Wafer position detection device and method

Abstract

This invention provides a wafer position detection device and method. The wafer position detection device includes: a carrier plate with a limiting groove, an image acquisition module installed in the limiting groove, an image processing module communicatively connected to the image acquisition module, and a main control device communicatively connected to the image processing module. The carrier plate is configured to fix the wafer. The image acquisition module acquires a position image of the wafer and outputs it to the image processing module. The image processing module calculates the actual offset of the wafer based on the position image, and determines the wafer offset state information based on preset reference information and the actual offset, and outputs it to the main control device. The main control device controls the robotic arm to perform the wafer picking operation based on the offset state information. Using this invention, the wafer offset state can be determined by acquiring a wafer position image before the robotic arm picks up the wafer, thereby controlling the wafer picking operation. This effectively avoids wafer breakage accidents caused by picking errors, ensuring production safety and efficiency.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing technology, and particularly relates to a wafer position detection device and method. Background Technology

[0002] In the semiconductor manufacturing field, Physical Vapor Deposition (PVD) is widely used for the deposition of metal thin films. PVD processes are typically performed within a vacuum chamber. The basic process involves a robotic arm transferring a wafer from a transport position onto a support tray (such as an electrostatic chuck) within the chamber. After the process is complete, the robotic arm re-enters the chamber to retrieve the wafer and transfer it to the next station. To ensure process uniformity and stability, the wafer's position within the chamber must be precisely calibrated and fixed. However, in actual production, due to various complex factors (such as thermal stress during the process, disturbances in the airflow within the chamber, mechanical vibration, or slight drift in the support tray position), the completed wafer may deviate from its original, correct leveling position, or even experience severe "wafer drop" or "slippage."

[0003] Currently, most mainstream PVD equipment does not integrate a dedicated real-time wafer position detection device inside the chamber. The equipment control system typically assumes that the wafer is still in the predetermined position after the process is completed. Therefore, when the robotic arm enters the chamber to perform the wafer retrieval operation according to the preset program, if the wafer has shifted position, the end effector of the robotic arm will not be able to properly align and support the wafer edge or back side. This "misaligned wafer retrieval" can lead to several serious risks:

[0004] 1. Wafer Fragmentation: During the forced wafer retrieval process, the end effector of the robotic arm may collide with the edge of the wafer or generate uneven stress on the wafer, leading to the fracture of valuable wafers. This not only causes direct material loss, but the particles generated by the fracture can also contaminate the entire chamber and equipment, causing yield problems for subsequent batches of products.

[0005] 2. Equipment damage: Fragments generated by the rupture may fall into the bottom of the chamber or into the mechanical mechanism, scratching the surface of the precision bearing plate or jamming the transmission components, causing the equipment to need to be shut down for extensive maintenance and cleaning, reducing the overall utilization rate of the equipment.

[0006] 3. Process interruption and capacity loss: Handling fragmentation accidents, cleaning chambers, and repairing equipment require a lot of time, leading to production line interruptions and severely impacting overall capacity. Summary of the Invention

[0007] The purpose of this invention is to provide a wafer position detection device and method. This invention detects the wafer position status and determines whether there is a risk of wafer displacement or falling before the robotic arm performs the wafer picking action, thereby controlling the equipment to take safety measures and effectively avoiding wafer breakage accidents caused by inaccurate wafer picking.

[0008] To achieve the above objectives, the present invention provides a wafer position detection device, which includes:

[0009] A carrier plate with a limiting groove is provided, an image acquisition module is installed in the limiting groove, an image processing module is communicatively connected to the image acquisition module, and a main control device is communicatively connected to the image processing module.

[0010] The carrier disk is configured to fix the wafer. The image acquisition module is configured to acquire the position image of the wafer and output the position image to the image processing module. The image processing module is configured to calculate the actual offset of the wafer based on preset reference information and the position image, and determine the offset state information of the wafer based on the preset reference information and the actual offset. It is also configured to output the offset state information to the main control device. The main control device is configured to control the wafer picking operation of the robotic arm based on the offset state information.

[0011] Optionally, the image acquisition module includes a shielding cover, a camera module integrated within the shielding cover, and a heat dissipation substrate placed between the shielding cover and the camera module and in close contact with the shielding cover and the camera module;

[0012] The shielding cover is configured to protect the camera module and shield magnetic and electric fields. The camera module is configured to acquire position images of the wafer and output the position images to the image processing module. The heat dissipation substrate is configured to conduct the heat generated by the camera module to the outer layer of the shielding cover to achieve heat dissipation.

