Wafer edge searching method, system, device and medium

Abstract

The invention discloses a wafer edge searching method, system and device and a storage medium, the method is realized through a wafer edge finder, the wafer edge finder comprises a rotating platform, a first sensor and a second sensor, and the method comprises the following steps: obtaining the center position of a wafer arranged on the rotating platform; when the central position does not coincide with the center of the rotating platform, determining a first distance from the first sensor to the side edge of the wafer and a second distance from the second sensor to the side edge of the wafer; according to the first distance and the second distance, the center position is adjusted to coincide with the center of the rotating platform; and when the central position coincides with the center of the rotating platform, controlling the rotating platform and the wafer to rotate at a preset rotating speed and perform edge searching to obtain an edge searching result. The method can be widely applied to the technical field of semiconductors.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a wafer edge finding method, system, device and storage medium. Background Art

[0002] An image edge finder is an edge detection instrument based on machine vision. Its principle is to use image processing technology to automatically measure the position and shape of the edge of the wafer to be measured. The image edge finder collects wafer images through a camera and converts the images into digital signals. The digital signals are processed and analyzed using image processing algorithms to detect the edge of the wafer. Common edge detection algorithms include the Canny algorithm, the Sobel algorithm, the Laplacian algorithm, etc. These algorithms can accurately detect the position and shape of the edge of the wafer by analyzing the brightness changes of image pixels. However, when there are reflections or shadows on the surface of the wafer, the image edge finding method will affect the clarity and contrast of the image. In addition, the image acquisition process may be affected by noise interference, and the absorption and reflection characteristics of light by wafers of different colors and textures are different, which will lead to inaccurate edge detection. Therefore, there are still technical problems that need to be solved in the relevant technology. Summary of the invention

[0003] The purpose of this application is to solve one of the technical problems existing in the prior art to at least a certain extent.

[0004] To this end, an object of an embodiment of the present application is to provide a wafer edge finding method, system, device and storage medium, which can improve the accuracy of wafer detection.

[0005] In order to achieve the above-mentioned technical objectives, the technical solutions adopted in the embodiments of the present application include: a wafer edge finding method, which is implemented by a wafer edge finder, and the wafer edge finder includes a rotating platform, a first sensor and a second sensor, and the method includes: obtaining the center position of the wafer placed on the rotating platform; when the center position does not coincide with the center of the rotating platform, determining the first distance from the first sensor to the side edge of the wafer and determining the second distance from the second sensor to the side edge of the wafer; according to the first distance and the second distance, adjusting the center position to coincide with the center of the rotating platform; when the center position coincides with the center of the rotating platform, controlling the rotating platform and the wafer to rotate at a preset speed and perform edge finding to obtain an edge finding result.

[0006] In addition, a wafer edge finding method according to the above embodiment of the present invention may also have the following additional technical features:

[0007] Further, in an embodiment of the present application, the center position is adjusted to coincide with the center of the rotating platform according to the first distance and the second distance:

[0008] determining an average distance difference between the first distance and the second distance;

[0009] When the first distance is greater than the average distance difference, moving the wafer to adjust the center position to the left to coincide with the center of the rotating platform;

[0010] When the first distance is smaller than the average distance difference, the wafer is moved to adjust the center position to the right to coincide with the center of the rotating platform.

[0011] Further, in the embodiment of the present application, determining the average distance difference between the first distance and the second distance specifically includes:

[0012] determining a distance difference between the first distance and the second distance;

[0013] Half of the distance difference is taken as the average distance difference.

[0014] Further, in an embodiment of the present application, determining the distance difference between the first distance and the second distance includes: subtracting the first distance from the second distance to obtain the distance difference.

[0015] Furthermore, in an embodiment of the present application, when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search to obtain an edge search result, including: when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search, and when the distance between the side edge of the wafer and the scanner is less than a first preset distance, the edge search result is a depression on the side edge of the wafer; when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search, and when the distance between the side edge of the wafer and the scanner is greater than the first preset distance, the edge search result is a bulge on the side edge of the wafer.

