Real-time Error Compensation Control System for Wafer Probe Station Based on Multi-Sensor Fusion

Abstract

The present invention relates to the technical field of semiconductor manufacturing equipment. Specifically, it relates to a real-time error compensation control system for a wafer probe station based on multi-sensor fusion, including a probe displacement detection module, a mapping relation table construction module, a deviation comparison module, a deviation compensation acquisition module, a probe station calibration module, and a management database. This system constructs the mapping relation between probes based on the actual position coordinates of each probe at each time point, compares with the preset ideal coordinates, calculates the components of the position deviation vector of each probe at each time point on each axis, and then constructs a linear regression model. Combining the mapping relation between probes, it calculates the final deviation compensation vector of the probes. By setting limiting conditions and generating control instructions in combination with the deviation compensation vector, it dynamically corrects the movement of the probe station to ensure that the probes always maintain a high position accuracy during the working process, improving the quality and efficiency of the overall work.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing equipment, and more specifically, it is a real-time error compensation control system for a wafer prober based on multi-sensor fusion. Background Art

[0002] At present, with the booming development of the semiconductor industry, the chip manufacturing process is constantly moving towards smaller feature sizes and higher integration levels, which poses extremely stringent requirements for the wafer testing link. As a key bridge connecting the wafer and the testing equipment, the positioning accuracy of the wafer prober directly affects the accuracy and reliability of chip testing, and thus is related to the yield and production efficiency of the entire semiconductor manufacturing process, occupying a crucial position in the semiconductor manufacturing industrial chain.

[0003] However, the existing wafer probers will generate various errors during the actual movement process, resulting in a decrease in transmission accuracy, causing the probe to deviate from the preset trajectory during movement, and reducing the accuracy and reliability of wafer testing. Therefore, real-time error detection of the wafer prober is of great importance.

[0004] The existing Chinese patent with the application number 202010490517.9 discloses a motion control error compensation system and method based on cloud-edge collaboration. This solution builds a digital twin system to establish an error compensation simulation environment, simulates and selects an optimal error algorithm for processing requirements and sends it to the edge server. The edge server combines real-time processing data, calls the optimal algorithm to calculate the compensation amount, and integrates it with the motion control program to generate an instruction to complete error compensation.

[0005] However, this solution has the following deficiencies: This solution mainly obtains the error compensation amount based on the interaction between the central server and the edge server, and does not make full use of the internal correlation information between various parameters, which may lead to incomplete and inaccurate compensation calculations. At the same time, it does not clearly mention the direct comparison with the ideal state, and it may be difficult to intuitively determine the error degree and specific deviation direction, which is not conducive to quickly and accurately positioning the compensation requirements.

[0006] The existing Chinese patent with the application number 201010281777.1 discloses a remote control device for a prober and its control method. This solution transmits the test data to the server, and the server compares the verification information with the test data. If it is correct, it proceeds to the test of the next instruction; if it is incorrect, it automatically sends an error message to the wireless communication device used by the monitor through wireless communication, improving the fault response efficiency.

[0007] The following are the deficiencies of this solution: In the solution, only whether the test result is correct is judged to feedback the error, and the magnitude of the error is not quantified. In actual applications, errors of different degrees have different impacts on wafer testing. The lack of quantification is not conducive to evaluating the severity of the error and taking corresponding precise compensation measures, and cannot provide accurate data support for subsequent error correction. Summary of the Invention

[0008] To overcome the shortcomings in the background technology, the embodiments of the present invention provide a real-time error compensation control system for a wafer probe station based on multi-sensor fusion, which can effectively solve the problems involved in the above background technology.

[0009] The object of the present invention can be achieved through the following technical solutions: The present invention provides a real-time error compensation control system for a wafer probe station based on multi-sensor fusion, including: a probe displacement detection module, configured to construct a global coordinate system and obtain the actual position coordinates of each probe at each time point.

[0010] A mapping relationship table construction module, configured to construct the mapping relationship between probes based on the actual position coordinate data of each probe at each time point.

[0011] A deviation comparison module, configured to compare the actual position coordinates of each probe at each time point with the preset ideal coordinates, and calculate the components of the position deviation vector of each probe at each time point on each axis.

[0012] A deviation compensation acquisition module, configured to construct a linear regression model according to the components of the position deviation vector of each probe at each time point on each axis, and calculate the final deviation compensation vector of the probe in combination with the mapping relationship between probes.

[0013] A probe station correction module, configured to set limiting conditions, generate a control instruction in combination with the deviation compensation vector, and perform dynamic correction on the movement of the probe station.

[0014] A management database, configured to store the actual position coordinate data of each probe at each time point, the preset ideal coordinate data, the constructed mapping relationship table, and the parameter estimation values of the linear regression model.

