Wafer loading table and system and method for adjusting wafer loading pressure on line

Abstract

The invention provides a wafer loading table and a system and method for online adjusting wafer loading pressure, and belongs to the technical field of semiconductor chemical mechanical polishing, the wafer loading table comprises a carrying table body and a plurality of pressure actuator sets, the carrying table body is used for bearing wafers, and the bearing surface of the carrying table body is provided with a plurality of pressure response areas; and the plurality of pressure actuator groups are arranged in the plurality of pressure response areas in a one-to-one correspondence manner, and the pressure actuator groups are used for providing upward supporting force for the wafer. According to the wafer loading table, the carrying table body is divided into the multiple pressure response areas, and the pressure actuator sets are arranged in the pressure response areas, so that the carrying table body can dynamically respond and adjust the supporting force on the wafer in real time, and pressure nonuniformity generated when a polishing head presses downwards is actively counteracted; the problem of microcracks or fragmentation caused by local stress concentration when the wafer is loaded is avoided, and the loading yield of the wafer is greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of semiconductor chemical mechanical polishing, and particularly relates to a wafer loading stage, a system and a method for online adjusting the wafer loading pressure. Background Art

[0002] In the chemical mechanical polishing (CMP) process, the wafer needs to be transferred to the loading area by a robotic arm, and then the polishing head presses down and adsorbs the wafer to achieve the loading of the wafer, so as to facilitate the subsequent wafer polishing process. However, the traditional loading area is a rigid or uniformly elastic support structure. During the wafer loading stage, the uneven downward pressure of the polishing head will cause local stress concentration when the wafer contacts the loading area, thus damaging the wafer.

[0003] In the prior art, the polishing head of the CMP equipment usually adopts multi-zone independent pressure control to achieve pressure uniformity during the polishing process. On this basis, some solutions optimize the control of the polishing head zone pressure to achieve the uniformity of the downward pressure when loading the wafer. However, during actual loading, the contact time between the polishing head and the loading area is short and the dynamic response requirement is high. Especially in the scenario where the adjustment delay of the polishing head zone pressure or the support characteristics of the loading area are passively affected by the mechanical structure, it is difficult to achieve real-time balance of the downward pressure, and there is still a problem that the force on the wafer surface is unbalanced, resulting in microcracks or even fragmentation in the edge or weak areas. Summary of the Invention

[0004] The embodiments of the present invention provide a wafer loading stage, a system and a method for online adjusting the wafer loading pressure, aiming to solve the problem that during the wafer loading process, due to the uneven downward pressure of the polishing head, local stress concentration occurs in the wafer, resulting in microcracks or even fragmentation of the wafer.

[0005] To achieve the above object, the technical solution adopted by the present invention is: In the first aspect, a wafer loading stage is provided, including: A stage body for supporting the wafer, and a plurality of pressure response areas are provided on the supporting surface of the stage body; and A plurality of pressure actuator groups are respectively arranged in the plurality of pressure response areas, and the pressure actuator groups are used to provide an upward supporting force for the wafer.

[0006] In combination with the first aspect, in a possible implementation manner, the pressure actuator group includes a plurality of pressure actuators arranged at intervals in the corresponding pressure response area.

[0007] In some embodiments, the pressure actuator is one of a piezoelectric ceramic actuator, an air film chamber, and a hydraulic cylinder.

[0008] In combination with the first aspect, in a possible implementation manner, the multiple pressure response areas are arranged in concentric rings nested in sequence from the center to the periphery or in a grid arranged in a vertical and horizontal cross pattern.

[0009] In some embodiments, a plurality of pressure sensors and a plurality of displacement sensors are provided in the pressure response area. The pressure sensors are used to monitor the pressure exerted on the wafer in real time, and the displacement sensors are used to monitor the deformation amount of the wafer in real time. The beneficial effect of a wafer loading stage provided by the present invention lies in that: by dividing a plurality of pressure response areas on the stage body and arranging a pressure actuator group in the pressure response area, the stage body can dynamically respond and adjust the supporting force on the wafer in real time, actively offset the pressure non-uniformity when the polishing head presses down, and avoid micro-cracks or fragmentation problems caused by local stress concentration when the wafer is loaded.

