A wafer calibration method and calibration system

Abstract

This application provides a wafer calibration method and system. The method includes: placing the wafer on a calibration platform and acquiring an overexposed image of the wafer; acquiring a calibration reference for the calibration platform; calculating a calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image; moving the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value; identifying the wafer's identification information, registering the wafer as calibrated, and resetting the calibration platform. The technical solution of this application can improve the accuracy and stability of wafer calibration to a certain extent.

Description

Technical Field

[0001] This application relates to the field of wafer calibration technology, and more specifically, to a wafer calibration method and calibration system. Background Technology

[0002] In automated optical inspection (AOI) systems, the accuracy and stability of wafer calibration are crucial, directly affecting the accuracy, stability, and repeatability of subsequent wafer surface defect detection algorithm results. Summary of the Invention

[0003] The embodiments of this application provide a wafer calibration method and calibration system, which can at least to some extent improve the accuracy and stability of wafer calibration.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to one aspect of the embodiments of this application, a wafer calibration method is provided, the method comprising: placing the wafer on a calibration platform and acquiring an overexposed image of the wafer; acquiring a calibration reference of the calibration platform and calculating a calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image; moving the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value; identifying the identification information of the wafer, registering the wafer as calibrated, and resetting the calibration platform.

[0006] In some embodiments of this application, placing the wafer on the calibration platform includes: placing the wafer on a bracket corner of the calibration platform using a robot, activating the vacuum suction cup on the calibration platform, and lowering the support bracket of the calibration platform for the wafer.

[0007] In some embodiments of this application, after activating the vacuum chuck on the calibration platform, the method further includes: obtaining the negative pressure value of the vacuum chuck; if the negative pressure value is continuously less than a negative pressure threshold, then closing the vacuum chuck, then repositioning the wafer by the robot, and then activating the vacuum chuck again.

[0008] In some embodiments of this application, acquiring an overexposed image of the wafer includes: adjusting the illumination of the wafer to make the wafer overexposed, and capturing the overexposed image of the wafer using an imaging device.

[0009] In some embodiments of this application, after acquiring the overexposed image of the wafer, the method further includes: detecting the image quality and image shooting position of the overexposed image; if the image quality is too low or the image shooting position is offset, then reinitializing the imaging device and re-capturing the overexposed image of the wafer.

[0010] In some embodiments of this application, calculating the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image includes: calculating at least one axial offset between the wafer and the calibration reference based on the calibration reference and the overexposed image; and calculating at least one circumferential offset between the wafer and the calibration reference based on the calibration reference and the overexposed image.

[0011] In some embodiments of this application, moving the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value includes: moving the wafer axially or circumferentially via the calibration platform according to the axial offset or the circumferential offset until the calibration deviation is less than a set deviation value.

[0012] In some embodiments of this application, identifying the wafer's identification information and registering the wafer as calibrated includes: controlling the calibration platform to move the wafer to the OCR, identifying the wafer's identification information, and registering the wafer as calibrated in the background.

[0013] In some embodiments of this application, resetting the calibration platform includes: controlling the motion platform to move to the wafer pick-up angle, turning off the vacuum chuck on the calibration platform, and raising the support for the wafer on the calibration platform to lift the wafer.

[0014] According to one aspect of the embodiments of this application, a wafer calibration system is provided, the system comprising: an imaging module for placing the wafer on a calibration platform and acquiring an overexposed image of the wafer; a data analysis module for acquiring a calibration reference of the calibration platform and calculating a calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image; a moving platform module for moving the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value; and an OCR recognition module for recognizing the identification information of the wafer, registering the wafer as calibrated, and resetting the calibration platform.

[0015] In some embodiments of this application, the technical solutions provided can accurately calculate the calibration deviation between the wafer and the calibration reference by analyzing the overexposed image of the wafer. Then, the position of the wafer can be adjusted according to the calibration deviation. This can effectively avoid the complex installation caused by too many platform axes, save internal space, and address the imaging stability issues caused by different wafer reflectivities. At the same time, it can effectively reduce the complexity of the algorithm, increase the support for various wafer processes, and serve the subsequent wafer surface defect detection process with better calibration accuracy and stability.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0018] Figure 1 A simplified flowchart of a wafer calibration method according to an embodiment of this application is shown;

[0019] Figure 2 A comparison diagram of a wafer and a calibration reference according to one embodiment of this application is shown;

[0020] Figure 3 A comparison diagram of a wafer and a calibration reference according to one embodiment of this application is shown;

[0021] Figure 4 A block diagram of a wafer calibration system according to one embodiment of this application is shown;

