Wafer alignment method and wafer alignment system

Abstract

This application provides a wafer alignment method and system. Based on first control parameters of a robotic arm, a reference piece is transferred to a first position on the surface of a stage by the robotic arm. At least three piezoelectric detectors are mounted on the surface of the reference piece near the stage, with the outer edge of the piezoelectric material flush with the outer edge of the reference piece. Voltage signals from each piezoelectric detector are collected. Based on the voltage signals and the positions of the piezoelectric detectors on the reference piece, movement parameters of the reference piece are determined. Based on the first control parameters and the movement parameters, second control parameters of the robotic arm are determined. Based on the second control parameters, the robotic arm transfers the wafer to be processed to a second position on the surface of the stage. At the second position, the distance difference between the center of the wafer to be processed and the center of the stage is less than a preset distance difference, thus achieving center alignment between the wafer to be processed and the stage. This improves alignment efficiency and accuracy.

Description

Technical Field

[0001] This application relates to the semiconductor field, and in particular to a wafer alignment method and a wafer alignment system. Background Technology

[0002] In semiconductor manufacturing processes, such as coating, etching, or deposition on wafers, ensuring the accurate positioning of the wafer on the electrostatic stage is crucial. Taking the wafer etching process as an example, assuming the wafer's position coordinates may deviate due to various reasons during transport into the etching cavity, such as structural deformation of the robotic arm or initial slippage when the wafer is transferred into the robotic arm, this deviation will adversely affect the alignment of the wafer and the electrostatic stage, directly leading to a decrease in wafer processing quality and yield.

[0003] In related technologies, mechanical alignment techniques are typically used to achieve wafer alignment. This method uses multiple positioning rollers to simultaneously push the wafer inward to achieve alignment and positioning.

[0004] However, this mechanical alignment method has certain limitations. Wafer edges typically have notches, and the positioning wheels can easily get stuck in these notches during alignment, leading to alignment failure and affecting subsequent processing. Furthermore, mechanical alignment can also result in uneven force distribution, further reducing alignment accuracy. Therefore, providing a suitable wafer alignment method has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, the purpose of this application is to provide a wafer alignment method and a wafer alignment system that improves alignment efficiency and accuracy, eliminates the need for manual calibration, and greatly improves wafer processing efficiency. The specific solution is as follows:

[0006] On one hand, this application provides a wafer alignment method, the method comprising:

[0007] Based on the first control parameters of the manipulator, the reference piece is transferred to a first position on the surface of the stage by the manipulator; at least three piezoelectric detectors are installed on the surface of the reference piece near the stage, the piezoelectric detectors include piezoelectric material, and the outer edge of the piezoelectric material is flush with the outer edge of the reference piece;

[0008] Collect the voltage signals of each of the piezoelectric detectors;

[0009] Based on the voltage signals and the positions of the piezoelectric detectors on the reference element, the movement parameters of the reference element are determined; the movement parameters include the movement distance and the movement direction.

[0010] Based on the first control parameters and the movement parameters, the second control parameters of the robotic arm are determined;

[0011] Based on the second control parameters, the robotic arm transfers the wafer to be processed to a second position on the surface of the stage; the wafer to be processed is the same size as the reference piece, and at the second position, the distance difference between the center of the wafer to be processed and the center of the stage is less than a preset distance difference.

[0012] Optionally, the piezoelectric material has a first dimension in the radial direction and a second dimension in the circumferential direction, wherein the first dimension is larger than the second dimension, and the difference between the first dimension and the second dimension is greater than a preset threshold.

[0013] The determination of the movement parameters of the reference element based on each of the voltage signals and the positions of each of the piezoelectric detectors on the reference element includes:

[0014] Based on each of the voltage signals, the compressed length of the piezoelectric material in each of the piezoelectric detectors in the radial direction is determined;

[0015] The movement parameters of the reference member are determined based on the respective compressed lengths and the positions of the respective piezoelectric detectors on the reference member.

[0016] Optionally, the piezoelectric materials in each of the piezoelectric detectors have the same shape and area. Determining the compressed length of the piezoelectric material in each of the piezoelectric detectors in the radial direction based on each of the voltage signals includes:

[0017] Based on the maximum compressed area of ​​the piezoelectric material, the maximum voltage signal corresponding to the maximum compressed area, and the second dimension of the piezoelectric material, the unit compression length corresponding to the unit voltage in the radial direction is determined.

[0018] For each of the voltage signals, the compressed length of the piezoelectric material in the radial direction in each of the piezoelectric detectors is determined based on the voltage signal and the unit compression length.

