Semiconductor wafer pick-and-place device and pick-and-place method

Abstract

The invention provides a semiconductor wafer pick-and-place device and a pick-and-place method, and belongs to the technical field of semiconductor pick-and-place, and the device comprises a laser detection module which is used for scanning a pick-and-place port and a related area in an FOUP where a wafer is located based on a three-dimensional laser irradiator; the adjustment analysis module is used for carrying out unit length cutting in the central axis direction of the taking and placing piece routing path, analyzing each cutting unit and determining whether the fingertip span needs to be adjusted or not; the action adjusting module is used for determining a safe pick-and-place starting position according to the wafer deformation condition, controlling a fingertip to execute pick-and-place actions according to a pick-and-place piece routing path, monitoring the pick-and-place actions executed by the fingertip in real time, adjusting the pick-and-place actions if the position and shape of the wafer are changed, and controlling the rhythm of lifting the wafer by the fingertip in combination with the distance difference of supporting points; and the verification module is used for controlling the laser detection module to perform scanning verification again after taking and placing are completed. And the wafer taking and placing yield is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor pick - and - place, and particularly to a semiconductor wafer pick - and - place device and a pick - and - place method. Background Art

[0002] In the semiconductor wafer production process, wafer pick - and - place is a key link. The current pick - and - place devices have significant defects: on the one hand, the design of the opening size of the fingertips of the pick - and - place device is unreasonable. If the opening is too small, it is easy for the wafer edge to sag and contact the pick - and - place component (fingertip). When the size is increased to an appropriate size (such as 200mm), due to the path limitation of the robot (Robot), it is easy to hit the wafer transfer cassette (FOUP) during pick - and - place. On the other hand, during the pick - and - place process, problems such as the fingertips entering from the place where the wafer has the largest deformation and the difference in the distance of the support points will cause a collision risk. Existing devices and methods are difficult to effectively solve these problems, and innovative designs are urgently needed to optimize the wafer pick - and - place process and ensure production safety and efficiency.

[0003] Therefore, the present invention proposes a semiconductor wafer pick - and - place device and a pick - and - place method. Summary of the Invention

[0004] The present invention provides a semiconductor wafer pick - and - place device and a pick - and - place method to solve the above - mentioned technical problems.

[0005] The present invention provides a semiconductor wafer pick - and - place device, including: A laser detection module, which is used to perform three - dimensional laser scanning on the pick - and - place port and relevant areas inside the FOUP where the wafer is located based on a three - dimensional laser irradiator, and pre - process the detection data to reconstruct the pick - and - place structure model; A path planning module, which is used to plan the pick - and - place path of the wafer in combination with the pick - and - place structure model, wafer, and FOUP parameters; An adjustment analysis module, which is used to perform unit - length cutting along the central axis direction of the pick - and - place path of the wafer, analyze each cutting unit to determine whether it is necessary to adjust the fingertip span, and if necessary, drive the fingertip assembly to adjust to the ideal span; An action adjustment module, which is used to determine the safe pick - and - place starting position according to the wafer deformation situation, control the fingertips to perform pick - and - place actions according to the pick - and - place path of the wafer, monitor the pick - and - place actions of the fingertips in real - time. If there are changes in the position and shape of the wafer, adjust the pick - and - place actions, and control the rhythm of the fingertips to lift the wafer in combination with the difference in the distance of the support points; A verification module, which is used to control the laser detection module to perform a second scan after pick - and - place is completed, verify the placement state of the wafer and store the pick - and - place process data for subsequent process optimization and device parameter adjustment; Among them, during the wafer manufacturing process, it includes: a crystal boat support structure and a fingertip structure; The wafer boat support structure is developed and designed based on a set platform, which is compatible with the standard wafer boat installation holes, and the lifting teeth on both sides of the wafer boat adopt a circular arc long tooth structure; At the same time, the length of rod-1 and rod-3 supports is increased based on the standard crystal boat structure; The fingertip structure adopts a 4-point lifting structure, combined with an arc fork finger shape, and increases the span of the fingertips to at least 200 mm.

[0006] Preferably, the laser detection module includes: An initial construction unit, configured to construct original laser coordinates and map detection data to the original laser coordinates to obtain an initial structure; A first interference unit is configured to perform three-dimensional substructure decomposition on the initial structure, obtain point cloud data of each three-dimensional substructure, and calculate an interference coefficient of each position point to construct an interference set; an interference cancellation unit, configured to perform interference cancellation processing based on the interference set to obtain a first structure; a distance difference construction unit, configured to respectively obtain a two-dimensional array of edge positions of each connecting line on the three-dimensional substructure, and perform distance difference construction on the two-dimensional array of edge positions to obtain a distance difference vector; The second interference unit is used to calculate the fitting value of each distance difference vector to obtain a reference set of each three-dimensional substructure; An adjustment unit is configured to modify the interference set based on the reference set to determine an adjustment position point, and adjust the first structure to obtain a second structure, wherein the second structure is a pick-and-place structure model.

[0007] Preferably, the adjustment analysis module includes: The extraction unit is used to extract the central axis L of the pick-and-place routing path, establish a path coordinate system, and perform unit length calculation along the direction of the central axis L. Cutting to form n cutting units Ci, where i=1,2,…,n; Constraint establishment unit, used to establish the spatial constraint equation for each cutting unit Ci :

[0008] in, Represents the three-dimensional space area corresponding to the cutting unit Ci; , Represents the boundary constraint values based on the y-axis and z-axis respectively; Represents the constraint value of the x-axis of the cutting unit Ci; Represents spatial coordinates; Function definition unit, used to define the spatial fitness function:

[0009] Among them, 、 、 are weight coefficients; represents the safety distance between the fingertip span d and the spatial boundary; represents the support stability function, which is related to the distance between support points and the distribution of the wafer centroid; represents the deformation influence function, considering the inhibitory effect of the span on the wafer deformation; Span solving unit, used to solve the optimal span d_i* for each cutting unit Ci: d_i* = argmax Fi, dmin < d_i* < dmax where dmin and dmax are the span ranges limited by the device physics; Function establishment unit, used to establish the span adjustment cost function:

[0010] Among them, is the span change cost coefficient; is the time cost coefficient; is the actual span value of the cutting unit Ci; is the time spent on span adjustment; Sequence solving unit, used to solve the global optimal span sequence by using the dynamic programming algorithm: .