[0015] Preferably, the specific analysis method of the probe displacement detection module is: obtaining the initial position information of each probe of the wafer probe station in the global coordinate system, collecting the image sequence of the movement of each probe at a set frame rate, taking two adjacent frames of images as a group, and obtaining the motion vectors of each pixel point in each group of images through the optical flow algorithm.

[0016] Determine the position of each probe in the image through image threshold segmentation technology, extract the optical flow vectors within the area of each probe, convert the optical flow vectors within the area of each probe into the motion trajectories in the actual space, and obtain the actual position coordinates of each probe at each time point.

[0017] Preferably, the specific analysis method of the mapping relationship table construction module is as follows: at the same time point, use the Euclidean distance formula to calculate the spatial distance between the actual position coordinates of each probe and the actual position coordinates of other probes. If the spatial distance between two probes at the same time point is less than the preset distance threshold, construct a mapping relationship based on position proximity between the two probes.

[0018] Arrange the actual position coordinates of each probe at each time point in chronological order to obtain the movement trajectories of each probe. Calculate the similarity of the movement trajectories of each pair of probes respectively. If the similarity of the movement trajectories of two probes is greater than the preset similarity threshold, construct a mapping relationship based on movement correlation between the two probes.

[0019] Construct a mapping relationship table A according to the mapping relationship based on position proximity and the mapping relationship based on movement correlation. The mapping relationship table A is used to present the association relationship between each probe.

[0020] Preferably, the mapping relationship table construction module further includes: assigning a unique first probe identifier to each probe respectively, and establishing a one-to-one first mapping relationship between four first probe identifiers and four probes. Among them, the first probe identifier is used to identify the identification chip on the corresponding probe.

[0021] Receive the second mapping relationship sent by the second control module of the wafer to be measured. Among them, the second control module is used to manage the measurement points on the wafer to be measured, and the second mapping relationship is used to indicate the correspondence between the second probe and the second probe identifier. The second probe is the probe corresponding to the measurement point on the wafer to be measured. The four first probe identifiers include the second probe identifier.

[0022] Determine the third mapping relationship according to the first mapping relationship and the second mapping relationship. The third mapping relationship is used to indicate the correspondence between each third probe and the second probe in the measurement channels for the four probes to perform measurement communication with the wafer to be measured. Among them, each second probe corresponds to a measurement point on the wafer to be measured. Determine the connection combination of each measurement point and the corresponding third probe according to the measurement requirements to form the measurement channel.

[0023] Construct a mapping relationship table B according to the third mapping relationship. The mapping relationship table B is used to present the correspondence between each third probe and the second probe and the association with the measurement points.

[0024] Preferably, the specific analysis method of the deviation comparison module is as follows: for the second probe corresponding to each measurement point, obtain the actual position coordinates of the corresponding third probe at each time point according to the mapping relationship.

[0025] Call the preset ideal coordinate data from the management database, where the ideal coordinates correspond to the measurement points and are associated with each probe through a mapping relationship.

[0026] Compare the actual position coordinates of each probe at each time point with the preset ideal coordinates, and calculate the components of the position deviation vector of each probe at each time point on each axis.

[0027] Preferably, the specific construction method of the linear regression model is: extract the position deviation components of each probe in each axis direction at each time point, use the time point as the independent variable, and the components of the position deviation vector on each axis as the dependent variable data. For each axis direction, establish a multiple linear regression model for each probe.

[0028] Fit the linear regression model, substitute the time point corresponding to the current moment as the independent variable data into the established linear regression model, and calculate the predicted position deviations of each probe in each axis direction.

[0029] Preferably, the specific analysis method of the final deviation compensation vector of the probe is: take the opposite value of the predicted position deviation of each probe in each axis direction to obtain the compensation vector of each probe in each axis direction, and combine the compensation vectors of each probe in each axis direction to obtain the preliminary deviation compensation vector of each probe.

[0030] For probes with a mapping relationship based on position proximity and whose predicted position deviations are within the set range, use the probe with the predicted position deviation as the reference probe, and based on the coordinates of the reference probe, calculate the opposite number of the difference between the actual coordinates of other probes and the reference coordinates in each axis direction as the supplementary compensation vector component of the probe on the corresponding axis.

[0031] Perform a weighted sum of the supplementary compensation vector component and the component of the preliminary deviation compensation vector on the corresponding axis to obtain the final compensation vector component of the probe on the corresponding axis, thereby obtaining the final deviation compensation vector of the probe.

[0032] Preferably, the specific analysis method of the final deviation compensation vector of the probe further includes: for a probe group with a mapping relationship based on motion correlation, monitor the changes in the predicted position deviations of each probe, screen out the probes with deviation changes greater than the set threshold, use the probes with predicted position deviation changes less than or equal to the set threshold as the reference probe group, calculate the average value of the deviation vectors of the reference probe group on each axis, calculate the difference between the probes with deviation changes greater than the set threshold and the average deviation of the reference probe group on each axis, and thereby determine the adjustment vector. Perform a weighted calculation of the adjustment vector and the preliminary deviation compensation vector to obtain the final deviation compensation vector of the probe.

