Wafer probe station real-time error compensation control system based on multi-sensor fusion

Abstract

The invention relates to the technical field of semiconductor manufacturing equipment, in particular to a wafer probe station real-time error compensation control system based on multi-sensor fusion, which comprises a probe displacement detection module, a mapping relation table construction module, a deviation comparison module, a deviation compensation acquisition module, a probe station correction module and a management database, the system constructs a mapping relation between probes based on actual position coordinates of each probe at each time point, compares the mapping relation with preset ideal coordinates, calculates components of position deviation vectors of each probe at each time point on each axis, and further constructs a linear regression model. The final deviation compensation vector of the probe is calculated in combination with the mapping relation between the probes, the motion of the probe station is dynamically corrected by setting limiting conditions and generating a control instruction in combination with the deviation compensation vector, it is guaranteed that the probe always keeps high position precision in the working process, and the overall working quality and efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor manufacturing equipment, and in particular to a real-time error compensation control system for a wafer probe station based on multi-sensor fusion. Background Art

[0002] As the semiconductor industry is booming, chip manufacturing processes are constantly moving towards smaller feature sizes and higher integration, which places extremely stringent requirements on the wafer testing process. The wafer probe station is a key bridge connecting the wafer and the testing equipment. Its positioning accuracy directly affects the accuracy and reliability of chip testing, which in turn affects the yield and production efficiency of the entire semiconductor manufacturing process. It occupies a pivotal position in the semiconductor manufacturing industry chain.

[0003] However, existing wafer probe stations will produce various errors during the actual movement process, resulting in reduced transmission accuracy, causing the probe to deviate from the preset trajectory during movement, reducing the accuracy and reliability of wafer testing. Therefore, real-time error detection of the wafer probe station is crucial.

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

[0005] However, this solution has the following shortcomings: it mainly obtains the error compensation amount based on the interaction between the central server and the edge server, and does not fully utilize the intrinsic correlation information between the parameters, which may lead to the compensation calculation being not comprehensive and accurate enough. At the same time, it does not explicitly mention the direct comparison with the ideal state, which may make it difficult to intuitively determine the degree of error and the specific deviation direction, which is not conducive to quickly and accurately locating the compensation needs.

[0006] The existing Chinese patent application number 201010281777.1 discloses a remote control device for a probe station and a control method thereof. The solution transmits test data to a server, and the server compares the verification information with the test data. If it is correct, the next instruction is tested. If it is wrong, the error information is automatically sent to the wireless communication device used by the monitor via wireless communication, thereby improving the fault response efficiency.

[0007] This solution has the following deficiencies: the solution only judges whether the test result is correct or not to feedback the error, and does not quantify the error size. In actual applications, different degrees of error have different impacts on wafer testing. The lack of quantification is not conducive to evaluating the severity of the error and taking corresponding accurate compensation measures, and cannot provide accurate data support for subsequent error correction. Summary of the invention

[0008] In order to overcome the shortcomings of the background technology, an embodiment of the present invention provides 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-mentioned background technology.

[0009] The purpose 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 for constructing a global coordinate system and obtaining the actual position coordinates of each probe at each time point.

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

[0011] 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.

[0012] The deviation compensation acquisition module is used 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 the probes.

[0013] The probe station correction module is used to set restriction conditions, generate control instructions in combination with deviation compensation vectors, and dynamically correct the movement of the probe station.

[0014] The management database 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 value of the linear regression model.

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

[0016] The position of each probe in the image is determined by image threshold segmentation technology, the optical flow vector in each probe area is extracted, and the optical flow vector in each probe area is converted into a motion trajectory in the actual space to 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: at the same time point, the Euclidean distance formula is used 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 a preset distance threshold, a mapping relationship based on position proximity is constructed between the two probes.

[0018] The actual position coordinates of each probe at each time point are arranged in chronological order to obtain the motion trajectory of each probe. The similarity of the motion trajectories of each two probes is calculated respectively. If the similarity of the motion trajectories of two probes is greater than the preset similarity threshold, a mapping relationship based on motion correlation is constructed between the two probes.

[0019] A mapping relationship table A is constructed according to the mapping relationship based on position proximity and the mapping relationship based on motion correlation, and the mapping relationship table A is used to present the association relationship between the probes.

