Grinding device and control method thereof

Abstract

The invention discloses a grinding device and a control method thereof. The grinding device comprises a grinding assembly, a measuring unit and a control unit. The grinding assembly comprises a grinding head and a grinding pad, and the grinding head is used for pressing a wafer to be ground on the surface of the grinding pad. The measuring unit is coupled with the grinding assembly and is configured to determine an actual measured value, and the actual measured value represents the actual contact area of the measuring unit and the part of the grinding fluid output to the grinding assembly. The control unit is coupled with the grinding assembly and the measuring unit and is configured to adjust the liquid flow of the grinding liquid according to the actual measured value. Through the arrangement of the technical characteristics, the accuracy of liquid flow control of the grinding liquid in the wafer grinding process can be improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular to a grinding device and a control method thereof. Background Art

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

[0003] During wafer polishing using the CMP process, the flow rate of the polishing liquid can affect the polishing effect and wafer quality. In related technologies, in addition to using a fixed liquid flow rate to polish wafers, optical film thickness measurement devices can be used to measure film thickness, thereby adjusting the liquid flow rate accordingly. However, this method has the disadvantages of cumbersome film thickness measurement and low accuracy, which in turn leads to low precision in the corresponding flow rate control. Summary of the Invention

[0004] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present application is how to improve the accuracy and convenience of controlling the liquid flow rate of the polishing liquid.

[0005] In order to solve at least one of the above-mentioned technical problems, the present application discloses a grinding device and a control method thereof.

[0006] According to one aspect of the present application, there is provided a grinding device, comprising:

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

[0008] a measuring unit coupled to the grinding assembly and configured to: determine an actual measurement value, the actual measurement value representing an actual contact area between the measuring unit and a portion of the grinding fluid output to the grinding assembly;

[0009] The control unit is coupled to the grinding assembly and the measuring unit, and is configured to adjust the liquid flow of the grinding liquid according to the actual measured value.

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

[0011] Calibrate the grinding process of the wafer to be ground and determine a standard measurement value, which represents the standard contact area between the measurement unit and a portion of the grinding fluid when the grinding calibration process is in a target grinding state;

[0012] A first preset mapping relationship is determined based on the standard measurement value and the liquid flow rate.

[0013] Optionally, the actual measured value represents the size of an actual bow 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 to:

[0015] Calibrate the polishing process of the wafer to be polished to determine a standard bow wave, which represents the size of a standard bow wave generated by the polishing fluid output to the polishing assembly on the surface of the polishing pad when the polishing calibration process is in a target polishing state;

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

[0017] Optionally, the control unit further comprises a flow controller;

[0018] The host computer is further configured to generate a flow adjustment instruction according to the actual measurement value, the standard measurement value and the first preset mapping relationship, or to generate a flow adjustment instruction according to the actual measurement value and the second preset mapping relationship;

[0019] The flow controller is coupled to the host computer and is configured to obtain a flow adjustment instruction and adjust the liquid flow of the grinding liquid output to the grinding assembly according to the flow adjustment instruction.

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

[0021] The polishing assembly further includes a slurry supply structure coupled to the flow controller and configured to provide polishing liquid to the polishing head and the polishing pad under the control of the flow controller.

[0022] Optionally, the measuring unit is fixed to an end of the grinding head close to the wafer to be ground;

[0023] In a direction perpendicular to the surface of the wafer to be polished, the measurement unit is located directly above the bow wave, which is generated on the surface of the polishing pad by the polishing liquid output to the polishing assembly.

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

[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 device further comprises a grinding platform and a grinding pad dresser,

[0028] The polishing pad is located on the polishing platform; the polishing pad dresser is in contact with the polishing pad and is used for dressing the polishing pad.