[0011] Preferably, the motion adjustment module includes: Starting position determination unit, used to obtain the three-dimensional topography of the wafer to construct a deformation model, calculate the deformation amount of each region, and select the region with the smallest deformation amount as the safe pick-and-place starting position; Threshold establishment unit, used to establish the safety threshold function: , where is the warpage; is the curvature; 、 are weight coefficients; Trajectory generation unit, used to plan the pick-and-place path according to the safe starting position and the safety threshold function, and generate the optimal trajectory curve .

[0012] Preferably, the motion adjustment module further includes: Support point optimization unit, used to analyze the distance difference of support points and establish a mechanical balance model: , where represents the support force receiving point i; G is the gravity of the wafer; is the uida stress; is the penalty coefficient; n represents the total number of support point symbols; An adaptive adjustment unit for real-time monitoring through multi-sensor fusion during the picking and placing process to construct an adaptive control algorithm: , where is the error vector, and are the wafer position offset, the form change amount, and the force distribution of the support points respectively; 、 、 are the PID parameter matrices; A control unit for controlling the lifting rhythm of the fingertips according to the difference in the distance of the support points and the real-time force conditions.

[0013] Preferably, the control unit includes: A rhythm generation unit for online optimizing the stage target force of the piecewise function based on reinforcement learning and the time constant , and generating the lifting rhythm Ft of the fingertips;

[0014] where t represents the time point during the picking and placing process of the fingertips; k0 represents the k0th segment.

[0015] Preferably, it further includes: An order determination unit for deciding the force application order of the support points through the distance-force collaborative priority function Pj:

[0016] where j is the support point number; 、 are the dynamic weights; is the distance difference between the jth support point and other support points; is the maximum value among all the support point distance differences; is the force deviation of the jth support point; is the maximum value of the force deviations of all the support points; A dynamic optimization unit for real-time feedback correction and dynamically optimizing the force control parameters to suppress the deformation of the wafer.

[0017] The present invention provides a semiconductor wafer picking and placing method, including: Step 1: Perform three-dimensional laser scanning on the picking and placing port and the relevant areas inside the FOUP where the wafer is located based on a three-dimensional laser irradiator, and preprocess the detection data to reconstruct the picking and placing structure model; Step 2: Plan the picking and placing path in combination with the picking and placing structure model, the wafer, and the FOUP parameters; Step 3: Perform unit length cutting along the central axis of the pick-and-place routing path, and analyze each cutting unit to determine whether the fingertip span needs to be adjusted. If necessary, drive the fingertip assembly to adjust to the ideal span; Step 4: Determine the safe pick-and-place starting position based on the wafer deformation, and control the fingertips to perform the pick-and-place action according to the pick-and-place routing path. Monitor the fingertips' pick-and-place action in real time. If there are changes in the wafer position or shape, adjust the pick-and-place action, and control the rhythm of the fingertips lifting the wafer based on the difference in the support point distance. Step 5: After the placement is completed, the laser detection module is controlled to scan again to verify the wafer placement status and store the placement process data for subsequent process optimization and device parameter adjustment; Among them, the wafer manufacturing process includes: wafer boat support structure and fingertip structure; The wafer boat support structure is developed and designed based on a set platform, which is compatible with the standard wafer boat installation holes, and the lifting teeth on both sides of the wafer boat adopt a circular arc long tooth structure; At the same time, the length of rod-1 and rod-3 supports is increased based on the standard crystal boat structure; The fingertip structure adopts a 4-point lifting structure, combined with an arc fork finger shape, and increases the span of the fingertips to at least 200 mm.

[0018] Preferably, step 1 comprises: Constructing laser original coordinates and mapping detection data to the laser original coordinates to obtain an initial structure; Decomposing the initial structure into three-dimensional substructures to obtain point cloud data of each three-dimensional substructure, and calculating the interference coefficient of each position point to construct an interference set; performing interference cancellation processing based on the interference set to obtain a first structure; Obtain a two-dimensional array of edge positions of each connecting line on the three-dimensional substructure, and construct a distance difference between the two-dimensional arrays of edge positions to obtain a distance difference vector; Calculate the fitting value of each distance difference vector to obtain a reference set of each three-dimensional substructure; The interference set is modified based on the reference set to determine an adjustment position point, and the first structure is adjusted to obtain a second structure, wherein the second structure is a pick-and-place structure model.

[0019] Preferably, step 2 includes: Extract the central axis L of the pick-and-place routing path, establish a path coordinate system, and perform unit length along the direction of the central axis L. Cutting to form n cutting units Ci, where i=1,2,…,n; For each cutting unit Ci, establish the spatial constraint equation :

[0020] Among them, represents the three-dimensional space region corresponding to the cutting unit Ci; , respectively represent the boundary constraint values based on the y-axis and z-axis; represents the constraint value of the x-axis of the cutting unit Ci; represents the space coordinate; Define the space fitness function:

[0021] Among them, , , are weight coefficients; represents the safety distance between the fingertip span d and the space boundary; represents the support stability function, which is related to the distance between support points and the distribution of the wafer center of gravity; represents the deformation influence function, considering the inhibitory effect of the span on the wafer deformation; For each cutting unit Ci, solve the optimal span d_i*: d_i* = argmax Fi, dmin < d_i* < dmax where dmin and dmax are the span ranges limited by the device physics; Establish the span adjustment cost function:

[0022] Among them, is the span change cost coefficient; is the time cost coefficient; is the actual span value of the cutting unit Ci; is the time spent on span adjustment; Use the dynamic programming algorithm to solve the global optimal span sequence: .