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

[0021] Receive a second mapping relationship sent by a second control module of the wafer to be tested, wherein the second control module is used to manage measurement points on the wafer to be tested, 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 tested, and the four first probe identifiers include the second probe identifier.

[0022] A third mapping relationship is determined based on the first mapping relationship and the second mapping relationship, and the third mapping relationship is used to indicate the correspondence between each third probe and the second probe in a measurement channel in which four probes perform measurement communication with the wafer to be measured, wherein each second probe corresponds to a measurement point on the wafer to be measured, and a connection combination between each measurement point and the corresponding third probe is determined according to measurement requirements to form the measurement channel.

[0023] A mapping relationship table B is constructed according to the third mapping relationship, and 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 point.

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

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

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

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

[0028] Fit the 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.

[0029] Preferably, the specific analysis method of the final deviation compensation vector of the probe is: taking the inverse value of the predicted position deviation in each coordinate axis direction of each probe to obtain the compensation vector in each coordinate axis direction of each probe, combining the compensation vectors in each coordinate axis direction of each probe to obtain the preliminary deviation compensation vector of each probe.

[0030] For probes with a mapping relationship based on position proximity and a predicted position deviation within a set range, the probe with the predicted position deviation is used as the reference probe, and the coordinates of the reference probe are used as a benchmark to calculate the negative 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] The supplementary compensation vector component and the component on the corresponding axis of the preliminary deviation compensation vector are weightedly summed 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 also includes: for a probe group having a motion correlation mapping relationship, monitoring the change in the predicted position deviation of each probe, screening probes with deviation changes greater than a set threshold, using each probe with a predicted position deviation change less than or equal to the set threshold as a reference probe group, calculating the average value of the deviation vector of the reference probe group on each coordinate axis, calculating the difference between the average deviation of the probe with a deviation change greater than the set threshold and the reference probe group on each coordinate axis, thereby determining an adjustment vector, performing weighted calculation on 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 restriction conditions is: setting a fixed sampling time interval, calculating the expected speed of each probe in the direction of each coordinate axis according to the deviation compensation vector of each probe and the sampling time interval, and calculating the acceleration change required for each probe to reach the expected speed according to the speed of each probe at the previous moment.

[0034] The maximum speed and maximum acceleration are limited. If the calculated expected speed exceeds the set maximum speed, the expected speed is limited to the maximum speed. If the calculated acceleration change exceeds the set maximum acceleration, the acceleration change is limited to the maximum acceleration.

[0035] Preferably, the specific analysis method of the probe station correction module is: determine the movement direction of each probe in the direction of each coordinate axis according to the positive or negative value of the deviation compensation vector of each probe, and generate a control instruction for controlling the movement of the wafer probe station according to the size of the deviation compensation vector and the expected speed and acceleration changes after limit adjustment.

[0036] The motion of the probe station is corrected according to the instruction information parsed from the control instruction, and during the motion of the probe station, the motion of the probe station is dynamically corrected by repeating the process of calculating the deviation compensation vector and generating the control instruction until each probe reaches the target position accurately.

[0037] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention constructs a mapping relationship between probes based on the actual position coordinates of each probe at each time point, which can accurately capture the position status 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 position are more targeted and accurate.

[0038] 2. The present invention calculates the components of the position deviation vector of each probe at each time point on each axis by comparing with the preset ideal coordinates, and then constructs a linear regression model. The final deviation compensation vector of the probe is calculated in combination with the mapping relationship between the probes, and compared with the preset ideal coordinates. The difference between the actual position and the ideal position of the probe can be clearly and intuitively found, which is convenient for quickly locating the problem. The deviation compensation vector is calculated in combination with the mapping relationship, and the correlation information between the probes is fully utilized, making the compensation more reasonable and effective, thereby improving the accuracy of probe positioning.

[0039] 3. The present invention sets restriction conditions and generates control instructions in combination with deviation compensation vectors to dynamically correct the movement of the probe station. Setting restriction conditions can ensure that the movement of the probe station is within a safe and reasonable range. Generating control instructions in combination with deviation compensation vectors can control the probe station in real time and accurately according to actual deviation conditions. Dynamic correction can respond to changes in the probe position in a timely manner, ensuring that the probe always maintains a high position accuracy during operation, thereby improving the overall work quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0041] Figure 1 This is a system module connection diagram of the present invention.

[0042] Figure 2 for Figure 1 The process judgment block diagram of the mapping relationship table A in the mapping relationship table construction module.