[0016] Furthermore, in an embodiment of the present application, when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed to obtain an edge search result. It also includes: when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed, and when the distance between the side edge of the wafer and the scanner is equal to a first preset distance, the edge search result is that there is no defect on the side edge of the wafer.

[0017] Furthermore, in the embodiment of the present application, the preset rotation speed is 300 revolutions per minute.

[0018] On the other hand, an embodiment of the present application further provides a wafer edge finding system, which is implemented by a wafer edge finder, wherein the wafer edge finder includes a rotating platform, a first sensor, and a second sensor, and the system includes:

[0019] A first processing unit, used for obtaining the center position of the wafer placed on the rotating platform;

[0020] a second processing unit, configured to determine, when the center position does not coincide with the center of the rotating platform, a first distance from the first sensor to a side edge of the wafer and a second distance from the second sensor to the side edge of the wafer;

[0021] a third processing unit, configured to adjust the center position to coincide with the center of the rotating platform according to the first distance and the second distance;

[0022] The fourth processing unit is used to control the rotating platform and the wafer to rotate at a preset speed and perform edge search to obtain an edge search result when the center position coincides with the center of the rotating platform.

[0023] On the other hand, the present application also provides a wafer edge finding device, comprising:

[0024] at least one processor;

[0025] at least one memory for storing at least one program;

[0026] When the at least one program is executed by the at least one processor, the at least one processor implements a wafer edge-finding method as described in any one of the invention contents.

[0027] In addition, the present application also provides a computer-readable storage medium, which stores processor-executable instructions. When the processor-executable instructions are executed by the processor, they are used to execute a wafer edge-finding method as described in any one of the above items.

[0028] The advantages and benefits of the present application will be partially given in the following description, and partially become apparent from the following description, or be understood through the practice of the present application:

[0029] The application can obtain the center position of a wafer placed on a rotating platform; when the center position does not coincide with the center of the rotating platform, determine the first distance from the first sensor to the side of the wafer and determine the second distance from the second sensor to the side of the wafer; according to the first distance and the second distance, adjust the center position to coincide with the center of the rotating platform; when the center position coincides with the center of the rotating platform, control the rotating platform and the wafer to rotate at a preset speed and perform edge search to obtain an edge search result. The application can improve the accuracy of wafer detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the steps of a wafer edge finding method in a specific embodiment of the present invention;

[0031] Figure 2 A schematic diagram of a process flow of a wafer edge finding method in another specific embodiment of the present invention;

[0032] Figure 3 A waveform diagram of a wafer edge finding method in a specific embodiment of the present invention;

[0033] Figure 4 A waveform diagram of a wafer edge finding method in another specific embodiment of the present invention;

[0034] Figure 5 It is a structural schematic diagram of a wafer edge-finding system in a specific embodiment of the present invention;

[0035] Figure 6 It is a schematic structural diagram of a wafer edge-finding device in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0036] The principles and processes of the wafer edge finding method, system, device and storage medium in the embodiments of the present invention are described below in conjunction with the accompanying drawings.

[0037] Reference Figure 1 The present application provides a wafer edge finding method, which is implemented by a wafer edge finder. The wafer edge finder includes a rotating platform, a first sensor and a second sensor. The method may include steps S101 to S104.

[0038] S101, obtaining the center position of a wafer placed on a rotating platform.

[0039] S102 , when the center position does not coincide with the center of the rotating platform, determining a first distance from the first sensor to the side edge of the wafer and determining a second distance from the second sensor to the side edge of the wafer.

[0040] S103, adjusting the center position to coincide with the center of the rotating platform according to the first distance and the second distance.

[0041] S104, when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search to obtain an edge search result.

[0042] In summary, this embodiment can obtain the center position of the wafer placed on the rotating platform; when the center position does not coincide with the center of the rotating platform, determine the first distance from the first sensor to the side of the wafer and determine the second distance from the second sensor to the side of the wafer; according to the first distance and the second distance, adjust the center position to coincide with the center of the rotating platform; when the center position coincides with the center of the rotating platform, control the rotating platform and the wafer to rotate at a preset speed and perform edge search to obtain an edge search result. This application can improve the accuracy of wafer detection. .

