Method and device for calibrating position of silicon wafer on vertical furnace boat

Abstract

The invention provides a method and device for calibrating the position of a silicon wafer on a vertical furnace boat, and relates to the technical field of vertical furnace boat silicon wafer production.The method comprises the steps that S1, a wafer conveying instruction is sent to a wafer conveying mechanical arm; s2, conveying the wafer to the target slot position; s3, detecting the position of the wafer by a detection probe, and determining the position coordinate of the wafer on the wafer boat; s4, comparing the position coordinates of the wafer on the wafer boat with the coordinates of the wafer boat, outputting calibration data to the wafer transfer manipulator, and reloading the wafer by the wafer transfer manipulator until the wafer is concentric with the wafer boat; and S5, based on the actual position offset of the center of the wafer relative to the current target slot position of the wafer boat, thermal compensation position calibration is executed through the wafer transfer manipulator. According to the invention, the position of the wafer on the boat can be calibrated systematically, the accuracy and reliability of calibration are improved, the influence of thermal expansion on the position of the wafer is considered, the position precision of the wafer and the boat in a high-temperature environment is ensured through thermal compensation calibration, and the problem of position calibration of the silicon wafer on the vertical furnace boat can be effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of vertical furnace boat silicon wafer production, and particularly relates to a method and device for calibrating the position of silicon wafers on a vertical furnace boat. Background Art

[0002] In the semiconductor manufacturing field, the vertical furnace boat silicon wafer process is an important means to achieve key processes such as thin film deposition and diffusion. In this process, the wafer must be accurately loaded into the vertical slot of the wafer boat. The concentricity of the wafer and the wafer boat directly affects the uniformity and consistency of the film thickness after the process. If the wafer and the wafer boat are not concentric, it will lead to uneven heating and gas diffusion conditions in different areas of the wafer surface, which will cause the film thickness deviation to exceed the process requirements, ultimately affecting the performance and yield of the chip. However, existing vertical furnace systems generally lack the function of calibrating the position of the wafer on the wafer boat: on the one hand, the wafer position deviation can only be indirectly inferred through the film thickness deviation after the process, and it is impossible to detect and calibrate the position of each wafer in real time before the process; on the other hand, the existing technology does not take into account the position offset of the wafer boat and the wafer caused by thermal expansion during high-temperature processes, and it is difficult to maintain the concentricity of the two in a dynamic temperature environment. It is even more impossible to achieve precise alignment of the wafer and the wafer boat through a systematic calibration process, which makes it difficult to effectively guarantee process stability and product yield. Summary of the Invention

[0003] The present invention provides a method and device for calibrating the position of silicon wafers on a vertical furnace boat, so as to solve at least one of the technical problems mentioned above.

[0004] To solve the above technical problems, the present invention discloses a method and device for calibrating the position of silicon wafers on a vertical furnace boat, the method comprising the following steps: S1, determine the vertical slot position on the wafer boat to which the wafer is to be transferred, use it as the target slot, and send a wafer transfer instruction to the wafer transfer robot; S2: After receiving the wafer transfer instruction, the wafer transfer robot transfers the wafer to the target slot. At the same time, the detection fixing mechanism moves the detection probe to the detection position of the target slot through the detection lifting mechanism. S3. After the wafer is transferred, the detection probe detects the wafer position and determines the position coordinates of the wafer on the wafer boat; S4. Compare the position coordinates of the wafer on the wafer boat with the wafer boat coordinates, output the calibration data to the wafer transfer robot, and the wafer transfer robot reloads the wafer and repeats the detection and calibration process until the wafer and the wafer boat are concentric; S5. After the furnace temperature rises to the target temperature and becomes thermally stable, temperature monitoring is performed to calculate the actual position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion. Based on the actual position offset of the wafer center relative to the current target slot of the wafer boat, thermal compensation position calibration is performed by the wafer transfer robot.

[0005] Preferably, step S1 includes: S11, calculating the three-dimensional spatial coordinates of the target slot based on the preset target slot number and the slot distribution model of the wafer boat; S12. The control system converts the three-dimensional spatial coordinate information of the target slot into a film transmission instruction and sends it to the film transmission robot. The film transmission instruction contains the coordinate information of the target slot and the relevant parameters of the film transmission action. The relevant parameters of the film transmission action include the movement speed, acceleration and film transmission time of the film transmission robot.

[0006] Preferably, step S2 includes: S21. After receiving the wafer transfer instruction, the robotic arm obtains the motion parameters of each joint based on the coordinate information of the target slot in the instruction, controls the gripper to grab the wafer and move it to the target slot of the wafer boat according to the planned path; S22. The control system sends a command to the detection lifting mechanism. The detection lifting mechanism drives the detection fixing mechanism to move in the vertical direction according to the Z-axis coordinate of the target slot, and moves the detection probe to the detection position of the target slot.

[0007] Preferably, step S3 includes: S31, the detection probe emits a laser beam toward the edge of the wafer, obtains the time from the laser beam being emitted to being reflected back to the detection probe, calculates the distance from the detection probe to the edge of the wafer, measures using multiple detection probes to obtain distance data from multiple detection probes to the edge of the wafer, and obtains multiple wafer edge point coordinates based on the distance data from multiple detection probes to the edge of the wafer; S32, selecting three coordinates from multiple wafer edge point coordinates obtained from the distance data from multiple detection probes to the wafer edge, and calculating the position coordinates of the wafer on the wafer boat using a three-point circle determination algorithm based on the three wafer edge point coordinates ( ).