[0019] Optionally, at least three of the piezoelectric detectors are uniformly distributed on the surface of the reference element.

[0020] Optionally, in the horizontal direction, the size of the stage is less than or equal to the size of the reference piece.

[0021] In another aspect, embodiments of this application also provide a wafer alignment system, the system comprising:

[0022] The stage, robot arm, reference piece, and wafer to be processed are located within the chamber;

[0023] A host computer is used to control the robot to transfer the reference piece to a first position on the surface of the platform based on the first control parameters of the robot; at least three piezoelectric detectors are installed on the surface of the reference piece near the platform, the piezoelectric detectors include piezoelectric material, and the outer edge of the piezoelectric material is flush with the outer edge of the reference piece;

[0024] A data processor is used to acquire the voltage signals of each of the piezoelectric detectors;

[0025] The data processor is further configured to determine the movement parameters of the reference element based on the respective voltage signals and the positions of the respective piezoelectric detectors on the reference element; the movement parameters include movement distance and movement direction;

[0026] The host computer is also used to determine the second control parameters of the robotic arm based on the first control parameters and the movement parameters;

[0027] The host computer is also used to transfer the wafer to be processed to a second position on the surface of the stage by the robotic arm based on the second control parameters; the wafer to be processed is the same size as the reference piece, and at the second position, the distance difference between the center of the wafer to be processed and the center of the stage is less than a preset distance difference.

[0028] Optionally, the piezoelectric material has a first dimension in the radial direction and a second dimension in the circumferential direction, the first dimension being larger than the second dimension, and the difference between the first dimension and the second dimension being greater than a preset threshold; the data processor is further configured to:

[0029] Based on each of the voltage signals, the compressed length of the piezoelectric material in each of the piezoelectric detectors in the radial direction is determined;

[0030] The movement parameters of the reference member are determined based on the respective compressed lengths and the positions of the respective piezoelectric detectors on the reference member.

[0031] Optionally, the piezoelectric material in each of the piezoelectric detectors has the same shape and area; the data processor is further configured to:

[0032] Based on the maximum compressed area of ​​the piezoelectric material, the maximum voltage signal corresponding to the maximum compressed area, and the second dimension of the piezoelectric material, the unit compression length corresponding to the unit voltage in the radial direction is determined.

[0033] For each of the voltage signals, the compressed length of the piezoelectric material in the radial direction in each of the piezoelectric detectors is determined based on the voltage signal and the unit compression length.

[0034] Optionally, the system further includes:

[0035] A signal transceiver device is used to acquire the movement parameters and send them to the host computer.

[0036] A power supply device for supplying power to the data processor and the signal transceiver.

[0037] Optionally, the data processor, the signal transceiver, and the power supply are located within the cavity of the reference component.

[0038] This application provides a wafer alignment method and system. Based on first control parameters of a robotic arm, a reference component is transferred to a first position on the surface of a stage, which is offset from the center of the stage. To align the center of the reference component with the center of the stage, at least three piezoelectric detectors can be mounted on the surface of the reference component near the stage. Each piezoelectric detector comprises a piezoelectric material, which generates a voltage signal when subjected to external pressure. To ensure that the voltage signal from the piezoelectric material accurately reflects the pressure between the reference component and the stage, the outer edge of the piezoelectric material is flush with the outer edge of the reference component, thus the pressure between the piezoelectric material and the stage is equivalent to the pressure between the reference component and the stage. The voltage signals from each piezoelectric detector can then be acquired; the magnitude of the voltage signal reflects the area of ​​pressure. Based on the voltage signals and the positions of each piezoelectric detector on the reference component, movement parameters of the reference component can be determined. These movement parameters include the movement distance and direction, indicating how the reference component needs to be moved to align its center with the center of the stage. Based on the first control parameters and the movement parameters, a second control parameter for the robot arm is determined. This second control parameter enables center alignment between the reference piece and the stage. Therefore, when the wafer to be processed is placed on the stage, based on the second control parameter, the robot arm can transfer the wafer to a second position on the stage surface. At this second position, the distance difference between the center of the wafer and the center of the stage is less than a preset distance difference, thus achieving center alignment between the wafer and the stage. The wafer and the reference piece are of equal size. By setting multiple piezoelectric sensors, the difference in voltage signals can indicate the deviation of the reference piece (representing the wafer) from the stage. This allows for the determination of how the robot arm should place the reference piece, i.e., determining the accurate second control parameter, achieving center alignment between the wafer and the stage. This improves alignment efficiency and accuracy, eliminates the need for manual calibration, and significantly increases wafer processing efficiency. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A schematic flowchart of a wafer alignment method provided in an embodiment of this application is shown;

[0041] Figure 2 A schematic diagram of a semiconductor chamber provided in an embodiment of this application is shown;

[0042] Figure 3 A schematic diagram of the structure of a reference component provided in an embodiment of this application is shown;

[0043] Figure 4 A cross-sectional view of a reference component provided in an embodiment of this application is shown;

[0044] Figure 5 This illustration shows a schematic diagram of a reference component and a stage not being aligned, as provided in an embodiment of this application.