[0023] Compared with the prior art, the beneficial effects of this application are as follows: Starting from accurately constructing the pick-and-place structure model with three-dimensional laser, planning a reasonable pick-and-place path, dynamically adjusting the fingertip span, real-time monitoring and adjusting the pick-and-place actions, and finally verifying and accumulating data for optimization. It can make the pick-and-place process of semiconductor wafers more accurate and stable, reduce problems such as collisions and deformations, improve the yield of wafer pick-and-place, and can also continuously optimize the overall process and equipment of semiconductor manufacturing through data accumulation, improving the efficiency and quality of the entire semiconductor production.

[0024] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0025] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0026] The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description. They are used in conjunction with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings: Figure 1 is a structural diagram of a semiconductor wafer pick-and-place device in an embodiment of the present invention; Figure 2 is a flowchart of a semiconductor wafer pick-and-place method in an embodiment of the present invention; Figure 3 is a pick-and-place structural diagram in an embodiment of the present invention; Figure 4 is a measured laser structural diagram in an embodiment of the present invention; Figure 5 is a fingertip lifting diagram in an embodiment of the present invention; Figure 6 is a top view comparison diagram of the front-end sag of the wafer caused by gravity in an embodiment of the present invention; Figure 7 is an embodiment diagram of an arc long-tooth crystal boat in the present invention; Figure 8 is another embodiment diagram of an arc long-tooth crystal boat in the present invention. Detailed Embodiments

[0027] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not intended to limit the present invention.

[0028] The present invention provides a semiconductor wafer pick-and-place device, as Figure 1 shown, including: A laser detection module, configured to perform three-dimensional laser scanning on the pick-and-place port and relevant regions inside the FOUP where the wafer is located based on a three-dimensional laser irradiator, and preprocess the detection data to reconstruct a pick-and-place structure model; A path planning module, configured to plan a pick-and-place path in combination with the pick-and-place structure model, wafer, and FOUP parameters; An adjustment analysis module is used to perform unit-length cutting along the central axis direction of the pick-and-place path, analyze each cutting unit to determine whether the fingertip span needs to be adjusted, and if so, drive the fingertip assembly to adjust to the ideal span; An action adjustment module is used to determine the safe pick-and-place starting position according to the deformation of the wafer, control the fingertips to perform pick-and-place actions along the pick-and-place path, monitor the pick-and-place actions of the fingertips in real time, adjust the pick-and-place actions if there are changes in the position and shape of the wafer, and control the rhythm of the fingertips to lift the wafer in combination with the difference in the distance of the support points; A verification module is used to control the laser detection module to perform a second scan after pick-and-place is completed, verify the placement state of the wafer and store the pick-and-place process data for subsequent process optimization and device parameter adjustment.

[0029] Preferably, the laser detection module includes: An initial construction unit is used to construct the laser original coordinates and map the detection data to the laser original coordinates to obtain an initial structure; A first interference unit is used to split the initial structure into three-dimensional sub-structures, obtain the point cloud data of each three-dimensional sub-structure, and calculate the interference coefficient of each position point to construct an interference set; An interference elimination unit is used to perform interference elimination processing depending on the interference set to obtain a first structure; A distance difference construction unit is used to respectively form a two-dimensional array of the edge positions of each connecting line on the three-dimensional sub-structure, and construct a distance difference for the two-dimensional array of the edge positions to obtain a distance difference vector; A second interference unit is used to calculate the fitting value of each distance difference vector to obtain a reference set of each three-dimensional sub-structure; An adjustment unit is used to correct the interference set depending on the reference set to determine the adjustment position points, and adjust the first structure to obtain a second structure, where the second structure is a pick-and-place structure model; Among them, during the wafer manufacturing process, there are: a wafer boat support structure and a fingertip structure; The wafer boat support structure is developed and designed based on a set platform, is compatible with the standard wafer boat mounting holes, and the lifting teeth on both sides of the wafer boat adopt an arc long tooth structure, as Figure 7 and 8 shown.

[0030] At the same time, based on the standard wafer boat structure, the lengths of the rod-1 and rod-3 supports are increased; The fingertip structure adopts a 4-point lifting structure, cooperates with an arc-shaped interdigitated shape, and increases the span of the fingertips to at least 200 mm.

[0031] Preferably, the adjustment analysis module includes: An extraction unit for extracting the central axis L of the pick-and-place path, establishing a path coordinate system, and performing unit length cutting along the direction of the central axis L to form n cutting units Ci, where i = 1, 2,..., n; A constraint establishment unit for establishing a spatial constraint equation for each cutting unit Ci: where represents the three-dimensional space region corresponding to the cutting unit Ci; :

[0032] where, represent the boundary constraint values based on the y-axis and z-axis respectively; , represents the constraint value of the x-axis of the cutting unit Ci; represents the spatial coordinate; A function definition unit for defining a spatial fitness function: where,

[0033] where, , , are weight coefficients; represents the safety distance between the fingertip span d and the spatial boundary; represents a support stability function related to the support point spacing and the wafer center of gravity distribution; represents a deformation influence function considering the inhibitory effect of the span on wafer deformation; A span solving unit for solving the optimal span d_i* for each cutting unit Ci: d_i* = argmax Fi, dmin < d_i* < dmax where dmin and dmax are the span ranges limited by the device physics; A function establishment unit for establishing a span adjustment cost function:

[0034] where, is the span change cost coefficient; is the time cost coefficient; is the actual span value of the cutting unit Ci; is the time spent on span adjustment; A sequence solving unit for solving the global optimal span sequence using the dynamic programming algorithm: .

[0035] Preferably, the motion adjustment module includes: The starting position determination unit is used to obtain the deformation model of the three-dimensional topography of the wafer, calculate the deformation amounts of each region, and select the region with the smallest deformation amount as the safe pick-and-place starting position; The threshold establishment unit is used to establish a safety threshold function: , where is the warpage; is the curvature; , are the weight coefficients; The trajectory generation unit is used to plan the pick-and-place path according to the safe starting position and the safety threshold function, and generate the optimal trajectory curve .