[0010] Compared with the prior art, a wafer loading stage provided in this embodiment can convert traditional passive support into active response. Through the two-way collaborative optimization of the supporting force control at the stage body end and the downward pressure regulation at the polishing head end, it breaks through the technical bottleneck of simply relying on the polishing head adjustment, realizes the closed-loop control of the balanced force on the wafer, and greatly improves the loading yield of the wafer.

[0011] In the second aspect, an embodiment of the present invention further provides a system for online adjusting the wafer loading pressure, including a wafer loading stage as described in any one of the foregoing, a polishing head, a polishing head controller, and a main control machine. A plurality of pressure zones are provided on the polishing head, and the pressure zones are arranged in a one-to-one correspondence with the pressure response areas up and down. The polishing head controller is used to calibrate, monitor, and adjust the pressure of each pressure zone. The main control machine is electrically connected to the pressure actuator, the pressure sensor, the displacement sensor, and the polishing head controller respectively.

[0012] The beneficial effect of a system for online adjusting the wafer loading pressure provided by the present invention lies in that: compared with the prior art, in a system for online adjusting the wafer loading pressure according to the present invention, by arranging a plurality of pressure response areas on the stage body in a one-to-one correspondence with a plurality of pressure zones on the polishing head up and down, during the process of the polishing head pressing down on the wafer, when a certain pressure zone contacts the upper surface of the wafer, the corresponding pressure response area can respond simultaneously with this pressure zone, act on the lower surface of the wafer with an upward supporting force, and actively offset the downward pressure of this pressure zone, thereby realizing the balanced force on this area of the wafer and improving the safety of wafer loading.

[0013] In the third aspect, an embodiment of the present invention further provides a method for online adjusting the wafer loading pressure, which uses the system for online adjusting the wafer loading pressure as described above to perform online adjustment of the wafer loading pressure. The method for online adjusting the wafer loading pressure includes the following steps: S1. pre-calibrate the pressure value and the pressing timing of each pressure zone on the polishing head by using the polishing head controller, and send the calibrated pressure value and the pressing timing of each pressure zone to the main control machine; S2. The polishing head moves downward, and each of the pressure zones contacts the upper surface of the wafer on the stage body in sequence according to a pre-calibrated downward pressing sequence, and presses the wafer downward at a calibrated pressure value; S3. The main control machine sends an action signal to the pressure actuator in the corresponding pressure response area, and the pressure actuator outputs a compensating support force to act on the lower surface of the wafer to balance the force on the wafer; S4. The pressure sensor continuously monitors the pressure on the wafer, the displacement sensor continuously monitors the deformation of the wafer, and the main control machine continuously receives the pressure information and deformation information of the wafer until the wafer is stably loaded onto the polishing head.

[0014] In combination with the third aspect, in a possible implementation, in step S3, the main control machine calculates the compensating support force according to the calibrated pressure value of the pressure zone, and the compensating support force is the product of the calibrated pressure value and the adjustment coefficient.

[0015] In some embodiments, step S3 also includes: the main control machine predicts the action of the next pressure zone according to the calibrated pressure value and the downward pressure timing of each pressure zone, and calculates the compensatory support force of the next pressure response zone.

[0016] In combination with the third aspect, in a possible implementation, in step S5, when the pressure or deformation of the wafer exceeds a safety threshold, the main control machine starts an alarm program and stops loading.

[0017] The beneficial effect of the method for online adjusting wafer loading pressure provided by the present invention is that: compared with the prior art, the method for online adjusting wafer loading pressure of the present invention forms an upper and lower bidirectional force field control mechanism through pre-calibration of the polishing head partition pressure and active compensation of the pressure response zone of the carrier body, which systematically solves the stress imbalance problem in the wafer loading stage. At the same time, through the closed-loop control algorithm, millisecond-level pressure compensation is ensured, which not only reduces the breakage rate of the wafer, but also greatly improves the process accuracy and production efficiency, and promotes the development of CMP equipment towards intelligence and high compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a top view of a wafer loading platform provided by an embodiment of the present invention; Figure 2 A schematic diagram of a top view of another embodiment of a wafer loading platform provided by an embodiment of the present invention; Figure 3 Schematic diagram of the structure of a wafer loading stage, a polishing head, and a wafer provided by an embodiment of the present invention; Figure 4 Schematic diagram of the system structure for online adjustment of wafer loading pressure provided by an embodiment of the present invention; Figure 5 Schematic flow chart of wafer loading using a system for online adjustment of wafer loading pressure provided by an embodiment of the present invention.