[0029] According to another aspect of the present application, a method for controlling a grinding device is provided, comprising:

[0030] Fixing the wafer to be ground by the grinding assembly;

[0031] A polishing slurry is provided to the wafer to be polished, and the polishing slurry forms a bow wave on the polishing pad;

[0032] Reading an actual measurement value of the measurement unit, and generating a flow adjustment instruction based on the actual measurement value and a first preset mapping relationship; the actual measurement value is obtained based on the measurement unit measuring the bow wave;

[0033] Based on the flow adjustment instruction, the liquid flow rate of the polishing liquid is adjusted.

[0034] Optionally, before generating the flow adjustment instruction according to the actual measurement value and the preset mapping relationship, the method includes:

[0035] A standard measurement value corresponding to the wafer to be ground is obtained; the standard measurement value represents a standard contact area between the measuring unit and a portion of the grinding fluid when the grinding calibration process is in a target grinding state.

[0036] Optionally, the preset mapping relationship includes a first preset mapping relationship, and the actual measurement value represents an actual contact area between the measuring unit and a portion of the grinding fluid output to the grinding assembly;

[0037] Generates flow adjustment instructions based on actual measured values ​​and preset mapping relationships, including:

[0038] Calculating a first measurement value variation based on the actual measurement value and the standard measurement value;

[0039] When the change in the first measurement value is greater than the preset change, a flow adjustment instruction is generated according to the first preset mapping relationship.

[0040] Optionally, before generating the flow adjustment instruction according to the actual measurement value and the preset mapping relationship, the method includes:

[0041] A standard bow wave corresponding to the wafer to be ground is obtained; the standard bow wave represents 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.

[0042] Optionally, the preset mapping relationship further includes a second preset mapping relationship, and the actual measurement value represents the size of an actual bow wave generated on the surface of the polishing pad by the polishing fluid output to the polishing assembly;

[0043] Generates flow adjustment instructions based on actual measured values ​​and preset mapping relationships, including:

[0044] calculating a second measurement value variation based on the actual measurement value and the standard bow wave;

[0045] When the variation of the second measurement value is greater than the preset variation, a flow adjustment instruction is generated according to the second preset mapping relationship.

[0046] The grinding device of the embodiment of the present application is provided with a measuring unit in the grinding component, and enables it to obtain an actual measurement value corresponding to the actual contact area of ​​the portion of the grinding liquid output to the grinding component, and is provided with a control unit to dynamically adjust the liquid flow rate of the grinding liquid based on the actual measurement value, thereby achieving precise control of the liquid flow rate of the grinding liquid and improving the convenience and real-time performance of the flow control.

[0047] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0049] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0050] Figure 1 A schematic structural diagram corresponding to a grinding device provided by an exemplary embodiment of the present disclosure;

[0051] Figure 2 A schematic flow chart corresponding to the grinding calibration method provided by an exemplary embodiment of the present disclosure;

[0052] Figure 3 This is a flow chart corresponding to the grinding device control method provided by the exemplary embodiment of the present disclosure.

[0053] Description of reference numerals:

[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 DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0060] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

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

[0062] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0063] The term "and / or" as used herein describes an association relationship between associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent the existence of A alone, the simultaneous existence of A and B, and the existence of B alone. Furthermore, the term "at least one" as used herein refers to any combination of at least two of any one or more of a plurality of items. For example, "at least one of A, B, and C" can represent any one or more elements selected from the set consisting of A, B, and C.

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

[0065] Figure 1 Schematic diagram of the structure of the grinding device provided by the exemplary embodiment of the present disclosure. Figure 1 As shown, a grinding device comprises:

[0066] The grinding assembly 20 includes a grinding head 21 and a grinding pad 25. The grinding head 21 is used to press the wafer 10 to be ground onto the surface of the grinding pad 25. The grinding assembly 20 also includes a retaining ring 26. The retaining ring 26 is circumferentially arranged around the wafer 10 to be ground and is used to cooperate with the grinding head 21 to fix the wafer 10 to be ground.