[0045] Figure 6 This illustration shows a schematic diagram of a reference component and a stage provided in an embodiment of this application. Detailed Implementation

[0046] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0047] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0048] Secondly, this application provides a detailed description in conjunction with schematic diagrams. When detailing the embodiments of this application, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0049] For ease of understanding, the wafer alignment method and wafer alignment system provided in this application will be described in detail below with reference to the accompanying drawings.

[0050] refer to Figure 1 The diagram shown is a schematic flowchart of a wafer alignment method provided in an embodiment of this application. The method may include the following steps.

[0051] S101, based on the first control parameters of the robot arm, the reference piece 1 is transferred to a first position on the surface of the stage 2 by the robot arm.

[0052] A stage 2, which can be an electrostatic stage 2, is provided within chamber 3 for placing the wafer to be processed. During center alignment of the wafer to be processed and stage 2, a reference piece 1 can be used first for alignment, replacing the wafer. After alignment, the reference piece 1 is then replaced with the wafer, ensuring that the center of the wafer is substantially aligned with the center of stage 2. The wafer to be processed and the reference piece 1 have the same dimensions; for example, their diameters can be equal. This ensures that the wafer to be processed is aligned at the same position as the reference piece 1 during alignment. The reference piece 1 can be, for example, a wafer-like structure. Figure 2 The figure shows a schematic diagram of a semiconductor chamber provided in an embodiment of this application. The chamber 33 has a stage 2, on which a reference piece 1 is placed. The robot arm is not shown in the figure.

[0053] The first control parameter enables the robot arm to transfer the reference piece 1 to a first position on the surface of the platform 2. This first control parameter controls the robot arm's movement path and the placement position of the reference piece 1 on the platform 2. That is, the robot arm can move according to the first control parameter to place the reference piece 1 at the first position on the platform 2. Since alignment is not performed at this point, the first position is offset from the center of the platform 2; that is, the center of the reference piece 1 at the first position does not coincide with the center of the platform 2.

[0054] To achieve wafer alignment, at least three piezoelectric detectors 11 are mounted on the surface of the reference piece 1 near the stage 2. Each piezoelectric detector 11 includes a piezoelectric material, and the outer edge of the piezoelectric material is flush with the outer edge of the reference piece 1.

[0055] Specifically, the piezoelectric detector 11 can be located between the reference piece 1 and the stage 2. The robot arm transfers the reference piece 1 into the chamber 3 and places it on the upper surface of the stage 2; this position of the reference piece 1 is the first position. At this time, due to the weight of the reference piece 1 itself, the piezoelectric detector 11 located below the reference piece 1 will be compressed by the reference piece 1 and the stage 2. When the reference piece 1 and the stage 2 are not aligned, i.e., the alignment is poor, the reference piece 1 may be partially on the stage 2, with another part suspended in the air. This will cause the detection surface of the piezoelectric detector 11 at different positions to be compressed to varying degrees. For example, the entire detection surface of some piezoelectric detectors 11 may be compressed, while only a portion of the detection surface of some piezoelectric detectors 11 may be compressed.

[0056] The piezoelectric detector 11 includes a piezoelectric material. When mechanical stress is applied to the piezoelectric material, the charge distribution inside the material changes, thereby generating a voltage on the surface of the material, so that the piezoelectric detector 11 can output a voltage signal.

[0057] In other words, when the reference piece 1 and the stage 2 are not aligned, the compressed area of ​​the piezoelectric detectors 11 located at different positions is also different, resulting in different voltage signals generated by each piezoelectric detector 11. That is, the magnitude of the voltage signal can reflect the amount of compressed area.

