A polishing apparatus and a control method thereof

Abstract

This application discloses a polishing apparatus and its control method. The polishing apparatus includes a polishing component, a measuring unit, and a control unit. The polishing component includes a polishing head and a polishing pad, the polishing head being used to press the wafer to be polished onto the surface of the polishing pad. The measuring unit is coupled to the polishing component and configured to determine an actual measured value, the actual measured value representing the actual contact area between the measuring unit and a portion of the polishing slurry output to the polishing component. The control unit is coupled to both the polishing component and the measuring unit and is configured to adjust the liquid flow rate of the polishing slurry based on the actual measured value. By configuring the above-described technical features, the accuracy of the liquid flow rate control of the polishing slurry during wafer polishing can be improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, specifically to a grinding apparatus and its control method. Background Technology

[0002] CMP (Chemical Mechanical Polishing) is a process used to planarize the surface of a wafer during semiconductor manufacturing.

[0003] In the CMP (Chemical Metallurgy) process for wafer polishing, the flow rate of the polishing slurry can affect the polishing effect and wafer quality. In related technologies, besides using a fixed flow rate for wafer polishing, optical film thickness measuring devices can be used to measure film thickness, allowing for adjustment of the slurry flow rate based on the film thickness. However, this method suffers from cumbersome film thickness measurement and low accuracy, which in turn leads to low accuracy in the corresponding flow control. Summary of the Invention

[0004] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by this application is how to improve the accuracy and convenience of liquid flow control of grinding fluid.

[0005] To address at least one of the aforementioned technical problems, this application discloses a grinding apparatus and its control method.

[0006] According to one aspect of this application, a grinding apparatus is provided, comprising:

[0007] The polishing assembly includes a polishing head and a polishing pad, wherein the polishing head is used to press the wafer to be polished onto the surface of the polishing pad;

[0008] The measuring unit, coupled to the polishing assembly, is configured to: determine an actual measured value, which characterizes the actual contact area between the measuring unit and a portion of the polishing fluid output to the polishing assembly;

[0009] The control unit, coupled to the grinding assembly and the measuring unit, is configured to adjust the liquid flow rate of the grinding fluid based on actual measured values.

[0010] Optionally, the control unit includes a host computer, which is used for:

[0011] The grinding process of the wafer to be ground is calibrated to determine the standard measurement value. The standard measurement value characterizes the standard contact area between the measuring unit and part of the grinding fluid when the grinding calibration process is in the target grinding state.

[0012] The first preset mapping relationship is determined based on standard measurements and liquid flow rate.

[0013] Optionally, the actual measured value characterizes the magnitude of the actual bow-shaped wave generated on the surface of the polishing pad by the polishing fluid output to the polishing assembly;

[0014] The control unit includes a host computer, which is used for:

[0015] The grinding process of the wafer to be ground is calibrated to determine the standard bow wave. The standard bow wave characterizes the size of the standard bow wave generated on the surface of the grinding pad by the grinding fluid output to the grinding component when the grinding calibration process is in the target grinding state.

[0016] The second preset mapping relationship is determined based on the standard bow-shaped wave and the liquid film thickness of the polishing slurry.

[0017] Optionally, the control unit may also include a flow controller;

[0018] The host computer is also configured to generate flow adjustment instructions based on actual measured values, standard measured values ​​and a first preset mapping relationship, or to generate flow adjustment instructions based on actual measured values ​​and a second preset mapping relationship.

[0019] The flow controller is coupled to the host computer and is configured to acquire flow adjustment commands and adjust the flow rate of the grinding fluid output to the grinding assembly according to the flow adjustment commands.

[0020] Optionally, the control unit includes a flow controller.

[0021] The grinding assembly also includes a slurry supply structure coupled to a flow controller and configured to supply grinding fluid to the grinding head and grinding pad under the control of the flow controller.

[0022] Optionally, the measuring unit is fixed at one end of the grinding head near the wafer to be ground;

[0023] In a direction perpendicular to the surface of the wafer to be polished, the measuring unit is positioned directly above the bow-shaped wave, which is generated on the surface of the polishing pad by the polishing fluid output to the polishing assembly.