[0067] The measuring unit 30 is coupled to the polishing assembly 20 and is configured to determine an actual measurement value, where the actual measurement value represents an 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 is coupled to the polishing assembly 20 and the measuring unit 30 and is configured to adjust the liquid flow rate of the polishing liquid according to the actual measured value.

[0069] In some embodiments, the grinding device can be applied to the CMP process of semiconductor manufacturing to achieve flattening of the wafer surface. During the grinding process of the CMP process, the liquid flow rate of the grinding liquid can directly affect the grinding effect and the quality of the wafer grinding. The grinding device disclosed in the present application, by introducing a measuring unit 30 and a control unit 40, can accurately control the liquid flow rate of the grinding liquid during the grinding process of the wafer 10 to be ground, so that the grinding process is always in the target grinding state, thereby improving the quality of wafer grinding. At the same time, due to the precise control of the liquid flow rate of the grinding liquid, the liquid film thickness formed by the grinding liquid can be kept stable, so as to save the consumption of the grinding liquid and reduce costs.

[0070] The grinding assembly 20 is used to fix and grind the wafer. The grinding assembly 20 may include a grinding head 21, a grinding pad 25, and a retaining ring 26. Figure 1 As shown, the wafer 10 to be ground is positioned 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 press the wafer 10 against the surface of the polishing pad 25. Simultaneously, the retaining ring 26 is provided around the outer periphery of the wafer 10 to further secure the wafer 10 to be ground.

[0071] Please continue reading Figure 1 The grinding head 21 includes a rotating part 23 and a sliding part 22. There is an air film 24 between the sliding part 22 and the wafer to be ground 10. The air film 24 transfers the pressure applied by the grinding head 21 to the wafer to be ground 10; the rotating part 23 is connected to the sliding part 22, and the rotating part 23 drives the wafer to be ground 10 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 based on its structure and motion. The rotating portion 23 is located above the sliding portion 22 in a direction perpendicular to the surface of the wafer 10 to be polished, with an air film 24 between the sliding portion 22 and the wafer 10 to be polished. The air film 24 provides a buffer, protection, and pressure equalization between the sliding portion 22 and the wafer 10 to be polished. The polishing head 21 can cooperate with the air film 24 to achieve adsorption of the wafer 10 to be polished, and the air film 24 transmits the pressure applied by the polishing head 21 to the wafer 10 to be polished.

[0073] During the grinding process, the sliding portion 22 slides, driving the wafer 10 to be ground to slide back and forth relative to the grinding pad 25. As the rotating portion 23 rotates, the sliding portion 22 drives the wafer 10 to be ground relative to the grinding pad 25. The arrangement of the sliding portion 22 and the rotating portion 23 ensures that each area of ​​the surface of the wafer 10 to be ground periodically contacts a different area of ​​the grinding pad 25. This prevents variations in the 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 arrangement of 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 and other factors that could affect the grinding effect. Furthermore, an air film 24 is provided between the grinding head 21 and the wafer 10 to be ground. The air film 24 cushions and transmits the pressure applied by the grinding head 21 to the wafer 10 to be ground. This ensures uniform contact between the pressure and the wafer 10 to be ground, preventing excessive or insufficient pressure in local areas, and protects the wafer 10 to be ground, preventing direct contact from affecting its quality.

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

[0076] In some embodiments, during the polishing process, the polishing liquid output from the slurry supply structure 27 to the polishing assembly 20 has a liquid film thickness on the polishing pad 25. The liquid flow rate of the polishing liquid is changed under the control of the flow controller 42 to maintain the liquid film thickness within a stable range.

