Wafer dynamic deviation correction method and device and computer equipment

Abstract

The application provides a wafer dynamic deviation correction method, device and computer equipment. The wafer dynamic deviation correction method comprises the following steps: acquiring the position information of a robot when the robot carries a reference wafer and triggers a sensor as reference position information and the position information of the robot when the robot carries a wafer to be detected and triggers the sensor as actual position information; calculating the deviation value of the reference wafer and the wafer to be detected on a preset straight line path according to the reference position information and the actual position information; and correcting the final placement position of the wafer to be detected according to the deviation value. The application can ensure that the final placement positions of all wafers to be detected are consistent with the placement position of the reference wafer, and the dynamic deviation correction effect can be achieved.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to a method, apparatus and computer equipment for dynamic wafer correction. Background Technology

[0002] In wafer handling processes, theoretically, the relative position between the wafer and the robotic arm that handles it should remain fixed. However, in practical applications, after multiple processes and handling operations, the wafer may deviate from the center position of the robotic arm's fingers, causing wafer drop or collision. To ensure the consistency and accuracy of the final wafer placement, the robotic arm needs to automatically correct the wafer position on its fingers. This dynamic correction technology is called Active Wafer Centering (AWC). The AWC wafer automatic centering function automatically corrects the deviation between the actual center and the reference center during the robotic arm's wafer transfer process, ensuring that the wafer is accurately transported to the designated position.

[0003] In existing technologies, there is limited research on dynamic deviation correction methods for wafer handling. Some existing solutions employ two high-precision through-beam laser sensors, requiring complex calibration and calculations to obtain the final deviation value. Furthermore, high-precision through-beam laser sensors are not inexpensive, and solutions utilizing multiple sensors clearly do not save costs. Additionally, the calibration and calculation methods are complex, resulting in a poor user experience. Summary of the Invention

[0004] The purpose of this application is to provide a method, apparatus, and computer device for dynamic wafer correction, which can solve the problems of high cost, complex calculation, and poor user experience in the dynamic correction of wafer handling in the prior art.

[0005] To address the aforementioned technical problems, this application provides a wafer dynamic correction method. The method includes: acquiring, as reference position information, the position of the robotic arm when moving a reference wafer along a preset straight path to trigger a sensor, and as actual position information, the position of the robotic arm when moving a wafer to be tested to trigger a sensor; calculating the deviation value between the reference wafer and the wafer to be tested along the preset straight path based on the reference position information and the actual position information; and correcting the final placement position of the wafer to be tested based on the deviation value.

[0006] The step of acquiring the robot arm's position as reference position information when it moves the reference wafer along a preset straight path to trigger the sensor, and the robot arm's position as actual position information when it moves the wafer to be tested to trigger the sensor, includes: acquiring two sets of first Cartesian positions of the robot arm's end effector based on the robot arm coordinate system when the reference wafer triggers the sensor twice; calculating the reference arc length of the reference wafer triggering the sensor twice based on the two sets of first Cartesian positions; and calculating the reference arc height of the reference wafer triggering the sensor twice based on the reference arc length.

[0007] The step of obtaining two sets of first Cartesian positions of the end effector of the robot based on the robot coordinate system when the reference wafer triggers the sensor twice includes: acquiring and latching two sets of first position information of the motor encoders of each axis of the robot when the reference wafer triggers the sensor twice via a high-speed input port; converting the two sets of first position information into the first joint angle of the robot by the reduction ratio of the joints of the robot and the motor and the motor resolution; and substituting the first joint angle into the forward kinematics model of the robot to obtain the two sets of first Cartesian positions.

[0008] The step of acquiring the reference position information of the robot arm transporting the reference wafer along a preset straight path and the actual position information of the wafer to be tested includes: acquiring two sets of second Cartesian positions of the end effector of the robot arm based on the robot arm coordinate system when the wafer to be tested triggers the sensor twice; calculating the first arc length of the wafer to be tested triggering the sensor twice based on the two sets of second Cartesian positions; and calculating the first arc height of the wafer to be tested triggering the sensor twice based on the first arc length.

[0009] The step of obtaining two sets of second Cartesian positions of the end effector of the robot based on the robot coordinate system when the wafer under test triggers the sensor twice includes: acquiring and locking two sets of second position information of the motor encoders of each axis of the robot when the wafer under test triggers the sensor twice via a high-speed input port; converting the two sets of second position information into the second joint angle of the robot by the reduction ratio of the joints of the robot and the motor and the motor resolution; and substituting the second joint angle into the kinematic model of the robot to obtain the two sets of second Cartesian positions.

[0010] The step of calculating the deviation values ​​of the reference wafer and the wafer to be tested on the preset straight path based on the reference position information and the actual position information includes: determining a first compensation deviation value of the reference wafer and the wafer to be tested along a first direction in a second coordinate system based on the reference arc length and the first arc length; determining a second deviation compensation value of the reference wafer and the wafer to be tested along a second direction in a second coordinate system based on the reference arc height and the first arc height; and converting the first compensation deviation value and the second deviation compensation value to the robot coordinate system to obtain the deviation value of the reference wafer and the wafer to be tested.

[0011] The step of determining the first compensation deviation value of the reference wafer and the wafer to be tested along the first direction in the second coordinate system based on the reference arc length and the first arc length includes: confirming the time sequence of the two triggering of the sensor by the reference wafer and the wafer to be tested respectively; obtaining the first offset distance of the reference wafer and the wafer to be tested along the first direction in the second coordinate system based on the time sequence, the reference arc length and the first arc length; and determining the first compensation deviation value based on the first offset distance.