[0008] Preferably, step S3 further includes: S33, Wafer edge distance data collected based on detection probe (j=1, 2, 3..., M, M ), where j is the total number of detection probes, combined with the installation coordinates of the detection probes ( , ), calculate the wafer edge point coordinate set ; S34, based on wafer edge point coordinate set Perform ellipse fitting to obtain the wafer edge ellipse equation, and calculate the ellipticity error E based on the wafer edge ellipse equation; S35, calculating the ellipticity error E based on the wafer edge ellipse equation to perform a debris risk determination, and determining whether to terminate the calibration operation of step S4 based on the determination result: When E> When the wafer is judged to be deformed or edge-collapsed, is the ellipticity error threshold; When the reflected signal intensity of K consecutive detection probes is less than the preset minimum value of the reflected signal intensity or the reflected signal return time is greater than the preset maximum value of the reflected signal return time, it is determined that microscopic debris or cracks exist; If it is determined that any one or more of deformation, edge collapse, microscopic fragments or cracks occur, the calibration operation of step S4 is terminated, otherwise step S4 is continued.

[0009] Preferably, step S4 includes: S41, the position coordinates of the wafer on the wafer boat ( ) and the coordinates of the center point of the crystal boat target slot ( ) to compare and calculate the position deviation 、 and ; S42, based on position deviation 、 and , generate calibration data through the calibration algorithm, the calibration data includes the coordinate offset that the film transfer robot needs to adjust when transferring the film next time; S43, the control system sends the calibration data to the wafer transfer robot, and the wafer transfer robot adjusts the gripping position of the gripper and the motion trajectory of the robot arm according to the calibration data, and readjusts the wafer; S44, repeating steps S2 and S3 to perform position detection and calibration on the readjusted wafer until the deviation between the position coordinates of the wafer and the coordinates of the center point of the target slot of the wafer boat is within a preset error range, and the wafer is considered to be concentric with the wafer boat.

[0010] Preferably, step S5 includes: S51. After the wafer and the wafer boat are concentric, the vertical furnace is heated to the target temperature and maintained thermally stable; S52, monitor the thermal expansion state of the crystal boat in real time through the temperature sensors distributed around the crystal boat, and collect the current temperature value ; S53, Silicon material thermal expansion coefficient based on wafer , wafer nominal radius , thermal expansion coefficient of Jingzhou And the target slot center reference temperature , calculate the actual position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion; S54, inputting into the control system an actual x-direction position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion and an actual y-direction position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion; S55, the control system converts the actual x-direction position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion and the actual y-direction position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion into a thermal compensation instruction and sends it to the wafer transfer robot; S56, the film conveyor adjusts the gripper motion trajectory based on the thermal compensation instruction, and adjusts the motion trajectory according to the compensation vector (- ,- ) Re-adjust the wafer position and verify the residual deviation between the wafer center and the target slot center after thermal compensation through the detection probe until the residual deviation between the wafer center and the target slot center is within the preset allowable error range.

[0011] Preferably, based on the thermal expansion coefficient of silicon material of the wafer , wafer nominal radius , thermal expansion coefficient of Jingzhou And the target slot center reference temperature , calculate the actual position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion: ; ; ;in, is the difference between the current temperature and the reference temperature at the center of the target slot. and They are the x-axis and y-axis distances from the center of the target slot to the thermal expansion reference point of the wafer boat. The thermal expansion reference point is set at the center of the wafer boat base. The x-axis position offset of the wafer center relative to the current target slot of the wafer boat caused by thermal expansion. It is the actual position offset of the wafer center in the y direction relative to the current target slot of the wafer boat due to thermal expansion.

[0012] A device for calibrating the position of silicon wafers on a vertical furnace boat, comprising: The wafer boat is provided with multiple vertical slots for carrying wafers; Temperature sensor, installed on the wafer boat, used to collect real-time temperature inside the furnace; Wafers are used to fit into the slots of the wafer boat; The detection lifting mechanism is fixedly installed in the vertical furnace boat system and is used to drive the detection fixing mechanism to rise and fall; The detection fixing mechanism is installed on the detection lifting mechanism. A number of detection probes are provided on the detection fixing mechanism. The detection probes are used to be lifted and lowered with the detection lifting mechanism to the slot to be detected on the wafer boat. The position coordinates of the wafer on the wafer boat are obtained by measuring the distance between the edge of the wafer and the detection probes; The wafer transfer robot is used to grab the wafer through the robotic arm and gripper structure and transfer it to the designated slot of the wafer boat; The control system is electrically connected to the temperature sensor, the film transfer manipulator, the detection lifting mechanism, and the detection probe, and is used to send film transfer instructions, process detection data, and generate calibration signals.

[0013] Preferably, it also includes: Edge reconstruction unit for wafer edge distance data collected by the detection probe and the installation coordinates of the detection probe ( , ), calculate the wafer edge point coordinate set ; Ellipse fitting unit for wafer edge point coordinate sets Perform ellipse fitting to obtain the wafer edge ellipse equation, and calculate the ellipticity error E based on the wafer edge ellipse equation; The defect judgment unit calculates the ellipticity error E based on the wafer edge ellipse equation to perform debris risk judgment, and determines whether to terminate the calibration operation of step S4 based on the judgment result.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention can systematically calibrate the position of the wafer on the wafer boat through the steps of determining the target slot, transferring the wafer, detecting the position, comparing the coordinate calibration and thermal compensation, thereby improving the accuracy and reliability of the calibration, taking into account the influence of thermal expansion on the wafer position, ensuring the position accuracy of the wafer and the wafer boat in a high-temperature environment through thermal compensation calibration, ensuring the stability and consistency of subsequent processes, and effectively solving the problem of position calibration of silicon wafers on a vertical furnace boat. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 A side view of the silicon wafer position calibration device on a vertical furnace boat of the present invention; Figure 2 This is a top view of the silicon wafer position calibration device on the vertical furnace boat of the present invention.