[0077] Furthermore, the grinding device also includes a grinding platform 50 and a grinding pad dresser 51. Figure 1 As shown, the polishing pad 25 is located on the polishing platform 50 ; the polishing pad dresser 51 is in contact with the polishing pad 25 for dressing the polishing 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 can be the same size as the polishing platform 50. The polishing pad conditioner 51 is movably mounted on the polishing platform 50 via the polishing pad 25. Prior to wafer polishing, the polishing pad 25 can be corrected 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 close to the wafer 10 to be polished; in the 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 liquid 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 portion 22. When the polishing liquid is output to the polishing assembly 20, the presence of the polishing liquid on the polishing pad 25 generates a bow wave 31 on the outermost ring of the retaining ring 26 due to the rotation of the rotating portion 23 of the polishing head 21, the movement of the sliding portion 22 of the polishing head 21, and the pressure applied by the polishing head 21.

[0081] During the actual polishing process of the wafer 10 to be polished, the reading of the liquid sensor, i.e., the actual measurement value, is used to represent the actual contact area between the portion of the polishing liquid that splashes onto the liquid sensor and the polishing liquid that generates the bow wave 31. Since the thickness of the bow wave 31 is inversely correlated with the thickness of the polishing liquid film, and a larger contact area indicates a thicker bow wave 31, it can be understood that when the actual measurement value is larger, a larger amount of polishing liquid is not participating in the polishing of the wafer 10 to be polished by the polishing assembly 20 during the current polishing process, but instead splashes onto the outside of the retaining ring 26, generating the bow wave 31. At this time, the polishing liquid film thickness is relatively small, and the polishing liquid flow rate should be adjusted to ensure that the film thickness can be stably maintained at the target polishing state. The measurement unit 30 transmits the actual measurement value to the control unit 40, so that the control unit 40 can adjust the polishing liquid flow rate based on the actual measurement value. The target polishing state can correspond to a standard measurement value, which can be stored in the host computer 41. After obtaining the actual measurement value, the host computer 41 compares it with the standard measurement value to determine whether the liquid flow rate needs to be adjusted.

[0082] By fixing the measuring unit 30 on the sliding part 22 and aligning the position of the bow wave 31 formed by the polishing liquid 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 instruction based on the actual measurement value, the standard measurement value and the first preset mapping relationship; the standard measurement value represents the standard contact area between the measuring unit 30 and part of the grinding liquid 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 obtain a flow adjustment instruction and adjust the liquid flow of the grinding liquid output to the grinding assembly 20 according to the flow adjustment instruction.

[0086] In some embodiments, as Figure 1As shown, the host computer 41 is coupled to the flow controller 42 and the measuring unit 30 respectively. The standard measurement value and the first preset mapping relationship are stored in the host computer 41. After the host computer 41 obtains the actual measurement value from the measuring unit 30, it calculates the measurement value change based on the actual measurement value and the standard measurement value. When the measurement value change is greater than or equal to the preset change, it indicates that the liquid flow of the grinding liquid needs to be adjusted at this time. Among them, the measurement value change can be the difference between the actual measurement value and the standard measurement value, and the ratio to the standard measurement value; the preset change can be 5%, and can also be adjusted according to specific grinding requirements. The flow adjustment of the grinding liquid can be reduced or supplemented by 5 ml each time, and can be adjusted according to the specific grinding process. When the measurement value change is less than the preset change, there is no need to adjust the liquid flow of the grinding liquid.

[0087] When it is determined that the liquid flow rate of the grinding liquid needs to be adjusted, a flow adjustment instruction including a target liquid flow rate can be determined based on a first preset mapping relationship. The target liquid flow rate is the liquid flow rate when the actual measurement value is equal to the standard measurement value. The first preset mapping relationship is obtained based on calibration of the grinding process and is used to characterize the correlation between the standard measurement value and the liquid flow rate.

[0088] Host computer 41 sends the flow adjustment instruction to flow controller 42. Flow controller 42 is coupled to slurry supply structure 27 and adjusts the liquid flow of slurry supply structure 27 based on the flow adjustment instruction so that the liquid flow reaches the target liquid flow. By combining the actual measurement value, the standard measurement value, and the first preset mapping relationship, the liquid flow of the polishing liquid is adjusted, which can improve the convenience, accuracy, and timeliness of liquid flow adjustment.