[0024] Optionally, the grinding assembly also includes a retaining ring, which is arranged circumferentially around the wafer to be ground and is used to fix the wafer to be ground in conjunction with the grinding head.

[0025] Optionally, an air film is provided between the grinding head and the wafer to be ground, and the air film transmits the pressure applied by the grinding head to the wafer to be ground;

[0026] The grinding head includes a rotating part and a sliding part. The rotating part is connected to the sliding part, and the rotating part drives the wafer to be ground to move through the sliding part.

[0027] Optionally, the grinding apparatus also includes a grinding platform and a grinding pad dresser.

[0028] The grinding pad is located on the grinding platform; the grinding pad dresser contacts the grinding pad and is used to dress the grinding pad.

[0029] According to another aspect of this application, a method for controlling a grinding apparatus is provided, comprising:

[0030] The wafer to be ground is fixed by the grinding assembly;

[0031] A polishing slurry is provided to the wafer to be polished, and the polishing slurry forms an arc-shaped wave on the polishing pad;

[0032] The actual measurement value of the measuring unit is read, and a flow adjustment command is generated based on the actual measurement value and the first preset mapping relationship; the actual measurement value is obtained by the measuring unit measuring the bow wave;

[0033] Adjust the liquid flow rate of the grinding slurry based on the flow adjustment command.

[0034] Optionally, before generating the flow adjustment command based on the actual measured value and the preset mapping relationship, the method includes:

[0035] Obtain the standard measurement value corresponding to the wafer to be ground; the standard measurement value characterizes the standard contact area between the measuring unit and part of the grinding fluid when the grinding calibration process is in the target grinding state.

[0036] Optionally, the preset mapping relationship includes a first preset mapping relationship, where the actual measured value characterizes the actual contact area between the measuring unit and a portion of the polishing fluid output to the polishing assembly;

[0037] Based on actual measurements and preset mapping relationships, a flow adjustment command is generated, including:

[0038] The change in the first measured value is calculated based on the actual measured value and the standard measured value;

[0039] If the change in the first measured value is greater than the preset change, a flow adjustment command is generated according to the first preset mapping relationship.

[0040] Optionally, before generating the flow adjustment command based on the actual measured value and the preset mapping relationship, the method includes:

[0041] Obtain the standard bow-shaped wave corresponding to the wafer to be ground; the standard bow-shaped wave characterizes the size of the standard bow-shaped wave generated on the surface of the grinding pad by the grinding fluid output to the grinding component when the grinding calibration process is in the target grinding state.

[0042] Optionally, the preset mapping relationship also includes a second preset mapping relationship, whereby the actual measured value characterizes the magnitude of the actual bow-shaped wave generated on the surface of the polishing pad by the polishing fluid output to the polishing component;

[0043] Based on actual measurements and preset mapping relationships, a flow adjustment command is generated, including:

[0044] The change in the second measurement value is calculated based on the actual measured value and the standard bow wave.

[0045] If the change in the second measured value is greater than the preset change, a flow adjustment command is generated according to the second preset mapping relationship.

[0046] The grinding apparatus of this application embodiment includes a measuring unit in the grinding assembly, which is capable of acquiring an actual measurement value corresponding to the actual contact area of ​​a portion of the grinding fluid output to the grinding assembly. A control unit is also provided to dynamically adjust the liquid flow rate of the grinding fluid based on the actual measurement value, thereby achieving precise control of the liquid flow rate of the grinding fluid and improving the convenience and real-time performance of flow control.

[0047] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of this application, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0050] Figure 1 A schematic diagram of the structure of the grinding apparatus provided as an exemplary embodiment of this disclosure;

[0051] Figure 2 A schematic flowchart of the grinding calibration method provided as an exemplary embodiment of this disclosure;

[0052] Figure 3 A schematic flowchart corresponding to the grinding apparatus control method provided in an exemplary embodiment of this disclosure.