[0043] Figure 3 for Figure 1 Flowchart of mapping relationship table B in the mapping relationship table construction module. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] See also 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, the right as the positive direction, the direction perpendicular to the x-axis and in the plane of the workbench as the y-axis, the upward direction as the positive direction of the y-axis, the direction perpendicular to the plane of the workbench as the Z-axis, and the positive direction of the Z-axis away from the plane of the workbench upward.

[0049] 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 each probe movement at the set frame rate, taking two adjacent frames of images as a group, and obtaining the motion vector 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 discover abnormal or unstable motion.

[0050] The position of each probe in the image is determined by image threshold segmentation technology, and the optical flow vector in each probe area is extracted. The optical flow vector in each probe area is converted into a motion trajectory in the actual space to obtain the actual position coordinates of each probe at each time point. The optical flow vector information obtained based on image analysis is combined with the probe motion in the real space to obtain the accurate position of the probe in the real environment.

[0051] It should be noted that the specific analysis method of the actual position coordinates of each probe at each time point is: from the captured image sequence, two adjacent frames of images are selected as a group, recorded as frame A and frame B, and a group of feature points are selected from frame A. For each feature point, its corresponding matching point is found in frame B, and the optical flow vector of each pixel point in the two frames of images is calculated by the set of simultaneous equations. Each vector is represented by an arrow, the direction of the arrow represents the direction of movement 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 the feature points of all optical flow vectors calculated previously. If the feature point is located in the probe area, extract the corresponding optical flow vector. For the optical flow vector in the probe area, multiply its coordinates with the pixel size of the camera to obtain its displacement in the actual space. Convert the pixel displacement to the global coordinate system, and combine the displacement 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 the probes based on the actual position coordinate data of each probe at each time point.

[0054] See also Figure 2As shown, the specific analysis method of the mapping relationship table construction module is: at the same time point, the Euclidean distance formula is used 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 a preset distance threshold, a mapping relationship based on position proximity is constructed between the two probes; by constructing a mapping relationship based on position proximity, those probe combinations with potential interference risks can be identified in time, so that measures can be taken 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 , Indicates distance, They represent the actual position coordinates of probes one and two respectively, and a distance threshold is established according to the average value of the spatial distance between the actual position coordinates of each probe and the actual position coordinates of other probes.

[0056] The actual position coordinates of each probe at each time point are arranged in chronological order to obtain the motion trajectory of each probe, and the similarity of the motion trajectories of each two probes is calculated respectively. If the similarity of the motion trajectories of two probes is greater than the preset similarity threshold, a mapping relationship based on motion correlation is constructed between the two probes. For probes with high similarity in motion trajectories, there may be certain functional correlations. After constructing a mapping relationship based on motion correlation, a collaborative motion control strategy can be implemented for these probes.

[0057] It should be noted that, in a specific embodiment, there are probes A and B, and the coordinates of several equidistant points are taken in the motion trajectories of probes A and B, respectively. The distance between the coordinates of each point in the motion trajectory of probe A and the coordinates of each point in the motion trajectory of probe B is obtained by using the Euclidean distance formula, and the distance between the motion trajectories of probes A and probe B is obtained by taking the average value. ,pass The similarity of the motion trajectories of probe A and probe B is obtained, and a similarity threshold is established according to the average value of the similarity between the motion trajectory of each probe and the motion trajectory of other probes.

[0058] A mapping relationship table A is constructed according to the mapping relationship based on position proximity and the mapping relationship based on motion correlation, and the mapping relationship table A is used to present the association relationship between the probes; the association relationship between the probes based on position proximity and motion correlation can be presented in an intuitive tabular form, so that the relationship between the probes can be quickly and clearly understood.

[0059] Please refer to Table 1 for details, which lists some representative data.

[0060] Table 1. Mapping relationship table A

[0061]

[0062] See also Figure 3 As shown, the mapping relationship table construction module also includes: S1. Assigning a unique first probe identifier to each probe, thereby establishing a one-to-one first mapping relationship between four first probe identifiers and four probes, wherein the first probe identifier is used to identify the identification chip on the corresponding probe; and accurate identification and positioning of each probe can be achieved.