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

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

[0091] In some embodiments, the calibration wafer is a wafer that is being ground during the calibration process. Each set of grinding data includes the parameters of the grinding pad 25, the parameters of the grinding head 21, the calibration measurement values ​​of the measuring unit 30, and the liquid flow rate at different times. Since the pressure applied by the grinding head 21 remains unchanged during the grinding process, but as the service life of the grinding pad 25 and the service life of the grinding head 21 increase, and the thickness becomes thinner, the pressure applied by the grinding head 21 is indirectly reduced. The reduced pressure causes less grinding liquid to be squeezed out, making the liquid film thickness of the grinding liquid larger and affecting the grinding efficiency and grinding quality. Therefore, the grinding data can include the parameters of the grinding pad 25 that characterize the service life of the grinding pad 25, and the parameters of the grinding head 21 that characterize the service life of the grinding head 21. The calibration measurement value is the contact area between the portion of the grinding liquid that generates the bow wave 31 and the measuring unit 30 during the calibrated grinding process.

[0092] Step S202 : performing uniformity comparison on the plurality of ground calibration wafers to determine a target calibration wafer from the plurality of ground calibration wafers.

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

[0094] In some embodiments, the target calibration wafer is a calibration wafer with the best wafer surface uniformity after grinding, and the average value of multiple calibration measurement values ​​of the target calibration wafer can be determined as the standard measurement value.

[0095] According to the multiple polishing pad 25 parameters, the multiple polishing head 21 parameters, the multiple calibration measurement values ​​and the multiple liquid flow rates in the multiple sets of polishing 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 a parameter of the polishing pad 25, B is a parameter of the polishing head 21, and C is the liquid flow rate. Therefore, when Y is a standard measurement value, after determining the polishing pad 25 parameter A and the polishing head 21 parameter B, the polishing liquid flow rate can be determined.

[0098] This application also discloses another calibration method for the grinding process. In this embodiment, the grinding process of the wafer and the data fitting process are both the same as Figure 2 The corresponding methods are the same, only the actual measured values ​​and liquid flow rates in the obtained 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 represents the magnitude of the actual bow wave 31 generated on the surface of the polishing pad 25 by the polishing slurry output to the polishing assembly 20. The standard bow wave 31 represents the magnitude of the standard bow wave 31 generated on the surface of the polishing pad 25 by the polishing slurry output to the polishing assembly 20 during the target polishing state during the polishing calibration process.

[0100] Specifically, the measurement unit 30 can also be used to measure the size of the bow wave 31. The size of the bow wave 31 can be the thickness of the bow wave 31. Since the thickness of the bow wave 31 is correlated with the thickness of the liquid film, and the liquid flow rate is also correlated with the liquid film thickness, a second preset mapping relationship can be established based on the thickness of the bow wave 31 and the liquid film thickness to adjust the liquid flow rate of the polishing liquid.

[0101] When the actual measurement value and the standard measurement value represent the size of the bow wave 31 , the host computer 41 is used to calibrate the polishing process of the wafer 10 to be polished, determine the standard bow wave 31 , and determine a 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 further configured to generate a flow adjustment instruction based on the actual measurement value and the second preset mapping relationship. When the liquid flow rate is adjusted so that the measured value difference between the actual measurement value and the standard measurement value is less than the preset difference, it can be considered that the liquid film thickness has stabilized and the current grinding process is in the target grinding state.

[0103] Correspondingly, the technical solution of this application also discloses a control method for a grinding device, which is applied to the grinding device 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 : providing polishing liquid to the wafer 10 to be polished, and reading the actual measurement value of the measuring unit 30 .

[0106] Step S303: Generate a flow adjustment instruction according to the actual measurement value and the preset mapping relationship.