[0036] Preferably, the motion adjustment module further includes: The support point optimization unit is used to analyze the distance difference of the support points and establish a mechanical equilibrium model: , where represents the support force receiving point i; G is the gravity of the wafer; is the uida stress; is the penalty coefficient; n represents the total number of support force point symbols; The adaptive adjustment unit is used to construct an adaptive control algorithm through multi-sensor fusion real-time monitoring during the pick-and-place process: , where is the error vector, and are respectively the wafer position offset, the shape change amount, and the support point force distribution; , , are the PID parameter matrices; The control unit is used to control the lifting rhythm of the fingertips according to the support point distance difference and the real-time force condition.

[0037] Preferably, the control unit includes: The rhythm generation unit is used to online optimize the stage target force and the time constant of the piecewise function based on reinforcement learning, and generate the lifting rhythm Ft of the fingertips;

[0038] where t represents the time point of the fingertips during the pick-and-place process; k0 represents the k0th segment.

[0039] Preferably, it further includes: The sequence determination unit is used to decide the force application sequence of the support points through the distance-force coordination priority function Pj:

[0040] Among them, j is the support point number; , are dynamic weights; is the distance difference between the j-th support point and other support points; is the maximum value among all the distance differences of the support points; is the force deviation of the j-th support point; is the maximum value of the force deviations of all support points; The dynamic optimization unit is used for real-time feedback correction and dynamically optimizes the force control parameters to suppress the deformation of the wafer.

[0041] In this embodiment, the boat can be represented by Boat, and the finger can be represented by Finger.

[0042] In this embodiment, the lifting teeth on both sides of the boat adopt an arc long tooth structure, which can completely eliminate the contact friction with the wafer backside alloy compared with the support teeth of the ordinary boat.

[0043] Droop suppression effect: This structure can reduce the front-end droop of the Taiko wafer caused by gravity by about 50%. For example, when the front-end droop of the wafer caused by the ordinary boat is 11.88 mm, the boat with the arc long tooth structure can reduce the droop to about 6.89 mm, as Figure 6 shown.

[0044] By optimizing the support structure, the wafer loading capacity of the wafer boat is increased by about 25% compared with the standard boat design. The specific data is as follows: When the wafer warpage is 2.5 mm, the wafer loading capacity of the standard boat is 100 pieces, and the wafer loading capacity of the special boat can reach 125 pieces.

[0045] When the wafer warpage is 4 mm, the wafer loading capacity of the standard boat is 78 pieces, and the wafer loading capacity of the special boat can reach 100 pieces.

[0046] When the wafer warpage is 6 mm, the wafer loading capacity of the standard boat is 65 pieces, and the wafer loading capacity of the special boat can reach 85 pieces.

[0047] When the wafer warpage is 8 mm, the wafer loading capacity of the standard boat is 50 pieces, and the wafer loading capacity of the special boat can reach 65 pieces.

[0048] The existing boat cannot meet the support requirements of the Taiko wafer, and the Pitch value needs to be increased to about 15 mm to adapt to the deformation situation and support requirements of the wafer.

[0049] In this embodiment, the newly designed finger adopts a 4-point lifting structure, combined with an arc finger shape, so that the wafer contacts the finger only at 4 points on the ring, reducing the damage to the wafer surface.

[0050] Span Design: To solve the problem that the opening of the fingertips is too small during wafer picking, causing the wafer edge to sag and contact the fingertips, the span of the fingertips is increased to at least about 200 mm to adapt to the size and deformation of Taiko wafers.

[0051] Regarding the potential collision risk when the fingertips enter the FOUP from the location with the largest wafer deformation during wafer pick-up and placement, optimize the position and path of the fingertips entering the FOUP to avoid entering from the location with the largest deformation.

[0052] Support Point Distance Adjustment: Considering the problem of asynchronous wafer lifting caused by differences in the support point distance during wafer picking, through optimizing the motion control of the fingertips, ensure the wafer is lifted smoothly and reduce the collision risk. For example, Figure 5 as shown, the pitch size > the front-end sag + the wafer lift amount, where Wafer represents the wafer.

[0053] The design of the boat support structure and the Wafer fingertip structure in wafer manufacturing effectively solves problems such as deformation, damage, and collision of Taiko wafers during support and pick-up / placement by optimizing the support point distribution, adopting an arc long-tooth structure, increasing the support length, adjusting the fingertip span, and optimizing the pick-up / placement path, improving the yield and production efficiency of wafer manufacturing. At the same time, the design of the boat structure also realizes an increase in the wafer loading capacity and reduces the production cost.

[0054] In this embodiment, for the laser measurement structure as Figure 4 shown, for the pick-up / placement structure as Figure 3 shown, where A01 represents that the opening of the fingertip part is too small, part A02 represents contact with the Finger, and A03 represents a sag of 5.1 mm here.

[0055] In this embodiment, the three-dimensional laser irradiator is a device that can emit laser light and receive reflected light to construct three-dimensional spatial information. For example, in the semiconductor wafer pick-up / placement scenario, it is like "taking pictures" of the inside of the FOUP and the pick-up / placement port area, but obtaining three-dimensional data in a laser way. Like common industrial three-dimensional laser scanners, they can accurately scan the three-dimensional contour of an object.

[0056] FOUP (Front Opening Unified Pod) is a wafer transfer cassette, a container used to store and transfer wafers in semiconductor manufacturing. For example, it can be like a "protective box" that safely transfers wafers from one process to the next, with a specific structure inside to support the wafers and prevent them from being damaged during transfer.

[0057] The pick-and-place structure model is a virtual model obtained by processing the three-dimensional data of the inside of the FOUP, the pick-and-place opening, and related areas scanned, and is used to simulate the pick-and-place environment and actions. For example, it is like building a "digital twin" scene exactly the same as the actual pick-and-place scenario, and subsequent pick-and-place path planning and the like can be simulated in this model.

[0058] The laser original coordinate is the coordinate system established by the three-dimensional laser irradiator itself and serves as the basic reference for detecting data. Just like we draw a coordinate system on paper, the data obtained by laser scanning are all "placed" in this coordinate system to record positions. For example, the coordinates of a certain point scanned are (x = 10mm, y = 20mm, z = 30mm) in this coordinate system.