[0016] In the figure: 1. Wafer boat; 2. Wafer; 3. Detection fixing mechanism; 4. Detection lifting mechanism; 5. Wafer transfer robot; 30. Detection probe. DETAILED DESCRIPTION

[0017] 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 used to illustrate and explain the present invention, and are not used to limit the present invention.

[0018] In addition, in the present invention, descriptions such as "first" and "second" are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but this must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0019] The present invention provides the following embodiments Example 1 The embodiment of the present invention provides a method and device for calibrating the position of silicon wafers on a vertical furnace boat, such as Figure 1-2 As shown, the following steps are included: S1, determining the vertical slot position on the wafer boat 1 to which the wafer 2 is to be transferred, taking it as the target slot, and sending a wafer transfer instruction to the wafer transfer robot 5; S2, after receiving the wafer transfer instruction, the wafer transfer robot 5 transfers the wafer 2 to the target slot, and at the same time, the detection fixing mechanism 3 moves the detection probe 30 to the detection position of the target slot through the detection lifting mechanism 4; S3, after the wafer transfer is completed, the detection probe 30 detects the position of the wafer 2 and determines the position coordinates of the wafer 2 on the wafer boat 1; S4, comparing the position coordinates of wafer 2 on wafer boat 1 with the coordinates of wafer boat 1, outputting calibration data to wafer transfer robot 5, which reloads wafer 2 and repeats the detection and calibration process until wafer 2 is concentric with wafer boat 1; S5. After the furnace temperature rises to the target temperature and becomes thermally stable, temperature monitoring is performed to calculate the actual position offset of the center of wafer 2 relative to the current target slot of wafer boat 1 due to thermal expansion. Based on the actual position offset of the center of wafer 2 relative to the current target slot of wafer boat 1, thermal compensation position calibration is performed by the wafer transfer robot 5.

[0020] The working principle and beneficial effects of the above technical solution are as follows: when working, the vertical slot to which the wafer 2 is about to be transferred on the wafer boat 1 is first determined as the target slot, and a transfer instruction containing the target slot coordinate information and transfer action related parameters is sent to the transfer robot 5. After receiving the instruction, the transfer robot 5 transfers the wafer 2 to the target slot according to the planned path, and at the same time, the detection fixing mechanism 3 moves the detection probe 30 to the detection position of the target slot through the detection lifting mechanism 4. After the transfer is completed, the detection probe 30 detects the position of the wafer 2 to determine its position coordinates on the wafer boat 1, compares the coordinates with the coordinates of the center point of the target slot of the wafer boat 1, and outputs calibration data to the transfer robot 5. The transfer robot 5 reloads the wafer 2 and repeats the detection and calibration process until the wafer 2 is concentric with the wafer boat 1. After the furnace temperature rises to the target temperature and is thermally stable, the temperature is monitored by the temperature sensor, and the actual position offset of the center of the wafer 2 relative to the current target slot of the wafer boat 1 caused by thermal expansion is calculated. Based on the offset, the thermal compensation position calibration is performed by the transfer robot 5; The present invention can systematically calibrate the position of wafer 2 on wafer boat 1 through the steps of determining target slot position, transferring wafer 2, detecting position, comparing coordinate calibration and thermal compensation, thereby improving the accuracy and reliability of calibration, taking into account the influence of thermal expansion on the position of wafer 2, ensuring the position accuracy of wafer 2 and wafer boat 1 in a high temperature environment through thermal compensation calibration, ensuring the stability and consistency of subsequent processes, and effectively solving the problem of position calibration of silicon wafers on a vertical furnace boat.

[0021] Example 2 Based on Example 1, step S1 includes: S11, calculating the three-dimensional spatial coordinates of the target slot based on the preset target slot number and the slot distribution model of the wafer boat 1; S12. The control system converts the three-dimensional spatial coordinate information of the target slot into a film transmission instruction and sends it to the film transmission robot 5. The film transmission instruction contains the coordinate information of the target slot and the relevant parameters of the film transmission action. The relevant parameters of the film transmission action include the moving speed, acceleration and film transmission time of the film transmission robot 5.

[0022] In this embodiment, the slot distribution model of the wafer boat 1 is based on the actual structure of the wafer boat 1. A spatial coordinate system is established with a fixed point (such as the geometric center or a corner point) of the wafer boat 1 as the coordinate origin. The coordinates of each slot ( ) is obtained by measurement, and i represents the slot number.

[0023] The working principle and beneficial effects of the above technical solution are as follows: Based on the preset target slot number and the slot distribution model of the wafer boat 1, a spatial coordinate system is established with a fixed point on the wafer boat 1 as the coordinate origin. The coordinates of each slot are obtained by measurement, and the three-dimensional spatial coordinates of the target slot are calculated. The control system converts this three-dimensional spatial coordinate information into a film transfer instruction containing the target slot coordinate information and film transfer action parameters such as the movement speed, acceleration, and film transfer time of the film transfer robot 5, and sends it to the film transfer robot 5. The present invention uses the pre-set target slot number and the slot distribution model of the wafer boat 1 to calculate the three-dimensional spatial coordinates of the target slot, so that the wafer transfer instruction has a clear coordinate basis, ensuring that the wafer transfer robot 5 can accurately obtain the target slot information, and by converting the coordinate information into instructions containing parameters related to the wafer transfer action, precise control of the action of the wafer transfer robot 5 is achieved, thereby improving the accuracy and efficiency of the wafer transfer, and laying the foundation for the subsequent accurate transmission and position calibration of the wafer 2. This calculation method based on the model and coordinates ensures the scientificity and reliability of the slot positioning.

