result is used to indicate whether the detection signal is reflected by the lower polishing pad or by the silicon wafer carrier.

[0031] In some embodiments, the reflection result includes the time difference between the transmitting component transmitting the detection signal and the receiving component receiving the detection signal, and the phase difference between the transmitting component transmitting the detection signal and the receiving component receiving the detection signal;

[0032] Based on the reflection result, controlling the cleaning nozzle to stop or start spraying cleaning fluid includes:

[0033] The target distance between the transmitting component and the signal reflection point is determined based on the time difference and the phase difference.

[0034] The thickness of the silicon wafer carrier is determined based on the target distance;

[0035] When the target distance is a first distance, it is determined that the detection signal is reflected by the lower polishing pad; when the target distance is a second distance, it is determined that the detection signal is reflected by the silicon wafer carrier disk, wherein the first distance is greater than the second distance.

[0036] When the detection signal is reflected by the lower polishing pad, the cleaning nozzle is controlled to spray cleaning fluid; when the detection signal is reflected by the silicon wafer carrier, the cleaning nozzle is controlled to stop spraying cleaning fluid.

[0037] In some embodiments, the reflection result includes the signal strength of the detected signal;

[0038] Based on the reflection result, controlling the cleaning nozzle to stop or start spraying cleaning fluid includes:

[0039] Based on the signal strength of the detection signal, determine whether the detection signal is reflected by the lower polishing pad or by the silicon wafer carrier.

[0040] When the detection signal is reflected by the lower polishing pad, the cleaning nozzle is controlled to spray cleaning fluid; when the detection signal is reflected by the silicon wafer carrier, the cleaning nozzle is controlled to stop spraying cleaning fluid.

[0041] In some embodiments, the method further includes:

[0042] When the detection signal is reflected from the silicon wafer carrier, a warning message is generated.

[0043] The embodiments of the present invention have the following beneficial effects:

[0044] The polishing pad cleaning device provided in this embodiment of the invention emits a detection signal to the lower polishing pad through the transmitting component in the detection component, and receives the detection signal reflected by the lower polishing pad or the silicon wafer carrier through the receiving component. Based on the reflection result of the detection signal, it is determined whether the detection signal is reflected by the lower polishing pad or the silicon wafer carrier. If the detection signal is emitted by the lower polishing pad, it means that the transmission path of the detection signal does not pass through the silicon wafer carrier. At this time, the cleaning nozzle is controlled to rotate between the upper and lower polishing pads and spray cleaning liquid (such as high-purity water) onto the upper and lower polishing pads. This can prevent the cleaning liquid from being blocked by the silicon wafer carrier and ensure that all the cleaning liquid is sprayed onto the upper and lower polishing pads, thus ensuring the cleaning effect. If the detection result determines that the detection signal is reflected by the silicon wafer carrier, it means that the transmission path of the detection signal passes through the silicon wafer carrier. In order to prevent the cleaning liquid from being sprayed onto the silicon wafer carrier and causing a glaze layer to appear on the polishing pad, the cleaning nozzle is controlled to stop spraying the cleaning liquid. Attached Figure Description

[0045] Figure 1 This is one of the structural schematic diagrams of the polishing pad cleaning device provided in an embodiment of the present invention;

[0046] Figure 2 This is the second schematic diagram of the structure of the polishing pad cleaning device provided in the embodiment of the present invention;

[0047] Figure 3 This is a flowchart illustrating the polishing pad cleaning method provided in an embodiment of the present invention.

[0048] Figure label:

[0049] 1: Upper mounting plate; 2: Lower mounting plate; 3: Upper polishing pad; 4: Lower polishing pad; 5: Silicon wafer carrier; 51: Accommodation hole; 6: Connecting arm; 7: Cleaning nozzle; 8: First motion trajectory; 9: First detection component; 10: Second detection component; 11: Second motion trajectory; 301-303: Steps. Detailed Implementation

[0050] To make the technical problems, technical solutions and advantages of the embodiments of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0052] To address the problem of poor cleaning effect caused by the high-purity water being blocked by the support plate during polishing pad cleaning in the prior art, this invention provides a polishing pad cleaning device and a polishing pad cleaning method.