[0012] The determination of the second deviation compensation value of the reference wafer and the wafer to be tested along the second direction in the second coordinate system based on the reference arc height and the first arc height includes: obtaining the second offset distance of the reference wafer and the wafer to be tested along the second direction in the second coordinate system based on the reference arc length and the first arc length; and determining the second compensation deviation value based on the second offset distance.

[0013] To address the aforementioned technical problems, this application also provides a wafer dynamic correction device, comprising: an acquisition module for acquiring reference position information of a robotic arm transporting a reference wafer along a preset straight path and actual position information of a wafer to be inspected; a calculation module for calculating the deviation values ​​of the reference wafer and the wafer to be inspected along the preset straight path based on the reference position information and the actual position information; and a correction module for the robotic arm to correct the final placement position of the wafer to be inspected based on the deviation values.

[0014] To address the aforementioned technical problems, this application also provides a computer device, including a memory and a processor. The memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the steps of the wafer dynamic correction method as described in any of the preceding claims.

[0015] Compared with the prior art, the embodiments of this application have the following main advantages:

[0016] This application provides a method, apparatus, and computer device for dynamic wafer bias correction. By acquiring the position of the robot arm that triggers the sensor while moving the reference wafer along a preset straight path as reference position information and the position of the robot arm that triggers the sensor while moving the wafer to be tested as actual position information, the relative deviation between the two on the preset straight path is calculated based on the reference position information and the actual position information. The deviation is then corrected by the robot arm, ensuring that the final placement position of all wafers to be tested is consistent with the placement position of the reference wafer, thus achieving a dynamic bias correction effect. Attached Figure Description

[0017] To more clearly illustrate the solutions in this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating one embodiment of the wafer dynamic bias correction method of this application;

[0019] Figure 2 This is a schematic diagram of the wafer handling process in this application;

[0020] Figure 3 This is a flowchart illustrating an implementation method of step S100 of this application;

[0021] Figure 4 This is a flowchart illustrating one embodiment of step S110 of this application;

[0022] Figure 5 This is a flowchart illustrating another embodiment of step S100 of this application;

[0023] Figure 6 This is a flowchart illustrating one embodiment of step S140 of this application;

[0024] Figure 7 This is a flowchart illustrating one embodiment of step S200 of this application;

[0025] Figure 8 This is a flowchart illustrating one embodiment of step S210 of this application;

[0026] Figure 9 This is a schematic diagram of the first embodiment of the reference wafer and the wafer to be tested trigger sensor of this application;

[0027] Figure 10 This is a schematic diagram of a second embodiment of the reference wafer and the wafer to be tested trigger sensor of this application;

[0028] Figure 11 This is a schematic diagram of a third embodiment of the reference wafer and the wafer to be tested trigger sensor of this application;

[0029] Figure 12 This is a schematic diagram of the fourth embodiment of the reference wafer and the wafer to be tested trigger sensor of this application;

[0030] Figure 13 This is a flowchart illustrating one embodiment of step S220 of this application;

[0031] Figure 14 This is a schematic diagram of the fifth embodiment of the reference wafer and the wafer to be tested trigger sensor of this application;

[0032] Figure 15 This is a schematic diagram of one embodiment of the wafer dynamic bias correction device of this application;

[0033] Figure 16 This is a schematic diagram of a computer device according to an embodiment of the present application. Detailed Implementation

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The terms “comprising” and “having,” and any variations thereof, in the specification, claims, and foregoing drawings, are intended to cover non-exclusive inclusion. The terms “first,” “second,” etc., in the specification, claims, or foregoing drawings are used to distinguish different objects and not to describe a particular order.

[0035] Based on the above description in this specification, those skilled in the art will also understand that terms used, such as "upper," "lower," "front," "rear," "left," "right," "length," "width," "thickness," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," "center," "longitudinal," "transverse," "clockwise," or "counterclockwise," are terms indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings of this specification. They are only for the purpose of facilitating the explanation of the present invention and simplifying the description, and do not imply that the devices or elements involved must have the specific orientation, or be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms should not be understood or interpreted as limitations on the present invention.

[0036] In the foregoing description of this specification, unless otherwise expressly specified and limited, the terms "fixed," "installed," "connected," or "linked" should be interpreted broadly. For example, the term "linked" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can refer to the internal communication of two components or the interaction between two components. Therefore, unless otherwise expressly limited in this specification, those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] It is understandable that, for ease of description, the wafer used in the calibration process is referred to as the reference wafer, while the wafer whose deviation value needs to be corrected during the robotic arm's handling is referred to as the wafer to be inspected. The handling path of the robotic arm from the starting point to the final placement point is defined as a linear motion path (i.e., the preset linear path hereinafter referred to in this application), and the coordinate system of the robotic arm's end effector does not rotate relative to the robotic arm coordinate system during the motion. Therefore, it can be assumed that the direction of motion along the linear path is consistent with the direction of the coordinate system of the robotic arm's end effector. Thus, the angle between the direction of motion along the preset linear path and the robotic arm coordinate system is the angle between the coordinate system of the robotic arm's end effector and the robotic arm coordinate system, which is the attitude angle θ. If we denote the robot's coordinate system as {A}, take the direction along the straight motion path as the X-axis and determine the direction perpendicular to the straight motion path as the Y-axis using the right-hand rule, and take the origin of the {A} coordinate system as the origin, we can establish a coordinate system denoted as {B} (i.e., the second coordinate system mentioned below in this application). Then the relationship between {A} and {B} is that {B} coincides with the origin of {A}, and the angle of rotation around the Z-direction is the attitude angle θ.