[0019] In the figure: 1. Stage body; 11. Pressure response area; 2. Pressure actuator; 3. Polishing head; 31. Pressure partition; 4. Polishing head controller; 5. Main control unit. Detailed implementation manners

[0020] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or indirectly on the other element. It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or several of such features. In the description of the present invention, the meaning of "a plurality" and "several" is two or more, unless otherwise specifically defined.

[0022] Please refer to Figures 1 to 5 , and now a wafer loading stage provided by the present invention will be described. A wafer loading stage includes a stage body 1 and a plurality of pressure actuator groups. The stage body 1 is used to support the wafer, and a plurality of pressure response areas 11 are provided on the supporting surface of the stage body 1; a plurality of pressure actuator groups are correspondingly disposed in a plurality of pressure response areas 11, and the pressure actuator groups are used to provide an upward supporting force for the wafer.

[0023] A wafer loading stage provided in this embodiment divides a plurality of pressure response regions 11 on the stage body 1, and arranges a pressure actuator group in the pressure response regions 11, enabling the stage body 1 to dynamically respond and adjust the supporting force on the wafer in real time, actively offsetting the pressure non-uniformity when the polishing head 3 presses down, and avoiding micro-cracks or fragmentation problems caused by local stress concentration when the wafer is loaded.

[0024] Compared with the prior art, a wafer loading stage provided in this embodiment can transform traditional passive support into active response, forming a two-way collaborative optimization through the control of the supporting force at the stage body 1 end and the regulation of the downward pressure at the polishing head 3 end, breaking through the technical bottleneck that solely relies on the adjustment of the polishing head 3, achieving a closed-loop control of the balanced force on the wafer, and greatly improving the loading yield of the wafer.

[0025] Specifically, the stage body 1 has a supporting cavity, the pressure response regions 11 are divided on the bottom of the supporting cavity, the pressure actuator group is connected to the stage body 1 and is located in the supporting cavity. The wafer is placed above the pressure actuator group.

[0026] In some possible implementation manners, the above-mentioned pressure actuator group adopts a structure such as Figure 1 or Figure 2 shown in the figure. Refer to Figure 1 or Figure 2 , the pressure actuator group includes a plurality of pressure actuators 2 arranged at intervals in the corresponding pressure response regions 11.

[0027] In this embodiment, the pressure actuator group includes one or more pressure actuators 2, and preferably adopts a structural form in which a plurality of pressure actuators 2 are arranged in one pressure response region 11. From another perspective, that is to say, the partition structure of a plurality of pressure response regions 11 is formed by the arrangement method of multiple pressure actuator groups.

[0028] By arranging a plurality of pressure actuators 2 at intervals in each pressure response region 11, a high-density control structure is formed, which can perform sub-zone level fine-tuning on different regions of the wafer (especially the edge and weak parts), further improving the uniformity of the force on the wafer.

[0029] In some possible implementation manners, the pressure actuator 2 is one of a piezoelectric ceramic actuator, an air film chamber, and a hydraulic cylinder. In this embodiment, the pressure actuator 2 preferably is a piezoelectric ceramic actuator.

[0030] The core of the piezoelectric ceramic actuator is based on the inverse piezoelectric effect: when an external voltage is applied to the piezoelectric ceramic material, its internal lattice structure undergoes polarization deformation, resulting in mechanical displacement (elongation or contraction) of the material at the micro scale. The displacement amount is linearly related to the applied voltage, the response time is extremely short (in the microsecond to millisecond level), and it has high repeat accuracy.

[0031] By sending a high-voltage pulse signal to the piezoelectric ceramic actuator in the corresponding pressure response area 11, it is possible to drive it to rapidly elongate (or contract), thereby raising (or lowering) the support height of the corresponding area and achieving the purpose of dispersing concentrated stress. That is, by applying an appropriate voltage to the piezoelectric ceramic actuator, it is possible to adjust the topography of the bearing surface of the stage body 1 at the microscale, thereby actively offsetting the local downward pressure.

[0032] Furthermore, the piezoelectric ceramic actuator is small in size (as small as a few millimeters square), supports the arrangement of a high-density pressure actuator 2 array in a limited space, realizes more refined sub-zone control, and is particularly suitable for edge stress optimization of large-sized wafers.