[0058] To ensure that the voltage signal from the piezoelectric material accurately reflects the compression between the reference piece 1 and the stage 2, the outer edge of the piezoelectric material needs to be flush with the outer edge of the reference piece 1. In other words, the piezoelectric sensor is positioned at the edge of the reference piece 1, thus the compression between the piezoelectric material and the stage 2 is equivalent to the compression between the reference piece 1 and the stage 2. This avoids the situation where placing the piezoelectric sensor in the center of the reference piece 1 would result in all piezoelectric sensors having the same compression area even if the reference piece 1 is not aligned with the center of the stage 2, leading to equal voltage signals and misjudgments of alignment. Furthermore, the number of piezoelectric detectors 11 can be greater than or equal to three, for example, four. In one possible implementation, at least three piezoelectric detectors 11 are evenly distributed on the surface of the reference piece 1, with a sufficiently large distance between them, allowing each detector 11 to accurately reflect the contact between the reference piece 1 and the stage 2 at its location. Avoid placing all piezoelectric sensors in the same small area, which would result in their voltage signals being basically the same and not differing enough. This would make it impossible to accurately determine how to move reference 1 based on the differences in order to achieve alignment and improve the accuracy of the alignment between reference 1 and the wafer.

[0059] In one possible implementation, the size of the stage 2 in the horizontal direction is smaller than or equal to the size of the reference part 1. For example, the diameter of the stage 2 is smaller and the diameter of the reference part 1 is larger. Thus, during alignment, the boundary of the stage 2 can completely coincide with the boundary of the reference part 1, or the boundary of the reference part 1 can be slightly larger. This facilitates the robot arm in grasping the reference part 1 and avoids situations where the reference part 1 is too small, causing the robot arm to be unable to grasp the edge of the reference part 1 smoothly, resulting in grasping failure.

[0060] S102, collect the voltage signals of each piezoelectric detector 11.

[0061] Specifically, the corresponding voltage signal can be collected through each piezoelectric detector 11.

[0062] S103, based on each voltage signal and the position of each piezoelectric detector 11 on the reference 1, determine the movement parameters of the reference 1.

[0063] Specifically, since the magnitude of the voltage signal can reflect the compression of the piezoelectric detector 11, that is, the size of the contact area between the piezoelectric material and the stage 2, it is possible to know the contact situation between the reference piece 1 and the stage 2. If the voltage signal detected by a certain piezoelectric detector 11 is relatively small, it means that the contact area between the reference piece 1 and the stage 2 at the location of the piezoelectric detector 11 is relatively small.

[0064] Furthermore, the position of the piezoelectric detectors 11 on the reference piece 1 can provide direction for the subsequent alignment of the reference piece 1. By analyzing the voltage signals detected by each piezoelectric detector 11 and the position of each piezoelectric detector 11, the contact situation between the reference piece 1 and the stage 2 can be determined, such as the direction and distance of the reference piece 1 from the stage 2. This allows for the determination of how the reference piece 1 should be moved to achieve calibration, i.e., the determination of the movement parameters of the reference piece 1.

[0065] The movement parameters of the reference component 1 can include the movement distance and the movement direction. That is, after the reference component 1 moves according to the movement distance and the movement direction, the center of the reference component 1 and the platform 2 can be aligned.

[0066] refer to Figure 3 The figure shows a schematic diagram of a reference component provided in an embodiment of this application. The figure shows four piezoelectric detectors 11 evenly distributed on the surface of the reference component 1. The first piezoelectric detector 111 is located at the upper part of the reference component 1, the second piezoelectric detector 112 is located at the left part of the reference component 1, the third piezoelectric detector 113 is located at the lower part of the reference component 1, and the fourth piezoelectric detector 114 is located at the right part of the reference component 1. Figure 3 The reference body 151 and the wire harness groove 152 are also shown, the wire harness groove 152 being used for wiring.

[0067] refer to Figure 4 The figure shown is a cross-sectional view of a reference component provided in an embodiment of this application. The second piezoelectric detector 112 is located on the far left, the fourth piezoelectric detector 114 is located on the far right, and the third piezoelectric detector 113 and the fourth piezoelectric detector 114 are in the middle. The reference component 1 also has a cavity 153, which is used to house the data processor 14, the signal transceiver device 13, the power supply device 12, and the reserved expansion position 16.