[0039] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0040] Please combine Figure 1 , Figure 1 This is a flowchart illustrating one embodiment of the wafer dynamic bias correction method of this application. The wafer dynamic bias correction method provided by this application includes the following steps:

[0041] S100 acquires the reference position information of the sensor when the robot arm moves the reference wafer along a preset straight path and the actual position information of the wafer to be tested.

[0042] It is understandable that the transport path of the robot arm needs to be determined in advance before performing step S100 of this application, that is, the preset straight path of this application. In a specific application scenario of this application, the robot arm first determines the starting point of the robot arm carrying the wafer and the final placement position of the wafer by teaching the points, thereby determining the transport path of the straight movement (preset straight path).

[0043] Please combine further Figure 2 , Figure 2 This is a schematic diagram of the wafer handling process in this application, as shown below. Figure 2 During the robotic arm's handling of wafers, as long as the sensor (in this application, a through-beam laser sensor) is installed within the robotic arm's linear motion path, and the wafer blocks the through-beam laser sensor for a period of time during movement, the through-beam laser sensor will exhibit two signal transitions. The first occurs the instant the wafer blocks the through-beam laser sensor, and the second occurs the instant the wafer moves away from the sensor and no longer blocks it. These edge signals at these two moments are captured by a high-speed input interface, recording the encoder positions of the motors on each joint axis of the robotic arm within tens of microseconds. This process is called high-speed position latching, and the encoder positions recorded by these two triggers can be used to assist in calculating the wafer's position. It should also be noted that this application only requires one through-beam laser sensor to calculate the wafer's deviation from a reference. There are no special requirements for the sensor's installation position; as long as the wafer edge sweeps across the sensor during the wafer handling process, it is sufficient.

[0044] Please refer to further information. Figure 3 , Figure 3 This is a flowchart illustrating an embodiment of step S100 of this application, as shown below. Figure 3 Step S100 of this application further includes the following sub-steps:

[0045] S110, acquire the two sets of first Cartesian positions of the robot's end effector based on the robot's coordinate system when the sensor is triggered twice on the reference wafer.

[0046] Please refer to further information. Figure 4 , Figure 4 This is a flowchart illustrating an embodiment of step S110 of this application, as shown below. Figure 4 Step S110 of this application further includes the following sub-steps:

[0047] S111 acquires and latches two sets of first position information of the motor encoders of each axis of the robot arm when the reference wafer triggers the sensor twice.

[0048] Understandably, in this application, after determining the preset straight path for the robotic arm to transport the wafer, a reference wafer is first placed at the final wafer placement position. Then, the robotic arm moves to the final placement position, retrieves the reference wafer, and moves back to the starting point of the transport process, before initiating another transport operation. As described above, during the robotic arm's transport process, the through-beam laser sensor experiences two edge signal transitions. This application can record, through a high-speed latching method, two sets of first position information about the motor encoders of each axis of the robotic arm when the through-beam laser sensor is triggered.

[0049] S112, the first joint angle of the robot is obtained by converting the two sets of first position information into the reduction ratio of the joints of the robot and the motor and the resolution of the motor.

[0050] Optionally, the first joint angle can be calculated from these two sets of first position information using the reduction ratio of the joints of the robotic arm and the motor, as well as the motor resolution.

[0051] S113, substitute the first joint angle into the forward kinematics model of the manipulator to obtain two sets of first Cartesian positions (x,y) and attitude angles θ.

[0052] Optionally, the process of obtaining the reference position information of the robotic arm carrying the reference wafer along a preset straight path in this application is called calibration. That is, the robotic arm carries the reference wafer along a preset straight path in advance to determine the position information of the reference wafer, which is then used as a reference. Specifically, in this application, through the above data acquisition and processing process, two sets of first Cartesian positions (x0, y0) and (x1, y1) of the end effector of the robotic arm based on the robotic arm coordinate system can be obtained at the two triggering of the sensor by the reference wafer.

[0053] In the above embodiments, by adopting high-speed latching technology, the consistency of position can be guaranteed, and it is not affected by the speed of the robot arm. Even at high speed, the correction accuracy can still be guaranteed.

[0054] S120 calculates the reference arc length of the sensor triggered twice by the reference wafer based on the two sets of first Cartesian positions.

[0055] Furthermore, using the two sets of first Cartesian positions (x0, y0) and (x1, y1) as reference positions, and connecting the two points of the Cartesian positions of the two robot end caps based on the robot coordinate system {A}, the straight-line distance can be obtained. Since the entire handling process is along a straight-line motion path, the length of this straight-line distance is the arc chord length of the reference wafer when it triggers the through-beam laser sensor twice. Therefore, the arc length is calculated as follows:

[0056]

[0057] This arc length L0 is used as the reference arc length of the reference wafer.

[0058] S130, the reference arc height of the reference wafer for triggering the sensor twice is calculated based on the reference arc length.

[0059] Furthermore, the reference arc height of the sensor triggered twice by the reference wafer can be obtained using the formula for the arc height of a circle. The arc height formula is as follows:

[0060]

[0061] The formula for calculating the reference arc height is as follows:

[0062]

[0063] Where R is the radius of the reference wafer, which is a known quantity, and the arc height H0 is used as the reference arc height.

