Electrostatic chucking method and system for a wafer

Abstract

An electrostatic chucking method and system for a wafer, the method comprising: placing the wafer on an electrostatic chucking plate; the electrostatic chucking plate being provided with a plurality of ring electrodes centered on a first position; obtaining a warping height of the wafer at the first position; and in response to the warping height being less than or equal to a first height threshold, controlling the plurality of ring electrodes to be sequentially powered from the first position radially outward at a preset time interval. Thus, by realizing local and gradual electrostatic chucking, not only can the structural damage caused by large deformation in the wafer be reduced, ensuring device performance and product yield, but also the adhesion bubbles between the wafer and the chucking plate during electrostatic chucking can be avoided, the uniformity of the process film layer can be improved during processing, which is conducive to further improving device performance and product yield, the accuracy and reliability of the test can be improved during testing, and the number of broken pieces can be reduced.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a method and system for electrostatic adsorption of wafers. Background Technology

[0002] With the development of ultra-thin wafers with thinner back sides, in the manufacturing process of related semiconductor devices, it is often necessary to adsorb and position the wafer on an adsorption plate to provide mechanical support or for movement and transportation.

[0003] In existing technologies, vacuum adsorption is commonly used, but it suffers from low controllability, poor adsorption uniformity, and the negative pressure at the vacuum adsorption pores easily causes deformation. In contrast, electrostatic adsorption can avoid these problems.

[0004] However, the ultra-thinness and significant warpage of wafers present certain drawbacks to electrostatic adsorption. During electrostatic adsorption, the wafer undergoes rapid and significant deformation, which can easily damage the internal structure, affecting device performance and product yield. Furthermore, it can easily create bonding bubbles due to the enclosed air. During processing, these bubbles reduce the flatness of the wafer surface, leading to uneven processing films and directly impacting device performance and yield. During testing, these bubbles affect accuracy, and the affected areas are easily penetrated by test probes, causing wafer breakage. Summary of the Invention

[0005] To address at least one problem existing in the prior art, the purpose of this application is to provide a method and system for electrostatic adsorption of wafers. By achieving localized, stepwise electrostatic adsorption, it not only helps reduce structural damage caused by large deformations within the wafer, ensuring device performance and product yield, but also avoids the formation of bonding bubbles between the wafer and the adsorption plate during electrostatic adsorption, effectively optimizing the bonding effect. Consequently, during processing, it can improve the uniformity of the process film layer, which is beneficial for further improving device performance and product yield. During testing, it can improve the accuracy and reliability of testing and reduce wafer breakage.

[0006] To achieve the above objectives, this application provides a wafer electrostatic adsorption method, wherein the method is applied to an electrostatic adsorption system, the electrostatic adsorption system including an electrostatic adsorption plate, and a plurality of annular electrodes arranged on the electrostatic adsorption plate centered at a first position; the method includes, The wafer is placed on the electrostatic adsorption plate; Obtain the warpage height of the wafer at the first position; In response to the warpage height being less than or equal to a first height threshold, the plurality of annular electrodes are controlled to be energized sequentially from the first position outwards at preset time intervals.

[0007] Furthermore, the electrostatic adsorption system further includes an air blowing unit; the method further includes, In response to the warpage height being greater than a first height threshold and less than a second height threshold, the blowing unit is controlled to start and blow air downward or diagonally downward toward the first region of the wafer corresponding to the first position. The plurality of ring electrodes are controlled to be energized sequentially from the first position outwards radially at preset time intervals.

[0008] Furthermore, after the step of controlling the start of the air blowing unit, the method further includes, The air pressure parameter value for blowing is determined based on the warpage height and the thickness of the wafer; The blowing unit is controlled to blow air at the specified air pressure parameter value.

[0009] Furthermore, the method also includes, A pre-configured pressure parameter table is provided; wherein, the pressure parameter table includes multiple pressure parameter values, each pressure parameter value corresponding to a specific warp height range and wafer thickness range; The step of determining the air pressure parameter value of the blowing air based on the warpage height and the wafer thickness includes, Obtain the thickness of the wafer; Retrieve the air pressure parameter table; The wafer thickness range corresponding to the gas pressure parameter table is determined based on the wafer thickness, and the warpage height range corresponding to the gas pressure parameter table is determined based on the warpage height. The air pressure parameter value for blowing is determined based on the corresponding wafer thickness range and the corresponding warpage height range.