[0053] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a polishing pad cleaning device applied to a double-sided polishing equipment. The double-sided polishing equipment includes an upper fixed plate 1 and a lower fixed plate 2 arranged opposite to each other. An upper polishing pad 3 is provided on the side of the upper fixed plate 1 facing the lower fixed plate 2, and a lower polishing pad 4 is provided on the side of the lower fixed plate 2 facing the upper fixed plate 1. Multiple silicon wafer carriers 5 are provided on the lower polishing pad 4. During the polishing process, the silicon wafer is first placed in the receiving hole 51 of the silicon wafer carrier 5. Polishing is achieved by the high pressure of the upper and lower fixed plates, the rotation of the upper and lower fixed plates, and the rotation of the silicon wafer carrier 5 driven by the inner and outer pin rings.

[0054] The polishing pad cleaning device includes:

[0055] A fixing bracket is provided on one side of the lower polishing pad 4;

[0056] The cleaning nozzle 7, which is connected to the fixed bracket via the connecting arm 6, is rotatable around the fixed bracket. When the cleaning nozzle 7 rotates between the upper polishing pad 3 and the lower polishing pad 4, the cleaning nozzle 7 is used to spray cleaning liquid onto the upper polishing pad 3 and the lower polishing pad 4.

[0057] A detection assembly fixedly connected to the cleaning nozzle 7 includes a transmitting assembly and a receiving assembly. The transmitting assembly is used to transmit a detection signal to the lower polishing pad 4, and the receiving assembly is used to receive the detection signal reflected by the lower polishing pad 4 or the silicon wafer carrier 5.

[0058] The processor is configured to acquire the reflection result of the detection signal and determine, based on the reflection result, whether the detection signal is reflected by the lower polishing pad 4 or by the silicon wafer carrier disk 5.

[0059] It should be noted that, since multiple silicon wafer carriers 5 are arranged on the lower polishing pad 4, and there is a gap between every two adjacent silicon wafer carriers 5, the polishing pad cleaning device provided in this embodiment of the invention aims to achieve the effect of rotating the cleaning nozzle 7 through the connecting arm 6 within the gap between adjacent silicon wafer carriers 5 and spraying cleaning liquid into the gap. In this state, as... Figure 1 As shown, the first movement trajectory 8 of the cleaning nozzle 7 is as follows: Figure 2 As shown.

[0060] For example, the cleaning solution is ultrapure water. It should be noted that other liquids with cleaning effects besides ultrapure water can also be used as the cleaning solution provided in the embodiments of the present invention, and are not limited thereto.

[0061] Because the lower polishing pad 4 and the silicon wafer carrier 5 are made of different materials, the reflection intensity of the detection signal received by the receiving component after reflection by the lower polishing pad 4 and the silicon wafer carrier 5 is different. Using this characteristic, it can be determined whether the detection signal is reflected by the lower polishing pad 4 or the silicon wafer carrier 5. Alternatively, because the lower polishing pad 4 and the silicon wafer carrier 5 are at different heights in the vertical direction, the transmission distance of the detection signal after reflection by the lower polishing pad 4 and the silicon wafer carrier 5 is different. Based on this characteristic, it can also be determined whether the detection signal is reflected by the lower polishing pad 4 or the silicon wafer carrier 5.

[0062] Furthermore, since a receiving hole 51 for accommodating the silicon wafer is provided inside the silicon wafer carrier 5, and this receiving hole 51 is a through hole, in order to avoid the situation where the detection signal is reflected through the lower polishing pad 4 corresponding to the receiving hole 51, preferably, during detection, the cleaning nozzle 7 is controlled to drive the detection component to rotate gradually from the edge of the lower polishing pad 4 to the center of the lower polishing pad 4. After the cleaning nozzle 7 rotates to between the upper polishing pad 3 and the lower polishing pad 4, the transmitting component emits a detection signal in real time in the direction of the lower polishing pad 4, and the receiving component receives the detection signal in real time. If the reflection result of the detection signal indicates that the detection signal is reflected through the lower polishing pad 4, the cleaning nozzle 7 is controlled to spray cleaning liquid onto the upper polishing pad 3 and the lower polishing pad 4. If the reflection result indicates that the detection signal is reflected through the silicon wafer carrier 5, the cleaning nozzle 7 is controlled to stop spraying cleaning liquid onto the upper polishing pad 3 and the lower polishing pad 4.