[0053] Explanation of reference numerals in the attached figures:

[0054] 10 - Wafer to be ground;

[0055] 20-Grinding assembly, 21-Grinding head, 22-Sliding part, 23-Rotating part, 24-Air film, 25-Grinding pad, 26-Retaining ring, 27-Slurry supply structure;

[0056] 30 - Measurement unit, 31 - Bow wave;

[0057] 40-Control unit, 41-Host computer, 42-Flow controller;

[0058] 50 - Grinding platform, 51 - Grinding pad dresser. Detailed Implementation

[0059] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this application.

[0060] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or server that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0061] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0062] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0063] In this document, the term "and / or" describes a relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0064] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0065] Figure 1 A schematic diagram of the structure corresponding to the grinding apparatus provided in an exemplary embodiment of this disclosure. For example... Figure 1 As shown, a grinding apparatus includes:

[0066] The polishing assembly 20 includes a polishing head 21 and a polishing pad 25. The polishing head 21 is used to press the wafer 10 to be polished onto the surface of the polishing pad 25. The polishing assembly 20 also includes a retaining ring 26, which is arranged circumferentially around the wafer 10 to be polished and is used to fix the wafer 10 to be polished in conjunction with the polishing head 21.

[0067] The measuring unit 30, coupled to the polishing assembly 20, is configured to determine an actual measured value, which characterizes the actual contact area between the measuring unit 30 and a portion of the polishing fluid output to the polishing assembly 20.

[0068] The control unit 40, coupled to the grinding assembly 20 and the measuring unit 30, is configured to adjust the liquid flow rate of the grinding fluid according to the actual measured value.

[0069] In some embodiments, the polishing apparatus can be applied to the CMP process in semiconductor manufacturing to achieve wafer surface planarization. During the CMP polishing process, the flow rate of the polishing slurry directly affects the polishing effect and wafer polishing quality. The polishing apparatus disclosed in this application, by introducing a measuring unit 30 and a control unit 40, can precisely control the flow rate of the polishing slurry during the polishing process of the wafer 10 to be polished, ensuring that the polishing process is always in the target polishing state, thereby improving the wafer polishing quality. Simultaneously, due to the precise control of the polishing slurry flow rate, the thickness of the liquid film formed by the polishing slurry can remain stable, thereby saving polishing slurry consumption and reducing costs.

[0070] The polishing assembly 20 is used to hold and polish the wafer. The polishing assembly 20 may include a polishing head 21, a polishing pad 25, and a retaining ring 26. Figure 1 As shown, the wafer 10 to be polished is located between the polishing pad 25 and the polishing head 21, and a retaining ring 26 is provided around its circumference. The polishing head 21 applies pressure to the wafer 10 to be polished, so that the wafer 10 to be polished is pressed against the surface of the polishing pad 25. At the same time, by providing the retaining ring 26 on the outer periphery of the wafer 10 to be polished, the wafer 10 to be polished is further fixed.

[0071] Please continue reading. Figure 1 The grinding head 21 includes a rotating part 23 and a sliding part 22. The sliding part 22 has an air film 24 between it and the wafer 10 to be ground. The air film 24 transmits the pressure applied by the grinding head 21 to the wafer 10 to be ground. The rotating part 23 is connected to the sliding part 22, and the rotating part 23 drives the wafer 10 to be ground to move through the sliding part 22.

[0072] In some embodiments, the polishing head 21 can be divided into a sliding portion 22 and a rotating portion 23 according to its structure and movement. In a direction perpendicular to the surface of the wafer 10 to be polished, the rotating portion 23 is located above the sliding portion 22, and an air film 24 is provided between the sliding portion 22 and the wafer 10 to be polished. The air film 24 serves to buffer, protect, and equalize pressure between the sliding portion 22 and the wafer 10 to be polished. The polishing head 21 can cooperate with the air film 24 to adsorb the wafer 10 to be polished, and the pressure applied by the polishing head 21 is transmitted to the wafer 10 to be polished through the air film 24.