[0010] Furthermore, the method also includes, In response to the warpage height being greater than or equal to a second height threshold, the wafer is flipped over and placed on an electrostatic adsorption plate; The warpage height at the first position corresponding to the flipped wafer is obtained and used as the warpage height.

[0011] Furthermore, after the step of controlling the plurality of ring electrodes to be sequentially energized radially outward from the first position at preset time intervals, the method further includes, Obtain height parameters at multiple locations on the wafer; In response to at least one of the height parameters being greater than the fitting height threshold, the plurality of annular electrodes are controlled to be energized sequentially from the first position radially inward at preset time intervals, and the warp height is reacquired.

[0012] Furthermore, the method also includes, The sequentially applied voltages of the plurality of ring electrodes are configured to increase sequentially.

[0013] Furthermore, the first position is the center of the electrostatic adsorption plate, corresponding to the center of the wafer or a region close to the center; the plurality of annular electrodes are concentric annular electrodes.

[0014] Furthermore, the electrostatic adsorption plate is provided with at least one air channel penetrating the electrostatic adsorption plate.

[0015] To achieve the above objectives, this application also provides an electrostatic adsorption system for wafers, the system comprising, An electrostatic adsorption plate, wherein multiple annular electrodes are arranged on the electrostatic adsorption plate centered at a first position; and, An electrostatic adsorption device is used to control the electrostatic adsorption of the wafer by the electrostatic adsorption plate. The electrostatic adsorption device includes, The wafer mounting module is used to place the wafer on the electrostatic adsorption plate; The acquisition module is used to acquire the warpage height of the wafer at the first position; The control module, in response to the warpage height being less than or equal to a first height threshold, controls the plurality of annular electrodes to be energized sequentially from the first position radially outward at preset time intervals.

[0016] This application discloses a method and system for electrostatic adsorption of wafers. The method employs an electrostatic adsorption plate with multiple annular electrodes centered at a first position. The wafer is placed on the electrostatic adsorption plate, and the warpage height at the corresponding first position is obtained. In response to a warpage height less than or equal to a first height threshold, the multiple annular electrodes are sequentially energized radially outward from the first position at preset time intervals. This achieves localized, gradual electrostatic adsorption, which not only helps reduce structural damage caused by large deformations within the wafer, ensuring device performance and product yield, but also avoids the formation of bonding bubbles between the wafer and the adsorption plate during electrostatic adsorption, effectively optimizing the bonding effect. Furthermore, during processing, it improves the uniformity of the process film, further enhancing device performance and product yield. During testing, it improves the accuracy and reliability of testing and reduces wafer breakage.

[0017] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the electrostatic adsorption plate according to an embodiment of this application; Figure 2 This is a flowchart of an electrostatic adsorption method according to an embodiment of this application; Figure 3 Here is a flowchart of an electrostatic adsorption method according to another embodiment of this application; Figure 4 This is a structural block diagram of the electrostatic adsorption system according to an embodiment of this application. Detailed Implementation

[0019] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0020] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0021] It should be noted that the concepts of "first" and "second" mentioned in this application are only used to distinguish different devices, modules, units or data, and are not used to limit the order of the functions performed by these devices, modules, units or data or their interdependencies.

[0022] It should be noted that the terms "one" and "multiple" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be understood as "one or more". "Multiple" should be understood as two or more.

[0023] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0024] First, it should be noted that the electrostatic adsorption method for wafers in this application is applied to an electrostatic adsorption system, which includes an electrostatic adsorption plate. For example... Figure 1As shown, the electrostatic adsorption plate 100 has multiple annular electrodes (E1, E2, E3, E4) arranged around a first position O. These annular electrodes (E1, E2, E3, E4) are arranged in a ring-like configuration on the plate surface. In a specific example, the first position O can be the center of the electrostatic adsorption plate, corresponding to the center of the wafer or a region close to the center. The multiple annular electrodes (E1, E2, E3, E4) are preferably concentric annular electrodes.

[0025] It is understood that the first position can also be any other position of the electrostatic adsorption plate, and this application does not impose any specific restrictions on this.

[0026] It should be noted that the multiple ring electrodes form a parallel structure, allowing them to be energized independently or sequentially to generate electrostatic attraction. The shapes of the multiple ring electrodes can be circular, elliptical, square, hexagonal, etc. This application does not impose any specific limitations in this regard.