[0107] Step S304: adjusting the flow rate of the polishing liquid based on the flow rate adjustment instruction.

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

[0109] Because the measurement unit 30 is located on the polishing head 21 and directly above the bow wave 31, the measurement unit 30 can measure the contact area between a portion of the polishing slurry and the measurement unit 30 in the polishing slurry forming the bow wave 31 as the actual measurement value. Alternatively, the measurement unit 30 can measure the size of the bow wave 31 as the actual measurement value.

[0110] In some embodiments, the preset mapping relationship includes a first preset mapping relationship and a second preset mapping relationship. The measured value change includes a first measured value change and a second measured value change. When the actual measured value represents the actual contact area between the measurement unit 30 and the portion of the polishing liquid output to the polishing assembly 20, before generating the flow adjustment instruction, it is necessary to first obtain the standard measurement value stored in the host computer 41.

[0111] When generating a flow adjustment instruction, a first measurement value change is calculated based on the actual measurement value and the standard measurement value, and when the first measurement value change is greater than the preset change, a first preset mapping relationship is used to generate a flow adjustment instruction including a target liquid flow, so that the liquid flow of the grinding liquid provided by the slurry providing structure is adjusted under the control of the flow controller 42.

[0112] In some embodiments, when the actual measurement value represents the actual bow wave size generated by the polishing fluid output to the polishing assembly 20 on the surface of the polishing pad 25 , it is necessary to first obtain the standard bow wave stored in the host computer 41 before generating the flow adjustment instruction.

[0113] When generating a flow adjustment instruction, the second measurement value change is calculated based on the actual measurement value and the standard bow wave, and when the second measurement value change is greater than the preset change, a second preset mapping relationship is used to generate a flow adjustment instruction including the target liquid flow, so that the liquid flow of the grinding liquid provided by the slurry providing structure is adjusted under the control of the flow controller 42.

[0114] Through the control method of the above-mentioned grinding device, the actual measurement value corresponding to the actual contact area of ​​the part of the grinding liquid output to the grinding component 20 is obtained according to the measuring unit 30, and the liquid flow rate of the grinding liquid is dynamically adjusted based on the actual measurement value according to the control unit 40, thereby realizing precise control of the liquid flow rate of the grinding liquid and improving the convenience and real-time performance of the flow control.

[0115] In most cases, when the polishing liquid does not contain an inhibitor, a liquid film that is too thick or too thin will affect the polishing effect. Specifically, a liquid film that is too thick will increase the polishing rate, resulting in over-polishing, while a liquid film that is too thin will reduce the polishing rate, resulting in residual polishing material. The polishing device disclosed in the embodiment of the present application can stabilize the liquid film thickness by adjusting the liquid flow rate to the corresponding target polishing state, avoiding the impact of a liquid film that is too thick or too thin on the polishing quality and polishing efficiency, thereby improving the stability and uniformity of the polishing process, thereby improving the 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 understood to indicate or imply relative importance or implicitly specify 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, "plurality" means two or more, unless otherwise specifically defined.

[0117] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0118] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0119] The above are only preferred embodiments of the present application and are not intended to limit the present application in any form. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application shall still fall within the scope of the technical solution of the present application. The selection of terms used in this article is intended to best explain the principles, practical applications, or technical improvements of each embodiment in the market, or to enable other ordinary technicians in this technical field to understand the embodiments disclosed herein.

Claims

1. A grinding device, characterized in that: The device comprises: A grinding assembly, comprising a grinding head and a grinding pad, wherein the grinding head is used to press the wafer to be ground onto the surface of the grinding pad; a measuring unit coupled to the grinding assembly and configured to: determine an actual measurement value, the actual measurement value representing an actual contact area between the measuring unit and a portion of the grinding fluid output to the grinding assembly; The control unit is coupled to the grinding assembly and the measuring unit, and is configured to adjust the liquid flow of the grinding liquid according to the actual measurement value.