[0073] During the grinding process, when the sliding part 22 slides, it can drive the wafer 10 to be ground to slide back and forth relative to the grinding pad 25. When the rotating part 23 rotates, it drives the wafer 10 to be ground to move relative to the grinding pad 25 through the sliding part 22. By setting the sliding part 22 and the rotating part 23, each area of ​​the surface of the wafer 10 to be ground periodically contacts different areas of the grinding pad 25, avoiding differences in grinding effect between different areas of the surface of the wafer 10 to be ground due to local wear or performance differences of the grinding pad 25, thereby achieving uniform grinding and improving the planarization effect of the wafer 10 to be ground.

[0074] The grinding assembly 20 ensures that the wafer 10 to be ground is stably fixed during the grinding process, thereby preventing displacement of the wafer 10 from affecting the grinding effect. Simultaneously, an air film 24 is provided between the grinding head 21 and the wafer 10 to be ground. The air film 24 buffers and transmits the pressure applied by the grinding head 21 to the wafer 10, ensuring uniform contact between the pressure and the wafer 10, preventing excessive or insufficient pressure in localized areas, and protecting the wafer 10 from direct contact that could affect its quality.

[0075] Please continue reading. Figure 1 In the grinding apparatus, the grinding assembly 20 also includes a slurry supply structure 27, which is coupled to a flow controller 42 and configured to supply grinding fluid to the grinding head 21 and the grinding pad 25 under the control of the flow controller 42.

[0076] In some embodiments, during the grinding process, the grinding slurry supplied by the slurry supply structure 27 to the grinding assembly 20 has a liquid film thickness on the grinding pad 25. The liquid flow rate of the grinding slurry is varied under the control of the flow controller 42 so that the liquid film thickness can be maintained within a stable range.

[0077] Furthermore, the grinding apparatus also includes a grinding platform 50 and a grinding pad dresser 51. For example... Figure 1 As shown, the grinding pad 25 is located on the grinding platform 50; the grinding pad dresser 51 is in contact with the grinding pad 25 and is used to dress the grinding pad 25.

[0078] In some embodiments, a polishing platform 50 is provided with a polishing assembly 20 and a polishing pad conditioner 51. In the polishing assembly 20, the polishing pad 25 may be the same size as the polishing platform 50. The polishing pad conditioner 51 is movably disposed on the polishing platform 50 via the polishing pad 25. Before wafer polishing, the polishing pad 25 can be modified by the polishing pad conditioner 51 to ensure the polishing performance of the polishing pad 25.

[0079] Please continue reading. Figure 1 The measuring unit 30 is fixed to one end of the polishing head 21 near the wafer 10 to be polished; in a direction perpendicular to the surface of the wafer 10 to be polished, the measuring unit 30 is located directly above the bow wave 31, which is generated on the surface of the polishing pad 25 by the polishing fluid output to the polishing assembly 20.

[0080] In some embodiments, the measuring unit 30 may be a liquid sensor and may be fixed to the sliding part 22. When the polishing slurry is output to the polishing assembly 20, due to the rotation of the polishing head 21 rotating part 23, the movement of the polishing head 21 sliding part 22, and the pressure applied by the polishing head 21, polishing slurry on the polishing pad 25 will generate an arc-shaped wave 31 on the outermost ring of the retaining ring 26.

[0081] During the actual polishing process of the wafer 10 to be polished, the reading of the liquid sensor, i.e., the actual measured value, is used to characterize the polishing slurry that generates the bow-shaped wave 31, the portion splashed onto the liquid sensor, and the actual contact area between the liquid sensor and the portion of the slurry. Since the thickness of the bow-shaped wave 31 is inversely correlated with the thickness of the polishing slurry film, and the larger the contact area, the thicker the bow-shaped wave 31, it can be concluded that when the actual measured value is larger, a significant amount of polishing slurry is not participating in the polishing assembly 20 for polishing the wafer 10 to be polished, but instead splashes to the outside of the holding ring 26 to generate the bow-shaped wave 31. In this case, the thickness of the polishing slurry film is relatively small, and the flow rate of the polishing slurry should be adjusted to ensure that the film thickness is stably maintained at the target polishing state. The measurement unit 30 sends the actual measured value to the control unit 40 so that the control unit 40 can adjust the flow rate of the polishing slurry based on the actual measured value. The target polishing state can correspond to a standard measured value, which can be stored in the host computer 41. When the host computer 41 obtains the actual measured value, it compares it with the standard measured value to determine whether the flow rate needs to be adjusted.