[0043] Further, in the embodiment of the present application, the step of adjusting the center position to coincide with the center of the rotating platform according to the first distance and the second distance specifically includes step S201-step S202 or step S201-step S203.

[0044] S201: Determine an average distance difference between a first distance and a second distance.

[0045] S202 , when the first distance is greater than the average distance difference, the wafer is moved to adjust the center position to the left to coincide with the center of the rotating platform.

[0046] S203 , when the first distance is smaller than the average distance difference, the wafer is moved to adjust the center position to the right to coincide with the center of the rotating platform.

[0047] Further, in the embodiment of the present application, the step of determining the average distance difference between the first distance and the second distance may specifically include steps S301 and S302.

[0048] S301: Determine a distance difference between a first distance and a second distance.

[0049] S302: Taking half of the distance difference as the average distance difference.

[0050] Further, in the embodiment of the present application, determining the distance difference between the first distance and the second distance includes subtracting the first distance from the second distance to obtain the distance difference.

[0051] Furthermore, in an embodiment of the present application, when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed to obtain an edge search result, which includes step S401 or step S402.

[0052] When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed. When the distance between the side edge of the wafer and the scanner is less than a first preset distance, the edge search result is a depression on the side edge of the wafer.

[0053] When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed. When the distance between the side edge of the wafer and the scanner is greater than a first preset distance, the edge search result is a bulge on the side edge of the wafer.

[0054] Furthermore, in an embodiment of the present application, when the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed to obtain an edge search result, which also includes step S403.

[0055] S403. When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed. When the distance between the side edge of the wafer and the scanner is equal to a first preset distance, the edge search result is that there is no defect on the side edge of the wafer.

[0056] Furthermore, in the embodiment of the present application, the preset rotation speed is 300 rpm.

[0057] The principle of this application is explained below with reference to the accompanying drawings:

[0058] Reference Figure 2-Figure 4 The wafer edge finding method of this embodiment includes step 1 and step 2.

[0059] Step 1: When the wafer to be measured coincides with the center of the platform, the platform rotates with the wafer to be measured (fixed speed is 300 rpm). The scanner of the edge finder continuously performs laser scanning. The distance between the scanner and the circular edge of the wafer to be measured is L (L can be obtained from the optical path difference). At this time, the gap distance is L1-Ln. Take the maximum absolute value to determine the position to be found. The platform speed is 300RPM, and the starting position of the platform is known. Assuming the sampling time is 30S, 150 sampled full waveforms can be obtained theoretically. The position where the platform needs to stop is the waveform period calculated and then combined with 300RPM to obtain the rotation position, which is then confirmed by the laser. (The standard waveform is similar to this, and the machine makes a judgment and then performs flat edge confirmation or adjusts the measurement position center operation).

[0060] Step 2: When the wafer to be measured does not coincide with the center of the platform, the platform vacuums the wafer to be measured and drives it to rotate, and the scanner continuously performs laser scanning. The distance between the scanner and the edge of the wafer to be measured is Lm-Lz. The platform speed is 300RPM, and the starting position of the platform is known. Assuming the sampling time is 30S, 150 sampling waveforms can be obtained theoretically. The adjustment position is that the distance between the wafer to be measured and the laser within one wavelength period is (Lm-Lz) / 2 (maximum-minimum). The position where the platform needs to stop is the rotation position obtained by combining the proportion after the waveform period calculation and 300RPM. The arm moves left and right according to the comparison of |Lm| and |Lz|, and the moving distance is obtained according to (Lm-Lz) / 2. |Lm| and |Lz| are the distance from the first sensor to the edge of the wafer and the distance from the second sensor to the edge of the wafer, respectively. Specifically, when the first distance |Lm| is greater than the average distance difference (Lm-Lz) / 2, the mobile wafer adjusts the center position to the left to coincide with the center of the rotating platform. When the first distance |Lm| is less than the average distance difference (Lm-Lz) / 2, the wafer is moved to adjust the center position to the right to coincide with the center of the rotating platform. After adjustment, the center of the wafer to be measured coincides with the center of the platform, and then the above step 1 is repeated for processing.