[0033] Specifically, the wires of the piezoelectric ceramic actuator can be led downward after passing through the stage body 1.

[0034] The air film cavity type pressure actuator is based on air floating support and pneumatic dynamic regulation technology. Its core is to form a controllable air film layer between the bearing surface of the stage body 1 and the wafer through gas pressure, and use the gas pressure distribution to realize dynamic support force adjustment.

[0035] Specifically, multiple independent air film cavities (air chambers) are designed inside the stage body 1. Each air film cavity corresponds to a pressure response area 11. The air film cavity is connected to an external gas source (such as compressed air or inert gas) through an air pipeline, and is equipped with a high-speed proportional valve and a pressure sensor to form a closed-loop control system.

[0036] By inflating the air film cavity through the external gas source and the air pipeline, increasing the air pressure in the air film cavity, and enhancing the air film stiffness, the support force of the corresponding pressure response area 11 can be improved to resist the downward pressure of the polishing head 3.

[0037] By using a high-speed proportional valve (response time < 10 ms) and a precision air pressure sensor, millisecond-level regulation of the air pressure in the air film cavity can be achieved.

[0038] The setting of the air film cavity realizes non-contact loading of the wafer and the stage body 1 through gas pressure, which can avoid local friction and stress concentration caused by traditional rigid contact, and is particularly suitable for the loading protection of ultra-thin wafers. At the same time, the air film has passive compliance. When the wafer has slight warping or thickness unevenness, the air film thickness can be automatically adjusted locally to achieve adaptive stress balance.

[0039] The hydraulic cylinder type pressure actuator is based on liquid pressure transmission and piston displacement control technology. By adjusting the pressure and flow rate of the hydraulic oil, it drives the piston to generate a controllable support force.

[0040] Specifically, the hydraulic cylinder is vertically arranged, and its driving end is connected with a supporting plate adapted to the pressure response area 11. The hydraulic oil enters the cylinder body of the hydraulic cylinder under the drive of the pump station, pushing the piston to move. By controlling the oil pressure, the supporting force of the supporting plate can be linearly adjusted, that is, the supporting force of the corresponding pressure response area 11 can be adjusted.

[0041] The hydraulic cylinder system can provide a supporting force ranging from hundreds of Newtons to thousands of Newtons, which is much higher than that of piezoelectric ceramics and air film chambers, and is suitable for the stable loading of overweight or large-sized wafers.

[0042] In some possible implementation manners, the above-mentioned pressure response area 11 adopts a structure as shown in Figure 1 or Figure 2 See Figure 1 or Figure 2 , and multiple pressure response areas 11 are arranged in concentric rings nested in sequence from the center to the periphery or in a grid layout of vertical and horizontal intersections.

[0043] In this embodiment, taking the piezoelectric ceramic actuator as an example, multiple piezoelectric ceramic actuators form a pressure actuator group, and the layout manner of multiple pressure actuator groups forms a partition structure of multiple pressure response areas 11. By arranging the pressure response area 11 in a concentric ring or grid partition structure, it is convenient to cover the entire wafer surface and realize the precise perception of the pressure at different positions on the wafer surface.

[0044] In some possible implementation manners, multiple pressure sensors and multiple displacement sensors are arranged in the pressure response area 11. The pressure sensors are used to monitor the pressure received by the wafer in real time, and the displacement sensors are used to monitor the deformation amount of the wafer in real time.

[0045] In this embodiment, multiple pressure sensors and multiple displacement sensors are arranged at intervals in the pressure response area 11 to comprehensively monitor the real-time data of the pressure and displacement of the wafer. When an abnormality occurs in the wafer, by analyzing the data of multiple pressure sensors and displacement sensors, the location and cause of the failure can be quickly determined. At the same time, the real-time data provided by the pressure sensors and displacement sensors can be used as feedback signals to optimize the pressure-related parameters in the wafer manufacturing process and improve the consistency of the wafer processing quality.

[0046] Specifically, the pressure sensor adopts a high-precision and high-sensitivity thin-film pressure sensor (detection threshold < 0.1 N) to ensure instantaneous contact recognition.

[0047] The displacement sensor can adopt an optical displacement sensor or a laser displacement sensor, or can also adopt the form of a strain gauge to monitor the bending deformation of the wafer in real time.