[0027] Figure 2 This is a flowchart of an electrostatic adsorption method for a wafer according to an embodiment of this application. Reference will be made below. Figure 2 The electrostatic adsorption method for wafers described in this application is described in detail.

[0028] In step 201, the wafer is placed on an electrostatic adsorption plate.

[0029] In a specific example, the wafer can first be transferred and placed on an electrostatic adsorption plate via the wafer loading module for positioning.

[0030] In step 202, the warpage height at the corresponding first position on the wafer is obtained.

[0031] Specifically, a laser ranging unit can be set above the first position to measure the vertical distance d1 from the laser ranging unit to the first position. After placing the wafer, the vertical distance d2 from the laser ranging unit to the corresponding first position on the wafer can be measured. Then, the warpage height h can be obtained using h = d1 - d2.

[0032] In step 203, in response to the warpage height being less than or equal to a first height threshold, multiple ring electrodes are controlled to be energized sequentially from the first position outwards at preset time intervals.

[0033] In other words, if the warpage height h is small, h ≤ h1, where h1 is the first height threshold, then based on a preset time interval, power can be applied sequentially from the first position outwards radially, i.e., E1, E2, ..., En are applied sequentially. By achieving localized, gradual electrostatic adsorption, not only can structural damage caused by large deformation inside the wafer be reduced, ensuring device performance and product yield, but also adhesion bubbles between the wafer and the adsorption plate can be avoided during electrostatic adsorption.

[0034] It should be noted that the first height threshold (and the subsequent second height threshold) may be preset based on different wafer sizes or thicknesses.

[0035] According to the wafer electrostatic chucking method of the embodiments of the present application, an electrostatic chuck plate is adopted, on which a plurality of annular electrodes centered at a first position are arranged; the wafer is placed on the electrostatic chuck plate; the warpage height of the wafer at the position corresponding to the first position is acquired; and in response to the warpage height being less than or equal to the first height threshold, the plurality of annular electrodes are controlled to be sequentially powered on radially outward from the first position at preset time intervals. Thereby, by realizing local stepwise electrostatic chucking, it not only helps reduce structural damage inside the wafer caused by large deformation, ensures device performance and product yield, but also can avoid bonding bubbles generated between the wafer and the chuck plate during electrostatic chucking, improve the flatness of the wafer surface, effectively optimize the bonding effect, and further improve the uniformity of the process film layer during the processing, which is beneficial to further improving device performance and product yield; during the testing process, the accuracy and reliability of testing can be improved, and wafer breakage can be reduced.

[0036] In the embodiments of the present application, the electrostatic chuck system further includes a gas blowing unit. Reference Figure 3 shows that the method further includes the following steps: Step 204: In response to the warpage height being greater than the first height threshold and less than the second height threshold, control the gas blowing unit to start, and blow gas downward or obliquely downward toward the first region of the wafer corresponding to the first position.

[0037] Step 205: Control the plurality of annular electrodes to be sequentially powered on radially outward from the first position at preset time intervals.

[0038] That is, when the warpage height h is relatively large, that is, h1<h<h2 (h2 is the second height threshold), the region corresponding to the first position on the wafer can be slightly pressed down with the assistance of air flow, and then the plurality of annular electrodes are sequentially powered on for chucking radially outward. That is, for wafers with different warpage degrees, different local stepwise electrostatic chucking strategies are preferably adopted to further reduce structural damage inside the wafer caused by large deformation and avoid the generation of bonding bubbles.

[0039] Further, with reference Figure 3 shows that after the step of controlling the gas blowing unit to start, the method further includes the following steps: Step 2041: Determine the air pressure parameter value for gas blowing based on the warpage height and the thickness of the wafer.

[0040] Step 2042: Control the gas blowing unit to blow gas downward or obliquely downward at the air pressure parameter value.

[0041] In a specific example, the air pressure parameter value for air blowing can be determined through a look-up table method or an empirical formula based on the warpage height and the thickness of the wafer. Specifically, after obtaining the warpage height h, if h1<h<h2 is satisfied, the air pressure parameter value for air blowing is determined based on the pre-input wafer thickness corresponding to the warpage height, and the air blowing unit is automatically controlled to blow air to the wafer at a preferred air pressure, which improves the intelligence and auxiliary effect of the air flow assistance.

[0042] Further, the method may further include pre-configuring an air pressure parameter table.