[0082] By fixing the measuring unit 30 to the sliding part 22 and aligning it with the position of the bow-shaped wave 31 formed by the polishing slurry on the polishing pad 25 in a direction perpendicular to the wafer surface, the actual measurement value can be obtained in a timely and accurate manner, thereby improving the accuracy of liquid flow control.

[0083] Please continue reading. Figure 1 The control unit 40 includes a host computer 41 and a flow controller 42.

[0084] The host computer 41 is configured to generate a flow adjustment command based on the actual measured value, the standard measured value and the first preset mapping relationship; the standard measured value represents the standard contact area between the measuring unit 30 and part of the grinding fluid when the grinding calibration process is in the target grinding state.

[0085] The flow controller 42 is coupled to the host computer 41 and is configured to acquire flow adjustment instructions and adjust the flow rate of the polishing fluid output to the polishing assembly 20 according to the flow adjustment instructions.

[0086] In some embodiments, such as Figure 1As shown, the host computer 41 is coupled to the flow controller 42 and the measurement unit 30. The host computer 41 stores standard measurement values ​​and a first preset mapping relationship. After obtaining the actual measurement value from the measurement unit 30, the host computer 41 calculates the change in measurement value based on the actual and standard measurement values. When the change in measurement value is greater than or equal to the preset change, it indicates that the flow rate of the grinding fluid needs to be adjusted. The change in measurement value can be the difference between the actual and standard measurement values, or the ratio of the actual to the standard measurement value; the preset change can be 5%, or it can be adjusted according to specific grinding requirements. The flow rate of the grinding fluid can be adjusted by decreasing or increasing by 5 ml each time, depending on the specific grinding process. When the change in measurement value is less than the preset change, there is no need to adjust the flow rate of the grinding fluid.

[0087] When it is determined that the flow rate of the grinding slurry needs to be adjusted, a flow adjustment command, including a target flow rate, can be determined based on a first preset mapping relationship. The target flow rate is the flow rate at which the actual measured value equals the standard measured value. The first preset mapping relationship is obtained based on the calibration of the grinding process and is used to characterize the correlation between the standard measured value and the flow rate.

[0088] The host computer 41 sends a flow adjustment command to the flow controller 42. The flow controller 42 is coupled to the slurry supply structure 27 and adjusts the liquid flow rate of the slurry supply structure 27 based on the flow adjustment command to make the liquid flow rate the target liquid flow rate. By combining actual measured values, standard measured values, and a first preset mapping relationship, the liquid flow rate of the grinding fluid can be adjusted, which can improve the convenience, accuracy, and timeliness of liquid flow rate adjustment.

[0089] In some embodiments, the host computer 41 is further configured to calibrate the grinding process of the wafer 10 to be ground, in order to determine standard measurement values; and to determine a first preset mapping relationship based on the standard measurement values ​​and the liquid flow rate. Figure 2 As shown, the calibration of the grinding process in this embodiment includes:

[0090] Step S201: Grind multiple calibration wafers to obtain multiple ground calibration wafers, and obtain multiple sets of grinding data corresponding to each calibration wafer.

[0091] In some embodiments, the calibration wafer is the wafer that is being ground during the calibration process. Each set of grinding data includes parameters of the grinding pad 25, parameters of the grinding head 21, calibration measurement values ​​of the measurement unit 30, and liquid flow rate at different times. During the grinding process, the pressure applied by the grinding head 21 remains constant, but as the lifespan of the grinding pad 25 and the grinding head 21 increases, and their thickness decreases, the pressure applied by the grinding head 21 indirectly decreases. This decrease in pressure results in less polishing fluid being extruded, leading to a greater thickness of the polishing fluid film and affecting grinding efficiency and quality. Therefore, the grinding data may include parameters of the grinding pad 25 characterizing the lifespan of the grinding pad 25, and parameters of the grinding head 21 characterizing the lifespan of the grinding head 21. The calibration measurement value is the contact area between the portion of the polishing fluid that generates the bow-shaped wave 31 and the measurement unit 30 during the calibration grinding process.