[0068] As an example, see reference Figure 5The diagram shows a misalignment between a reference element 1 and a stage 2 according to an embodiment of this application. (a) is a top view, and (b) is a side view. In (a), the reference element edge 154 and the stage edge 21 are specifically shown. The reference element edge 154 is the largest circle, and the stage edge 21 is the second largest circle. The specific relationship between the compressed areas of each piezoelectric detector 11 is S112>S111=S113>S114. The shaded area in the figure represents the compressed area. The fourth piezoelectric detector 114 has the smallest compressed area, and the second piezoelectric detector 112 has the largest compressed area. The voltage signal magnitude relationship is V112>V111=V113>V114. Therefore, it can be seen that the offset direction of the reference element 1 is the lateral direction, specifically from the direction of the second piezoelectric detector 112 to the direction of the fourth piezoelectric detector 114, as shown in (b). Reference component 1 needs to be moved to the left to achieve centering. The direction of movement is to the left, and the distance of movement can be calculated based on the difference in voltage signals.

[0069] S104, based on the first control parameters and the movement parameters, determine the second control parameters of the robot arm.

[0070] Specifically, when the reference piece 1 and the platform 2 are not aligned, the control parameters corresponding to the robot are the first control parameters. Based on the first control parameters, the movement parameters are considered to redetermine the control parameters for the robot, namely the second control parameters. The second control parameters can achieve alignment between the reference piece 1 and the platform 2.

[0071] refer to Figure 6 The diagram shown is a schematic diagram of the alignment of a reference piece and a stage provided in an embodiment of this application. In (b), it can be seen that the center of the stage 2 is aligned with the center of the reference piece 1. In (a), the shadow areas of each piezoelectric detector 11 are equal, that is, the compressed areas are equal, which indicates that the center alignment has been achieved.

[0072] S105, based on the second control parameters, the wafer to be processed is transferred to a second position on the surface of the stage 2 by a robotic arm.

[0073] Specifically, after determining the second control parameters, the wafer to be processed can be transferred into chamber 3 for semiconductor processing. That is, under the control of the second control parameters, the robot can transfer the wafer to be processed to a second position on the surface of stage 2. At the second position, the distance difference between the center of the wafer to be processed and the center of stage 2 is less than a preset distance difference. In other words, the center difference between the two is small enough that their centers can be considered to coincide. Thus, under the action of the second control parameters, the center alignment between the wafer to be processed and stage 2 can be achieved.

[0074] In this way, by setting up multiple piezoelectric sensors, the difference in voltage signals can be used to reflect the deviation of the reference piece 1, which represents the wafer to be processed, from the stage 2. This allows the robot arm to determine how to place the reference piece 1, that is, to determine the accurate second control parameters, thereby achieving center alignment between the wafer to be processed and the stage 2. This improves alignment efficiency and accuracy, eliminates the need for manual calibration, and greatly improves wafer processing efficiency.

[0075] In one possible implementation, the piezoelectric material has a first dimension in the radial direction and a second dimension in the circumferential direction, the first dimension being larger than the second dimension, and the difference between the first dimension and the second dimension being greater than a preset threshold. In S103, based on the various voltage signals and the positions of the various piezoelectric detectors 11 on the reference element 1, the movement parameters of the reference element 1 are determined, which may specifically include S1031-S1032.

[0076] S1031, based on each voltage signal, determine the radial compression length of the piezoelectric material in each piezoelectric detector 11.

[0077] Specifically, the radial direction can be along the diameter of reference part 1, and the circumferential direction is perpendicular to the radial direction, which is along the tangent direction of reference part 1. The radial dimension of the piezoelectric material can be denoted as the first dimension, and the circumferential dimension can be denoted as the second dimension. The first dimension is larger than the second dimension; for example, the first dimension can be the length, and the second dimension can be the width. That is, the length of the piezoelectric material must be greater than its width. The shape of the piezoelectric material is not specifically limited; for example, it can be rectangular, prismatic, etc.

[0078] The preset threshold can be any set threshold. If the difference between the first size and the second size is greater than the preset threshold, it means that the difference between the two is relatively large. For example, the first size can be much larger than the second size. In this case, the squeezed area of ​​the piezoelectric detector 11 can be approximated as a rectangular area.

[0079] Since the length of a piezoelectric material is much greater than its width, the change in the compression of the piezoelectric material in the radial direction is more obvious than the change in the compression in the circumferential direction. In other words, the magnitude of the voltage signal can better reflect the compression length of the piezoelectric material in the radial direction. Therefore, the compression length of the piezoelectric material in the radial direction can be determined based on the voltage signal.

[0080] S1032, based on each compressed length and the position of each piezoelectric detector 11 on the reference 1, determine the movement parameters of the reference 1.

[0081] Specifically, if the compressed length in the radial direction is relatively large, it means that the contact area between the reference piece 1 and the stage 2 in that direction is relatively large. If the compressed length is relatively small, it means that the contact area is relatively small. By adjusting the compressed length of all the piezoelectric detectors 11 to be equal, the alignment of the reference piece 1 and the stage 2 can be achieved.