[0033] Preferably, the specific operation method for setting the limiting conditions is as follows: Set a fixed sampling time interval. According to the deviation compensation vectors of each probe and the sampling time interval, calculate the expected velocity of each probe in each coordinate axis direction, and calculate the acceleration change required for each probe to reach the expected velocity based on the velocity of each probe at the previous moment.

[0034] Limit the maximum velocity and maximum acceleration. If the calculated expected velocity exceeds the set maximum velocity, then limit the expected velocity to the maximum velocity. If the calculated acceleration change exceeds the set maximum acceleration, then limit the acceleration change to the maximum acceleration.

[0035] Preferably, the specific analysis method of the probe stage correction module is as follows: Determine the movement direction of each probe in each coordinate axis direction according to the positive and negative of the deviation compensation vectors of each probe. Generate a control command for controlling the movement of the wafer probe stage based on the magnitude of the deviation compensation vector and the expected velocity and acceleration change after limiting adjustment.

[0036] Correct the movement of the probe stage according to the command information parsed from the control command. During the movement of the probe stage, dynamically correct the movement of the probe stage by repeating the processes of calculating the deviation compensation vector and generating the control command until each probe accurately reaches the target position.

[0037] Compared with the prior art, the present invention has the following beneficial effects: First, based on the actual position coordinates of each probe at each time point, the present invention constructs a mapping relationship between the probes, which can accurately capture the position states of each probe at different times, and at the same time deeply understand the relative position changes and interactions between the probes. Based on the mapping relationship of the actual position coordinates, the subsequent adjustment and control of the probe positions are more targeted and accurate.

[0038] Second, by comparing with the preset ideal coordinates, the present invention calculates the components of the position deviation vectors of each probe at each time point on each axis, and then constructs a linear regression model. Combining the mapping relationship between the probes, it calculates the final deviation compensation vector of the probes. By comparing with the preset ideal coordinates, it can clearly and intuitively find the difference between the actual position and the ideal position of the probes, which is convenient for quickly locating problems. Calculating the deviation compensation vector by combining the mapping relationship makes full use of the correlation information between the probes, makes the compensation more reasonable and effective, and improves the accuracy of probe positioning.

[0039] III. By setting limiting conditions and generating control instructions in combination with the deviation compensation vector, the movement of the probe station is dynamically corrected. Setting the limiting conditions can ensure that the movement of the probe station is carried out within a safe and reasonable range. Generating control instructions in combination with the deviation compensation vector can control the probe station in real time and accurately according to the actual deviation situation. The dynamic correction can respond in a timely manner to the change of the probe position, ensure that the probe always maintains a high position accuracy during the working process, and improve the quality and efficiency of the overall work. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0041] Figure 1 It is a connection diagram of the system modules of the present invention.

[0042] Figure 2 It is Figure 1 a flowchart judgment block diagram of mapping relationship table A in the mapping relationship table construction module in

[0043] Figure 3 It is Figure 1 a flowchart of mapping relationship table B in the mapping relationship table construction module in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0045] Please refer to Figure 1 as shown, a real-time error compensation control system for a wafer probe station based on multi-sensor fusion includes a probe displacement detection module, a mapping relationship table construction module, a deviation comparison module, a deviation compensation acquisition module, a probe station correction module, and a management database.

[0046] The management database is connected to the probe displacement detection module, the mapping relationship table construction module, the deviation compensation acquisition module, and the probe station correction module. The mapping relationship table construction module is connected to the probe displacement detection module, the deviation comparison module, and the deviation compensation acquisition module. The deviation comparison module is connected to the probe displacement detection module and the deviation compensation acquisition module.

[0047] The probe displacement detection module is used to construct a global coordinate system and obtain the actual position coordinates of each probe at each time point.

[0048] It should be noted that the global coordinate system takes the long side direction of the workbench as the x-axis, with the right direction as the positive direction. The direction perpendicular to the x-axis and within the workbench plane is defined as the y-axis, with the upward direction as the positive direction of the y-axis. The direction perpendicular to the workbench plane is the Z-axis, and the upward direction away from the workbench plane is the positive direction of the Z-axis.

[0049] The specific analysis method of the probe displacement detection module is as follows: Obtain the initial position information of each probe on the wafer probe stage in the global coordinate system, collect the image sequence of the movement of each probe at the set frame rate, take two adjacent frames of images as a group, and obtain the motion vectors of each pixel point in each group of images through the optical flow algorithm; it can capture the changes in the motion state of the probe at different times and promptly detect abnormal or unstable motion conditions.

[0050] Determine the position of each probe in the image through image threshold segmentation technology, extract the optical flow vectors within each probe region, convert the optical flow vectors within each probe region into motion trajectories in the actual space, and obtain the actual position coordinates of each probe at each time point; by combining the optical flow vector information obtained based on image analysis with the movement of the probe in the real space, the accurate position of the probe in the real environment can be obtained.