[0043] The air pressure parameter table includes a plurality of air pressure parameter values, and each air pressure parameter value corresponds to a specific warpage height interval and a specific wafer thickness interval.

[0044] Moreover, step 2041 may include: obtaining the thickness of the wafer; calling the air pressure parameter table; determining the corresponding wafer thickness interval in the air pressure parameter table according to the thickness of the wafer, and determining the corresponding warpage height interval in the air pressure parameter table according to the warpage height; determining the air pressure parameter value for air blowing according to the corresponding wafer thickness interval and the corresponding warpage height interval.

[0045] That is to say, the air pressure parameter table may be pre-configured. The rows of the air pressure parameter table may correspond to different warpage height intervals; the columns of the air pressure parameter table may correspond to different wafer thickness intervals; the sub-units of the air pressure parameter table may be the air pressure parameter values corresponding to the corresponding warpage height intervals and wafer thickness intervals. When the warpage height is greater than the first height threshold and less than the second height threshold, the air pressure parameter value can be determined by calling the air pressure parameter table based on the pre-input wafer thickness and the identified warpage height.

[0046] In the embodiment of the present application, with reference to Figure 3 as shown, the method further includes the following steps: Step 206, in response to the warpage height being greater than or equal to the second height threshold, turning over the wafer and placing it on an electrostatic adsorption plate.

[0047] Step 207, obtaining the warpage height at the first position corresponding to the turned-over wafer as the new warpage height.

[0048] That is to say, when the warpage height is too large, direct adsorption of the area near the first position or air flow assistance with a relatively high air pressure still cannot avoid certain damage to the internal structure. Therefore, by turning over the wafer to reduce the warpage height at the first position corresponding to the wafer, and then performing the above-mentioned local stepwise electrostatic adsorption method, a better local stepwise electrostatic adsorption effect can be achieved.

[0049] In this embodiment, the method further includes: in response to receiving an electrostatic adsorption termination command, controlling multiple annular electrodes to sequentially de-energize radially inward from a first position at preset time intervals. This enables localized, gradual electrostatic release, helping to further reduce structural damage caused by large deformations within the wafer, ensuring device performance and product yield.

[0050] In this embodiment of the application, reference is made to Figure 3 As shown, after controlling multiple ring electrodes to be energized sequentially, the method further includes the following steps: Step 208: Obtain height parameters at multiple locations on the wafer.

[0051] Step 209: In response to at least one height parameter being greater than the fitting height threshold, control multiple annular electrodes to be energized sequentially from the first position radially inward at preset time intervals, and reacquire a new warp height.

[0052] In other words, after electrostatic adsorption is formed, a detection and feedback mechanism is implemented to monitor the adhesion effect. Specifically, height parameters at multiple locations on the wafer can be determined using laser ranging or camera identification. If any height parameter exceeds a preset adhesion height threshold, multiple ring electrodes are automatically energized sequentially radially inward, i.e., E4, E3, E2, and E1 are energized in sequence. After energization, the warpage height is automatically reacquired, and the electrostatic adsorption method is repeated based on the new warpage height. This further improves the reliability of localized, gradual electrostatic adsorption.

[0053] In this embodiment of the application, the method further includes: the power-on voltages of the multiple ring electrodes, namely the power-on voltages of E1, E2, E3, and E4, are configured to increase sequentially to ensure that the wafer and the electrostatic chuck are tightly attached, so that there are no air bubbles between them, thereby balancing the adsorption effect and energy saving.

[0054] In this embodiment of the application, combined with Figure 1 As shown, at least one air channel 101 is provided on the electrostatic adsorption plate 100, penetrating the electrostatic adsorption plate 100.

[0055] Specifically, in the adsorption state, areas on the wafer that might otherwise have adhesion bubbles will not develop due to the air channels provided in the corresponding areas of the electrostatic adsorption plate 100. It is understood that the shape of the air channel 101 can be circular or any other suitable shape, as long as it allows air to flow from one side of the electrostatic adsorption plate through the channel to the other side; this application does not impose any specific limitations on this.