[0024] Example 3 Based on Example 1, step S2 includes: S21, after receiving the wafer transfer instruction, the robotic arm 5 obtains the motion parameters of each joint based on the coordinate information of the target slot in the instruction, controls the gripper to grab the wafer 2 and move it to the target slot of the wafer boat 1 according to the planned path; S22 , the control system sends a command to the detection lifting mechanism 4 , which drives the detection fixing mechanism 3 to move vertically according to the Z-axis coordinate of the target slot, and moves the detection probe 30 to the detection position of the target slot.

[0025] In this embodiment, the robotic arm obtains the motion parameters of each joint based on the coordinate information of the target slot in the instruction based on a kinematic algorithm. The kinematic algorithm is based on the structural parameters of the robotic arm (such as joint length, connecting rod length, etc.) and the target position coordinates, and the joint motion parameters are calculated through forward kinematics or inverse kinematics formulas. The joint motion parameters include motion angle and displacement.

[0026] In this embodiment, the detection position of the target slot is pre-set according to the thickness of the wafer 2 and the measurement requirements of the detection probe 30 .

[0027] The working principle and beneficial effects of the above technical solution are as follows: after receiving the wafer transfer instruction, the wafer transfer robot 5 calculates the motion parameters such as the motion angle and displacement of each joint based on the target slot coordinate information in the instruction through a kinematic algorithm based on the robot arm structure parameters and the target position coordinates, controls the gripper to grab the wafer 2 and move it to the target slot of the wafer boat 1 according to the planned path, and at the same time, the control system sends an instruction to the detection lifting mechanism 4. The detection lifting mechanism 4 drives the detection fixing mechanism 3 to move in the vertical direction according to the Z-axis coordinate of the target slot, and moves the detection probe 30 to the detection position pre-set according to the thickness of the wafer 2 and the measurement requirements of the detection probe 30; The wafer conveying robot 5 of the present invention obtains joint motion parameters through kinematic algorithms, can accurately control the movement of the robotic arm, realize accurate grasping of the wafer 2 by the gripper and transmission according to the planned path, ensure that the wafer 2 can accurately reach the target slot, and the detection lifting mechanism 4 moves the detection fixing mechanism 3 according to the Z-axis coordinate of the target slot, and moves the detection probe 30 to the preset detection position, ensuring that the detection probe 30 can detect the wafer 2 at the appropriate position, providing an accurate measurement basis for subsequent position detection. The coordinated action of the two improves the accuracy and efficiency of the entire wafer conveying and detection process.

[0028] Example 4 Based on Example 1, step S3 includes: S31, the detection probe 30 emits a laser beam toward the edge of the wafer 2, obtains the time from the laser beam being emitted to being reflected back to the detection probe 30, calculates the distance from the detection probe 30 to the edge of the wafer 2, measures using multiple detection probes 30, obtains distance data from multiple detection probes 30 to the edge of the wafer 2, and obtains multiple edge point coordinates of the wafer 2 based on the distance data from multiple detection probes 30 to the edge of the wafer 2; S32, selecting three coordinates from the multiple wafer 2 edge point coordinates obtained from the distance data from the multiple detection probes 30 to the wafer 2 edge, and calculating the position coordinates of the wafer 2 on the wafer boat 1 using a three-point circle determination algorithm based on the three wafer 2 edge point coordinates ( ).

[0029] In this embodiment, the distance from the detection probe 30 to the edge of the wafer 2 is: ;in, To detect the distance from the probe 30 to the edge of the wafer 2, is the speed of light, is the time from the laser beam being emitted to being reflected back to the detection probe 30, is the refractive index of air.

[0030] In this embodiment, the position coordinates of the wafer 2 on the wafer boat 1 are calculated using a three-point circle determination algorithm based on the distance data from the three detection probes 30 to the edge of the wafer 2 ( )include: The coordinates of the three edge points of wafer 2 are known to be , and , let the center coordinates of wafer 2 be , then the coordinates of the three wafer 2 edge points and the center coordinates of wafer 2 satisfy the following formula:

[0031] have to: ; ; in, ; ; ; Assume the coordinates of the center point of the target slot are ( ), then the position coordinates of wafer 2 on wafer boat 1 ( )middle , ; , then the position coordinates of wafer 2 on wafer boat 1 ( ) = ( ),in, They respectively represent the horizontal coordinate, vertical coordinate and vertical coordinate of the center of the wafer 2 in the coordinate system with the fixed point of the wafer boat 1 as the origin.

[0032] The working principle and beneficial effects of the above technical solution: The present invention uses the laser beam reflection time to calculate the distance from the detection probe 30 to the edge of the wafer 2, combines the measurement data of multiple detection probes 30, and accurately calculates the position coordinates of the wafer 2 on the wafer boat 1 through the three-point circle determination algorithm. This method uses the high precision of laser measurement and the mathematical principle of the three-point circle determination algorithm to accurately determine the center position of the wafer 2, providing accurate data support for subsequent position calibration.