[0022] Figure 5 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown. Detailed Implementation

[0023] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0024] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0025] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0026] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0027] It should be noted that "multiple" in this article refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0028] It should be noted that this application involves semiconductor-related content, primarily concerning wafers. A wafer refers to a silicon wafer used to fabricate silicon semiconductor circuits, and its raw material is silicon. High-purity polycrystalline silicon is dissolved, doped with silicon crystal seeds, and then slowly pulled out to form cylindrical single-crystal silicon. After grinding, polishing, and slicing, the silicon ingot forms a silicon wafer, or wafer. Domestic wafer production lines mainly use 8-inch and 12-inch wafers. The main wafer processing methods are wafer fabrication and batch processing, i.e., processing one or more wafers simultaneously. As semiconductor feature sizes become smaller and processing and measurement equipment becomes more advanced, new data characteristics have emerged in wafer processing. Simultaneously, the reduction in feature size increases the impact of airborne particles on the quality and reliability of the processed wafer, and with improved cleanliness, new data characteristics regarding particle count have also emerged.

[0029] Please see Figure 1 .

[0030] Figure 1A simplified flowchart of a wafer calibration method according to an embodiment of this application is shown, as follows: Figure 1 As shown, the method may include steps S101-S104:

[0031] Step S101: Place the wafer on the calibration platform and acquire an overexposed image of the wafer.

[0032] Step S102: Obtain the calibration reference of the calibration platform, and calculate the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image.

[0033] Step S103: Based on the calibration deviation, move the wafer via the calibration platform until the calibration deviation is less than a set deviation value.

[0034] Step S104: Identify the identification information of the wafer, register the wafer as calibrated, and reset the calibration platform.

[0035] In this application, by analyzing the overexposed image of the wafer, the calibration deviation between the wafer and the calibration reference can be accurately calculated. The wafer position can then be adjusted according to the calibration deviation. This effectively avoids the complex installation caused by too many platform axes, saves internal space, and addresses imaging stability issues caused by different wafer reflectivities. At the same time, it can effectively reduce the complexity of the algorithm and increase the support for various wafer processes. It can serve the subsequent wafer surface defect detection process with better calibration accuracy and stability.

[0036] In this application, the method for placing a wafer on a calibration platform may include: placing the wafer onto a bracket corner of the calibration platform using a robot, activating the vacuum chuck on the calibration platform, and lowering the support bracket for the wafer on the calibration platform so that the wafer can be firmly gripped onto the vacuum chuck. Introducing a robot for operation can reduce manual labor and improve operational accuracy.

[0037] In this application, the descent speed of the support can also be set. When the wafer is larger, the descent speed of the support needs to be slower, so as to avoid the support descending too fast and causing the chuck to not be able to hold the wafer tightly, resulting in slight movement of the wafer and causing errors in the subsequent calibration process.

[0038] In this application, when the wafer is placed on the calibration platform, a wafer sensor can be used to determine whether the wafer matches the wafer in the calibration plan. The wafer sensor can also be used to determine whether the wafer is properly positioned. If the wafer is not properly positioned, a repositioning operation can be triggered: the robot is reset, and the robot picks up the wafer again and repositions it.

[0039] In this application, after activating the vacuum chuck on the calibration platform, the method may further include: acquiring the negative pressure value of the vacuum chuck; if the negative pressure value remains below a negative pressure threshold, then closing the vacuum chuck, repositioning the wafer using the robot, and then reactivating the vacuum chuck. The vacuum chuck can be used to fix the wafer, preventing positional changes before calibration operations and ensuring the accuracy of subsequent calibrations. When the negative pressure value is below the negative pressure threshold, it indicates that the vacuum chuck is not firmly holding the wafer, and subsequent movement may result in displacement. Therefore, the wafer needs to be repositioned, and the vacuum chuck needs to perform a firming operation again.

[0040] In this application, the method for acquiring an overexposed image of the wafer may include: adjusting the illumination of the wafer to an overexposed state, and capturing an overexposed image of the wafer using an imaging device. Because the wafer has relatively high transparency, in order to accurately determine the actual orientation of the wafer for subsequent calibration operations, it is necessary to acquire an overexposed image of the wafer to accurately determine its actual orientation.

[0041] In this application, besides directly capturing an overexposed image by changing the lighting, an overexposed image can also be obtained by capturing an image with normal exposure and then processing it for overexposure using image processing software. Based on the above solution, overexposure processing via image processing software eliminates the need to install adjustable brightness lighting equipment on the device, which simplifies the installation and setup of the equipment and reduces hardware-level operations.