2. The grinding device according to claim 1, characterized in that The control unit includes a host computer, which is used to: Calibrate the grinding process of the wafer to be ground to determine a standard measurement value, where the standard measurement value represents a standard contact area between the measurement unit and the portion of the grinding fluid when the grinding calibration process is in a target grinding state; A first preset mapping relationship is determined based on the standard measurement value and the liquid flow rate.

3. The grinding device according to claim 1, characterized in that The actual measurement value represents the size of the actual bow wave generated by the polishing fluid output to the polishing assembly on the surface of the polishing pad; The control unit includes a host computer, which is used to: Calibrate the polishing process of the wafer to be polished to determine a standard bow wave, wherein the standard bow wave represents the size of a standard bow wave generated by the polishing fluid output to the polishing assembly on the surface of the polishing pad when the polishing calibration process is in a target polishing state; A second preset mapping relationship is determined based on the standard bow wave and the liquid film thickness of the polishing liquid.

4. The grinding device according to claim 2 or 3, characterized in that The control unit also includes a flow controller; The host computer is further configured to generate a flow adjustment instruction according to the actual measurement value, the standard measurement value and the first preset mapping relationship, or to generate the flow adjustment instruction according to the actual measurement value and the second preset mapping relationship; The flow controller is coupled to the host computer and is configured to obtain the flow adjustment instruction and adjust the liquid flow of the grinding liquid output to the grinding assembly according to the flow adjustment instruction.

5. The grinding device according to claim 1, characterized in that The measuring unit is fixed to one end of the grinding head close to the wafer to be ground; In a direction perpendicular to the surface of the wafer to be ground, the measuring unit is located directly above a bow wave generated on the surface of the grinding pad by the grinding fluid output to the grinding assembly.

6. A method for controlling a grinding device according to any one of claims 1 to 5, characterized in that: The method comprises: Fixing the wafer to be ground by the grinding assembly; Providing a polishing liquid to the wafer to be polished and reading the actual measurement value of the measuring unit; generating a flow adjustment instruction according to the actual measurement value and a preset mapping relationship; Based on the flow adjustment instruction, the liquid flow of the polishing liquid is adjusted.

7. The control method of the grinding device according to claim 6, characterized in that: Before generating the flow adjustment instruction according to the actual measurement value and the preset mapping relationship, the method includes: A standard measurement value corresponding to the wafer to be ground is obtained; the standard measurement value represents a standard contact area between the measurement unit and the portion of the grinding fluid when the grinding calibration process is in a target grinding state.

8. The control method of the grinding device according to claim 7, characterized in that: The preset mapping relationship includes a first preset mapping relationship, and the actual measurement value represents an actual contact area between the measuring unit and a portion of the polishing liquid output to the polishing assembly; The generating of the flow adjustment instruction according to the actual measurement value and the preset mapping relationship includes: Calculating a first measurement value variation based on the actual measurement value and the standard measurement value; When the change in the first measurement value is greater than a preset change, the flow adjustment instruction is generated according to the first preset mapping relationship.

9. The control method of the grinding device according to claim 6, characterized in that: Before generating the flow adjustment instruction according to the actual measurement value and the preset mapping relationship, the method includes: A standard bow wave corresponding to the wafer to be ground is obtained; the standard bow wave represents the size of a 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 a target grinding state.

10. The control method of the grinding device according to claim 9, characterized in that: The preset mapping relationship further includes a second preset mapping relationship, wherein the actual measurement value represents the size of an actual bow wave generated by the polishing fluid output to the polishing assembly on the surface of the polishing pad; The generating of the flow adjustment instruction according to the actual measurement value and the preset mapping relationship includes: Calculating a second measurement value variation based on the actual measurement value and the standard bow wave; When the variation of the second measurement value is greater than the preset variation, the flow adjustment instruction is generated according to the second preset mapping relationship.

Images