[0063] S2. Receive a second mapping relationship sent by a second control module of the wafer to be tested, wherein the second control module is used to manage measurement points on the wafer to be tested, and the second mapping relationship is used to indicate the correspondence between a second probe and a second probe identifier, and the second probe is a probe corresponding to the measurement point on the wafer to be tested, and the four first probe identifiers include the second probe identifier; so that a clear connection is established between the measurement point on the wafer to be tested and the specific probe, thereby ensuring the accuracy and pertinence of the measurement operation. By receiving the second mapping relationship, the probe station system can be effectively connected with the second control module to achieve accurate execution of the measurement task, thereby improving the coordination and efficiency of the entire test process.

[0064] S3. Determine a third mapping relationship based on the first mapping relationship and the second mapping relationship, wherein the third mapping relationship is used to indicate the correspondence between each third probe and the second probe in a measurement channel in which four probes perform measurement communication with the wafer to be tested, wherein each second probe corresponds to a measurement point on the wafer to be tested, and a connection combination of each measurement point and the corresponding third probe is determined according to measurement requirements to form the measurement channel; the third mapping relationship ensures that each second probe can establish an accurate correspondence with a suitable third probe, and when performing wafer testing, the accurate correspondence can ensure the accuracy and reliability of the measurement data and avoid measurement errors caused by mismatch between the probe and the measurement point.

[0065] S4. Construct a mapping relationship table B according to the third mapping relationship, wherein 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 point.

[0066] Please refer to Table 2 for details, which lists some representative data.

[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: for the second probe corresponding to each measurement point, according to its corresponding third probe in the mapping relationship, the actual position coordinates of the third probe at each time point are obtained; obtaining the actual position coordinates of each time point helps to track the dynamic changes of the probe during the measurement process.

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

[0072] The actual position coordinates of each probe at each time point are compared with the preset ideal coordinates, and the components of the position deviation vector of each probe at each time point on each axis are calculated; this helps to accurately determine the source and direction of the deviation, and provides detailed information for adjusting the probe position or optimizing the measurement process, thereby improving the precision and accuracy 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: split the actual position coordinates of each probe at each time point from the preset ideal coordinates, and respectively obtain the difference between the values ​​of each probe at each time point on the x, y, z axis and the ideal coordinates on the x, y, z axis, 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 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 the probes.

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

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

[0077] The time point corresponding to the current moment is substituted into the constructed linear regression model as the independent variable data, and the predicted position deviation of each probe in each coordinate axis direction is calculated; the probe can be fine-tuned in time according to the latest prediction results to keep the probe as close to the ideal position as possible, thereby improving the stability and reliability of the measurement and adapting to different measurement environments and changes in conditions.

[0078] The specific analysis method of the final deviation compensation vector of the probe is: taking the inverse value of the predicted position deviation in each coordinate axis direction of each probe to obtain the compensation vector in each coordinate axis direction of each probe, combining the compensation vectors in each coordinate axis direction of each probe to obtain the preliminary deviation compensation vector of each probe.

[0079] It should be noted that the compensation vector is obtained by taking the opposite value of the predicted position deviation in each coordinate axis direction of each probe. Based on a simple and direct error correction logic, the predicted position deviation represents the deviation between the actual position of the probe and the ideal position. Taking the opposite value can initially offset this deviation and allow the probe to move closer to the ideal position, laying the foundation for subsequent more precise adjustments and improving the initial accuracy of probe positioning.

[0080] For probes with a mapping relationship based on position proximity and a predicted position deviation within a set range, the probe with the predicted position deviation is used as the reference probe, and the coordinates of the reference probe are used as a benchmark to calculate the opposite 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; adjacent probes may be affected by similar external factors and have a certain correlation with each other. 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] The supplementary compensation vector components are weightedly summed with the components on the corresponding axes of the preliminary deviation compensation vector to obtain the final compensation vector components of the probe on the corresponding axes, thereby obtaining the final deviation compensation vector of the probe; the weighted summation method can flexibly balance the effects of preliminary compensation and supplementary compensation, and reasonably allocate the weights of the two according to actual conditions, thereby achieving more accurate error compensation and further improving 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 -5 as the supplementary compensation vector component. 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), and the weighting coefficient of the supplementary compensation vector component is set to 0.6, and the weighting coefficient of the preliminary deviation compensation vector component is set to 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 , the final deviation compensation vector of probe B is .