[0064] The calibration process is now complete.

[0065] Please refer to further information. Figure 5 , Figure 5 This is a flowchart illustrating another embodiment of step S100 of this application, as shown below. Figure 5 Step S100 of this application further includes the following sub-steps:

[0066] S140, acquire two sets of second Cartesian positions of the end effector of the robot based on the robot coordinate system when the sensor is triggered twice on the wafer to be tested.

[0067] Please refer to further information. Figure 6 , Figure 6 This is a flowchart illustrating an embodiment of step S140 of this application, as shown below. Figure 6 Step S140 of this application further includes the following sub-steps:

[0068] S141 acquires and latches two sets of second position information of the motor encoders of each axis of the robot arm when the sensor is triggered twice by the wafer under test through the high-speed input port.

[0069] Understandably, the path the robotic arm takes to begin moving the wafer under test is the same as the path used during calibration; both are preset straight paths, which will cause the through-beam laser sensor signal to change twice. As described above, two sets of second position information about the motor encoders of each axis of the robotic arm are recorded twice when the robotic arm triggers the through-beam laser sensor while carrying the wafer under test, using a high-speed latching method.

[0070] S142, the two sets of second position information are converted into the second joint angle of the robot arm by the reduction ratio of the joints of the robot arm and the motor and the resolution of the motor.

[0071] Optionally, the second joint angle can be calculated from these two sets of second position information using the reduction ratio of the robot's joints and the motor, as well as the motor resolution.

[0072] S143, Substitute the second joint angle into the forward kinematics model of the manipulator to obtain the two sets of second Cartesian positions (x2, y2) and (x3, y3).

[0073] In the above embodiments, by adopting high-speed latching technology, the consistency of position can be guaranteed, and it is not affected by the speed of the robot arm. Even at high speed, the correction accuracy can still be guaranteed.

[0074] S150, the first arc length of the two triggering sensors of the wafer to be tested is calculated based on the two sets of second Cartesian positions.

[0075] Furthermore, using the two sets of second Cartesian positions (x2, y2) and (x3, y3) as the positions of the robotic arm that trigger the sensor signal on the wafer to be tested, and connecting the two points of the second Cartesian positions of the robotic arm end caps based on the robotic arm coordinate system {A}, the straight-line distance can be obtained. Since the entire handling process is along a straight-line motion path, the length of this straight-line distance is the arc chord length of the wafer to be tested when it triggers the through-beam laser sensor twice. Therefore, the arc length is calculated as follows:

[0076]

[0077] This arc length L1 is used as the first arc length of the wafer to be tested.

[0078] S160, calculate the first arc height of the sensor triggered twice by the wafer to be tested based on the first arc length.

[0079] Furthermore, the reference arc height of the sensor triggered twice by the reference wafer can be obtained using the formula for the arc height of a circle. The arc height formula is as follows:

[0080]

[0081] The formula for calculating the reference arc height is as follows:

[0082]

[0083] Where R is the radius of the wafer to be tested, which is a known quantity, and this arc height H1 is used as the first arc height of the wafer to be tested.

[0084] S200 calculates the deviation values ​​of the reference wafer and the wafer to be tested on the preset straight path based on the reference position information and the actual position information.

[0085] Understandably, since the robotic arm moves along the same straight-line path each time it handles the wafer to be inspected or the reference wafer, the offset distance ΔD along the straight-line path, i.e., the first direction (X-axis) of the second coordinate system {B}, can be calculated first. x Then calculate the offset distance ΔD in the vertical direction of the movement along the preset straight path, that is, the second direction (Y-axis) of the second coordinate system {B}. y .

[0086] Please see Figure 7 , Figure 7 This is a flowchart illustrating an embodiment of step S200 of this application, as shown below. Figure 7 Step S200 of this application further includes the following sub-steps:

[0087] S210, determine the first compensation deviation value of the reference wafer and the wafer to be tested in the second coordinate system along the first direction based on the reference arc length and the first arc length.

[0088] Please see Figure 8 , Figure 8 This is a flowchart illustrating an embodiment of step S210 of this application, as shown below. Figure 8 Step S210 of this application further includes the following sub-steps:

[0089] S211, confirm the timing sequence of the sensor triggering on the reference wafer and the wafer under test respectively.

[0090] It is understood that in this application, the positional relationship between the wafer to be tested and the reference wafer can only be one of the following four possibilities:

[0091] 1. The time when the sensor is triggered twice by the reference wafer is earlier than that of the wafer to be tested;

[0092] 2. The reference wafer triggers the sensor for the first time before the wafer under test, and the second trigger of the sensor is later than the wafer under test;

[0093] 3. The time when the reference wafer triggers the sensor twice is later than that of the wafer under test;

[0094] 4. The time when the reference wafer first triggers the sensor is later than that of the wafer under test, and the time when the second sensor triggers is earlier than that of the wafer under test.

[0095] S212, based on the time sequence, reference arc length and first arc length, obtain the first offset distance of the reference wafer and the wafer to be tested in the second coordinate system along the first direction.

[0096] S213, determine the first compensation deviation value based on the first offset distance.

[0097] The following describes in detail the calculation method of the first compensation deviation value of the reference wafer and the wafer to be tested in the second coordinate system along the first direction in this application, based on the above four situations.

[0098] 1. The time when the sensor is triggered twice by the reference wafer is earlier than that of the wafer under test.