[0059] The initial structure is the preliminary three-dimensional structure obtained after mapping the detection data to the laser original coordinate.

[0060] The three-dimensional sub-structure is the small three-dimensional part obtained after splitting the initial structure. For example, splitting the three-dimensional model of the inside structure of the FOUP into parts such as the rack for supporting the wafer and the box body, and each part is a three-dimensional sub-structure, which is convenient for separate analysis and processing.

[0061] The point cloud data is the set of coordinates of a large number of points after three-dimensional laser scanning, and these points form information such as the contour of the object. For example, when scanning a sphere, the point cloud data is the coordinates of the densely packed points on the surface of the sphere, and the shape of the sphere can be restored through these points.

[0062] The interference coefficient is a value that measures the degree of interference (such as noise, abnormal reflection, etc.) of each position point in the three-dimensional sub-structure. For example, during scanning, some dust reflects the laser, resulting in inaccurate data for the corresponding point, and the interference coefficient of this point is high, which is used to mark that this point may be unreliable.

[0063] The interference set is the set of relevant interference information such as the interference coefficients of all position points, which marks the points that may have problems.

[0064] The first structure is the three-dimensional structure after eliminating interference, which is closer to the real situation than the initial structure, but there may still be deficiencies and needs further correction.

[0065] The connection line is the line at the connection part between three-dimensional sub-structures. For example, at the connection place between the split support rack and the box body, there is a virtual connection line to represent their connection relationship.

[0066] The two-dimensional array of edge positions is the coordinate array that records the edge positions of the connection line in the two-dimensional plane (which can be projected based on three-dimensional coordinates). For example, projecting the connection line onto a certain plane (such as the x-y plane) and recording the x and y coordinates of the edge points to form an array, which is convenient for analyzing the situation at the connection.

[0067] The distance difference vector is a vector obtained by calculating the distance differences of the data in the two-dimensional array of edge positions, which reflects the distance change at the joint. For example, for the points on both sides of the joint line, calculate their distance differences in a certain direction and form a vector from these differences to see whether the joint is smooth or not.

[0068] The fitted value is a value obtained by mathematically fitting the distance difference vector (such as linear fitting, curve fitting, etc.), which is used to evaluate the law of the distance difference. For example, if the data of the distance difference vector roughly conforms to a straight line, the fitted value is the relevant parameters of this straight line, such as the slope, intercept, etc., which can be used to judge whether the joint is normal.

[0069] The reference set is a set composed of information such as the fitted values of each three-dimensional sub-structure, which serves as the basis for correcting the interference set.

[0070] The second structure (pick-and-place structure model): After correction and adjustment, it is a model that accurately reflects the structure of the pick-and-place scenario and is the basis for subsequent steps, which can more accurately simulate the actual pick-and-place environment.

[0071] In this embodiment, the routing path of the pick-and-place wafer is the movement route when picking and placing the wafer with the fingertips. For example, the route from the position of the wafer in the FOUP to the processing position where the wafer is placed in the equipment should be reasonably planned to avoid collisions, etc.

[0072] The central axis L is the central axis of the routing path of the pick-and-place wafer and is an important reference for path planning. The path is distributed around it. For example, if the routing path is a space similar to a pipe, the central axis is the central line of the pipe.

[0073] The path coordinate system is a coordinate system established for planning the routing path of the pick-and-place wafer, which is convenient for describing information such as the position of the path. Similar to the coordinate system of a map, by placing the path in this coordinate system, the movement of the fingertips can be planned using coordinate values.

[0074] The cutting unit Ci is a small unit obtained by dividing the path along the direction of the central axis L. For example, divide a long path, like cutting a sausage, into small segments, and each segment is a cutting unit, which is convenient for analyzing one by one.

[0075] The space constraint equation is an equation that describes the restrictions on the three-dimensional space region where the cutting unit Ci is located. For example, when the cutting unit is in space, there are ranges in the x, y, and z directions, and this equation stipulates these ranges.

[0076] The space fitness function is a function that comprehensively considers factors such as safety distance, support stability, and deformation suppression to evaluate whether parameters such as the fingertip span are appropriate. It is like an "examiner" that scores different span schemes, and the one with a higher score is more appropriate.

[0077] The weight coefficient is a coefficient used to adjust the importance of factors such as safety distance, support stability, and deformation suppression in the evaluation. For example, when taking an ultra-thin wafer, more importance may be attached to deformation suppression, so it is adjusted upwards.

[0078] The safety distance is the distance between the fingertip span d and the spatial boundary (such as the inner wall of the FOUP, etc.), ensuring that the fingertips do not collide during movement. For example, if the safety distance is required to be at least 2 mm, it means that the distance between the fingertips and the surrounding boundary must be greater than or equal to 2 mm.

[0079] The support stability function is related to the distance between the support points (the distance between the points where the fingertips support the wafer) and the distribution of the wafer's center of gravity, and is a function for evaluating whether the support is stable. For example, if the distance between the support points is reasonable and the wafer's center of gravity is in a suitable position, the value of this function is high and the support is stable.

[0080] The deformation influence function is a function that considers the influence of the span on the wafer deformation. If the span is appropriate, the wafer deformation can be suppressed, and the function value is good.

[0081] The optimal span d_i* is the fingertip span that can maximize the value of the space fitness function in each cutting unit Ci. That is, in this small unit, the most suitable fingertip span to ensure safe and stable picking and placing.

[0082] The span adjustment cost function is a function that measures the "cost" (such as time, mechanical loss, etc.) incurred when adjusting the fingertip span. For example, adjusting the span takes time, and the longer the time, the higher the cost. This function quantifies these costs.

[0083] The span change cost coefficient is a coefficient used to adjust the degree of influence of the span change magnitude on the cost. A large span change may result in a large mechanical loss, and this coefficient reflects this influence.

[0084] The time cost coefficient is a coefficient that adjusts the degree of influence of the time spent on adjusting the span on the cost. The longer the time, the higher the cost corresponding to this coefficient.