[0061] On the other hand, refer to Figure 5 , the embodiment of the present application also provides a wafer edge finding system, which includes a wafer edge finder, the wafer edge finder includes a rotating platform, a first sensor and a second sensor, and the system also includes: a first processing unit 1001, a second processing unit 1002, a third processing unit and a fourth processing unit 1004. The first processing unit 1001 can be used to obtain the center position of a wafer placed on the rotating platform. The second processing unit 1002 can be used to determine the first distance from the first sensor to the side of the wafer and the second distance from the second sensor to the side of the wafer when the center position does not coincide with the center of the rotating platform. The third processing unit 1003 can be used to adjust the center position to coincide with the center of the rotating platform according to the first distance and the second distance. The fourth processing unit 1004 can be used to control the rotating platform and the wafer to rotate at a preset speed and perform edge finding when the center position coincides with the center of the rotating platform to obtain an edge finding result.

[0062] It should be noted that the acquisition unit can be any integrated circuit unit or microprocessor unit obtained by integrating a chip with processing functions and its peripheral circuits through existing integration technology. The first processing unit and the second processing unit can also be any integrated circuit module or microprocessor module obtained by integrating a chip with processing functions and its peripheral circuits through existing integration technology. The first processing unit and the second processing unit can also include one or more memories. One or more memories can be used to store the specific algorithm in this application.

[0063] In some embodiments of the present application, the first processing unit 1001 can be set in the same gateway or device with a processor as the second processing unit 1002. The specific device connection mode and device setting of the first processing unit 1001 and the second processing unit 1002 and the second processing unit 1002 and the third processing unit 1003 are not limited.

[0064] It should be noted that the contents of the above-mentioned wafer edge-finding method embodiment are all applicable to the present wafer edge-finding system embodiment. The functions specifically implemented by the present wafer edge-finding system embodiment are the same as those of the above-mentioned wafer edge-finding method embodiment, and the beneficial effects achieved are also the same as those achieved by the above-mentioned wafer edge-finding method embodiment.

[0065] Corresponding to the method, the embodiment of the present application also provides a wafer edge finding device, the specific structure of which can be referred to Figure 6 ,include:

[0066] At least one processor 1011.

[0067] At least one memory 1012 is used to store at least one program.

[0068] When at least one program is executed by at least one processor, the at least one processor implements a wafer edge finding method.

[0069] The contents of the above method embodiments are all applicable to the present device embodiments. The functions specifically implemented by the present device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0070] and Figure 1 Corresponding to the method, an embodiment of the present application further provides a computer-readable storage medium, which stores processor-executable instructions, and the processor-executable instructions are used to execute the wafer edge-finding method when executed by the processor.

[0071] The contents of the above-mentioned wafer edge-finding method embodiment are all applicable to the present storage medium embodiment. The functions specifically implemented by the present storage medium embodiment are the same as those of the above-mentioned wafer edge-finding method embodiment, and the beneficial effects achieved are also the same as those achieved by the above-mentioned wafer edge-finding method embodiment.

[0072] In some optional embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the present application is provided by way of example, for the purpose of providing a more comprehensive understanding of technology. The disclosed method is not limited to the operation and logic flow presented herein. The optional embodiment is expected, wherein the order of various operations can be changed and the sub-operation described as a part of a larger operation can be performed independently.

[0073] In addition, although the present application is described in the context of functional modules, it should be understood that, unless otherwise specified, one or more of the functions and / or features can be integrated into a single physical device and / or software module, or one or more functions and / or features can be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the present application. More specifically, in view of the properties, functions, and internal relationships of the various functional modules in the device disclosed herein, the actual implementation of the module will be understood within the conventional techniques of the engineer. Therefore, those skilled in the art can implement the present application set forth in the claims without excessive experimentation using ordinary techniques. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the present application, which is determined by the full scope of the attached claims and their equivalents.