[0048] Based on the same inventive concept, the embodiment of the present application also provides a system for online adjusting the wafer loading pressure. See Figure 3 andFigure 4 , an on-line wafer loading pressure adjustment system includes a wafer loading stage and a polishing head 3, a polishing head controller 4 and a main control unit 5 proposed in any one of the foregoing. A plurality of pressure zones 31 are provided on the polishing head 3, and the pressure zones 31 are arranged in a one-to-one correspondence with the pressure response zones 11 up and down. The polishing head controller 4 is used to calibrate, monitor and adjust the pressure of each pressure zone 31. The main control unit 5 is electrically connected to the pressure actuator 2, the pressure sensor, the displacement sensor and the polishing head controller 4 respectively.

[0049] For the on-line wafer loading pressure adjustment system provided in this embodiment, compared with the prior art, by arranging a plurality of pressure response zones 11 on the stage body 1 in a one-to-one correspondence with a plurality of pressure zones 31 on the polishing head 3, during the process of the polishing head 3 pressing down the wafer, when a certain pressure zone 31 contacts the upper surface of the wafer, the corresponding pressure response zone 11 can respond simultaneously with the pressure zone 31, and act on the lower surface of the wafer with an upward supporting force to actively offset the downward pressure of the pressure zone 31, thereby achieving the force balance in this area of the wafer and improving the safety of wafer loading.

[0050] Specifically, the polishing head controller 4 is built into the polishing head 3. The polishing head controller 4 is used to calibrate, real-time monitor and adjust the downward pressure value of each pressure zone 31, which belongs to the prior art in modern high-end chemical mechanical polishing equipment and will not be elaborated here. However, the polishing head controller 4 feeds back the real-time downward pressure of each pressure zone 31 to the main control unit 5 through an electrical signal for the main control unit 5 to perform real-time compensation calculation on the supporting force, which is still within the protection scope of the present invention.

[0051] As the core processing unit, the main control unit 5 receives the data signals of the pressure sensor, the displacement sensor and the polishing head controller 4, runs the control algorithm, and sends action instructions to the pressure actuator 2 and the polishing head 3. The setting of the main control unit 5 supports real-time data interaction, realizes the closed-loop control between the polishing head 3 and the stage body 1, ensures millisecond-level dynamic response, and adapts to the high-speed wafer production rhythm.

[0052] Based on the same inventive concept, the embodiment of the present application also provides a method for on-line adjusting the wafer loading pressure, and uses the foregoing on-line wafer loading pressure adjustment system to perform on-line adjustment of the wafer loading pressure. For the wafer loading process, see Figure 5 , the method for on-line adjusting the wafer loading pressure includes the following steps: S1. Use the polishing head controller 4 to pre-calibrate the pressure values and the downward pressure timing of each pressure zone 31 on the polishing head 3, and send the calibrated pressure values and the downward pressure timing of each pressure zone 31 to the main control unit 5; S2. The polishing head 3 moves downward, and each pressure zone 31 contacts the upper surface of the wafer on the stage body 1 in sequence according to a pre-calibrated downward pressing sequence, and presses the wafer downward at a calibrated pressure value; S3. The main control machine 5 sends an action signal to the pressure actuator 2 in the corresponding pressure response area 11, and the pressure actuator 2 outputs a compensating support force to act on the lower surface of the wafer so that the force on the wafer is balanced; S4. The pressure sensor continuously monitors the pressure on the wafer, the displacement sensor continuously monitors the deformation of the wafer, and the main control machine 5 continuously receives the pressure information and deformation information of the wafer until the wafer is stably loaded onto the polishing head 3.

[0053] It should be noted that a plurality of pressure zones 31 are provided on the polishing head 3, so that the plurality of pressure zones 31 contact and press down the wafer in turn in different time periods. On the one hand, this can avoid instantaneous concentrated loads and prevent the wafer from being crushed. On the other hand, by making the pressure zone 31 located in the center of the polishing head 3 contact the upper surface of the wafer first, and then making the peripheral pressure zones 31 contact the wafer in turn (such as in a spiral diffusion manner), it is helpful to discharge air or residual moisture on the contact surface, and further ensure the stable reliability of wafer loading.