[0051] It should be noted that the specific analysis method of the actual position coordinates of each probe at each time point is as follows: Select two adjacent frames of images from the captured image sequence as a group, denoted as frame A and frame B. Select a group of feature points from frame A. For each feature point, find its corresponding matching point in frame B, and solve the system of equations to calculate the optical flow vectors of each pixel point in these two frames of images. Each vector is represented by an arrow, the direction of the arrow represents the movement direction of the pixel point, and the length represents the amplitude of the movement.

[0052] Set the segmentation threshold, and divide frame A and frame B into foreground (probe) and background respectively. Traverse all the feature points of the optical flow vectors calculated before. If the feature point is within the probe region, extract its corresponding optical flow vector. For the optical flow vectors within the probe region, multiply their coordinates by the pixel size of the camera to obtain their displacements in the actual space, convert the pixel displacements into the global coordinate system, and combine with the displacements of the initial position of the probe at each time point to obtain the actual position coordinates of the probe at each time point.

[0053] The mapping relationship table construction module is used to construct the mapping relationship between probes based on the actual position coordinate data of each probe at each time point.

[0054] Please refer to Figure 2As shown, the specific analysis method of the mapping relationship table construction module is as follows: at the same time point, use the Euclidean distance formula to calculate the spatial distance between the actual position coordinates of each probe and the actual position coordinates of other probes. If the spatial distance between two probes at the same time point is less than the preset distance threshold, construct a mapping relationship based on position proximity between these two probes; constructing a mapping relationship based on position proximity can timely identify these probe combinations with potential interference risks, and thus take measures in advance, such as adjusting the probe movement path or speed, to avoid collision damage between probes.

[0055] It should be noted that the Euclidean distance formula is , represents the distance, respectively represent the actual position coordinates of the first and second probes, and a distance threshold is set according to the average value of the spatial distances between the actual position coordinates of each probe and the actual position coordinates of other probes.

[0056] Arrange the actual position coordinates of each probe at each time point in chronological order to obtain the movement trajectories of each probe. Calculate the similarity of the movement trajectories of each two probes respectively. If the similarity of the movement trajectories of two probes is greater than the preset similarity threshold, construct a mapping relationship based on movement correlation between these two probes; for probes with relatively high movement trajectory similarity, there may be a certain functional relevance. After constructing a mapping relationship based on movement correlation, a cooperative movement control strategy can be implemented for these probes.

[0057] It should be noted that in a specific embodiment, there are probe A and probe B. Take the coordinates of several equally spaced points in the movement trajectories of probe A and probe B respectively, and use the Euclidean distance formula to obtain the distances between the coordinates of each point in the movement trajectory of probe A and the coordinates of each point in the movement trajectory of probe B, and obtain the distance between the movement trajectories of probe A and probe B by taking the average value of them , through obtain the similarity of the movement trajectories of probe A and probe B, and set a similarity threshold according to the average value of the similarities of the movement trajectories of each probe and the movement trajectories of other probes.

[0058] Construct a mapping relationship table A according to the mapping relationship based on position proximity and the mapping relationship based on movement correlation. The mapping relationship table A is used to present the association relationships between each probe; it can present the association relationships between each probe based on position proximity and movement correlation in an intuitive table form, and can quickly and clearly understand the mutual relationships between probes.

[0059] Specifically refer to Table 1, in which some representative data are listed.

[0060] Table 1. Mapping Relationship Table A

[0061]

[0062] Please refer to Figure 3 As shown, the mapping relationship table construction module further includes: S1. Assign a unique first probe identifier to each probe respectively, thereby establishing a one-to-one first mapping relationship between four first probe identifiers and four probes. Among them, the first probe identifier is used to identify the identification chip on the corresponding probe; it can achieve precise identification and positioning of each probe.

[0063] S2. Receive the second mapping relationship sent by the second control module of the wafer to be measured. Among them, the second control module is used to manage the measurement points on the wafer to be measured, and the second mapping relationship is used to indicate the correspondence between the second probe and the second probe identifier. The second probe is the probe corresponding to the measurement point on the wafer to be measured. The four first probe identifiers include the second probe identifier; this enables a clear connection to be established between the measurement points on the wafer to be measured and specific probes, ensuring the accuracy and pertinence of the measurement operation. By receiving the second mapping relationship, the probe station system can effectively dock with the second control module, achieve accurate execution of the measurement task, and improve the coordination and efficiency of the entire test process.

[0064] S3. Determine the third mapping relationship according to the first mapping relationship and the second mapping relationship. The third mapping relationship is used to indicate the correspondence between each third probe and the second probe in the measurement channels for the four probes to conduct measurement communication with the wafer to be measured. Among them, each second probe corresponds to one measurement point on the wafer to be measured. Determine the connection combination between each measurement point and the corresponding third probe according to the measurement requirements to form the measurement channels; the third mapping relationship ensures that each second probe can establish an accurate correspondence with a suitable third probe. When conducting wafer testing, the accurate correspondence can ensure the accuracy and reliability of the measurement data, and avoid measurement errors caused by mismatches between the probes and the measurement points.