[0092] Step S202: Compare the uniformity of multiple polished calibration wafers to determine the target calibration wafer from the multiple polished calibration wafers.

[0093] Step S203: Perform data fitting on multiple sets of grinding data corresponding to the target calibration wafer to determine the standard measurement value and the first preset mapping relationship.

[0094] In some embodiments, the target calibration wafer is the calibration wafer with the best surface uniformity, provided that the thickness after grinding meets product requirements. The average of multiple calibration measurements of the target calibration wafer can be determined as the standard measurement.

[0095] Based on multiple grinding pad parameters 25, multiple grinding head parameters 21, multiple calibration measurements, and multiple liquid flow rates from multiple sets of grinding data, a first preset mapping relationship Y is obtained:

[0096] Y = m*A + n*B + k*C + D

[0097] Where m, n, k, and D are constants, A is the parameter of the grinding pad 25, B is the parameter of the grinding head 21, and C is the liquid flow rate. Therefore, when Y is a standard measurement value, after determining the parameter A of the grinding pad 25 and the parameter B of the grinding head 21, the liquid flow rate of the grinding fluid can be obtained.

[0098] This application also discloses another calibration method for the grinding process. In this embodiment, both the wafer grinding process and the data fitting process are related to... Figure 2 The corresponding method is the same, only the actual measured values ​​and liquid flow rate in the acquired grinding data change. The grinding process and data fitting process can be referred to the previous embodiment, and will not be repeated here. The changes in the grinding data will be explained below.

[0099] In this embodiment, the actual measured value characterizes the magnitude of the actual bow-shaped wave 31 generated by the polishing slurry output to the polishing assembly 20 on the surface of the polishing pad 25. The standard bow-shaped wave 31 characterizes the magnitude of the standard bow-shaped wave 31 generated by the polishing slurry output to the polishing assembly 20 on the surface of the polishing pad 25 when the polishing calibration process is in the target polishing state.

[0100] Specifically, the measuring unit 30 can also be used to measure the size of the bow wave 31, which can be the thickness of the bow wave 31. Since the thickness of the bow wave 31 is related to the thickness of the liquid film, and the liquid flow rate is also related to the thickness of the liquid film, a second preset mapping relationship can be constructed based on the thickness of the bow wave 31 and the thickness of the liquid film to adjust the liquid flow rate of the grinding fluid.

[0101] When the actual measured value and the standard measured value characterize the size of the bow wave 31, the host computer 41 is used to calibrate the grinding process of the wafer 10 to be ground, determine the standard bow wave 31, and determine the second preset mapping relationship based on the standard bow wave 31 and the liquid thickness.

[0102] Furthermore, in this embodiment, the host computer 41 is also configured to generate a flow adjustment command based on the actual measured value and the second preset mapping relationship. When the change in the measured value between the actual measured value and the standard measured value is less than the preset change by adjusting the liquid flow rate, the liquid film thickness can be considered to be stable, and the current grinding process is in the target grinding state.

[0103] Accordingly, this application also discloses a control method for a grinding apparatus, applicable to the grinding apparatus described in any of the above embodiments. Figure 3 As shown, the method includes:

[0104] Step S301: Fix the wafer 10 to be ground by the grinding assembly 20.

[0105] Step S302: Provide polishing slurry to the wafer 10 to be polished and read the actual measurement value of the measurement unit 30.

[0106] Step S303: Generate a flow adjustment command based on the actual measured value and the preset mapping relationship.

[0107] Step S304: Adjust the liquid flow rate of the grinding slurry based on the flow adjustment command.