[0054] Specifically, the pressure distribution information (pressure value and downward pressure sequence) of the pressure partition 31 on the polishing head 3 is pre-established by the polishing head controller 4, and the pressure distribution information is stored in the main control machine 5 to provide a reference for subsequent dynamic compensation. The polishing head 3 moves down each pressure partition 31 in stages according to the pre-calibrated downward pressure sequence. At the same time, the main control machine 5 quickly calculates the compensation support force opposite to the downward pressure according to the pre-calibrated downward pressure sequence and the calibrated pressure value, and sends an action instruction to the pressure actuator 2 in the corresponding pressure response area 11 on the stage body 1, so that the pressure response area 11 enters the compensation activation state, so that this part of the wafer is in a state of upper and lower force balance.

[0055] Each pressure response area 11 performs dynamic compensation response with the corresponding pressure partition 31 one by one according to the above steps. When the outermost pressure partition 31 completes the downward pressure, the outermost pressure response area 11 and the corresponding pressure partition 31 maintain a state of vertical balance, and the pressure partition 31 in the middle area performs a vacuum operation to absorb the wafer. After that, the outermost pressure response area 11 is reset, and the outermost pressure partition 31 enters a vacuum locking state for the outer edge of the wafer, and the wafer loading process is completed at this time.

[0056] During the above loading process, the actual pressure values of each pressure zone 31 are fed back in real time by the polishing head controller 4. The pressure sensor monitors the compensated pressure distribution in real time, and the displacement sensor detects the bending deformation amount of the wafer in real time. The main control unit 5 continuously compares the measured data with the calibrated data model. If a deviation is detected (such as the pressure in a certain zone exceeding the limit by ±5%), secondary compensation is immediately triggered. When the pressure fluctuations in all zones are stable within ±2%, and the deformation amount of the wafer is lower than the safety threshold (such as <0.5 μm), it is determined as stable loading, and the polishing head 3 completes the adsorption of the wafer.

[0057] A method for online adjusting the wafer loading pressure provided in this embodiment, compared with the prior art, forms an up-and-down bidirectional force field control mechanism through the pre-calibration of the polishing head 3's zonal pressure and the active compensation of the pressure response zone 11 of the stage body 1, systematically solving the stress imbalance problem in the wafer loading stage. At the same time, through the closed-loop control algorithm, it ensures millisecond-level pressure compensation, not only reducing the breakage rate of the wafer, but also greatly improving the process accuracy and production efficiency, and promoting the development process of CMP equipment towards intelligence and high compatibility.

[0058] In some possible implementation manners, in step S3, the main control unit 5 calculates the compensation support force according to the calibrated pressure value of the pressure zone 31, and the compensation support force is the product of the calibrated pressure value and the adjustment coefficient.

[0059] It should be noted that in the radial direction of the polishing head 3, the calibrated pressure values of each pressure zone 31 are linearly related. Correspondingly, in this embodiment, the pressure response zones 11 on the same direction of the stage body 1 are also theoretically linearly related. Since multiple pressure actuators 2 are arranged in each pressure response zone 11, in actual applications, in order to achieve more precise pressure perception on the wafer surface, the compensation support forces output by the multiple pressure actuators 2 in the radial direction within the same pressure response zone 11 are not the same.

[0060] In this embodiment, the compensation support force output by each pressure actuator 2 is set as the product of the calibrated pressure value of the corresponding pressure zone 31 and the adjustment coefficient. Specifically, the adjustment coefficient is comprehensively determined according to the position of the wafer surface corresponding to the pressure actuator 2 and the pressure and deformation amount received by the wafer at this position, so as to achieve more precise control of the loading pressure.

[0061] In some possible implementation manners, step S3 further includes: the main control unit 5 predicts the action of the next pressure zone 31 according to the calibrated pressure value and the downward pressure timing of each pressure zone 31, and calculates the compensation support force of the next pressure response zone 11.

[0062] Specifically, based on the timing correlation and pressure transmission law, the master controller 5 predicts the actions of the next pressure zone 31 and calculates in advance the compensation support force of the next pressure response zone 11. By calculating the compensation support force in advance, the physical delay between the action of the pressure actuator 2 and the downward pressure of the polishing head 3 is offset, so that the actual compensation and pressure application occur synchronously. For example, if it is predicted that the next pressure zone 31 will be triggered after 20 ms, the master controller 5 sends a preloading instruction 15 ms in advance to eliminate the influence of the delay of the pressure actuator 2, suppress the cross-zone pressure interference, and achieve global balance.