[0033] Example 5 Based on Example 1, step S3 further includes: S33, based on the wafer edge distance data collected by the detection probe 30 (j=1, 2, 3..., M, M ), where j is the total number of detection probes 30, combined with the installation coordinates of the detection probes 30 ( , ), calculate the wafer edge point coordinate set ; S34, based on wafer edge point coordinate set Perform ellipse fitting to obtain the wafer edge ellipse equation, and calculate the ellipticity error E based on the wafer edge ellipse equation; S35, calculating the ellipticity error E based on the wafer edge ellipse equation to perform a debris risk determination, and determining whether to terminate the calibration operation of step S4 based on the determination result: When E> When the wafer is judged to be deformed or edge-collapsed, is the ellipticity error threshold; When the reflected signal strength of K consecutive detection probes 30 is less than the preset minimum reflected signal strength or the reflected signal return time is greater than the preset maximum reflected signal return time, it is determined that microscopic debris or cracks exist; If it is determined that any one or more of deformation, edge collapse, microscopic fragments or cracks occur, the calibration operation of step S4 is terminated, otherwise step S4 is continued.

[0034] In this embodiment, based on the wafer edge distance data collected by the detection probe 30, (j=1, 2, 3..., M, M ), combined with the installation coordinates of the detection probe 30 ( , ), calculate the wafer edge point coordinate set : ;in, and are the horizontal and vertical coordinates of the wafer edge point corresponding to the j-th detection probe 30, and are the horizontal and vertical coordinates of the installation coordinates of the j-th detection probe 30, is the detection value of the jth detection probe 30, is the laser beam emission direction angle of the jth detection probe 30, for The cosine value of for The sine value of .

[0035] In this embodiment, the wafer edge ellipse equation is: (a>b); where x and y are the horizontal and vertical coordinates of any point on the edge of the wafer, respectively. and are the horizontal and vertical coordinates of the center of the ellipse, a and b are the lengths of the major and minor axes of the ellipse respectively; ;in, is the ellipticity error.

[0036] The working principle and beneficial effects of the above technical solution are as follows: by calculating the wafer edge point coordinate set through the distance data and installation coordinates collected by the detection probe 30, and then performing ellipse fitting and ellipticity error calculation, the shape defects of the wafer 2 can be effectively detected. The formula Based on the installation position and measurement distance of the detection probe 30, combined with the laser emission direction angle, the edge point coordinates are accurately calculated. The ellipse fitting algorithm describes the edge shape of the wafer by establishing an ellipse equation. By calculating the ellipticity error through the difference between the major and minor axes, the deformation degree of wafer 2 can be quantitatively evaluated. By setting the threshold, signal strength, and return time judgment conditions, defects such as deformation, edge collapse, microscopic fragments or cracks in wafer 2 can be discovered in a timely manner, avoiding invalid calibration of defective wafer 2, improving calibration efficiency and product quality, and ensuring the normal progress of subsequent processes.

[0037] Example 6 Based on Example 1, step S4 includes: S41, the position coordinates of wafer 2 on wafer boat 1 ( ) and the coordinates of the center point of the target slot of crystal boat 1 ( ) to compare and calculate the position deviation 、 and ; S42, based on position deviation 、 and , generating calibration data through a calibration algorithm, the calibration data including the coordinate offset that needs to be adjusted by the film transfer robot 5 during the next film transfer; S43, the control system sends the calibration data to the wafer transfer robot 5, and the wafer transfer robot 5 adjusts the gripping position of the gripper and the motion trajectory of the robot arm according to the calibration data, and readjusts the wafer 2; S44, repeat steps S2 and S3 to perform position detection and calibration on the readjusted wafer 2 until the deviation between the position coordinates of wafer 2 and the coordinates of the center point of the target slot of wafer boat 1 is within a preset error range, and wafer 2 is considered to be concentric with wafer boat 1.

[0038] In this embodiment, The value is usually 0.

[0039] The working principle and beneficial effects of the above technical solution are as follows: the present invention calculates the deviation and generates calibration data by comparing the position coordinates of wafer 2 and the coordinates of the center point of the target slot, and can accurately determine the direction and amplitude that the wafer transfer robot 5 needs to adjust. The calibration algorithm generates calibration data based on the deviation to ensure the scientificity and accuracy of the adjustment. The wafer transfer robot 5 adjusts the gripping position of the gripper and the movement trajectory of the robot arm according to the calibration data to achieve precise correction of the position of wafer 2. By repeating the detection and calibration process until the deviation is within the preset error range, the concentricity of wafer 2 and wafer boat 1 is guaranteed, and the accuracy and reliability of position calibration are improved. This closed-loop calibration mechanism can effectively eliminate errors and ensure that the position of wafer 2 on wafer boat 1 meets the process requirements.

[0040] Example 7 Based on Example 1, step S5 includes: S51, after the wafer 2 is concentric with the wafer boat 1, the vertical furnace is heated to the target temperature and kept thermally stable; S52, monitor the thermal expansion state of the wafer boat 1 in real time through the temperature sensors distributed around the wafer boat 1, and collect the current temperature value ; S53, based on the thermal expansion coefficient of silicon material of wafer 2 , wafer nominal radius , Thermal expansion coefficient of crystal boat 1 And the target slot center reference temperature , calculate the actual position offset of the center of wafer 2 relative to the current target slot of wafer boat 1 caused by thermal expansion; S54, inputting into the control system the actual x-direction position offset of the center of the wafer 2 relative to the current target slot of the wafer boat 1 caused by thermal expansion and the actual y-direction position offset of the center of the wafer 2 relative to the current target slot of the wafer boat 1 caused by thermal expansion; S55, the control system converts the actual position offset of the center of the wafer 2 relative to the current target slot of the wafer boat 1 in the x direction caused by thermal expansion and the actual position offset of the center of the wafer 2 relative to the current target slot of the wafer boat 1 in the y direction caused by thermal expansion into a thermal compensation instruction and sends it to the wafer transfer robot 5; S56, the film conveyor robot 5 adjusts the movement trajectory of the gripper based on the thermal compensation instruction, and adjusts the movement trajectory according to the compensation vector (- ,- ) Re-adjust the position of wafer 2 and verify the residual deviation between the center of wafer 2 and the center of the target slot after thermal compensation through the detection probe 30 until the residual deviation between the center of wafer 2 and the center of the target slot is within the preset allowable error range.