[0065] S4. Construct Mapping Relationship Table B according to the third mapping relationship. Mapping Relationship Table B is used to present the correspondence between each third probe and the second probe and the association with the measurement points.

[0066] Specifically refer to Table 2, in which some representative data are listed.

[0067] Table 2. Mapping Relationship Table B

[0068]

[0069] The deviation comparison module is used to compare the actual position coordinates of each probe at each time point with the preset ideal coordinates, and calculate the components of the position deviation vector of each probe at each time point on each axis.

[0070] The specific analysis method of the deviation comparison module is as follows: for the second probe corresponding to each measurement point, according to the corresponding third probe in the mapping relationship, obtain the actual position coordinates of the third probe at each time point; obtaining the actual position coordinates at each time point helps to track the dynamic changes of the probe during the measurement process.

[0071] Call the preset ideal coordinate data from the management database. The ideal coordinates correspond to the measurement points and are associated with each probe through the mapping relationship.

[0072] Compare the actual position coordinates of each probe at each time point with the preset ideal coordinates, and calculate the components of the position deviation vector of each probe at each time point on each axis; this helps to accurately judge the source and direction of the deviation, provides detailed information for adjusting the probe position or optimizing the measurement process, thereby improving the accuracy and precision of the measurement.

[0073] It should be noted that the specific calculation method of the components of the position deviation vector of each probe at each time point on each axis is as follows: split the actual position coordinates of each probe at each time point and the preset ideal coordinates respectively, and calculate the differences between the values of each probe at each time point on the x, y, z axes and the values of the ideal coordinates on the x, y, z axes to obtain the components of the position deviation vector of each probe at each time point on each axis.

[0074] The deviation compensation acquisition module is used to construct a linear regression model based on the components of the position deviation vector of each probe at each time point on each axis, and calculate the final deviation compensation vector of the probe in combination with the mapping relationship between the probes.

[0075] The specific construction method of the linear regression model is as follows: extract the position deviation components of each probe at each time point in each coordinate axis direction, take the time point as the independent variable, and the components of the position deviation vector on each axis as the dependent variable data. For each coordinate axis direction, establish a multiple linear regression model for each probe; the multiple linear regression model can simultaneously consider the position deviations in multiple coordinate axis directions and their relationship with time, can comprehensively evaluate the interaction and common change of deviations in different directions, and can describe the motion state of the probe more comprehensively. Compared with analyzing each direction or single factor separately, it can provide more accurate and detailed information.

[0076] It should be noted that divide the independent variable data and the dependent variable data into a training set and a test set according to a certain ratio, and use the training set data to obtain the estimated value of the regression coefficient and fit the optimal multiple linear regression equation.

[0077] Substitute the time point corresponding to the current moment as the independent variable data into the constructed linear regression model, and calculate the predicted position deviation of each probe in each coordinate axis direction; the probe can be fine-tuned in a timely manner according to the latest prediction results, so that the probe can be kept as close as possible to the ideal position, thereby improving the stability and reliability of the measurement and adapting to different measurement environments and condition changes.

[0078] The specific analysis method for the final deviation compensation vector of the probe is as follows: take the opposite value of the predicted position deviation of each probe in each coordinate axis direction to obtain the compensation vector of each probe in each coordinate axis direction, and combine the compensation vectors of each probe in each coordinate axis direction to obtain the preliminary deviation compensation vector of each probe.

[0079] It should be noted that taking the opposite value of the predicted position deviation of each probe in each coordinate axis direction to obtain the compensation vector is based on a simple and direct error correction logic. The predicted position deviation represents the deviation of the actual position of the probe from the ideal position. Taking the opposite value can initially offset this deviation, making the probe approach the ideal position and laying a foundation for more precise adjustment in the future, improving the initial accuracy of probe positioning.

[0080] For probes with a mapping relationship based on position proximity and whose predicted position deviation is within the set range, use the probe with the predicted position deviation as the reference probe, and based on the coordinates of the reference probe, calculate the opposite value of the difference between the actual coordinates of other probes and the reference coordinates in each axis direction as the supplementary compensation vector component of the probe in the corresponding axis; adjacent probes may be affected by similar external factors and there is a certain correlation between them. In this way, the compensation amount can be further refined, and the position information of adjacent probes can be fully utilized to optimize the compensation effect and make the compensation more in line with the actual situation.

[0081] Perform weighted summation of the supplementary compensation vector component and the component of the preliminary deviation compensation vector on the corresponding axis to obtain the final compensation vector component of the probe on the corresponding axis, thereby obtaining the final deviation compensation vector of the probe; the weighted summation method can flexibly balance the roles of the preliminary compensation and the supplementary compensation, reasonably allocate the weights of the two according to the actual situation, so as to achieve more accurate error compensation and further improve the positioning accuracy of the probe.