[0085] The global optimal span sequence is a set of optimal fingertip span adjustment sequences and values obtained by comprehensively considering the situations of each cutting unit through a dynamic programming algorithm.

[0086] In this embodiment, unit-length cutting is performed along the central axis direction of the pick-and-place path at a fixed small length (such as 5 mm), dividing the path into multiple small units. Just like using a ruler to make marks at fixed intervals to segment the path.

[0087] Cutting unit analysis is to analyze whether the fingertip span needs to be adjusted for each cut small unit. It depends on whether the current fingertip span in this small unit meets requirements such as spatial constraints and fitness, and decides whether to adjust.

[0088] The fingertip component is a part of the pick-and-place device that directly participates in picking and placing wafers and comes into contact with the wafers, and can adjust the span. It is like a human finger, but mechanical, capable of opening and closing to adjust the distance (span) to adapt to different situations.

[0089] The ideal span is the fingertip span that is most suitable for picking and placing wafers in a certain cutting unit after analysis, which can balance factors such as safety, stability, and efficiency.

[0090] In this embodiment, the deformation condition of the wafer refers to the change in the shape of the wafer during the picking and placing process, such as whether it is bent, warped, etc. For example, the wafer may bulge in the middle or sag at the edges due to its own stress, previous processing, etc.

[0091] The safe picking and placing starting position is a safe position to start picking and placing the wafer determined according to the deformation of the wafer. For example, if the edge of the wafer has a sag deformation, it cannot start from the most severely sagging place, but a position with less deformation and stable picking and placing should be found, such as the area with the least deformation as the starting position.

[0092] Real-time monitoring is to continuously monitor the changes in the position, shape, etc. of the wafer during the picking and placing operation of the fingertip. It is like installing a "real-time camera + sensor" during the picking and placing process to always monitor the situation of the wafer.

[0093] The difference in the distances of the support points refers to the different situations of the distances between multiple points where the fingertip supports the wafer. For example, if there are three support points and the distances between each pair are different, this difference will affect the support stability of the wafer and should be considered to control the lifting rhythm.

[0094] The rhythm of lifting the wafer is the pattern of force application, movement speed, etc. when the fingertip lifts the wafer. For example, some support points first slowly apply force to lift, and some later, with a sequence and rhythm of force application size to ensure the wafer is lifted smoothly.

[0095] In this embodiment, the placement state of the wafer refers to the state of the wafer at the target position after picking and placing, such as whether it is placed correctly, whether there is deviation, and whether the deformation changes, etc. For example, the wafer should be accurately placed on the chuck of the equipment without being crooked, which means a good placement state.

[0096] The data during the picking and placing process are various data recorded during the picking and placing process, such as the position of the fingertip, span, force application size, position change of the wafer, deformation data, etc. These data are like a "diary" recording the detailed situation of the picking and placing process.

[0097] Process optimization is to improve the overall semiconductor manufacturing process based on the data during the picking and placing process. For example, if it is found that the wafer is prone to deformation in a certain step during picking and placing, the previous processing process is adjusted to avoid this situation.

[0098] Device parameter adjustment involves adjusting the parameters of the pick-and-place device (such as the fingertip assembly and laser detection module) based on the data from the pick-and-place process. For example, if the data indicates that the span adjustment is not accurate enough, the parameters controlling the span in the device will be adjusted to ensure more accurate subsequent pick-and-place operations.

[0099] The beneficial effects of this technical solution include: starting with the precise construction of a pick-and-place structure model using 3D lasers, planning a reasonable pick-and-place path, dynamically adjusting fingertip span, real-time monitoring and adjustment of pick-and-place movements, and finally verifying and accumulating data for optimization. This makes the semiconductor wafer pick-and-place process more precise and stable, reducing problems such as collisions and deformation, and improving wafer pick-and-place yield. Data accumulation also allows for continuous optimization of the overall semiconductor manufacturing process and equipment, enhancing the efficiency and quality of overall semiconductor production.

[0100] The present invention provides a semiconductor wafer pick-and-place method, such as Figure 2 Shown, including: Step 1: Use a 3D laser illuminator to perform 3D laser scanning on the pick-and-place port and the relevant area inside the FOUP where the wafer is located, and pre-process the detection data to reconstruct the pick-and-place structure model; Step 2: Plan the pick-and-place routing path based on the pick-and-place structure model, wafer, and FOUP parameters; Step 3: Perform unit length cutting along the central axis of the pick-and-place routing path, and analyze each cutting unit to determine whether the fingertip span needs to be adjusted. If necessary, drive the fingertip assembly to adjust to the ideal span; Step 4: Determine the safe pick-and-place starting position based on the wafer deformation, and control the fingertips to perform the pick-and-place action according to the pick-and-place routing path. Monitor the fingertips' pick-and-place action in real time. If there are changes in the wafer position or shape, adjust the pick-and-place action, and control the rhythm of the fingertips lifting the wafer based on the difference in the support point distance. Step 5: After the placement is completed, the laser detection module is controlled to scan again to verify the wafer placement status and store the placement process data for subsequent process optimization and device parameter adjustment; Among them, the wafer manufacturing process includes: wafer boat support structure and fingertip structure; The wafer boat support structure is developed and designed based on a set platform, which is compatible with the standard wafer boat installation holes, and the lifting teeth on both sides of the wafer boat adopt a circular arc long tooth structure; At the same time, the length of rod-1 and rod-3 supports is increased based on the standard crystal boat structure; The fingertip structure adopts a 4-point lifting structure, combined with an arc fork shape, and increases the span of the fingertips to at least 200 mm.

[0101] Preferably, step 1 comprises: Constructing laser original coordinates and mapping detection data to the laser original coordinates to obtain an initial structure; Decomposing the initial structure into three-dimensional substructures to obtain point cloud data of each three-dimensional substructure, and calculating the interference coefficient of each position point to construct an interference set; performing interference cancellation processing based on the interference set to obtain a first structure; Obtain a two-dimensional array of edge positions of each connecting line on the three-dimensional substructure, and construct a distance difference between the two-dimensional arrays of edge positions to obtain a distance difference vector; Calculate the fitting value of each distance difference vector to obtain a reference set of each three-dimensional substructure; The interference set is modified based on the reference set to determine an adjustment position point, and the first structure is adjusted to obtain a second structure, wherein the second structure is a pick-and-place structure model.