[0063] It should also be noted that if the cleaning fluid is sprayed onto the silicon wafer carrier 5, it cannot clean the polishing fluid residue on the portion of the lower polishing pad 4 covered by the silicon wafer carrier 5. Over time, a ring-shaped polishing fluid glaze layer will form on this portion of the lower polishing pad, causing scratches or ring-shaped patterns on subsequent processed products, resulting in a large number of product defects. Therefore, the polishing pad cleaning device provided in this embodiment of the invention can reduce the problems of ring-shaped glaze and product defects caused by inadequate cleaning of the polishing pad.

[0064] As an optional embodiment, the detection component is disposed on the side of the cleaning nozzle 7;

[0065] The number of detection components is at least two, and the at least two detection components are evenly distributed along the circumference of the cleaning nozzle 7.

[0066] To ensure the detection effect of the detection signal, at least two detection components are evenly distributed around the cleaning nozzle 7 in this embodiment. The transmitting component in each detection component emits a detection signal to the lower polishing pad 4, and the corresponding receiving component receives the detection signal. When the reflection result of the detection signal corresponding to each detection component indicates that the detection signal is reflected by the lower polishing pad 4, the cleaning nozzle 7 is controlled to spray cleaning liquid onto the upper polishing pad 3 and the lower polishing pad 4, which can increase the accuracy of the detection.

[0067] As another optional embodiment, the connecting arm 6 is connected to the side of the cleaning nozzle 7;

[0068] The detection components are disposed on the side of the cleaning nozzle 7. There are two detection components. The first detection component 9 is disposed on the side of the cleaning nozzle 7 at the position furthest from the connecting arm 6. The second detection component 10 is disposed between the connecting arm 6 and the first detection component 9.

[0069] In this optional embodiment, the first detection component 9 is located at the furthest point from the connecting arm 6. The reflection result corresponding to the detection signal emitted by the first detection component 9 can determine whether the position on the cleaning nozzle 7 furthest from the connecting arm 6 covers the silicon wafer carrier 5. The second detection component 10 is located between the connecting arm 6 and the first detection component 9. The reflection result corresponding to the detection signal emitted by the second detection component can determine whether the position on the cleaning nozzle 7 between the connecting arm 6 and the first detection component 9 covers the silicon wafer carrier 5. If the reflection results corresponding to the detection signal emitted by the first detection component 9 and the detection signal emitted by the second detection component 10 both indicate that the detection signal is reflected by the lower polishing pad 4, controlling the cleaning nozzle 7 to spray cleaning liquid onto the upper polishing pad 3 and the lower polishing pad 4 can increase the accuracy of the detection.

[0070] Furthermore, in this optional embodiment, based on the characteristic that the transmission distance of the detection signal is different after the reflection result after the detection signal is reflected by the lower polishing pad 4 and the silicon wafer carrier 5, if the detection result corresponding to the detection signal emitted by the first detection component 9 indicates that the continuously emitted detection signal is reflected by the lower polishing pad 4, then by the silicon wafer carrier 5, and then by the lower polishing pad 4 again, the second trajectory 11 of the signal is as follows: Figure 2 As shown, the indicator detection signal in the reflection result corresponding to the continuous detection signal emitted by the second detection component 10 is reflected by the lower polishing pad 4. Therefore, the thickness of the silicon wafer carrier 5 can be determined based on the reflection results of the detection signals emitted by the first detection component 9 and the second detection component 10. Thus, this optional embodiment can also detect the thickness of the silicon wafer carrier 5, reducing the situation where the silicon wafer thickness is not up to standard due to the silicon wafer carrier being too thin.