[0041] Preferably, based on the thermal expansion coefficient of the silicon material of the wafer 2 , wafer nominal radius , Thermal expansion coefficient of crystal boat 1 And the target slot center reference temperature , calculate the actual position offset of the center of wafer 2 relative to the current target slot of wafer boat 1 due to thermal expansion: ; ; ;in, is the difference between the current temperature and the reference temperature at the center of the target slot. and They are the x-axis and y-axis distances from the center of the target slot to the thermal expansion reference point of the wafer boat 1. The thermal expansion reference point is set at the center of the base of the wafer boat 1. is the actual x-direction position offset of the center of wafer 2 relative to the current target slot of wafer boat 1 due to thermal expansion, is the actual position offset in the y direction of the center of the wafer 2 relative to the current target slot of the wafer boat 1 due to thermal expansion.

[0042] The working principle and beneficial effects of the above technical solution are as follows: considering the influence of temperature change on the thermal expansion of wafer 2 and wafer boat 1, the temperature is monitored in real time by temperature sensor, and the thermal expansion calculation formula is used to calculate the temperature. and , taking into account the thermal expansion coefficients of wafer 2 and wafer boat 1, the nominal radius of the wafer, and the distance from the target slot to the thermal expansion reference point, the position offset caused by thermal expansion can be accurately calculated. The compensation vector (- ,- ) Adjust the position of wafer 2 to achieve thermal compensation calibration, ensuring the position accuracy of wafer 2 and wafer boat 1 in a high-temperature environment. This thermal compensation mechanism effectively solves the impact of thermal expansion on the position of wafer 2, improves the adaptability and reliability of calibration, and ensures the stability of the position of wafer 2 during high-temperature processes.

[0043] Example 8 Based on Example 1, a device for calibrating the position of silicon wafers on a vertical furnace boat includes: Wafer boat 1, which is provided with multiple vertical slots for carrying wafers 2; The temperature sensor is installed on the wafer boat 1 and is used to collect the temperature inside the furnace in real time; Wafer 2, adapted to be installed in the slot of wafer boat 1; The detection lifting mechanism 4 is fixedly installed in the vertical furnace boat system and is used to drive the detection fixing mechanism 3 to move up and down; The detection fixing mechanism 3 is mounted on the detection lifting mechanism 4. A plurality of detection probes 30 are provided on the detection fixing mechanism 3. The detection probes 30 are used to be lifted and lowered along with the detection lifting mechanism 4 to the slot to be detected on the wafer boat 1. The position coordinates of the wafer 2 on the wafer boat 1 are obtained by measuring the distance between the edge of the wafer 2 and the detection probes 30. The wafer transfer robot 5 is used to grab the wafer 2 through the robot arm and the gripper structure and transfer it to the designated slot of the wafer boat 1; The control system is electrically connected to the temperature sensor, the film transfer manipulator 5, the detection lifting mechanism 4, and the detection probe 30, and is used to send film transfer instructions, process detection data, and generate calibration signals.

[0044] Preferably, it also includes: Edge reconstruction unit, used to detect the edge distance data of the wafer collected by the detection probe 30 and the installation coordinates of the detection probe 30 ( , ), calculate the wafer edge point coordinate set ; Ellipse fitting unit for wafer edge point coordinate sets Perform ellipse fitting to obtain the wafer edge ellipse equation, and calculate the ellipticity error E based on the wafer edge ellipse equation; The defect judgment unit calculates the ellipticity error E based on the wafer edge ellipse equation to perform debris risk judgment, and determines whether to terminate the calibration operation of step S4 based on the judgment result.

[0045] The working principle and beneficial effects of the above technical solution are as follows: the silicon wafer position calibration device on the vertical furnace boat includes a wafer boat 1, a temperature sensor, a wafer 2, a detection lifting mechanism 4, a detection fixing mechanism 3, a wafer conveying robot 5 and a control system. A plurality of vertical slots are arranged on the wafer boat 1 to carry the wafer 2. The temperature sensor is installed on the wafer boat 1 to collect the temperature in the furnace in real time. The detection lifting mechanism 4 is fixedly installed in the vertical furnace boat system to drive the detection fixing mechanism 3 to rise and fall. A plurality of detection probes 30 are provided on the detection fixing mechanism 3, which are lifted and lowered to the slot to be detected on the wafer boat 1 with the detection lifting mechanism 4. The position coordinates of the wafer 2 on the wafer boat 1 are obtained by measuring the distance between the edge of the wafer 2 and the detection probe 30, and the detection probe 30 is transmitted to the wafer boat 1. The wafer manipulator 5 grabs the wafer 2 through the robotic arm and gripper structure and transfers it to the designated slot of the wafer boat 1. The control system is electrically connected to the temperature sensor, the wafer transfer manipulator 5, the detection lifting mechanism 4, and the detection probe 30. It sends wafer transfer instructions, processes detection data, and generates calibration signals. It also includes an edge reconstruction unit, an ellipse fitting unit, and a defect judgment unit. The edge reconstruction unit calculates the wafer edge point coordinate set based on the wafer edge distance data and installation coordinates collected by the detection probe 30. The ellipse fitting unit performs ellipse fitting on the coordinate set to obtain an ellipse equation and calculate the ellipse error. The defect judgment unit performs fragmentation risk judgment based on the ellipse error and decides whether to terminate the calibration operation. The present invention realizes the precise calibration of the position of wafer 2 on wafer boat 1 through the coordinated work of various components. The vertical slot design of wafer boat 1 facilitates the carrying of wafer 2. The temperature sensor monitors the temperature in real time and provides data support for thermal compensation. The detection lifting mechanism 4 and the detection fixing mechanism 3 drive the detection probe 30 to accurately detect the position of wafer 2. The wafer conveying robot 5 realizes the precise transmission of wafer 2. The control system coordinates the actions of various components and processes data to generate calibration signals. The setting of edge reconstruction unit, ellipse fitting unit and defect judgment unit can effectively detect defects of wafer 2, avoid calibrating defective wafer 2, and improve calibration efficiency and product quality. The whole device has a reasonable structure and complete functions, which can meet the needs of silicon wafer position calibration on vertical furnace boat, ensure the position accuracy of wafer 2 on wafer boat 1, and provide guarantee for the smooth progress of subsequent processes.