[0042] In this application, after acquiring the overexposed image of the wafer, the method may further include: detecting the image quality and image capture position of the overexposed image; if the image quality is too low or the image capture position is offset, then re-initializing the imaging device and re-capturing the overexposed image of the wafer. In practical applications, imaging device malfunctions or calibration environment fluctuations may occur, easily leading to problems such as reduced quality, capture offset, or incomplete capture of the overexposed image. In such cases, it is necessary to initialize the imaging device and re-capture the image to reduce calibration errors.

[0043] In this application, to prevent imaging equipment failure or incorrect installation from affecting subsequent calibration operations, the image quality and shooting position of the overexposed image can be detected. The judgment of the image quality and shooting position of the overexposed image can be based on previously captured exposed images stored in a database. By comparing their respective positional and quality characteristics, it can be relatively easy to determine whether the overexposed image was captured correctly. If imaging equipment failure or incorrect installation occurs, the imaging equipment needs to be initialized and the image retaken to reduce calibration errors.

[0044] In this application, if the imaging device is initialized too many times, it can be determined that the imaging device itself is malfunctioning. Therefore, a fault message can be sent to the technician, such as issuing an alarm, turning on the alarm light on the imaging device (if an alarm light is set), or displaying a fault message on the technician's operating terminal, so that the technician can quickly intervene to troubleshoot the fault.

[0045] In this application, a database can be set up to store various data during the calibration process, such as overexposure images of each wafer, images of each wafer after calibration, and calibration parameters for each wafer. This allows technicians to easily view the data analysis results during system operation, and the system software provides a function to save the analysis results of edge-finding data.

[0046] In this application, calculating the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image includes: calculating at least one axial offset between the wafer and the calibration reference based on the calibration reference and the overexposed image; and calculating at least one circumferential offset between the wafer and the calibration reference based on the calibration reference and the overexposed image.

[0047] In this application, a coordinate system can be established, and the calibration reference can be determined by the coordinates or coordinate axes within the coordinate system. In the process of comparing with an overexposed image, the calibration deviation can also be calculated based on the same coordinate system.

[0048] In this application, the axial offset mainly refers to the offset of the wafer along each coordinate axis of the coordinate system, which can be adjusted by translating the wafer. The circumferential offset mainly refers to the angular offset between the positive direction of the wafer and the calibration reference, which can be adjusted by rotating the wafer; therefore, it is necessary to determine the positive direction of the wafer.

[0049] In this application, a reference wafer image can also be set as a calibration reference. The reference wafer image can be an overexposed image corresponding to each size. The position of the wafer in the image is the standard defect detection position. Therefore, when the size of the wafer to be calibrated is consistent with the size of the wafer in the reference wafer image, the standard defect detection position in the reference wafer image can be used as the calibration reference to adjust the position of the wafer to be calibrated in order to complete the calibration.

[0050] In this application, if the calibration deviation is already less than the set deviation value, the wafer movement step can be skipped, and the next step of identifying the wafer's identification information can be directly performed, registering the wafer as calibrated, and resetting the calibration platform. This is because if the calibration deviation is already less than the set deviation value, it indicates that the wafer is in a relatively accurate position, and no adjustment is needed before proceeding to the next defect detection process. To reduce operation time and speed up calibration, the wafer movement step can be skipped.

[0051] In this application, the method of moving the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value may include: moving the wafer axially or circumferentially via the calibration platform according to the axial offset or the circumferential offset until the calibration deviation is less than a set deviation value.

[0052] For example, please see Figure 2 , Figure 2 A comparison diagram of a wafer and a calibration reference according to one embodiment of this application is shown, as follows. Figure 2 As shown, in the coordinate system, the axial calibration reference can be the origin, and the circumferential calibration reference can be the y-axis. At this point, the positive direction of the wafer makes an angle α with the x-axis, and the center point is on the x-axis, 2 units away from the origin. Therefore, the axial offset is 2 units, and the circumferential offset is (90-α)°. Next, the wafer can be rotated counterclockwise by (90-α)° using the calibration platform, and then translated 2 units in the negative x-axis direction.