[0082] It should be noted that in a specific embodiment, the actual coordinates of probe A at the current moment are (1000, 2000, 500), and the actual coordinates of probe B are (1005, 2003, 502). In the X-axis direction, the difference is 1005 - 1000 = 5, and its opposite number is used as the supplementary compensation vector component, which is -5. In the Y-axis direction, the difference is 2003 - 2000 = 3, and the supplementary compensation vector component is -3. In the Z-axis direction, the difference is 502 - 500 = 2, and the supplementary compensation vector component is -2. The components of the preliminary deviation compensation vector of probe B on each axis are (-3, -2, -1). The weighted coefficient of the supplementary compensation vector component is set to 0.6, and the weighted coefficient of the preliminary deviation compensation vector component is 0.4. It is calculated that in the X-axis direction, the final compensation vector component is , in the Y-axis direction, the final compensation vector component is , in the Z-axis direction, the final compensation vector component is , and the final deviation compensation vector of probe B is .

[0083] The specific analysis method for the final deviation compensation vector of the probe further includes: for a probe group with a mapping relationship based on motion correlation, monitoring the change in the predicted position deviation of each probe, screening the probes with a deviation change greater than the set threshold, using the probes with a predicted position deviation change less than or equal to the set threshold as the reference probe group, calculating the average value of the deviation vectors of the reference probe group on each coordinate axis, calculating the difference between the probes with a deviation change greater than the set threshold and the average deviation of the reference probe group on each coordinate axis, thereby determining the adjustment vector, and performing weighted calculation on the adjustment vector and the preliminary deviation compensation vector to obtain the final deviation compensation vector of the probe; by comparing the average deviation to determine the adjustment amount of the abnormal probe, it is possible to more accurately identify and correct the abnormal deviation, making the movement of the entire probe group more coordinated.

[0084] It should be noted that in a specific embodiment, assume that probe A, probe B, and probe C have a mapping relationship based on motion correlation. We set the set threshold for the deviation change to ±5 microns. After monitoring, it is found that the predicted position deviation change of probe A in the X-axis direction is 3 microns, in the Y-axis direction is -2 microns, and in the Z-axis direction is 1 micron. The predicted position deviation change of probe B in the X-axis direction is 4 microns, in the Y-axis direction is -1 micron, and in the Z-axis direction is 2 microns. The predicted position deviation change of probe C in the X-axis direction is 8 microns, in the Y-axis direction is -6 microns, and in the Z-axis direction is 7 microns. Since the deviation change of probe C in each axis direction is greater than the set threshold, while the deviation changes of probe A and probe B are less than or equal to the set threshold, probe A and probe B are selected as the reference probe group.

[0085] The predicted position deviation vector of probe A is (3, -2, 1), and the predicted position deviation vector of probe B is (4, -1, 2). In the X-axis direction, the average deviation of the reference probe group is 3.5. In the Y-axis direction, the average deviation is -1.5. In the Z-axis direction, the average deviation is 1.5. The deviation difference between probe C and the reference probe group in the X-axis direction is 4.5, in the Y-axis direction is -4.5, and in the Z-axis direction is 5.5. Therefore, the adjustment vector is (4.5, -4.5, 5.5).

[0086] The preliminary deviation compensation vector of probe C is (−5, −4, −3). Set the weighting coefficient of the adjustment vector to 0.7 and the weighting coefficient of the preliminary deviation compensation vector components to 0.4. Calculate the final compensation vector components in the X-axis direction: , in the Y-axis direction: , in the Z-axis direction: , the final deviation compensation vector of probe C is .

[0087] The probe stage calibration module is used to set limiting conditions, generate control instructions in combination with the deviation compensation vector, and perform dynamic calibration on the movement of the probe stage.

[0088] The specific operation method for setting the limiting conditions is as follows: Set a fixed sampling time interval. According to the deviation compensation vectors of each probe and the sampling time interval, calculate the expected speed of each probe in each coordinate axis direction. Calculate the required acceleration change for each probe to reach the expected speed based on the speed of the previous moment of each probe; by combining the deviation compensation vector, ensure that the probe moves in the direction of eliminating the deviation at an appropriate speed, so that the probe can approach the target position more accurately, improving the accuracy of motion control.

[0089] It should be noted that in a specific embodiment, the deviation compensation vector of probe P in the X-axis direction is 0.5 mm, in the Y-axis direction is -0.3 mm, and in the Z-axis direction is 0.2 mm. Set the sampling interval to , and calculate the expected speed in each coordinate axis direction through the formula: on the x-axis: , on the y-axis: , on the z-axis: , where are the deviation compensation vectors of the probe in the x, y, and z axes respectively, and then calculate the required acceleration change for each coordinate axis direction to reach the expected speed: on the x-axis: , on the y-axis: , on the z-axis: , respectively represent the initial speeds of the probe in the x, y, and z axis directions.