[0056] In summary, the wafer electrostatic adsorption method according to the embodiments of this application employs an electrostatic adsorption plate having multiple annular electrodes centered at a first position; the wafer is placed on the electrostatic adsorption plate; the warpage height of the wafer at the corresponding first position is obtained; and in response to the warpage height being less than or equal to a first height threshold, the multiple annular electrodes are sequentially energized radially outward from the first position at preset time intervals. Thus, by achieving localized, gradual electrostatic adsorption, not only is structural damage caused by large deformation within the wafer reduced, ensuring device performance and product yield, but also adhesion bubbles between the wafer and the adsorption plate are avoided during electrostatic adsorption, improving the flatness of the wafer surface and effectively optimizing the bonding effect. Furthermore, during processing, the uniformity of the process film layer can be improved, further enhancing device performance and product yield; during testing, the accuracy and reliability of testing can be improved, and wafer breakage can be reduced.

[0057] Figure 4 This is a structural block diagram of a wafer electrostatic adsorption system according to an embodiment of this application. (Reference) Figure 4 As shown, the electrostatic adsorption system 300 for the wafer includes an electrostatic adsorption plate 310 and an electrostatic adsorption device 320.

[0058] Among them, the electrostatic adsorption plate 310 has multiple ring electrodes arranged on it with the first position as the center.

[0059] An electrostatic adsorption device 320 is used to control the electrostatic adsorption plate 310 to electrostatically adsorb the wafer. The electrostatic adsorption device 320 includes: a wafer loading module 321 for placing the wafer on the electrostatic adsorption plate 310; an acquisition module 322 for acquiring the warp height of the wafer at a corresponding first position; and a control module 323, which, in response to the warp height being less than or equal to a first height threshold, controls multiple annular electrodes to be sequentially energized radially outward from the first position at preset time intervals.

[0060] In this embodiment, the electrostatic adsorption system 300 further includes an air blowing unit (not shown in the figure). The control module 323 is also configured to: in response to a warpage height greater than a first height threshold and less than a second height threshold, control the air blowing unit to start and blow air downward or diagonally downward toward the first region of the wafer corresponding to the first position; and control multiple annular electrodes to be sequentially energized radially outward from the first position at preset time intervals.

[0061] Furthermore, the control module 323 is also used to: determine the air pressure parameter value for blowing based on the warp height and the thickness of the wafer after the control blowing unit is started; and control the blowing unit to blow air according to the air pressure parameter value.

[0062] Furthermore, the electrostatic adsorption device 320 also includes a configuration module (not shown in the figure), which is used to pre-configure a pressure parameter table. The pressure parameter table includes multiple pressure parameter values, each corresponding to a specific warpage height range and wafer thickness range.

[0063] Furthermore, the control module 323 is also used to: obtain the thickness of the wafer; retrieve the air pressure parameter table; determine the corresponding wafer thickness range in the air pressure parameter table based on the wafer thickness, and determine the corresponding warp height range in the air pressure parameter table based on the warp height; and determine the air pressure parameter value for blowing air based on the corresponding wafer thickness range and the corresponding warp height range.

[0064] In this embodiment of the application, the control module 323 is further configured to: respond to a warpage height greater than or equal to The second height threshold is used to flip the wafer and place it on an electrostatic adsorption plate 310; the warpage height of the wafer at the first position after flipping is obtained as the warpage height.

[0065] In this embodiment, the acquisition module 322 is further configured to: acquire height parameters at multiple locations on the wafer after the multiple ring electrodes are sequentially powered on. The control module 323 is further configured to: control the multiple ring electrodes to be sequentially powered off radially inward from the first position at preset time intervals in response to at least one height parameter being greater than the bonding height threshold, and reacquire the warpage height.

[0066] In this embodiment of the application, the configuration module is further configured to: configure the power-on voltage of the multiple ring electrodes to increase sequentially.

[0067] In this embodiment, the first position is the center of the electrostatic adsorption plate 310, corresponding to the center of the wafer or the area close to the center; the multiple ring electrodes are concentric ring electrodes.

[0068] In this embodiment of the application, at least one air channel is provided on the electrostatic adsorption plate 310 that penetrates the electrostatic adsorption plate 310.

[0069] Furthermore, as a preferred embodiment, the electrostatic adsorption plate may also be equipped with conductive plugs (not shown in the figure). These conductive plugs penetrate the electrostatic adsorption plate and protrude slightly from the corresponding surfaces of the plate at both ends. This allows for the transfer of charge from the wafer to the substrate during processes and electrostatic discharge tests where charged ions exist within the cavity. The charge is then rapidly discharged through the substrate's grounding device to prevent electrical failure of the device. This helps improve product yield and test reliability.