[0102] Preferably, step 2 includes: Extract the central axis L of the pick-and-place routing path, establish a path coordinate system, and perform unit length calculations along the direction of the central axis L. Cutting to form n cutting units Ci, where i=1,2,…,n; For each cutting unit Ci, establish the spatial constraint equation :

[0103] in, Represents the three-dimensional space area corresponding to the cutting unit Ci; , Represents the boundary constraint values based on the y-axis and z-axis respectively; Represents the constraint value of the x-axis of the cutting unit Ci; Represents spatial coordinates; Define the spatial fitness function:

[0104] in, 、 、 is the weight coefficient; It represents the safe distance between the fingertip span d and the space boundary; represents the support stability function, which is related to the support point spacing and the center of gravity distribution of the wafer; represents the deformation influence function, considering the inhibitory effect of span on wafer deformation; For each cutting unit Ci, solve the optimal span d_i*: d_i*=argmaxFi,dmin <d_i*<dmax Among them, dmin and dmax are the span ranges physically limited by the device; Establish a span adjustment cost function:

[0105] Among them, is the span change cost coefficient; is the time cost coefficient; is the actual span value of the cutting unit Ci; is the time spent on span adjustment; Use the dynamic programming algorithm to solve the global optimal span sequence: .

[0106] The beneficial effects of the above technical solutions are as follows: Starting from accurately constructing the pick-and-place structure model with three-dimensional laser, planning a reasonable pick-and-place path, dynamically adjusting the fingertip span, real-time monitoring and adjusting the pick-and-place actions, and finally verifying and accumulating data for optimization. It can make the semiconductor wafer pick-and-place process more accurate and stable, reduce problems such as collisions and deformations, improve the yield of wafer pick-and-place, and can also continuously optimize the overall process and equipment of semiconductor manufacturing through data accumulation, improving the efficiency and quality of the entire semiconductor production.

[0107] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A semiconductor wafer pick-and-place device, characterized in that, include: The laser detection module is used to perform three-dimensional laser scanning of the pick-and-place port and the relevant area inside the FOUP where the wafer is located based on a three-dimensional laser illuminator, and pre-process the detection data to reconstruct the pick-and-place structure model; A path planning module is used to plan a pick-and-place routing path based on the pick-and-place structure model, wafer, and FOUP parameters; An adjustment and analysis module is used to perform unit length cutting along the central axis of the pick-and-place piece routing path, and analyze each cutting unit to determine whether the fingertip span needs to be adjusted. If necessary, the fingertip assembly is driven to adjust to the ideal span; The action adjustment module is used to determine the safe pick-and-place starting position based on the wafer deformation, and control the fingertips to perform the pick-and-place action according to the pick-and-place wafer routing path. The fingertips perform the pick-and-place action in real time. If there are changes in the wafer position or shape, the pick-and-place action is adjusted, and the rhythm of the fingertips lifting the wafer is controlled based on the difference in the support point distance; The verification module is used to control the laser detection module to scan again after the placement is completed to verify the wafer placement status and store the placement process data for subsequent process optimization and device parameter adjustment; Among them, the wafer manufacturing process includes: wafer boat support structure and fingertip structure; The wafer boat support structure is developed and designed based on a set platform, which is compatible with the standard wafer boat installation holes, and the lifting teeth on both sides of the wafer boat adopt a circular arc long tooth structure; At the same time, the length of rod-1 and rod-3 supports is increased based on the standard crystal boat structure; The fingertip structure adopts a 4-point lifting structure, combined with an arc fork finger shape, and increases the span of the fingertips to at least 200 mm.

2. The semiconductor wafer pick-and-place device according to claim 1, wherein The laser detection module includes: An initial construction unit, configured to construct original laser coordinates and map detection data to the original laser coordinates to obtain an initial structure; A first interference unit is configured to perform three-dimensional substructure decomposition on the initial structure, obtain point cloud data of each three-dimensional substructure, and calculate an interference coefficient of each position point to construct an interference set; an interference cancellation unit, configured to perform interference cancellation processing based on the interference set to obtain a first structure; a distance difference construction unit, configured to respectively obtain a two-dimensional array of edge positions of each connecting line on the three-dimensional substructure, and perform distance difference construction on the two-dimensional array of edge positions to obtain a distance difference vector; The second interference unit is used to calculate the fitting value of each distance difference vector to obtain a reference set of each three-dimensional substructure; An adjustment unit is configured to modify the interference set based on the reference set to determine an adjustment position point, and adjust the first structure to obtain a second structure, wherein the second structure is a pick-and-place structure model.

3. The semiconductor wafer pick-and-place device according to claim 1, wherein The adjustment analysis module includes: An extraction unit is used to extract the central axis L of the pick-and-place film routing path, establish a path coordinate system, and perform unit-length cutting along the direction of the central axis L to form n cutting units Ci, where i = 1, 2, …, n; ​ A constraint establishing unit, configured to establish a spatial constraint equation for each cutting unit Ci : Among them, represents the three-dimensional space region corresponding to the cutting unit Ci; , respectively represent the boundary constraint values based on the y-axis and the z-axis; represents the constraint value of the x-axis of the cutting unit Ci; represents the space coordinates; Function definition unit, used to define the spatial fitness function: Among them, , , are weighting coefficients; represents the safe distance between the fingertip span d and the spatial boundary; represents the support stability function, which is related to the distance between the support points and the distribution of the wafer's center of gravity; represents the deformation influence function, considering the inhibitory effect of the span on the wafer deformation; The span solving unit is used to solve the optimal span d_i* for each cutting unit Ci: d_i*=argmaxFi,dmin <d_i*<dmax Where dmin and dmax are the span ranges limited by the physical limitations of the device; Function building unit, used to build span adjustment cost function: Among them, is the span change cost coefficient; is the time cost coefficient; is the actual span value of the cutting unit Ci; is the time spent on span adjustment; A sequence solving unit, which is used to solve the globally optimal span sequence by using a dynamic programming algorithm: .