[0099] Optionally, please combine further Figure 9 , Figure 9 This is a schematic diagram of the first embodiment of the reference wafer and the wafer to be tested trigger sensor of this application. Figure 9 It can be seen that the time of the sensor triggering by the reference wafer is earlier than that of the wafer to be tested. The first offset distance between the reference wafer and the wafer to be tested in the second coordinate system along the first direction can be calculated based on the relationship between the arc lengths:

[0100]

[0101] Considering this scenario, in the first direction (X-axis) of the second coordinate system {B}, the center positions of the reference wafer and the wafer to be tested based on the second coordinate system {B} must be such that the center of the reference wafer is ahead of the center of the wafer to be tested. Therefore, the actual compensation deviation value ΔM in the X-axis direction of the second coordinate system {B}, after compensation in the positive direction, yields the first compensation deviation value:

[0102] ΔM=ΔD x

[0103] Where, ΔD x L1 is the first offset distance, L0 is the first arc length of the wafer to be tested, L1 is the reference arc length of the reference wafer, and L3 is the positional deviation between the wafer to be tested and the reference wafer when the sensor is first triggered. The calculation expression for L3 is as follows:

[0104]

[0105] 2. The reference wafer triggers the sensor first before the wafer under test, and the second trigger triggers the sensor later than the wafer under test.

[0106] Optionally, please combine further Figure 10 , Figure 10 This is a schematic diagram of a second embodiment of the reference wafer and the wafer to be tested trigger sensor of this application. Figure 10 It can be seen that the reference wafer triggers the sensor for the first time before the wafer under test, and the second trigger triggers the sensor for the second time after the wafer under test. Based on the relationship between the arc lengths, the first offset distance between the reference wafer and the wafer under test in the second coordinate system along the first direction can be calculated as follows:

[0107]

[0108] Considering this scenario, in the first direction (X-axis) of the second coordinate system, the center positions of the reference wafer and the wafer under test must be such that the center of the reference wafer is behind the center of the wafer under test. Therefore, the actual compensated deviation value ΔM in the first direction of the second coordinate system, after being compensated in the negative direction, yields the first compensated deviation value:

[0109] ΔM=-ΔD x

[0110] 3. The time when the reference wafer triggers the sensor twice is later than that of the wafer under test.

[0111] Optionally, please combine further Figure 11 , Figure 11 This is a schematic diagram of the third embodiment of the reference wafer and the wafer to be tested trigger sensor of this application. Figure 11 It is known that the time when the reference wafer triggers the sensor twice is later than that of the wafer to be tested. Based on the relationship between the arc lengths, the first offset distance between the reference wafer and the wafer to be tested in the second coordinate system along the first direction can be calculated as follows:

[0112]

[0113] Considering this scenario, in the first direction (X-axis) of the second coordinate system {B}, the center positions of the reference wafer and the wafer to be tested based on the second coordinate system {B} must be such that the center of the reference wafer is behind the center of the wafer to be tested. Therefore, the actual compensation deviation value ΔM in the first direction of the second coordinate system {B}, after being compensated in the negative direction, yields the first compensation deviation value as follows:

[0114] ΔM=-ΔD x

[0115] 4. The first sensor trigger time of the reference wafer is later than that of the wafer under test, and the second sensor trigger time is earlier than that of the wafer under test.

[0116] Optionally, please combine further Figure 12 , Figure 12 This is a schematic diagram of the fourth embodiment of the reference wafer and the wafer to be tested trigger sensor of this application. Figure 12 It is known that the first sensor trigger time of the reference wafer is later than that of the wafer under test, and the second sensor trigger time is earlier than that of the wafer under test. Based on the relationship between the arc lengths, the first offset distance between the reference wafer and the wafer under test in the second coordinate system along the first direction can be calculated as follows:

[0117]

[0118] Considering this scenario, in the first direction (X-axis) of the second coordinate system {B}, the center positions of the reference wafer and the wafer to be tested based on the second coordinate system {B} must be such that the center of the reference wafer is behind the center of the wafer to be tested. Therefore, the actual compensation deviation value ΔM in the first direction of the second coordinate system {B}, after being compensated in the negative direction, yields the first compensation deviation value as follows:

[0119] ΔM=-ΔD x

[0120] Understandably, in order to distinguish and judge the above four cases in this application, a second coordinate system {B} can be established with the direction of movement along the straight path as the X-axis, the Y-axis determined according to the right-hand rule, and the origin as the origin of the robot's coordinate system. Simultaneously, the robot's coordinate system is represented as {A}. Then, according to coordinate transformation, the point p(x,y) under {A} can be transformed to {B}. Therefore, the 3×3 rotation matrix can be represented as:

[0121]

[0122] Therefore, it can be transformed into:

[0123]

[0124] The rotational relationship between the second coordinate system {B} and the robot arm coordinate system {A} is actually the relationship between the robot arm's end effector coordinate system and the robot arm coordinate system {A}, equivalent to rotating the robot arm around the Z-axis by an attitude angle θ. B p The rotation matrix T is:

[0125]

[0126] Knowing that points (x0, y0), (x1, y1), (x2, y2), and (x2, y2) are all based on the robot's coordinate system {A}, the corresponding coordinates can be obtained.