[0070] It should be noted that the explanation of the electrostatic adsorption method for wafers in the above embodiments also applies to an electrostatic adsorption system for wafers in the above embodiments, and will not be repeated here.

[0071] It should be understood that although the steps in the flowcharts in the accompanying drawings are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0072] It should be noted that the specific values ​​mentioned above are only for illustrating the implementation of this application in detail, and should not be construed as limitations on this application. In other examples, implementation methods, or embodiments, other values ​​may be selected according to this application, and no specific limitations are made here.

[0073] It will be understood by those skilled in the art that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for electrostatic adsorption of wafers, characterized in that, The method is applied to an electrostatic adsorption system, which includes an electrostatic adsorption plate and a plurality of annular electrodes arranged on the electrostatic adsorption plate with a first position as the center. The method includes, The wafer is placed on the electrostatic adsorption plate; Obtain the warpage height of the wafer at the first position; In response to the warpage height being less than or equal to a first height threshold, the plurality of annular electrodes are controlled to be energized sequentially from the first position outwards at preset time intervals; the energizing voltages of the sequential energizing are configured to increase sequentially.

2. The electrostatic adsorption method according to claim 1, characterized in that, The electrostatic adsorption system further includes an air blowing unit; the method further includes... In response to the warpage height being greater than a first height threshold and less than a second height threshold, the blowing unit is controlled to start and blow air downward or diagonally downward toward the first region of the wafer corresponding to the first position. The plurality of ring electrodes are controlled to be energized sequentially from the first position outwards radially at preset time intervals.

3. The electrostatic adsorption method according to claim 2, characterized in that, After the step of controlling the start of the air blowing unit, the method further includes, The air pressure parameter value for blowing is determined based on the warpage height and the thickness of the wafer; The blowing unit is controlled to blow air at the specified air pressure parameter value.

4. The electrostatic adsorption method according to claim 3, characterized in that, The method also includes, A pre-configured pressure parameter table is provided; wherein, the pressure parameter table includes multiple pressure parameter values, each pressure parameter value corresponding to a specific warp height range and wafer thickness range; The step of determining the air pressure parameter value of the blowing air based on the warpage height and the wafer thickness includes, Obtain the thickness of the wafer; Retrieve the air pressure parameter table; The wafer thickness range corresponding to the gas pressure parameter table is determined based on the wafer thickness, and the warpage height range corresponding to the gas pressure parameter table is determined based on the warpage height. The air pressure parameter value for blowing is determined based on the corresponding wafer thickness range and the corresponding warpage height range.

5. The electrostatic adsorption method according to claim 1, characterized in that, The method also includes, In response to the warpage height being greater than or equal to a second height threshold, the wafer is flipped over and placed on an electrostatic adsorption plate; The warpage height at the first position corresponding to the flipped wafer is obtained and used as the warpage height.

6. The electrostatic adsorption method according to claim 1, characterized in that, After the step of controlling the plurality of ring electrodes to be sequentially energized radially outward from the first position at preset time intervals, the method further includes, Obtain height parameters at multiple locations on the wafer; In response to at least one of the height parameters being greater than the fitting height threshold, the plurality of annular electrodes are controlled to be energized sequentially from the first position radially inward at preset time intervals, and the warp height is reacquired.

7. The electrostatic adsorption method according to claim 1, characterized in that, The first position is the center of the electrostatic adsorption plate, corresponding to the center of the wafer or a region close to the center; the plurality of annular electrodes are concentric annular electrodes.

8. The electrostatic adsorption method according to any one of claims 1-7, characterized in that, The electrostatic adsorption plate is provided with at least one air channel that penetrates the electrostatic adsorption plate.

9. An electrostatic adsorption system for wafers, used to implement the electrostatic adsorption method according to any one of claims 1-8, characterized in that, The system includes, An electrostatic adsorption plate, wherein a plurality of annular electrodes are arranged on the electrostatic adsorption plate with a first position as the center; and, An electrostatic adsorption device is used to control the electrostatic adsorption of the wafer by the electrostatic adsorption plate. The electrostatic adsorption device, include, The wafer mounting module is used to place the wafer on the electrostatic adsorption plate; The acquisition module is used to acquire the warpage height of the wafer at the first position; The control module, in response to the warpage height being less than or equal to a first height threshold, controls the plurality of annular electrodes to be energized sequentially from the first position radially outward at preset time intervals.

Images