[0071] Wherein, the distance between the second detection component 10 and the connecting arm 6 and the distance between the second detection component 10 and the first detection component 9 are equal, that is, the second detection component 10 is disposed between the connecting arm 6 and the first detection component 9, and the movement trajectory of the second detection component 10 is as shown in the first movement trajectory 8 above.

[0072] The first detection component 9 and the second detection component 10 are located at the same horizontal height. When detecting the thickness of the silicon wafer carrier 5 based on the above principle, or when determining whether the detection signal is reflected by the lower polishing pad 4 or the silicon wafer carrier 5 based on the characteristic that the transmission distance of the detection signal is different after reflection by the lower polishing pad 4 and the silicon wafer carrier 5, setting the first detection component 9 and the second detection component 10 at the same height allows for a simpler and faster determination of the thickness of the silicon wafer carrier 5 or whether the detection signal is reflected by the lower polishing pad 4 or the silicon wafer carrier 5.

[0073] In some embodiments, the transmitting component includes at least one of the following:

[0074] Radar signal transmitter;

[0075] Ultrasonic signal transmitter;

[0076] Laser signal transmitter;

[0077] The receiving component includes at least one of the following:

[0078] Radar signal receiver;

[0079] Ultrasonic signal receiver;

[0080] Laser signal receiver.

[0081] It should be noted that the types of transmitting and receiving components belonging to the same detection component must be consistent. Depending on the requirements, the types of transmitting and receiving components between different detection components may be different, and this embodiment does not impose any restrictions.

[0082] This invention also provides a double-sided polishing device, including the polishing pad cleaning device as described in any one of the above embodiments.

[0083] It should be noted that the double-sided polishing equipment provided in the embodiments of the present invention includes the polishing pad cleaning device as described above. Therefore, all embodiments of the polishing pad cleaning device described above are applicable to the double-sided polishing equipment and can achieve the same or similar technical effects.

[0084] like Figure 3 As shown, this embodiment of the invention also provides a polishing pad cleaning method, applied to the polishing pad cleaning apparatus as described in any one of the above descriptions, the method comprising:

[0085] Step 301: When the cleaning nozzle rotates between the upper polishing pad and the lower polishing pad, a detection signal is emitted to the lower polishing pad via the transmitting component, and a detection signal reflected by the lower polishing pad or silicon wafer carrier is received via the receiving component.

[0086] Preferably, in this step, when the cleaning nozzle rotates between the upper polishing pad and the lower polishing pad, a detection signal is emitted from the edge of the lower polishing pad to the center of the lower polishing pad via the transmitting component, and the detection signal is continuously emitted and received as the cleaning nozzle rotates.

[0087] Step 302: Obtain the reflection result of the detection signal.

[0088] The reflection result includes the reflection intensity of the detection signal, or the reflection result includes the transmission distance of the detection signal.

[0089] Step 303: Based on the reflection result, control the cleaning nozzle to stop or start spraying cleaning fluid;

[0090] The reflection result is used to indicate whether the detection signal is reflected by the lower polishing pad or by the silicon wafer carrier.

[0091] It should be noted that, due to the different materials of the lower polishing pad 4 and the silicon wafer carrier 5, the reflection intensity of the detection signal received by the receiving component after reflection by the lower polishing pad 4 and the silicon wafer carrier 5 is different. Based on the reflection results, it can be determined whether the detection signal is reflected by the lower polishing pad or the silicon wafer carrier. Alternatively, because the lower polishing pad 4 and the silicon wafer carrier 5 are at different heights in the vertical direction, the transmission distance of the detection signal after reflection by the lower polishing pad 4 and the silicon wafer carrier 5 is different. Based on the reflection results, it can be determined whether the detection signal is reflected by the lower polishing pad or the silicon wafer carrier.

[0092] As an optional embodiment, the reflection result includes the time difference between the transmitting component transmitting the detection signal and the receiving component receiving the detection signal, as well as the phase difference between the transmitting component transmitting the detection signal and the receiving component receiving the detection signal;

[0093] Based on the reflection result, controlling the cleaning nozzle to stop or start spraying cleaning fluid includes:

[0094] The target distance between the transmitting component and the signal reflection point is determined based on the time difference and the phase difference. Specifically, different detection signals have different transmission speeds. The target distance between the transmitting component and the signal reflection point can be calculated based on the transmission speed, time difference, and phase difference of the detection signals.