[0082] In other words, the magnitude of the compressed length can provide a basis for the movement distance of the reference piece 1. By using the compressed length and the position of the piezoelectric detector 11, the movement distance and direction of the reference piece 1 can be calculated. For example, if the compressed length of the piezoelectric material on the left is relatively large, the reference piece 1 needs to be moved to the right to reduce the compressed length.

[0083] In this way, by setting the piezoelectric material to have a relatively large dimension in the radial direction, the deviation of the reference part 1 in the radial direction can be more accurately reflected in the change of the extruded length. As a result, the voltage signal is basically caused by the change of the extruded length in the radial direction, and the change of the extruded length in the circumferential direction can be ignored. This allows the movement parameters of the reference part 1 to be determined quickly, and the accuracy of the movement parameters is also high.

[0084] To further improve alignment accuracy, all piezoelectric detectors 11 are of the same shape and area, so that differences in voltage signals can more accurately reflect the offset in the radial direction.

[0085] In one possible implementation, the shape and area of ​​the piezoelectric material in each piezoelectric detector 11 are equal. S1031 determines the extruded length of the piezoelectric material in each piezoelectric detector 11 in the radial direction based on each voltage signal, which may specifically include S10311-S10312.

[0086] S10311, based on the maximum compressed area of ​​the piezoelectric material, the maximum voltage signal corresponding to the maximum compressed area, and the second dimension of the piezoelectric material, determine the unit compression length corresponding to the unit voltage in the radial direction.

[0087] Specifically, the piezoelectric material has a maximum compressible area, which is the area of ​​the piezoelectric material. When the entire area of ​​the piezoelectric material is in contact with the stage 2, the compressible area at this time is the maximum compressible area. The voltage signal corresponding to the maximum compressible area is recorded as the maximum voltage signal.

[0088] Specifically, for each piezoelectric detector 11, based on the maximum compressed area S max Maximum voltage signal V maxGiven the second dimension h (i.e., width) of the piezoelectric material in the circumferential direction, the unit extrusion length dL under unit voltage can be determined. This unit extrusion length dL is the length in the radial direction. The specific expression is: dL = S max / (V max *h).

[0089] S10312, for each voltage signal, based on the voltage signal and the unit extrusion length, determine the extrusion length of the piezoelectric material in the radial direction in each piezoelectric detector 11.

[0090] Specifically, for each voltage signal, the radial compression length L can be calculated based on the magnitude of the voltage signal V and the unit compression length dL, where L = V * dL.

[0091] In this way, by setting the shape and area of ​​the piezoelectric material in each piezoelectric detector 11 to be equal, the first dimension and the second dimension of all piezoelectric detectors 11 are equal, and the unit extrusion length dL is also equal, so the calculated extrusion length L can be more accurate. Compared with the fact that the second dimension of different piezoelectric materials may differ, and the factors that cause differences in voltage signals also include the second dimension, thus causing the voltage signal difference to not accurately reflect the difference in the first dimension, by setting the second dimension of all piezoelectric sensors to be equal, the difference in voltage signal can only be caused by the difference in the first dimension. Therefore, by adjusting the position of the reference piece 1 based on the voltage signal to achieve alignment, the alignment accuracy can be higher.

[0092] As an example, when there are four piezoelectric detectors 11, the magnitudes of their voltage signals are related as follows: V112 > V111 = V113 > V114. Therefore, the magnitudes of their compressed areas are related as follows: S112 > S111 = S113 > S114. Using L = V * dL, the magnitudes of the compressed lengths of the piezoelectric detectors 11 are related as follows: L112 > L111 = L113 > L114. Reference 1 needs to move along the direction from the fourth piezoelectric detector 114 to the second piezoelectric detector 112, with a moving distance of (L112 - L114) / 2.

[0093] This application also provides a wafer alignment method. By setting multiple piezoelectric sensors, the difference in voltage signals can reflect the deviation of the reference piece representing the wafer to be processed from the stage. This allows the robot arm to determine how to place the reference piece, i.e., to determine the accurate second control parameters, thereby achieving center alignment between the wafer to be processed and the stage. This improves alignment efficiency and accuracy, eliminates the need for manual calibration, and greatly improves wafer processing efficiency.

[0094] This application embodiment also provides a wafer alignment system, which includes a stage 2, a robot arm, a reference piece 1 and a wafer to be processed located in a chamber 3, as well as a host computer and a data processor 14.