[0090] Limit the maximum speed and maximum acceleration. If the calculated desired speed exceeds the set maximum speed, limit the desired speed to the maximum speed. If the calculated acceleration change exceeds the set maximum acceleration, limit the acceleration change to the maximum acceleration. Limiting the maximum speed and maximum acceleration can effectively protect the probe station equipment. If the desired speed or acceleration change exceeds the range that the equipment can withstand, it may cause damage to mechanical components or system failures. By limiting, the damage caused to the equipment due to excessive speed or acceleration can be avoided, ensuring the normal operation and safety of the equipment.

[0091] The specific analysis method of the probe station calibration module is as follows: Determine the movement direction of each probe in each coordinate axis direction according to the positive and negative of the deviation compensation vector of each probe. Generate a control command for controlling the movement of the wafer probe station according to the magnitude of the deviation compensation vector and the desired speed and acceleration change after limit adjustment. The control command provides clear guidance for the movement control of the probe station, enabling the control command to accurately drive the probe to move in the correct direction, avoiding incorrect movement directions, and improving the accuracy of movement control.

[0092] Calibrate the movement of the probe station according to the command information parsed from the control command. During the movement of the probe station, dynamically calibrate the movement of the probe station by repeating the process of calculating the deviation compensation vector and generating the control command until each probe accurately reaches the target position. The dynamic calibration mechanism can monitor the movement state of the probe in real time and adjust the control command in a timely manner according to the actual situation, ensuring that the probe can overcome various interference factors and accurately reach the target position, greatly improving the positioning accuracy of the probe station and the reliability of the system.

[0093] Manage the database, which is used to store the actual position coordinate data of each probe at each time point, the preset ideal coordinate data, the constructed mapping relationship table, and the parameter estimation values of the linear regression model.

[0094] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention, and still be covered by the protection scope of the present invention.

Claims

1. A real-time error compensation control system for a wafer probe station based on multi-sensor fusion, characterized in that The system specifically includes the following modules: A probe displacement detection module that constructs a global coordinate system and obtains the actual position coordinates of each probe at each time point; A mapping relationship table construction module that constructs the mapping relationship between probes based on the actual position coordinates of each probe at each time point; A deviation comparison module that compares the actual position coordinates of each probe at each time point with the preset ideal coordinates and calculates the components of the position deviation vector of each probe at each time point on each axis; A deviation compensation acquisition module that constructs a linear regression model based on the components of the position deviation vector of each probe at each time point on each axis and calculates the final deviation compensation vector of the probe in combination with the mapping relationship between probes; Taking the opposite value of the predicted position deviation of each probe in each coordinate axis direction to obtain the compensation vector of each probe in each coordinate axis direction, and combining the compensation vectors of each probe in each coordinate axis direction to obtain the preliminary deviation compensation vector of each probe; For probes with a mapping relationship based on position proximity and a predicted position deviation within a set range, using the probe with the predicted position deviation as a reference probe, and taking the coordinates of the reference probe as a benchmark, calculating the opposite of the difference between the actual coordinates and the reference coordinates of other probes in each axis direction as the supplementary compensation vector component of the probe on the corresponding axis; Performing a weighted sum of the supplementary compensation vector component and the component on the corresponding axis of the preliminary deviation compensation vector to obtain the final compensation vector component of the probe on the corresponding axis, thereby obtaining the final deviation compensation vector of the probe; For a probe group with a mapping relationship based on motion correlation, monitoring the change of the predicted position deviation of each probe, screening the probes with a deviation change greater than the set threshold, using the probes with a predicted position deviation less than or equal to the set threshold as a reference probe group, calculating the average value of the deviation vectors of the reference probe group on each coordinate axis, calculating the difference between the deviation of the probe with a deviation change greater than the set threshold and the average deviation of the reference probe group on each coordinate axis, thereby determining the adjustment vector, and performing a weighted calculation of the adjustment vector and the preliminary deviation compensation vector to obtain the final deviation compensation vector of the probe; A probe stage correction module that sets limiting conditions, generates a control instruction in combination with the deviation compensation vector, and dynamically corrects the motion of the probe stage; A management database that stores the actual position coordinate data of each probe at each time point, the preset ideal coordinate data, the constructed mapping relationship table, and the parameter estimation values of the linear regression model.

2. The real-time error compensation control system for a wafer prober based on multi-sensor fusion according to claim 1, wherein, The specific analysis method of the probe displacement detection module is as follows: Obtaining the initial position information of each probe on the wafer probe stage in the global coordinate system, collecting an image sequence of the motion of each probe at a set frame rate, taking two adjacent frames of images as a group, and obtaining the motion vectors of each pixel point in each group of images through an optical flow algorithm; Determining the position of each probe in the image through image threshold segmentation technology, extracting the optical flow vectors within the area of each probe, and converting the optical flow vectors within the area of each probe into the motion trajectories in the actual space to obtain the actual position coordinates of each probe at each time point.