[0095] When the target distance is a first distance, it is determined that the detection signal is reflected by the lower polishing pad. When the target distance is a second distance, it is determined that the detection signal is reflected by the silicon wafer carrier. The first distance is greater than the second distance. The first distance and the second distance can be pre-calibrated. The first distance can be understood as the distance between the emitting component and the lower polishing pad, and the second distance can be understood as the distance between the emitting component and the silicon wafer carrier. Alternatively, it can be understood as the emitting component continuously emitting detection signals from the edge of the lower polishing pad to the center of the lower polishing pad. The target distance is determined to start as the first distance based on the reflection result of the detection signal. If the first distance is maintained thereafter, it indicates that the detection signal is always reflected by the lower polishing pad. If the target distance is determined to start as the first distance based on the reflection result of the detection signal, and then the target distance decreases to the second distance, it indicates that the detection signal is initially reflected by the lower polishing pad and then reflected by the silicon wafer carrier.

[0096] When the detection signal is reflected by the lower polishing pad, the cleaning nozzle is controlled to spray cleaning fluid. When the detection signal is reflected by the silicon wafer carrier, the cleaning nozzle is controlled to stop spraying cleaning fluid. This ensures that the cleaning fluid is sprayed onto the lower polishing pad, reducing problems such as ring glazing and product defects caused by inadequate cleaning of the polishing pad.

[0097] Furthermore, the method also includes:

[0098] The thickness of the silicon wafer carrier is determined based on the target distance.

[0099] Specifically, the control emission component continuously emits detection signals from the edge of the lower polishing pad to the center of the lower polishing pad. If the target distance is initially determined to be the first distance based on the reflection result of the detection signal, and then decreases to the second distance, it indicates that the detection signal was initially reflected from the lower polishing pad and then reflected from the silicon wafer carrier. Based on the change in the target distance, the thickness of the silicon wafer carrier can be determined. If the silicon wafer carrier is too thin, a warning is issued, thereby reducing the occurrence of substandard silicon wafer thickness due to an excessively thin silicon wafer carrier.

[0100] As another optional embodiment, the reflection result includes the signal strength of the detected signal;

[0101] Based on the reflection result, controlling the cleaning nozzle to stop or start spraying cleaning fluid includes:

[0102] Based on the signal strength of the detection signal, it is determined whether the detection signal is reflected by the polishing pad or by the silicon wafer carrier. If the detection signal is reflected by the polishing pad, the cleaning nozzle is controlled to spray cleaning fluid. If the detection signal is reflected by the silicon wafer carrier, the cleaning nozzle is controlled to stop spraying cleaning fluid. This ensures that the cleaning fluid is sprayed onto the lower polishing pad, reducing problems such as ring glazing and product defects caused by inadequate cleaning of the polishing pad.

[0103] In some embodiments, the method further includes:

[0104] When the detection signal is reflected by the silicon wafer carrier, a warning message is generated to remind the operator that the silicon wafer carrier is not positioned correctly on the lower polishing pad, allowing the operator to determine whether adjustment is necessary.

[0105] It should be noted that the polishing pad cleaning method provided in the embodiments of the present invention is applied to the polishing pad cleaning device as described in any one of the above. Therefore, all embodiments of the polishing pad cleaning device described above are applicable to this method and can achieve the same or similar technical effects.