[0074] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium and includes several programs to enable a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0075] The logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable programs for implementing the logical functions, and may be embodied in any computer-readable medium for use by a program execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch and execute a program from a program execution system, device or apparatus), or in conjunction with such program execution systems, devices or apparatuses. For purposes of this specification, a "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by a program execution system, device or apparatus, or in conjunction with such program execution systems, devices or apparatuses.

[0076] More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0077] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable program execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0078] In the above description of this specification, the description with reference to the terms "one embodiment / example", "another embodiment / example" or "certain embodiments / examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0079] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

[0080] The above is a specific description of the preferred implementation of the present application, but the present application is not limited to the embodiments. Technical personnel familiar with the field can also make various equivalent modifications or substitutions without violating the spirit of the present application. These equivalent modifications or substitutions are all included in the scope defined by the claims of the present application.

Claims

1. A wafer edge finding method, characterized in that: The method is implemented by a wafer edge finder, wherein the wafer edge finder includes a rotating platform, a first sensor and a second sensor, and the method includes: Acquiring the center position of the wafer placed on the rotating platform; When the center position does not coincide with the center of the rotating platform, determining a first distance from the first sensor to a side edge of the wafer and determining a second distance from the second sensor to the side edge of the wafer; According to the first distance and the second distance, adjusting the center position to coincide with the center of the rotating platform; When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search to obtain an edge search result.

2. A wafer edge finding method according to claim 1, characterized in that: The step of adjusting the center position to coincide with the center of the rotating platform according to the first distance and the second distance: determining an average distance difference between the first distance and the second distance; When the first distance is greater than the average distance difference, moving the wafer to adjust the center position to the left to coincide with the center of the rotating platform; When the first distance is smaller than the average distance difference, the wafer is moved to adjust the center position to the right to coincide with the center of the rotating platform.

3. A wafer edge finding method according to claim 2, characterized in that: The determining the average distance difference between the first distance and the second distance specifically includes: determining a distance difference between the first distance and the second distance; Half of the distance difference is taken as the average distance difference.

4. A wafer edge finding method according to claim 3, characterized in that: The determining a distance difference between the first distance and the second distance includes: The first distance is subtracted from the second distance to obtain the distance difference.

5. A wafer edge finding method according to claim 1, characterized in that: When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search to obtain an edge search result, including: When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and perform edge search, and when the distance between the side edge of the wafer and the scanner is less than a first preset distance, the edge search result is that a concavity appears on the side edge of the wafer; When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed. When the distance between the side edge of the wafer and the scanner is greater than a first preset distance, the edge search result is a bulge on the side edge of the wafer.

6. A wafer edge finding method according to claim 5, characterized in that: When the center position coincides with the center of the rotating platform, controlling the rotating platform and the wafer to rotate at a preset speed and performing edge search to obtain an edge search result, further comprising: When the center position coincides with the center of the rotating platform, the rotating platform and the wafer are controlled to rotate at a preset speed and edge search is performed. When the distance between the side edge of the wafer and the scanner is equal to a first preset distance, the edge search result is that there is no defect on the side edge of the wafer.

7. A wafer edge finding method according to claim 1, characterized in that: The preset rotation speed is 300 revolutions per minute.

8. A wafer edge finding system, characterized in that: The system includes a wafer edge finder, wherein the wafer edge finder includes a rotating platform, a first sensor, and a second sensor. The system also includes: A first processing unit, used for obtaining the center position of the wafer placed on the rotating platform; a second processing unit, configured to determine, when the center position does not coincide with the center of the rotating platform, a first distance from the first sensor to a side edge of the wafer and a second distance from the second sensor to the side edge of the wafer; a third processing unit, configured to adjust the center position to coincide with the center of the rotating platform according to the first distance and the second distance; The fourth processing unit is used to control the rotating platform and the wafer to rotate at a preset speed and perform edge search to obtain an edge search result when the center position coincides with the center of the rotating platform.

9. A wafer edge finding device, characterized in that include: at least one processor; at least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements a wafer edge-finding method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing instructions executable by a processor, characterized in that: The processor-executable instructions are used to execute a wafer edge-finding method as described in any one of claims 1-7 when executed by the processor.

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