[0053] For example, please see Figure 3 , Figure 3 A comparison diagram of a wafer and a calibration reference according to one embodiment of this application is shown, as follows. Figure 3As shown, in the coordinate system, the axial calibration reference can be the origin, and the circumferential calibration reference can be the y-axis. First, the positive direction of the wafer needs to be determined: the bright areas within the overexposed image are segmented by a brightness threshold, and connected component analysis is performed on the bright areas. The area with the largest area is taken as R0. Then, the smallest circumcircle region R1 of R0 is obtained. The coordinate difference between R1 and R0 is calculated to determine the flat-edge outer region R2. At this point, the center point coordinates P0 of the arc of R2 can be selected, and the center coordinates P1 of R1 can be obtained. A straight line is generated with P1 as the starting point and P0 as the ending point. The angle α between this straight line and the X-axis is calculated. The circumferential offset can be (90-α)°. In addition, P1 is on the x-axis, 2 units away from the origin, and the circumferential offset is 2 units. Next, the wafer can be rotated counterclockwise by (90-α)° using the calibration platform, and then translated 2 units in the negative x-axis direction.

[0054] In this application, the speed of adjusting the wafer can be determined based on the axial offset or the circumferential offset. The larger the axial offset or the circumferential offset, the faster the adjustment speed can be. As the offset gradually decreases, the adjustment speed can be gradually reduced, and finally the wafer can be stably calibrated.

[0055] In this application, before moving the wafer via the calibration platform, a self-test can be performed on the calibration platform to check whether the circumferential and axial movement units of the calibration platform are moving normally. If the circumferential and axial movement units of the calibration platform cannot move normally, a prompt can be issued to the technicians, allowing the technicians to quickly intervene and troubleshoot the problem.

[0056] In this application, identifying the wafer's identification information and registering the wafer as calibrated includes: controlling the calibration platform to move the wafer to the OCR, identifying the wafer's identification information, and registering the wafer as calibrated in the background.

[0057] It should be noted that OCR (Optical Character Recognition) mentioned in this application refers to the process by which electronic devices (such as scanners or digital cameras) examine characters printed on paper, determine their shapes by detecting dark and light patterns, and then translate the shapes into computer text using character recognition methods. In other words, for printed characters, it uses optical methods to convert the text in a paper document into a black-and-white dot matrix image file, and then uses recognition software to convert the text in the image into text format for further editing by word processing software. How to correct errors or utilize auxiliary information to improve recognition accuracy is the most important issue in OCR, hence the term ICR (Intelligent Character Recognition). The main indicators for evaluating the performance of an OCR system include: rejection rate, false recognition rate, recognition speed, user interface friendliness, product stability, ease of use, and feasibility.

[0058] In this application, only wafers registered as calibrated can undergo subsequent defect detection. The calibration status of each wafer can be registered in the background, and the registration results are networked to the subsequent defect detection process. The defect detection process needs to identify or acquire the calibration status of each wafer; defect detection is only performed when the current wafer's calibration status is identified or acquired as calibrated. Therefore, the technical solution provided in this application can effectively improve the alignment difficulty and detection accuracy of subsequent defect detection.

[0059] In this application, resetting the calibration platform includes: controlling the motion platform to move to the wafer pick-up angle, turning off the vacuum chuck on the calibration platform, and raising the support frame of the calibration platform for the wafer to lift the wafer.

[0060] An embodiment of a calibration system of this application will now be described with reference to the accompanying drawings.

[0061] Please see Figure 4 .

[0062] Figure 4 A block diagram of a wafer calibration system according to an embodiment of the present application is shown. The system includes an image module 401, a data analysis module 402, a mobile platform module 403, and an OCR recognition module 404.

[0063] In this application, the specific configuration of the calibration system can be:

[0064] The imaging module 401 is used to place the wafer on the calibration platform and acquire an overexposed image of the wafer.

[0065] The data analysis module 402 is used to obtain the calibration reference of the calibration platform and calculate the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image.

[0066] The moving platform module 403 is used to move the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value.

[0067] The OCR identification module 404 is used to identify the identification information of the wafer, register the wafer as calibrated, and reset the calibration platform.

[0068] In this application, the various modules can be distributed on the calibration platform, and the data analysis module can be loaded into a computer.

[0069] It should be noted that the computers described above generally consist of an arithmetic logic unit (ALU), a control unit, a memory, a keyboard, a display, a power supply, and some optional peripherals and electronic components, assembled manually or by machine. Low-end calculators use digital logic circuits to perform simple serial operations in their ALU and control units, and their random access memory has only one or two units for accumulation storage.

[0070] Please see Figure 5 .

[0071] Figure 5 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown.