4. The semiconductor wafer pick-and-place device according to claim 1, wherein, The action adjustment module includes: The starting position determination unit is used to obtain the three-dimensional topography of the wafer, build a deformation model, calculate the deformation of each area, and select the area with the smallest deformation as the safe pick-and-place starting position; A threshold establishing unit for establishing a safety threshold function: , where is the warping degree; is the curvature; , are weight coefficients; A trajectory generation unit, configured to plan a pick-and-place path according to a safe starting position and a safety threshold function, and generate an optimal trajectory curve .

5. The semiconductor wafer pick-and-place device according to claim 4, wherein, The action adjustment module further includes: The support point optimization unit is used to analyze the distance differences of support points and establish a mechanical equilibrium model: , where represents the support force receiving point i; G is the gravity of the wafer; is the uida stress; is the penalty coefficient; n represents the total number of support force point symbols; An adaptive adjustment unit, which is used to construct an adaptive control algorithm through real-time monitoring by multi-sensor fusion during the picking and placing process: , where is the error vector, and are the wafer position offset, the shape change amount, and the force distribution of the support points respectively; , , is the PID parameter matrix; The control unit is used to control the rhythm of fingertip lifting according to the difference in support point distance and real-time force conditions.

6. The semiconductor wafer pick-and-place device according to claim 5, wherein, The control unit comprises: A rhythm generation unit for online optimizing the stage target force of a piecewise function based on reinforcement learning and the time constant , to generate the lifting rhythm Ft of the fingertip; Where t represents the time point during the fingertip placement and removal process; k0 represents the k0th segment.

7. The semiconductor wafer pick-and-place device according to claim 5, characterized in that, Also includes: The sequence determination unit is used to determine the force application order of the support points through the distance-force coordination priority function Pj: Among them, j is the support point number; , are dynamic weights; is the distance difference between the j-th support point and other support points; is the maximum value among the distance differences of all support points; is the force deviation of the j-th support point; is the maximum value of the force deviations of all support points; a dynamic optimization unit for real-time feedback correction, dynamically optimizing the force control parameters to suppress the deformation of the wafer.

8. A method for picking and placing a semiconductor wafer, characterized in that, include: Step 1: Use a 3D laser illuminator to perform 3D laser scanning on the pick-and-place port and the relevant area inside the FOUP where the wafer is located, and pre-process the detection data to reconstruct the pick-and-place structure model; Step 2: Plan the pick-and-place routing path based on the pick-and-place structure model, wafer, and FOUP parameters; Step 3: Perform unit length cutting along the central axis of the pick-and-place routing path, and analyze each cutting unit to determine whether the fingertip span needs to be adjusted. If necessary, drive the fingertip assembly to adjust to the ideal span; Step 4: Determine the safe pick-and-place starting position based on the wafer deformation, and control the fingertips to perform the pick-and-place action according to the pick-and-place routing path. Monitor the fingertips' pick-and-place action in real time. If there are changes in the wafer position or shape, adjust the pick-and-place action, and control the rhythm of the fingertips lifting the wafer based on the difference in the support point distance. Step 5: After the placement is completed, the laser detection module is controlled to scan again to verify the wafer placement status and store the placement process data for subsequent process optimization and device parameter adjustment; Among them, the wafer manufacturing process includes: wafer boat support structure and fingertip structure; The wafer boat support structure is developed and designed based on a set platform, which is compatible with the standard wafer boat installation holes, and the lifting teeth on both sides of the wafer boat adopt a circular arc long tooth structure; At the same time, the length of rod-1 and rod-3 supports is increased based on the standard crystal boat structure; The fingertip structure adopts a 4-point lifting structure, combined with an arc fork finger shape, and increases the span of the fingertips to at least 200 mm.

9. The semiconductor wafer pick-and-place method according to claim 8, wherein Step 1 includes: Constructing laser original coordinates and mapping detection data to the laser original coordinates to obtain an initial structure; Decomposing the initial structure into three-dimensional substructures to obtain point cloud data of each three-dimensional substructure, and calculating the interference coefficient of each position point to construct an interference set; performing interference cancellation processing based on the interference set to obtain a first structure; Obtain a two-dimensional array of edge positions of each connecting line on the three-dimensional substructure, and construct a distance difference between the two-dimensional arrays of edge positions to obtain a distance difference vector; Calculate the fitting value of each distance difference vector to obtain a reference set of each three-dimensional substructure; The interference set is modified based on the reference set to determine an adjustment position point, and the first structure is adjusted to obtain a second structure, wherein the second structure is a pick-and-place structure model.

10. The semiconductor wafer pick-and-place method according to claim 9, wherein Step 2 includes: Extract the central axis L of the pick-and-place path, establish a path coordinate system, and perform unit length cutting along the direction of the central axis L to form n cutting units Ci, where i = 1, 2, …, n; For each cutting unit Ci, a spatial constraint equation is established : Among them, represents the three-dimensional space region corresponding to the cutting unit Ci; , respectively represent the boundary constraint values based on the y-axis and the z-axis; represents the constraint value of the x-axis of the cutting unit Ci; represents the space coordinates; Define the spatial fitness function: Among them, , , are weight coefficients; represents the safe distance between the fingertip span d and the spatial boundary; represents the support stability function, which is related to the distance between support points and the distribution of the wafer's center of gravity; represents the deformation influence function, considering the inhibitory effect of the span on the wafer deformation; For each cutting unit Ci, solve the optimal span d_i*: d_i*=argmaxFi,dmin <d_i*<dmax Among them, dmin and dmax are the span ranges physically limited by the device; Establish a span adjustment cost function: Among them, is the span change cost coefficient; is the time cost coefficient; is the actual span value of the cutting unit Ci; is the time spent on span adjustment; Use the dynamic programming algorithm to solve the globally optimal span sequence: .

Images