[0106] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A polishing pad cleaning device, applied to a double-sided polishing equipment, the double-sided polishing equipment comprising an upper fixed plate and a lower fixed plate arranged opposite to each other, an upper polishing pad being disposed on the side of the upper fixed plate facing the lower fixed plate, and a lower polishing pad being disposed on the side of the lower fixed plate facing the upper fixed plate, wherein a plurality of silicon wafer carriers are disposed on the lower polishing pad, and a gap exists between every two adjacent silicon wafer carriers, characterized in that, The polishing pad cleaning device includes: A fixing bracket is provided on one side of the lower polishing pad; A cleaning nozzle connected to the fixed bracket via a connecting arm is rotatable around the fixed bracket. When the cleaning nozzle rotates between the upper polishing pad and the lower polishing pad, it sprays cleaning fluid onto both pads. The connecting arm also drives the cleaning nozzle to rotate within the gap between adjacent silicon wafer carriers, spraying cleaning fluid into the gap. A detection assembly fixedly connected to the cleaning nozzle includes a transmitting assembly and a receiving assembly. The transmitting assembly transmits a detection signal to the lower polishing pad, and the receiving assembly receives the detection signal reflected by the lower polishing pad or the silicon wafer carrier. The processor is configured to acquire the reflection result of the detection signal, wherein the reflection result includes the time difference between the transmission component transmitting the detection signal and the reception component receiving the detection signal, and the phase difference between the transmission and reception of the detection signal; determine a target distance between the transmission component and the signal reflection point based on the time difference and the phase difference; determine that the detection signal is reflected by the lower polishing pad when the target distance is a first distance, and determine that the detection signal is reflected by the silicon wafer carrier when the target distance is a second distance, wherein the first distance is greater than the second distance; and control the cleaning nozzle to spray cleaning fluid when it is determined that the detection signal is reflected by the lower polishing pad, and control the cleaning nozzle to stop spraying cleaning fluid when it is determined that the detection signal is reflected by the silicon wafer carrier.

2. The polishing pad cleaning device according to claim 1, characterized in that, The connecting arm is connected to the side of the cleaning nozzle; The detection components are disposed on the side of the cleaning nozzle, and there are two detection components; The first detection component of the two detection components is located on the side of the cleaning nozzle at the position furthest from the connecting arm, and the second detection component of the two detection components is located between the connecting arm and the first detection component.

3. The polishing pad cleaning device according to claim 2, characterized in that, The distance between the second detection component and the connecting arm is equal to the distance between the second detection component and the first detection component.

4. The polishing pad cleaning device according to claim 2, characterized in that, The first detection component and the second detection component are located at the same horizontal level.

5. The polishing pad cleaning device according to claim 1, characterized in that, The launching component includes at least one of the following: Radar signal transmitter; Ultrasonic signal transmitter; Laser signal transmitter; The receiving component includes at least one of the following: Radar signal receiver; Ultrasonic signal receiver; Laser signal receiver.

6. A double-sided polishing device, characterized in that, The polishing pad cleaning device includes any one of claims 1-5.

7. A method for cleaning a polishing pad, characterized in that, The method, applied to the polishing pad cleaning apparatus as described in any one of claims 1-5, comprises: When the cleaning nozzle rotates between the upper polishing pad and the lower polishing pad, a detection signal is emitted to the lower polishing pad via the transmitting component, and a detection signal reflected by the lower polishing pad or silicon wafer carrier is received via the receiving component. The reflection result of the detection signal is obtained, wherein the reflection result includes the time difference between the transmitting component transmitting the detection signal and the receiving component receiving the detection signal, and the phase difference between the transmitting component transmitting the detection signal and the receiving component receiving the detection signal; a target distance between the transmitting component and the signal reflection point is determined based on the time difference and the phase difference; if the target distance is a first distance, it is determined that the detection signal is reflected by the lower polishing pad, and if the target distance is a second distance, it is determined that the detection signal is reflected by the silicon wafer carrier, wherein the first distance is greater than the second distance; if it is determined that the detection signal is reflected by the lower polishing pad, the cleaning nozzle is controlled to spray cleaning fluid, and if it is determined that the detection signal is reflected by the silicon wafer carrier, the cleaning nozzle is controlled to stop spraying cleaning fluid.

8. The method according to claim 7, characterized in that, The method further includes: The thickness of the silicon wafer carrier is determined based on the target distance.

9. The method according to claim 7, characterized in that, The method further includes: When the detection signal is reflected from the silicon wafer carrier, a warning message is generated.

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