[0072] It should be noted that, Figure 5 The computer system 500 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0073] like Figure 5 As shown, the computer system 500 includes a Central Processing Unit (CPU) 501, which can perform various appropriate actions and processes based on programs stored in Read-Only Memory (ROM) 502 or programs loaded from storage portion 508 into Random Access Memory (RAM) 503, such as performing the methods described in the above embodiments. The RAM 503 also stores various programs and data required for system operation. The CPU 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0074] The following components are connected to I / O interface 505: an input section 506 including a keyboard, mouse, etc.; an output section 507 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 508 including a hard disk, etc.; and a communication section 509 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 509 performs communication processing via a network such as the Internet. A drive 510 is also connected to I / O interface 505 as needed. A removable medium 511, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 510 as needed so that computer programs read from it can be installed into storage section 508 as needed.

[0075] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 509, and / or installed from removable medium 511. When the computer program is executed by central processing unit (CPU) 501, it performs various functions defined in the system of this application.

[0076] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such transmitted data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0077] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0078] The units described in the embodiments of this application can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0079] In another aspect, this application also provides a computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the wafer calibration method described in the above embodiments.

[0080] In another aspect, this application also provides a computer-readable medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The computer-readable medium carries one or more programs that, when executed by the electronic device, cause the electronic device to implement the wafer calibration method described in the above embodiments.

[0081] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0082] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the method according to the embodiments of this application.

[0083] Based on the above solution, for wafer manufacturing companies, compared with the laser wafer edge finding process, the technical solution of this application can provide faster wafer edge finding and calibration results, lower cost, lower failure rate, and bring users a better user experience. This can also significantly improve the reputation of the company's products, and may bring broader business opportunities and increase revenue.

[0084] For users, this can effectively improve their experience, making the wafer imaging position more stable, increasing UPH, reducing the failure rate, improving equipment efficiency, and relatively increasing the wafer surface defect detection capacity, thereby leading to higher production efficiency and increased profits.

[0085] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0086] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A wafer calibration method, characterized in that, The method includes: The wafer is placed on the calibration platform to obtain an overexposed image of the wafer; Obtain the calibration reference of the calibration platform, and calculate the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image; Based on the calibration deviation, the wafer is moved via the calibration platform until the calibration deviation is less than a set deviation value; Identify the wafer's identification information, register the wafer as calibrated, and reset the calibration platform.

2. The method according to claim 1, characterized in that, The step of placing the wafer on the calibration platform includes: The robot places the wafer onto the bracket corner of the calibration platform, activates the vacuum suction cup on the calibration platform, and lowers the support bracket of the calibration platform for the wafer.

3. The method according to claim 2, characterized in that, After activating the vacuum chuck on the calibration platform, the method further includes: The negative pressure value of the vacuum suction cup is obtained. If the negative pressure value is continuously less than the negative pressure threshold, the vacuum suction cup is turned off, the wafer is repositioned by the robot, and then the vacuum suction cup is turned back on.

4. The method according to claim 1, characterized in that, The process of acquiring the overexposed image of the wafer includes: The illumination of the wafer is adjusted to overexpose the wafer, and an overexposed image of the wafer is captured by an imaging device.

5. The method according to claim 4, characterized in that, After acquiring the overexposed image of the wafer, the method further includes: The image quality and image capture position of the overexposed image are detected. If the image quality is too low or the image capture position is offset, the imaging device is reinitialized and the overexposed image of the wafer is captured again.

6. The method according to claim 1, characterized in that, The step of calculating the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image includes: Calculate at least one axial offset between the wafer and the calibration reference based on the calibration reference and the overexposed image; Calculate at least one circumferential offset of the wafer and the calibration reference based on the calibration reference and the overexposed image.

7. The method according to claim 6, characterized in that, The step of moving the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value includes: Based on the axial offset or the circumferential offset, the wafer is moved axially or circumferentially by the calibration platform until the calibration deviation is less than a set deviation value.

8. The method according to claim 1, characterized in that, The step of identifying the wafer's identification information and registering the wafer as calibrated includes: The calibration platform is controlled to move the wafer to the OCR, identify the wafer's identification information, and register the wafer as calibrated in the background.

9. The method according to claim 1, characterized in that, The reset of the calibration platform includes: The calibration platform is moved to the wafer pick-up angle, the vacuum chuck on the calibration platform is turned off, and the support for the wafer on the calibration platform is raised to lift the wafer.

10. A wafer calibration system, characterized in that, The system includes: An imaging module is used to place the wafer on a calibration platform and acquire an overexposed image of the wafer; The data analysis module is used to obtain the calibration reference of the calibration platform and calculate the calibration deviation between the wafer and the calibration reference based on the calibration reference and the overexposed image. The moving platform module is used to move the wafer via the calibration platform according to the calibration deviation until the calibration deviation is less than a set deviation value; The OCR identification module is used to identify the identification information of the wafer, register the wafer as calibrated, and reset the calibration platform.

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