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

[0084] It should be noted that, in a specific embodiment, assuming that probe A, probe B and probe C have a mapping relationship based on motion correlation, we set the set threshold of the deviation change to ±5 microns. After monitoring, it is found that the predicted position deviation change of probe A is 3 microns in the X-axis direction, -2 microns in the Y-axis direction, and 1 micron in the Z-axis direction. The predicted position deviation change of probe B is 4 microns in the X-axis direction, -1 micron in the Y-axis direction, and 2 microns in the Z-axis direction. The predicted position deviation change of probe C is 8 microns in the X-axis direction, -6 microns in the Y-axis direction, and 7 microns in the Z-axis direction. Since the deviation change of probe C is greater than the set threshold in each axis direction, and the deviation change of probe A and probe B is 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, and 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, so the adjustment vector is (4.5, -4.5, 5.5).

[0086] The initial deviation compensation vector of probe C is (−5, −4, −3). The weight coefficient of the adjustment vector is set to 0.7, and the weight coefficient of the initial deviation compensation vector component is set to 0.4. The final compensation vector component in the X-axis direction is calculated as follows: , in the Y-axis direction: , in the Z-axis direction: , the final deviation compensation vector of probe C is .

[0087] The probe station correction module is used to set restriction conditions, generate control instructions in combination with deviation compensation vectors, and dynamically correct the movement of the probe station.

[0088] The specific operation method for setting the restriction conditions is: setting a fixed sampling time interval, calculating the expected speed of each probe in the direction of each coordinate axis according to the deviation compensation vector of each probe and the sampling time interval, and calculating the acceleration change required for each probe to reach the expected speed according to the speed of each probe at the previous moment; by combining the deviation compensation vector, ensuring that the probe moves at an appropriate speed in the direction of eliminating the deviation, so that the probe can approach the target position more accurately, thereby improving the accuracy of motion control.

[0089] It should be noted that, in a specific embodiment, the deviation compensation vector of the 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. The sampling interval is set to , calculate the expected speed in each coordinate axis direction by the formula: On the x-axis: , on the y-axis: , on the z-axis: ,in They are the deviation compensation vectors of the probe on the x, y, and z axes, respectively, and then the acceleration change required to achieve the desired speed in each coordinate axis direction is calculated: On the x-axis: , on the y-axis: , on the z-axis: , Represent the initial velocity of the probe in the x, y, and z axes respectively.

[0090] The maximum speed and maximum acceleration are limited. If the calculated expected speed exceeds the set maximum speed, the expected speed is limited to the maximum speed. If the calculated acceleration change exceeds the set maximum acceleration, the acceleration change is limited to the maximum acceleration. Limiting the maximum speed and maximum acceleration can effectively protect the probe station equipment. If the expected speed or acceleration change exceeds the range that the equipment can withstand, it may cause damage to mechanical components or system failure. Through limitation, damage to the equipment caused by 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 correction module is: determine the movement direction of each probe in the direction of each coordinate axis according to the positive or negative deviation compensation vector of each probe, and generate a control instruction for controlling the movement of the wafer probe station according to the size of the deviation compensation vector and the expected speed and acceleration changes after limit adjustment; the control instruction provides clear guidance for the motion control of the probe station, so that the control instruction can accurately drive the probe to move in the correct direction, avoid errors in the direction of movement, and improve the accuracy of motion control.

[0092] The movement of the probe station is corrected according to the instruction information parsed from the control instruction, and during the movement of the probe station, the movement of the probe station is dynamically corrected by repeating the process of deviation compensation vector calculation and control instruction generation until each probe accurately reaches the target position; the dynamic correction mechanism can monitor the movement state of the probe in real time, and adjust the control instruction in time according to the actual situation, to ensure that the probe can overcome various interference factors and accurately reach the target position, thereby greatly improving the positioning accuracy of the probe station and the reliability of the system.

[0093] The management database 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 value of the linear regression model.

[0094] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention and they are still 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: 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; A mapping relationship table construction module, used to construct a mapping relationship between probes based on the actual position coordinates of each probe at each time point; A 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; The deviation compensation acquisition module is used 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 the probes; The probe station correction module is used to set the restriction conditions, generate control instructions in combination with the deviation compensation vector, and dynamically correct the motion of the probe station; The management database 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 value of the linear regression model.