[0127] Based on the known quantities above, we can obtain:

[0128]

[0129] We can then obtain the coordinate values ​​originally described by the robot's coordinate system: (x0, y0), (x1, y1), (x2, y2), (x3, y3) and their corresponding coordinate values ​​in the second coordinate system {B}: (x4, y4), (x5, y5), (x6, y6), (x7, y7). By comparing the coordinate axis values ​​along the linear motion path in the second coordinate system {B}, it is easy to distinguish the four possible positional relationships between the wafer to be inspected and the reference wafer:

[0130] 1. When x4 is greater than x6 and x5 is greater than x7, it means that the reference wafer is triggered before the wafer under test in the first trigger, and the reference wafer is triggered before the wafer under test in the second trigger.

[0131] 2. When x4 is greater than x6 and x7 is greater than x5, it means that the reference wafer is triggered before the wafer under test in the first trigger, and the reference wafer is triggered after the wafer under test in the second trigger.

[0132] 3. When x6 is greater than x4 and x5 is greater than x7, it means that the reference wafer is triggered after the wafer under test in the first trigger, and the reference wafer is triggered before the wafer under test in the second trigger.

[0133] 4. When x6 is greater than x4 and x7 is greater than x5, it means that the reference wafer is triggered after the wafer under test in the first trigger and the reference wafer is triggered after the wafer under test in the second trigger.

[0134] S220, determine the second deviation compensation value of the reference wafer and the wafer to be tested in the second coordinate system along the second direction based on the reference arc height and the first arc height.

[0135] Please see Figure 13 , Figure 13 This is a flowchart illustrating an embodiment of step S220 of this application, as shown below. Figure 13 Step S220 of this application further includes the following sub-steps:

[0136] S221, based on the reference arc length and the first arc length, obtain the second offset distance of the reference wafer and the wafer to be tested along the second direction in the second coordinate system.

[0137] Optionally, a second offset distance between the reference wafer and the wafer under test along the second direction in the second coordinate system is calculated based on the reference arc height and the first arc height, and a second deviation compensation value between the reference wafer and the wafer under test along the second direction in the second coordinate system is determined based on the second offset distance. Optionally, in this application, after calculating the first offset distance ΔD between the reference wafer and the wafer under test along the first direction in the second coordinate system... x Then, a similar method can be used to calculate the second offset distance ΔD between the reference wafer and the wafer to be tested in the second coordinate system along the second direction. y .

[0138] Please combine further Figure 14 , Figure 14 This is a schematic diagram of the fifth embodiment of the reference wafer and the wafer to be tested trigger sensor of this application, as shown below. Figure 14 It can be seen that, in this direction, regardless of the positional relationship between the centers of the wafer under test and the reference wafer, the second offset distance ΔD along the second direction in the second coordinate system can be determined simply by using the difference in arc height of the corresponding arc. y ,Right now:

[0139] ΔD y =H0-H1S222, determine the second compensation deviation value based on the second offset distance.

[0140] Furthermore, the second compensation deviation value in the compensation direction is considered to be:

[0141] ΔN=H0-H1

[0142] Where, ΔD y H1 is the second offset distance, H1 is the first arc height of the wafer to be tested, and H0 is the reference arc length of the reference wafer.

[0143] S230, the first compensation deviation value and the second deviation compensation value are converted into the robot coordinate system to obtain the deviation values ​​of the reference wafer and the wafer to be tested.

[0144] Optionally, after the above calculations, the first compensation deviation value ΔM along the first direction (X-axis) in the second coordinate system {B} and the second compensation deviation ΔN along the second direction (Y-axis) in the second coordinate system {B} are obtained respectively. Finally, the first compensation deviation value ΔM and the second deviation compensation value ΔN need to be transformed into the robot arm coordinate system {A} to correct the deviation. This can be done using a rotation matrix. The deviation values ​​(ΔX, ΔY) based on the robot's coordinate system {A} are obtained:

[0145]

[0146] Thus we can obtain:

[0147]

[0148] Here, θ is the attitude angle between the robot and the end effector, which can be obtained through forward kinematics calculation.

[0149] It is understandable that after obtaining the position and length information of the reference wafer and the wafer to be inspected, the above process, through analysis using the basic characteristics of a circle, reveals that the two-dimensional planar deviation (ΔX, ΔY) between the wafer to be inspected and the reference wafer is actually the deviation between the center position of the wafer to be inspected and the center position of the reference wafer in the common reference coordinate system {A} of the robot arm. Moreover, since a circle has only one constant radius value, no matter how much the wafer to be inspected and the reference wafer rotate around their own center, it will not change the timing of the triggering of the through-beam laser sensor during the wafer handling process. Therefore, the deviation (ΔX, ΔY) between the wafer to be inspected and the reference wafer can be calculated using a certain algorithm based on the Cartesian position information and chord length information of the wafer to be inspected and the reference wafer processed above.

[0150] S300: The robotic arm corrects the final placement position of the wafer to be inspected based on the deviation value.

[0151] Furthermore, by using a robotic arm to compensate for the deviation values ​​(ΔX, ΔY) to the final wafer placement position, dynamic correction can be achieved. It is understood that the entire process of calculating the deviation values ​​(ΔX, ΔY) between the wafer to be inspected and the reference wafer in this application does not require calculating the relationship between the actual center position of the wafer and the robotic arm's coordinate system {A}. Ultimately, it only needs to calculate the relative deviation between the wafer to be inspected and the reference wafer. By correcting this deviation value (ΔX, ΔY) using the robotic arm, it can be ensured that the final placement position of all wafers to be inspected is consistent with the placement position of the reference wafer, thus achieving the dynamic correction effect.