[0046] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for calibrating the position of silicon wafers on a vertical furnace boat, characterized in that: The following steps are involved: S1, determining the vertical slot position on the wafer boat (1) to which the wafer (2) is to be transferred, taking it as the target slot, and sending a wafer transfer instruction to the wafer transfer robot (5); S2, the wafer transfer robot (5) transfers the wafer (2) to the target slot after receiving the wafer transfer instruction, and at the same time, the detection fixing mechanism (3) moves the detection probe (30) to the detection position of the target slot through the detection lifting mechanism (4); S3, after the wafer transmission is completed, the detection probe (30) detects the position of the wafer (2) and determines the position coordinates of the wafer (2) on the wafer boat (1); S4, comparing the position coordinates of the wafer (2) on the wafer boat (1) with the coordinates of the wafer boat (1), outputting the calibration data to the wafer transfer robot (5), and the wafer transfer robot (5) reloads the wafer (2) and repeats the detection and calibration process until the wafer (2) is concentric with the wafer boat (1); S5. After the furnace temperature rises to the target temperature and becomes thermally stable, temperature monitoring is performed to calculate the actual position offset of the center of the wafer (2) relative to the current target slot of the wafer boat (1) due to thermal expansion. Based on the actual position offset of the center of the wafer (2) relative to the current target slot of the wafer boat (1), thermal compensation position calibration is performed by the wafer transfer robot (5).

2. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 1, wherein: Step S1 includes: S11, calculating the three-dimensional spatial coordinates of the target slot based on the preset target slot number and the slot distribution model of the crystal boat (1); S12, the control system converts the three-dimensional spatial coordinate information of the target slot into a film transmission instruction and sends it to the film transmission robot (5). The film transmission instruction includes the coordinate information of the target slot and relevant parameters of the film transmission action. The relevant parameters of the film transmission action include the moving speed, acceleration and film transmission time of the film transmission robot (5).

3. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 1, wherein: Step S2 includes: S21, after the wafer transfer robot (5) receives the wafer transfer instruction, the robot arm obtains the motion parameters of each joint based on the coordinate information of the target slot in the instruction, controls the gripper to grab the wafer (2) and moves it to the target slot of the wafer boat (1) according to the planned path; S22, the control system sends a command to the detection lifting mechanism (4), and the detection lifting mechanism (4) drives the detection fixing mechanism (3) to move in the vertical direction according to the Z-axis coordinate of the target slot, and moves the detection probe (30) to the detection position of the target slot.

4. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 1, wherein: Step S3 includes: S31, the detection probe (30) emits a laser beam toward the edge of the wafer (2), obtains the time from the emission to the reflection of the laser beam back to the detection probe (30), calculates the distance from the detection probe (30) to the edge of the wafer (2), measures with multiple detection probes (30), obtains multiple distance data from the detection probes (30) to the edge of the wafer (2), and obtains multiple edge point coordinates of the wafer (2) based on the distance data from the multiple detection probes (30) to the edge of the wafer (2); S32, obtaining distance data from multiple detection probes (30) to the edge of the wafer (2) and selecting three coordinates from multiple wafer (2) edge point coordinates, and calculating the position coordinates of the wafer (2) on the wafer boat (1) using a three-point circle determination algorithm based on the three wafer (2) edge point coordinates ( ).

5. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 1, wherein: Step S3 further includes: S33, based on the wafer edge distance data collected by the detection probe (30) (j=1, 2, 3..., M, M ), where j is the total number of detection probes (30), combined with the installation coordinates of the detection probes (30) ( , ), calculate the wafer edge point coordinate set ; S34, based on wafer edge point coordinate set Perform ellipse fitting to obtain the wafer edge ellipse equation, and calculate the ellipticity error E based on the wafer edge ellipse equation; S35, calculating the ellipticity error E based on the wafer edge ellipse equation to perform a debris risk determination, and determining whether to terminate the calibration operation of step S4 based on the determination result: When E> When the wafer is judged to be deformed or edge-collapsed, is the ellipticity error threshold; When the reflected signal intensity of K consecutive detection probes (30) is less than a preset minimum reflected signal intensity or the reflected signal return time is greater than a preset maximum reflected signal return time, it is determined that microscopic debris or cracks exist; If it is determined that any one or more of deformation, edge collapse, microscopic fragments or cracks occur, the calibration operation of step S4 is terminated, otherwise step S4 is continued.

6. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 1, wherein: Step S4 includes: S41, the position coordinates of the wafer (2) on the wafer boat (1) ( ) and the coordinates of the center point of the target slot of Jingzhou (1) ( ) to compare and calculate the position deviation 、 and ; S42, based on position deviation 、 and , generating calibration data through a calibration algorithm, the calibration data including the coordinate offset that the film transfer robot (5) needs to adjust when transferring the film next time; S43, the control system sends the calibration data to the wafer transfer robot (5), and the wafer transfer robot (5) adjusts the gripping position of the gripper and the motion trajectory of the robot arm according to the calibration data, and readjusts the wafer (2); S44, repeating steps S2 and S3 to perform position detection and calibration on the readjusted wafer (2) until the deviation between the position coordinates of the wafer (2) and the coordinates of the center point of the target slot of the wafer boat (1) is within a preset error range, and the wafer (2) is considered to be concentric with the wafer boat (1).

7. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 1, wherein: Step S5 includes: S51, after the wafer (2) and the wafer boat (1) are concentric, heating the vertical furnace to the target temperature and maintaining thermal stability; S52, monitor the thermal expansion state of the crystal boat (1) in real time through temperature sensors distributed around the crystal boat (1), and collect the current temperature value ; S53, Thermal Expansion Coefficient of Silicon Material Based on Wafer (2) , wafer nominal radius 、The thermal expansion coefficient of the crystal boat (1) And the target slot center reference temperature , calculating the actual position offset of the center of the wafer (2) relative to the current target slot of the wafer boat (1) caused by thermal expansion; S54, for inputting into the control system an actual position offset in the x direction of the center of the wafer (2) relative to the current target slot of the wafer boat (1) caused by thermal expansion and an actual position offset in the y direction of the center of the wafer (2) relative to the current target slot of the wafer boat (1) caused by thermal expansion; S55, the control system converts the actual position offset of the center of the wafer (2) relative to the current target slot of the wafer boat (1) in the x direction caused by thermal expansion and the actual position offset of the center of the wafer (2) relative to the current target slot of the wafer boat (1) caused by thermal expansion into a thermal compensation instruction and sends it to the wafer conveyor manipulator (5); S56, the film conveyor manipulator (5) adjusts the movement trajectory of the gripper based on the thermal compensation instruction, and adjusts the movement trajectory according to the compensation vector (- ,- ) readjust the position of the wafer (2), and verify the residual deviation between the center of the wafer (2) and the center of the target slot after thermal compensation by using the detection probe (30), until the residual deviation between the center of the wafer (2) and the center of the target slot is within a preset allowable error range.

8. The method for calibrating the position of silicon wafers on a vertical furnace boat according to claim 7, wherein: Based on the thermal expansion coefficient of silicon material in the wafer (2) , wafer nominal radius 、The thermal expansion coefficient of the crystal boat (1) And the target slot center reference temperature , calculate the actual position offset of the center of the wafer (2) relative to the current target slot of the wafer boat (1) due to thermal expansion: ； ； ;in, is the difference between the current temperature and the reference temperature at the center of the target slot. and are the x-axis and y-axis distances from the center of the target slot to the thermal expansion reference point of the crystal boat (1), respectively. The thermal expansion reference point is set at the center of the base of the crystal boat (1). is the actual position offset in the x direction of the center of the wafer (2) relative to the current target slot of the wafer boat (1) due to thermal expansion, It is the actual position offset in the y direction of the center of the wafer (2) relative to the current target slot of the wafer boat (1) due to thermal expansion.

9. A device for calibrating the position of silicon wafers on a vertical furnace boat, configured to perform position calibration using the method for calibrating the position of silicon wafers on a vertical furnace boat according to any one of claims 1 to 8, characterized in that: include: A wafer boat (1), wherein a plurality of vertical slots are provided on the wafer boat (1) for carrying wafers (2); A temperature sensor, mounted on the crystal boat (1), is used to collect the temperature inside the furnace in real time; A wafer (2) adapted to be mounted in a slot of the wafer boat (1); A detection lifting mechanism (4) is fixedly installed in the vertical furnace boat system and is used to drive the detection fixing mechanism (3) to rise and fall; A detection fixing mechanism (3) is mounted on the detection lifting mechanism (4), and a plurality of detection probes (30) are provided on the detection fixing mechanism (3). The detection probes (30) are used to be lifted and lowered along with the detection lifting mechanism (4) to the slot to be detected on the wafer boat (1), and the position coordinates of the wafer (2) on the wafer boat (1) are obtained by measuring the distance between the edge of the wafer (2) and the detection probes (30); A wafer transfer robot (5) is used to grab the wafer (2) and transfer it to a designated slot of the wafer boat (1) through a robotic arm and a gripper structure; The control system is electrically connected to the temperature sensor, the film transfer manipulator (5), the detection lifting mechanism (4), and the detection probe (30), and is used to send film transfer instructions, process detection data, and generate calibration signals.

10. The device for calibrating the position of silicon wafers on a vertical furnace boat according to claim 9, wherein: Also includes: An edge reconstruction unit for wafer edge distance data collected by a detection probe (30) and the installation coordinates of the detection probe (30) ( , ), calculate the wafer edge point coordinate set ; Ellipse fitting unit for wafer edge point coordinate sets Perform ellipse fitting to obtain the wafer edge ellipse equation, and calculate the ellipticity error E based on the wafer edge ellipse equation; The defect judgment unit calculates the ellipticity error E based on the wafer edge ellipse equation to perform debris risk judgment, and determines whether to terminate the calibration operation of step S4 based on the judgment result.

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