2. According to claim 1, a real-time error compensation control system for a wafer probe station based on multi-sensor fusion, characterized in that: The specific analysis method of the probe displacement detection module is: Obtain the initial position information of each probe of the wafer probe station in the global coordinate system, collect the image sequence of each probe movement according to the set frame rate, take two adjacent frames of images as a group, and obtain the motion vector of each pixel in each group of images through the optical flow algorithm; The position of each probe in the image is determined by image threshold segmentation technology, the optical flow vector in each probe area is extracted, and the optical flow vector in each probe area is converted into a motion trajectory in the actual space to obtain the actual position coordinates of each probe at each time point.

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

4. According to claim 3, a real-time error compensation control system for a wafer probe station based on multi-sensor fusion is characterized in that: The mapping relationship table construction module also includes: S1. Assigning a unique first probe identifier to each probe, thereby establishing a first mapping relationship between four first probe identifiers and four probes in a one-to-one correspondence, wherein the first probe identifier is used to identify an identification chip on a corresponding probe; S2. Receive a second mapping relationship sent by a second control module of the wafer to be tested, wherein the second control module is used to manage the measurement points on the wafer to be tested, the second mapping relationship is used to indicate the correspondence between the second probe and the second probe identifier, the second probe is a probe corresponding to the measurement point on the wafer to be tested, and the four first probe identifiers include the second probe identifier; S3. Determine a third mapping relationship according to the first mapping relationship and the second mapping relationship, wherein the third mapping relationship is used to indicate a corresponding relationship between each third probe and the second probe in a measurement channel in which four probes communicate with the wafer to be measured, wherein each second probe corresponds to a measurement point on the wafer to be measured, and a connection combination of each measurement point and the corresponding third probe is determined according to measurement requirements to form the measurement channel; S4. Construct a mapping relationship table B according to the third mapping relationship, wherein 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 point.

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

6. According to claim 5, a wafer probe station real-time error compensation control system based on multi-sensor fusion is characterized in that: The specific construction method of the linear regression model is: Extract the position deviation component of each probe in the direction of each coordinate axis at each time point, take the time point as the independent variable, and the component of the position deviation vector on each axis as the dependent variable data, and establish a multivariate linear regression model for each probe in the direction of each coordinate axis; Fit the 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. The real-time error compensation control system for a wafer probe station based on multi-sensor fusion according to claim 6, characterized in that: The specific analysis method of the final deviation compensation vector of the probe is: Taking the inverse 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, 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, the probe with the predicted position deviation is used as a reference probe, and the coordinates of the reference probe are used as a reference to calculate the opposite 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; The supplementary compensation vector component and the component on the corresponding axis of the preliminary deviation compensation vector are weightedly summed to obtain the final compensation vector component of the probe on the corresponding axis, thereby obtaining the final deviation compensation vector of the probe.

8. The 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 final deviation compensation vector of the probe also includes: For the probe group with a motion correlation mapping relationship, monitor the change of the predicted position deviation of each probe, screen 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 vector of the reference probe group on each coordinate 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 coordinate axis, thereby determining the adjustment vector, and perform weighted calculation on the adjustment vector and the preliminary deviation compensation vector to obtain the final deviation compensation vector of the probe.

9. The 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 operation method of setting the restriction conditions is as follows: A fixed sampling time interval is set, and the expected speed of each probe in the direction of each coordinate axis is calculated according to the deviation compensation vector of each probe and the sampling time interval, and the acceleration change required for each probe to reach the expected speed is calculated according to the speed of each probe at the previous moment; The maximum speed and maximum acceleration are limited. If the calculated expected speed exceeds the set maximum speed, the expected speed is limited to the maximum speed. If the calculated acceleration change exceeds the set maximum acceleration, the acceleration change is limited to the maximum acceleration.

10. The real-time error compensation control system for a wafer probe station based on multi-sensor fusion according to claim 9, characterized in that: The specific analysis method of the probe station calibration module is: Determine the movement direction of each probe in the direction of each coordinate axis according to the positive or negative sign of the deviation compensation vector of each probe, and generate a control instruction for controlling the movement of the wafer probe station according to the size of the deviation compensation vector and the expected speed and acceleration changes after limit adjustment; The motion of the probe station is corrected according to the instruction information parsed from the control instruction, and during the motion of the probe station, the motion of the probe station is dynamically corrected by repeating the process of calculating the deviation compensation vector and generating the control instruction until each probe reaches the target position accurately.

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