[0108] In some embodiments, the wafer 10 to be polished is fixed to the polishing pad 25 by the interaction between the polishing head 21, the air film 24 and the retaining ring 26, and the polishing slurry is provided by the slurry supply structure to polish the wafer 10. Due to the movement of the polishing head 21, the polishing slurry can form an arc-shaped wave 31 located outside the retaining ring 26 on the polishing pad 25.

[0109] Since the measuring unit 30 is located on the grinding head 21 and directly above the bow-shaped wave 31, it can measure the contact area between a portion of the grinding fluid and the unit itself, which forms the bow-shaped wave 31, as an actual measurement value. Alternatively, the measuring unit 30 can measure the size of the bow-shaped wave 31 as an actual measurement value.

[0110] In some embodiments, the preset mapping relationship includes a first preset mapping relationship and a second preset mapping relationship. The change in the measured value includes a first change in the measured value and a second change in the measured value. When the actual measured value represents the actual contact area between the measuring unit 30 and a portion of the polishing fluid output to the polishing assembly 20, the standard measured value stored in the host computer 41 needs to be obtained before generating the flow adjustment command.

[0111] When generating a flow adjustment command, the change in the first measured value is calculated based on the actual measured value and the standard measured value. If the change in the first measured value is greater than the preset change, a flow adjustment command including the target liquid flow rate is generated using the first preset mapping relationship, so that the liquid flow rate of the grinding fluid provided by the slurry providing structure is adjusted under the control of the flow controller 42.

[0112] In some embodiments, when the actual measured value characterizes the actual bow-shaped wave generated on the surface of the polishing pad 25 by the polishing fluid output to the polishing assembly 20, the standard bow-shaped wave stored in the host computer 41 needs to be obtained before generating the flow adjustment command.

[0113] When generating the flow adjustment command, the change in the second measured value is calculated based on the actual measured value and the standard bow wave. If the change in the second measured value is greater than the preset change, the flow adjustment command including the target liquid flow rate is generated using the second preset mapping relationship, so that the liquid flow rate of the grinding fluid provided by the slurry providing structure is adjusted under the control of the flow controller 42.

[0114] By using the control method of the above-mentioned grinding device, the actual measurement value corresponding to the actual contact area of ​​a portion of the grinding fluid output to the grinding assembly 20 is obtained by the measuring unit 30, and the liquid flow rate of the grinding fluid is dynamically adjusted by the control unit 40 based on the actual measurement value, thereby achieving precise control of the liquid flow rate of the grinding fluid and improving the convenience and real-time performance of flow control.

[0115] In most cases, when the polishing slurry does not contain inhibitors, both excessively thick and thin slurry films will affect the polishing effect. Specifically, an excessively thick slurry film will increase the polishing rate, leading to over-polishing, while an excessively thin slurry film will decrease the polishing rate, resulting in residual polished material. The polishing apparatus disclosed in this application, by adjusting the liquid flow rate to the corresponding target polishing state, can stabilize the slurry film thickness, avoiding the impact of excessively thick or thin slurry films on polishing quality and efficiency, thereby improving the stability and uniformity of the polishing process, and ultimately enhancing polishing quality and product yield.

[0116] In the description of this application, the terms "first" and "second" 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 as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0117] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0118] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0119] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent variations, or alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the market of the various embodiments, or to enable other persons skilled in the art to understand the various embodiments disclosed herein.

Claims

1. A grinding apparatus, characterized in that, The device includes: A polishing assembly includes a polishing head and a polishing pad, wherein the polishing head is used to press the wafer to be polished onto the surface of the polishing pad; A measuring unit, coupled to the polishing assembly, is fixed to one end of the polishing head near the wafer to be polished. In a direction perpendicular to the surface of the wafer, the measuring unit is positioned directly above a bow-shaped wave generated on the surface of the polishing pad by polishing slurry output to the polishing assembly. The measuring unit is configured to: determine an actual measured value, which characterizes the actual contact area between the measuring unit and a portion of the polishing slurry output to the polishing assembly; or, the actual measured value characterizes the magnitude of the actual bow-shaped wave generated on the surface of the polishing pad by the polishing slurry output to the polishing assembly. The control unit, coupled to the grinding assembly and the measuring unit, is configured to adjust the liquid flow rate of the grinding fluid based on the actual measured value.