[0152] Understandably, the wafer dynamic correction method used in this application has a simple algorithm, utilizing the basic properties of a circle, such as chord length, arc height, radius, and the fact that rotation angles do not change the center position, as well as basic coordinate transformation principles (robot joint angles to Cartesian positions, rotation matrix transformations, etc.). The accuracy is mainly affected by the wafer radius R and the position accuracy recorded when the sensor is triggered. The wafer exhibits good consistency, and the radius value R is stable. Furthermore, the use of a single high-precision through-beam laser sensor ensures timely signal triggering, and high-speed latching guarantees the accuracy of position acquisition. Therefore, this scheme is stable, reliable, and has high correction accuracy.

[0153] In the above embodiments, by acquiring the position of the robot arm that triggers the sensor by moving the reference wafer along a preset straight path as reference position information and the position of the robot arm that triggers the sensor by moving the wafer to be tested as actual position information, and by calculating the relative deviation value between the two on the preset straight path based on the reference position information and the actual position information, and by correcting the deviation value by the robot arm, it can be ensured that the final placement position of all wafers to be tested is consistent with the placement position of the reference wafer, thereby achieving a dynamic correction effect.

[0154] To address the aforementioned technical problems, this application also provides a dynamic wafer bias correction device. Please refer to [link / reference] for details. Figure 15 , Figure 15 This is a schematic diagram of one embodiment of the wafer dynamic bias correction device of this application, as shown below. Figure 15 The wafer dynamic correction device 200 provided in this application includes an acquisition module 210, a calculation module 220, and a correction module 230.

[0155] The acquisition module 210 is used to acquire the reference position information of the trigger sensor when the robot moves the reference wafer along a preset straight path and the actual position information of the wafer to be tested.

[0156] The calculation module 220 is used to calculate the deviation values ​​of the reference wafer and the wafer to be tested on the preset straight path based on the reference position information and the actual position information;

[0157] The correction module 230 is used by the robot arm to correct the final placement position of the wafer to be inspected based on the deviation value.

[0158] It is understood that each module of the wafer dynamic bias correction device in this application is used to execute the steps in the above-described wafer dynamic bias correction method implementation, and will not be repeated here.

[0159] In the above embodiments, by acquiring the position of the robot arm that triggers the sensor by moving the reference wafer along a preset straight path as reference position information and the position of the robot arm that triggers the sensor by moving the wafer to be tested as actual position information, and by calculating the relative deviation value between the two on the preset straight path based on the reference position information and the actual position information, and by correcting the deviation value by the robot arm, it can be ensured that the final placement position of all wafers to be tested is consistent with the placement position of the reference wafer, thereby achieving a dynamic correction effect.

[0160] To address the aforementioned technical problems, embodiments of this application also provide a computer device. Please refer to [link / reference needed] for details. Figure 16 , Figure 16 This is a basic structural block diagram of the computer device in this embodiment.

[0161] The computer device 300 includes a memory 301, a processor 302, and a network interface 303 that are interconnected via a system bus. It should be noted that... Figure 16 Only a computer device 300 with components 301-303 is shown in this document; however, it should be understood that implementation of all shown components is not required, and more or fewer components may be implemented alternatively. Those skilled in the art will understand that the computer device described herein is a device capable of automatically performing numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes, but is not limited to, microprocessors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), embedded devices, etc.

[0162] The computer device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The computer device can interact with the user via a keyboard, mouse, remote control, touchpad, or voice control.

[0163] The memory 301 includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the memory 301 may be an internal storage unit of the computer device 300, such as the hard disk or memory of the computer device 300. In other embodiments, the memory 301 may also be an external storage device of the computer device 300, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the computer device 300. Of course, the memory 301 may also include both the internal storage unit and the external storage device of the computer device 300. In this embodiment, the memory 301 is typically used to store the operating system and various application software installed on the computer device 300, such as computer-readable instructions for interface calling methods. Furthermore, the memory 301 can also be used to temporarily store various types of data that have been output or will be output.

[0164] In some embodiments, the processor 302 may be a central processing unit (CPU), controller, microcontroller, microprocessor, or other data processing chip. The processor 302 is typically used to control the overall operation of the computer device 300. In this embodiment, the processor 302 is used to execute computer-readable instructions stored in the memory 301 or to process data, such as executing computer-readable instructions for a wafer dynamic spin correction method.

[0165] The network interface 303 may include a wireless network interface or a wired network interface, which is typically used to establish communication connections between the computer device 300 and other electronic devices.

[0166] In the above embodiments, by acquiring the position of the robot arm that triggers the sensor by moving the reference wafer along a preset straight path as reference position information and the position of the robot arm that triggers the sensor by moving the wafer to be tested as actual position information, and by calculating the relative deviation value between the two on the preset straight path based on the reference position information and the actual position information, and by correcting the deviation value by the robot arm, it can be ensured that the final placement position of all wafers to be tested is consistent with the placement position of the reference wafer, thereby achieving a dynamic correction effect.

[0167] This application also provides another embodiment, namely, a computer-readable storage medium storing computer-readable instructions that can be executed by at least one processor to cause the at least one processor to perform the steps of the wafer dynamic spin correction method described above.

[0168] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods of the various embodiments of this application.

[0169] Obviously, the embodiments described above are only some embodiments of this application, not all embodiments. The accompanying drawings show preferred embodiments of this application, but do not limit the patent scope of this application. This application can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this application's specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the scope of patent protection of this application.