3. A real-time error compensation control system for a wafer probe station based on multi-sensor fusion according to claim 1, characterized in that, The specific analysis method of the mapping relationship table construction module is as follows: At the same time point, use the Euclidean distance formula to calculate the spatial distance between the actual position coordinates of each probe and the actual position coordinates of other probes. If the spatial distance between two probes at the same time point is less than the preset distance threshold, then construct a mapping relationship based on position proximity between the two probes; Arrange the actual position coordinates of each probe at each time point in chronological order to obtain the movement trajectories of each probe. Calculate the similarity of the movement trajectories of each pair of probes respectively. If the similarity of the movement trajectories of two probes is greater than the preset similarity threshold, then construct a mapping relationship based on movement correlation between the two probes; Construct a mapping relationship table A according to the mapping relationship based on position proximity and the mapping relationship based on movement correlation. The mapping relationship table A is used to present the association relationship between each probe.

4. The real-time error compensation control system of a wafer prober based on multi-sensor fusion according to claim 3, characterized in that, The mapping relationship table construction module further includes: S1. Assign a unique first probe identifier to each probe respectively, thereby establishing a one-to-one first mapping relationship between four first probe identifiers and four probes. Among them, the first probe identifier is used to identify the identification chip on the corresponding probe; S2. Receive the second mapping relationship sent by the second control module of the wafer to be measured. Among them, the second control module is used to manage the measurement points on the wafer to be measured, and the second mapping relationship is used to indicate the corresponding relationship between the second probe and the second probe identifier. The second probe is the probe corresponding to the measurement point on the wafer to be measured, and the four first probe identifiers include the second probe identifier; S3. Determine the third mapping relationship according to the first mapping relationship and the second mapping relationship. The third mapping relationship is used to indicate the corresponding relationship between each third probe and the second probe in the measurement channels for the four probes to perform measurement communication with the wafer to be measured. Among them, each second probe corresponds to a measurement point on the wafer to be measured. Determine the connection combination of each measurement point and the corresponding third probe according to the measurement requirements to form the measurement channel; S4. Construct a mapping relationship table B according to the third mapping relationship. The mapping relationship table B is used to present the corresponding relationship between each third probe and the second probe and the association with the measurement points.

5. The real-time error compensation control system of a wafer probe station based on multi-sensor fusion according to claim 4, characterized in that, The specific analysis method of the deviation comparison module is: For the second probe corresponding to each measurement point, obtain the actual position coordinates of the third probe at each time point according to the third probe corresponding to it in the mapping relationship; Call the preset ideal coordinate data from the management database. The ideal coordinates correspond to the measurement points and are associated with each probe through the mapping relationship; Compare the actual position coordinates of each probe at each time point with the preset ideal coordinates, and calculate the components of the position deviation vector of each probe at each time point on each axis.

6. The real-time error compensation control system of a wafer probe station based on multi-sensor fusion according to claim 5, characterized in that, The specific construction method of the linear regression model is: Extract the position deviation components of each probe in each coordinate axis direction at each time point. Use the time point as the independent variable and the components of the position deviation vector on each axis as the dependent variable data. For each coordinate axis direction, establish a multiple linear regression model for each probe; Fit a linear regression model, substitute the time point corresponding to the current moment as the independent variable data into the constructed linear regression model, and calculate the predicted position deviation of each probe in each coordinate axis direction.

7. A real-time error compensation control system for a wafer prober based on multi-sensor fusion according to claim 1, characterized in that, The specific operation method for setting the limit conditions is as follows: Set a fixed sampling time interval, calculate the expected velocity of each probe in each coordinate axis direction according to the deviation compensation vector of each probe and the sampling time interval, and calculate the acceleration change required for each probe to reach the expected velocity according to the velocity of each probe at the previous moment; Limit the maximum velocity and maximum acceleration. If the calculated expected velocity exceeds the set maximum velocity, limit the expected velocity to the maximum velocity. If the calculated acceleration change exceeds the set maximum acceleration, limit the acceleration change to the maximum acceleration.

8. A real-time error compensation control system for a wafer probe station based on multi-sensor fusion according to claim 7, characterized in that The specific analysis method of the probe stage correction module is as follows: Determine the movement direction of each probe in each coordinate axis direction according to the positive and negative of the deviation compensation vector of each probe, and generate a control command for controlling the movement of the wafer probe stage according to the magnitude of the deviation compensation vector and the expected velocity and acceleration change after being limited and adjusted; Correct the movement of the probe stage according to the command information parsed from the control command, and during the movement of the probe stage, dynamically correct the movement of the probe stage by repeating the process of calculating the deviation compensation vector and generating the control command until each probe accurately reaches the target position.

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