2. The grinding apparatus according to claim 1, characterized in that, The control unit includes a host computer, which, when the actual measurement value characterizes the actual contact area between the measuring unit and a portion of the polishing fluid output to the polishing assembly, is used to: The grinding process of the wafer to be ground is calibrated to determine a standard measurement value. The standard measurement value represents the standard contact area between the measuring unit and the portion of the grinding fluid when the grinding calibration process is in the target grinding state. A first preset mapping relationship is determined based on the standard measurement value and the liquid flow rate; A flow adjustment command is generated based on the actual measured value, the standard measured value, and the first preset mapping relationship.

3. The grinding apparatus according to claim 1, characterized in that, The control unit includes a host computer, wherein the actual measured value characterizes the magnitude of the actual bow-shaped wave generated on the surface of the polishing pad by the polishing fluid output to the polishing assembly; The host computer is used for: The grinding process of the wafer to be ground is calibrated to determine a standard bow wave. The standard bow wave characterizes the size of the standard bow wave generated on the surface of the grinding pad by the grinding fluid output to the grinding assembly when the grinding calibration process is in the target grinding state. A second preset mapping relationship is determined based on the standard bow-shaped wave and the liquid film thickness of the polishing slurry; A flow adjustment command is generated based on the actual measured value and the second preset mapping relationship.

4. The grinding apparatus according to claim 2 or 3, characterized in that, The control unit also includes a flow controller; The flow controller is coupled to the host computer and is configured to acquire the flow adjustment command and adjust the flow rate of the polishing fluid output to the polishing assembly according to the flow adjustment command.

5. A control method for a grinding apparatus as described in any one of claims 1 to 4, characterized in that, The method includes: The wafer to be ground is fixed by the grinding assembly; A polishing slurry is provided to the wafer to be polished, and the actual measurement value of the measurement unit is read. A flow adjustment command is generated based on the actual measured value and the preset mapping relationship; The flow rate of the grinding fluid is adjusted based on the flow rate adjustment command.

6. The control method for the grinding apparatus according to claim 5, characterized in that, Before generating the flow adjustment instruction based on the actual measurement value and the preset mapping relationship, the method includes: Obtain the standard measurement value corresponding to the wafer to be ground; the standard measurement value characterizes the standard contact area between the measuring unit and the portion of the grinding fluid when the grinding calibration process is in the target grinding state.

7. The control method for the grinding apparatus according to claim 6, characterized in that, The preset mapping relationship includes a first preset mapping relationship, and the actual measured value represents the actual contact area between the measuring unit and a portion of the polishing fluid output to the polishing assembly; The step of generating a flow adjustment command based on the actual measured value and a preset mapping relationship includes: The change in the first measurement value is calculated based on the actual measurement value and the standard measurement value; If the change in the first measured value is greater than the preset change, the flow adjustment instruction is generated according to the first preset mapping relationship.

8. The control method for the grinding apparatus according to claim 5, characterized in that, Before generating the flow adjustment instruction based on the actual measurement value and the preset mapping relationship, the method includes: Obtain a standard bow-shaped wave corresponding to the wafer to be ground; the standard bow-shaped wave characterizes the magnitude of the standard bow-shaped wave generated on the surface of the grinding pad by the grinding fluid output to the grinding assembly when the grinding calibration process is in the target grinding state.

9. The control method for the grinding apparatus according to claim 8, characterized in that, The preset mapping relationship also includes a second preset mapping relationship, and the actual measured value characterizes the size of the actual bow-shaped wave generated on the surface of the polishing pad by the polishing fluid output to the polishing component; The step of generating a flow adjustment instruction based on the actual measured value and a preset mapping relationship includes: The change in the second measurement value is calculated based on the actual measured value and the standard bow wave. If the change in the second measured value is greater than the preset change, the flow adjustment command is generated according to the second preset mapping relationship.

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