Claims

1. A method for dynamic bias correction of wafers, characterized in that, The aforementioned wafer dynamic bias correction method includes: The robot arm's position when it triggers the sensor by moving a reference wafer along a preset straight path is obtained as reference position information, and its position when it triggers the sensor by moving a wafer to be tested is obtained as actual position information. This includes: obtaining two sets of first Cartesian positions of the robot arm's end effector based on the robot arm coordinate system when the reference wafer triggers the sensor twice; calculating the reference arc length of the reference wafer triggering the sensor twice based on the two sets of first Cartesian positions; and calculating the reference arc height of the reference wafer triggering the sensor twice based on the reference arc length. The deviation values ​​of the reference wafer and the wafer to be tested on the preset straight path are calculated based on the reference position information and the actual position information. The robotic arm corrects the final placement position of the wafer to be inspected based on the deviation value.

2. The wafer dynamic bias correction method according to claim 1, characterized in that, The acquisition of the two sets of first Cartesian positions of the end effector of the robot arm based on the robot arm coordinate system when the sensor is triggered twice by the reference wafer includes: The high-speed input port is used to acquire and latch two sets of first position information of the motor encoders of each axis of the manipulator when the reference wafer triggers the sensor twice; The first joint angle of the robot is obtained by converting the two sets of first position information into the reduction ratio of the joints of the robot and the motor and the motor resolution. Substituting the first joint angle into the forward kinematics model of the robot arm, the two sets of first Cartesian positions are obtained.

3. The wafer dynamic bias correction method according to claim 1, characterized in that, The steps of acquiring the robot arm's position triggering the sensor when it moves a reference wafer along a preset straight path as reference position information and the robot arm's position triggering the sensor when it moves a wafer to be tested as actual position information include: The robot arm's end effector acquires two sets of second Cartesian positions based on the robot arm coordinate system when the sensor is triggered twice on the wafer to be inspected. The first arc length of the sensor triggered twice by the wafer under test is calculated based on the two sets of second Cartesian positions. The first arc height of the two triggering events of the sensor by the wafer to be tested is calculated based on the first arc length.

4. The wafer dynamic bias correction method according to claim 3, characterized in that, The acquisition of two sets of second Cartesian positions of the end effector of the robot arm based on the robot arm coordinate system when the sensor is triggered twice on the wafer to be inspected includes: The high-speed input port is used to acquire and lock two sets of second position information of the motor encoders of each axis of the robot arm when the sensor is triggered twice by the wafer to be tested; The two sets of second position information are converted into the second joint angle of the manipulator by the reduction ratio of the joints of the manipulator and the motor and the resolution of the motor. Substituting the second joint angle into the forward kinematics model of the robot arm, the two sets of second Cartesian positions are obtained.

5. The wafer dynamic bias correction method according to claim 3, characterized in that, The step of calculating the deviation values ​​of the reference wafer and the wafer to be tested on the preset straight path based on the reference position information and the actual position information includes: The first compensation deviation value of the reference wafer and the wafer to be tested in the second coordinate system along the first direction is determined based on the reference arc length and the first arc length. The second coordinate system is a coordinate system established with the origin of the robot coordinate system as the origin, the direction of movement along the preset straight path as the X-axis direction, and the Y-axis direction perpendicular to the direction of movement along the preset straight path determined by the right-hand rule. The second deviation compensation value of the reference wafer and the wafer to be tested in the second coordinate system along the second direction is determined based on the reference arc height and the first arc height. The first compensation deviation value and the second deviation compensation value are converted into the coordinate system of the robot arm to obtain the deviation values ​​of the reference wafer and the wafer to be tested.

6. The wafer dynamic bias correction method according to claim 5, characterized in that, The step of determining the first compensation deviation value of the reference wafer and the wafer to be tested along the first direction in the second coordinate system based on the reference arc length and the first arc length includes: Confirm the timing sequence of the two triggering of the sensor on the reference wafer and the wafer to be tested, respectively; Based on the time sequence, the reference arc length, and the first arc length, the first offset distance of the reference wafer and the wafer to be tested along the first direction in the second coordinate system is obtained; The first compensation deviation value is determined based on the first offset distance.

7. The wafer dynamic bias correction method according to claim 5, characterized in that, Determining the second deviation compensation value of the reference wafer and the wafer to be tested along the second direction in the second coordinate system based on the reference arc height and the first arc height includes: The second offset distance of the reference wafer and the wafer to be tested along the second direction in the second coordinate system is obtained based on the reference arc length and the first arc length. The second compensation deviation value is determined based on the second offset distance.

8. A dynamic bias correction device for wafers, characterized in that, The correction device includes: The acquisition module acquires the robot arm's position when it triggers the sensor by moving a reference wafer along a preset straight path as reference position information, and the robot arm's position when it triggers the sensor by moving a wafer to be tested as actual position information. This includes: acquiring two sets of first Cartesian positions of the robot arm's end effector based on the robot arm coordinate system when the reference wafer triggers the sensor twice; calculating the reference arc length of the reference wafer triggering the sensor twice based on the two sets of first Cartesian positions; and calculating the reference arc height of the reference wafer triggering the sensor twice based on the reference arc length. The calculation module is used to calculate the deviation value between the reference wafer and the wafer to be tested on the preset straight path based on the reference position information and the actual position information. The correction module is used by the robotic arm to correct the final placement position of the wafer to be inspected based on the deviation value.

9. A computer device, characterized in that, The device includes a memory and a processor, wherein the memory stores computer-readable instructions, and the processor executes the computer-readable instructions to implement the steps of the wafer dynamic correction method as described in any one of claims 1 to 7.

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