[0095] The host computer is used to control the robot to transfer the reference piece 1 to a first position on the surface of the stage 2 based on the first control parameters of the robot; at least three piezoelectric detectors 11 are installed on the side surface of the reference piece 1 near the stage 2, the piezoelectric detectors 11 include piezoelectric material, and the outer edge of the piezoelectric material is flush with the outer edge of the reference piece 1.

[0096] The data processor 14 is used to acquire the voltage signals of each piezoelectric detector 11;

[0097] The data processor 14 is also used to determine the movement parameters of the reference element 1 based on the various voltage signals and the positions of the various piezoelectric detectors 11 on the reference element 1; the movement parameters include the movement distance and the movement direction.

[0098] The host computer is also used to determine the second control parameters of the robot arm based on the first control parameters and the movement parameters;

[0099] The host computer is also used to transfer the wafer to be processed to a second position on the surface of the stage 2 by a robotic arm based on the second control parameters; the wafer to be processed is the same size as the reference piece 1, and at the second position, the distance difference between the center of the wafer to be processed and the center of the stage 2 is less than a preset distance difference.

[0100] refer to Figure 3 As shown, a data processor 14 is installed on the reference component 1. The data processor 14 can acquire voltage signals and calculate the movement parameters of the reference component 1 based on the voltage signals, thereby converting the difference in voltage signals into the position difference of the reference component 1.

[0101] In one possible implementation, the piezoelectric material has a first dimension in the radial direction and a second dimension in the circumferential direction, the first dimension being larger than the second dimension, and the difference between the first dimension and the second dimension being greater than a preset threshold; the data processor 14 is further configured to:

[0102] Based on each voltage signal, the radial compression length of the piezoelectric material in each piezoelectric detector 11 is determined;

[0103] Based on each compressed length and the position of each piezoelectric detector 11 on the reference 1, the movement parameters of the reference 1 are determined.

[0104] In one possible implementation, the piezoelectric material in each piezoelectric detector 11 has the same shape and area; the data processor 14 is also used for:

[0105] Based on the maximum extruded area of ​​the piezoelectric material, the maximum voltage signal corresponding to the maximum extruded area, and the second dimension of the piezoelectric material, the unit extrusion length corresponding to the unit voltage in the radial direction is determined.

[0106] For each voltage signal, the radial compression length of the piezoelectric material in each piezoelectric detector 11 is determined based on the voltage signal and the unit compression length.

[0107] In one possible implementation, the system also includes:

[0108] Signal transceiver 13 is used to acquire movement parameters and send them to the host computer;

[0109] The power supply device 12 is used to supply power to the data processor 14 and the signal transceiver device 13.

[0110] Among them, the signal transceiver 13 can be a wireless signal transceiver 13, which can transmit information through wireless communication, and the power supply device 12 can be a wireless charging power supply.

[0111] In one possible implementation, the data processor 14, the signal transceiver 13, and the power supply 12 are located within the cavity 153 of the reference component 1. Furthermore, a reserved expansion space 16 can be provided within the cavity 153, such as... Figure 3 As shown and Figure 4 As shown, by placing them within the cavity 153, they do not occupy any area outside the reference component 1, do not affect the contact between the reference component 1 and the stage 2, and improve the space utilization of the cavity 153. Reference Figure 3 As shown, reference component 1 also has a wire harness slot 152, thereby enabling the connection of each piezoelectric detector 11 with devices such as the data processor 14.

[0112] This application also provides a wafer alignment system. By setting multiple piezoelectric sensors, the difference in voltage signals can reflect the deviation of the reference piece representing the wafer to be processed from the stage. This allows the system to determine how the robot should place the reference piece, i.e., to determine the accurate second control parameters, thereby achieving center alignment between the wafer to be processed and the stage. This improves alignment efficiency and accuracy, eliminates the need for manual calibration, and greatly improves wafer processing efficiency.

[0113] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0114] The above description is merely a preferred embodiment of this application. Although this application has disclosed preferred embodiments above, it is not intended to limit this application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of this application. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall still fall within the protection scope of the technical solutions of this application.