[0063] In some possible implementation manners, in step S5, when the pressure or deformation amount of the wafer exceeds the safety threshold, the master controller 5 starts an alarm program and stops loading.

[0064] The start of the alarm program can enable the operator to quickly learn about the abnormal situation in the production process, which is convenient for timely troubleshooting and analysis of the problem, finding out the reasons for the excessive pressure or deformation amount, such as improper parameter setting, quality problems of the wafer itself, etc., so as to take corresponding measures for improvement, strengthen the quality control of the production process, and improve the consistency and reliability of the product. At the same time, by stopping loading in time, further damage to the wafer can be avoided, the quality and integrity of the wafer can be protected, and the production cost can be reduced.

[0065] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A wafer loading platform, characterized in that: include: A carrier body, used for supporting the wafer, wherein the supporting surface of the carrier body has a plurality of pressure response areas; as well as A plurality of pressure actuator groups are arranged in a one-to-one correspondence in the plurality of pressure response areas, and the pressure actuator groups are used to provide an upward supporting force for the wafer.

2. A wafer loading platform as claimed in claim 1, characterized in that: The pressure actuator group includes a plurality of pressure actuators arranged at intervals in the corresponding pressure response areas.

3. A wafer loading platform as claimed in claim 2, characterized in that: The pressure actuator is one of a piezoelectric ceramic actuator, an air film cavity and a hydraulic cylinder.

4. A wafer loading platform as claimed in claim 1, characterized in that: The plurality of pressure response areas are arranged in the form of concentric rings which are arranged in sequence from the center to the periphery, or in the form of a grid which intersects vertically and horizontally.

5. A wafer loading platform as claimed in claim 2, characterized in that: A plurality of pressure sensors and a plurality of displacement sensors are arranged in the pressure response area. The pressure sensors are used to monitor the pressure exerted on the wafer in real time, and the displacement sensors are used to monitor the deformation of the wafer in real time.

6. A system for adjusting wafer loading pressure online, characterized in that: It comprises a wafer loading platform as described in any one of claims 1 to 5, a polishing head, a polishing head controller and a main control machine, the polishing head is provided with a plurality of pressure zones, the pressure zones are arranged one by one in an upper and lower correspondence with the pressure response zones, the polishing head controller is used to calibrate, monitor and adjust the pressure of each of the pressure zones, and the main control machine is electrically connected to the pressure actuator, the pressure sensor, the displacement sensor and the polishing head controller respectively.

7. A method for adjusting wafer loading pressure online, characterized in that: The system for adjusting wafer loading pressure online as claimed in claim 6 is used to adjust wafer loading pressure online, and the method for adjusting wafer loading pressure online comprises the following steps: S1. pre-calibrate the pressure value and the pressing timing of each pressure zone on the polishing head by using the polishing head controller, and send the calibrated pressure value and the pressing timing of each pressure zone to the main control machine; S2. The polishing head moves downward, and each of the pressure zones contacts the upper surface of the wafer on the stage body in sequence according to a pre-calibrated downward pressing sequence, and presses the wafer downward at a calibrated pressure value; S3. The main control machine sends an action signal to the pressure actuator in the corresponding pressure response area, and the pressure actuator outputs a compensating support force to act on the lower surface of the wafer to balance the force on the wafer; S4. The pressure sensor continuously monitors the pressure on the wafer, the displacement sensor continuously monitors the deformation of the wafer, and the main control machine continuously receives the pressure information and deformation information of the wafer until the wafer is stably loaded onto the polishing head.

8. The method for adjusting wafer loading pressure online according to claim 7, characterized in that: In step S3, the main control machine calculates the compensation support force according to the calibrated pressure value of the pressure zone, and the compensation support force is the product of the calibrated pressure value and the adjustment coefficient.

9. The method for adjusting wafer loading pressure online according to claim 8, characterized in that: Step S3 also includes: the main control machine predicts the action of the next pressure zone according to the calibrated pressure value and the downward pressure sequence of each pressure zone, and calculates the compensating support force of the next pressure response zone.

10. The method for adjusting wafer loading pressure online according to claim 7, characterized in that: In step S5, when the pressure or deformation of the wafer exceeds a safety threshold, the host control machine starts an alarm program and stops loading.

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