Claims

1. A wafer alignment method, characterized in that, The method includes: Based on the first control parameters of the manipulator, the reference piece is transferred to a first position on the surface of the stage by the manipulator; at least three piezoelectric detectors are installed on the surface of the reference piece near the stage, the piezoelectric detectors include piezoelectric material, and the outer edge of the piezoelectric material is flush with the outer edge of the reference piece; Collect the voltage signals of each of the piezoelectric detectors; Based on the voltage signals and the positions of the piezoelectric detectors on the reference element, the movement parameters of the reference element are determined; the movement parameters include the movement distance and the movement direction. Based on the first control parameters and the movement parameters, the second control parameters of the robotic arm are determined; Based on the second control parameters, the robotic arm transfers the wafer to be processed to a second position on the surface of the stage; the wafer to be processed is the same size as the reference piece, and at the second position, the distance difference between the center of the wafer to be processed and the center of the stage is less than a preset distance difference.

2. The method according to claim 1, characterized in that, The piezoelectric material has a first dimension in the radial direction and a second dimension in the circumferential direction. The first dimension is larger than the second dimension, and the difference between the first dimension and the second dimension is greater than a preset threshold. The determination of the movement parameters of the reference element based on each of the voltage signals and the positions of each of the piezoelectric detectors on the reference element includes: Based on each of the voltage signals, the compressed length of the piezoelectric material in each of the piezoelectric detectors in the radial direction is determined; The movement parameters of the reference member are determined based on the respective compressed lengths and the positions of the respective piezoelectric detectors on the reference member.

3. The method according to claim 2, characterized in that, The piezoelectric materials in each of the piezoelectric detectors have the same shape and area. Based on each of the voltage signals, the compressed length of the piezoelectric material in each of the piezoelectric detectors in the radial direction is determined, including: Based on the maximum compressed area of ​​the piezoelectric material, the maximum voltage signal corresponding to the maximum compressed area, and the second dimension of the piezoelectric material, the unit compression length corresponding to the unit voltage in the radial direction is determined. For each of the voltage signals, the compressed length of the piezoelectric material in the radial direction in each of the piezoelectric detectors is determined based on the voltage signal and the unit compression length.

4. The method according to any one of claims 1-3, characterized in that, At least three of the piezoelectric detectors are uniformly distributed on the surface of the reference element.

5. The method according to any one of claims 1-3, characterized in that, In the horizontal direction, the size of the stage is less than or equal to the size of the reference piece.

6. A wafer alignment system, characterized in that, The system includes: The stage, robot arm, reference piece, and wafer to be processed are located within the chamber; A host computer is used to control the robot to transfer the reference piece to a first position on the surface of the platform based on the first control parameters of the robot; at least three piezoelectric detectors are installed on the surface of the reference piece near the platform, the piezoelectric detectors include piezoelectric material, and the outer edge of the piezoelectric material is flush with the outer edge of the reference piece; A data processor is used to acquire the voltage signals of each of the piezoelectric detectors; The data processor is further configured to determine the movement parameters of the reference element based on the respective voltage signals and the positions of the respective piezoelectric detectors on the reference element; the movement parameters include movement distance and movement direction; The host computer is also used to determine the second control parameters of the robotic arm based on the first control parameters and the movement parameters; The host computer is also used to transfer the wafer to be processed to a second position on the surface of the stage by the robotic arm based on the second control parameters; the wafer to be processed is the same size as the reference piece, and at the second position, the distance difference between the center of the wafer to be processed and the center of the stage is less than a preset distance difference.

7. The wafer alignment system according to claim 6, characterized in that, The piezoelectric material has a first dimension in the radial direction and a second dimension in the circumferential direction, wherein the first dimension is larger than the second dimension, and the difference between the first dimension and the second dimension is greater than a preset threshold; the data processor is further configured to: Based on each of the voltage signals, the compressed length of the piezoelectric material in each of the piezoelectric detectors in the radial direction is determined; The movement parameters of the reference member are determined based on the respective compressed lengths and the positions of the respective piezoelectric detectors on the reference member.

8. The wafer alignment system according to claim 7, characterized in that, The piezoelectric materials in each of the aforementioned piezoelectric detectors have the same shape and area; the data processor is further configured to: Based on the maximum compressed area of ​​the piezoelectric material, the maximum voltage signal corresponding to the maximum compressed area, and the second dimension of the piezoelectric material, the unit compression length corresponding to the unit voltage in the radial direction is determined. For each of the voltage signals, the compressed length of the piezoelectric material in the radial direction in each of the piezoelectric detectors is determined based on the voltage signal and the unit compression length.

9. The wafer alignment system according to claim 6, characterized in that, The system also includes: A signal transceiver device is used to acquire the movement parameters and send them to the host computer. A power supply device for supplying power to the data processor and the signal transceiver.

10. The wafer alignment system according to claim 9, characterized in that, The data processor, the signal transceiver, and the power supply are located within the cavity of the reference component.

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