[0013] Optionally, the shielding cover includes at least three shielding structures; the three shielding structures, from the inside out, are a magnetic field shielding layer, an insulating and thermally conductive layer, and an electric field shielding layer.

[0014] Optionally, the shield is a sealed housing, and the camera module includes a CMOS sensor, a lens mount electrically connected to the CMOS sensor, and a signal processing component; the CMOS sensor is configured to acquire image data of the wafer captured by the lens mount, and the signal processing component is configured to process the image data to obtain the position image and output the position image to the image processing module; a transparent window is provided on the side of the shield facing the lens mount.

[0015] Optionally, the image acquisition module is integrated into a housing, which is detachably installed within the limiting groove.

[0016] Optionally, the detection device further includes a gas injection pipe and a drive shaft that carries the carrier disk; the drive shaft has a hollow pipe; the gas injection pipe passes through the hollow pipe and extends towards the groove after surrounding the limiting groove at one end near the carrier disk, so as to introduce process gas into the surface area of ​​the wafer; the transmission line between the image acquisition module and the image processing module passes through the hollow pipe.

[0017] Based on the same inventive concept, this invention also proposes a wafer position detection method. This method utilizes the wafer position detection device described above. Before performing a wafer removal operation on the wafer placed on the carrier disk, the detection method performs the following steps:

[0018] The image acquisition module acquires a position image of the wafer and outputs the position image to the image processing module;

[0019] The image processing module calculates the actual offset of the wafer based on the preset reference information and the position image, determines the offset status information of the wafer based on the preset reference information and the actual offset, and outputs the offset status information to the main control device.

[0020] The main control device controls the robotic arm's chip-picking operation based on the received offset status information.

[0021] Optionally, the preset reference information includes the standard center coordinates of the carrier disk, pixel equivalent, edge point number threshold, and maximum allowable offset; the offset status information includes unknown offset status, severe offset status, and normal offset status; the image processing module calculates the actual offset of the wafer based on the preset reference information and the position image, and determines the offset status information of the wafer based on the preset reference information and the actual offset, including:

[0022] The location image is preprocessed and features are extracted to obtain the set of edge point coordinates and the number of edge points in the location image;

[0023] Determine whether the number of edge points is less than the edge point number threshold: if yes, the offset status information is "offset status unknown"; if no, perform the following steps:

[0024] Based on the set of edge point coordinates of the location image, the center coordinates of the location image are obtained by random sampling; and the actual offset of the wafer is calculated based on the center coordinates, the standard center coordinates, and the pixel equivalent; and the offset status information is determined based on the maximum allowable offset and the actual offset.

[0025] Optionally, the location image is preprocessed and feature extracted to obtain the set of edge point coordinates and the number of edge points in the location image, including:

[0026] The location image is converted into a grayscale image, and Gaussian filtering and edge detection are performed on the grayscale image to obtain a set of edge point coordinates of the location image;

[0027] The number of edge points is determined based on the set of edge point coordinates of the location image.

[0028] Optionally, the preset reference information further includes a minimum point distance preset value and a maximum point distance preset value for the location image; the step of obtaining the center coordinates of the location image using a random sampling method based on the set of edge point coordinates of the location image includes:

[0029] Randomly select edge points from the set of edge point coordinates that are between the minimum and maximum preset point distance values ​​to form edge point pairs, and construct the equation of the perpendicular bisector of the edge point pairs.

[0030] The center coordinates of the position image are calculated by fitting the perpendicular bisector equation.

[0031] Optionally, the step of calculating the actual offset of the wafer based on the center coordinates, the standard center coordinates, and the pixel equivalent, and determining the offset status information based on the maximum allowable offset and the actual offset, includes:

[0032] The pixel offset of the wafer is calculated based on the center coordinates of the circle and the standard center coordinates of the circle, and the actual offset of the wafer is calculated based on the pixel offset and the pixel equivalent.

[0033] Determine whether the actual offset is greater than the maximum allowable offset:

[0034] If yes, the offset status information is a severe offset state; if no, the offset status information is a normal offset state, and the normal offset state includes the actual offset amount.

[0035] Optionally, the main control device controls the robotic arm's wafer-picking operation based on the received offset status information, including:

[0036] When the offset status information indicates an unknown offset status or a severe offset status, the robotic arm is controlled to stop the wafer picking operation and an alarm is triggered; when the status judgment parameter indicates a normal offset status, the robotic arm is controlled to pick up the wafer normally and perform offset calibration based on the actual offset amount.

[0037] Compared with the prior art, the wafer position detection device and method provided by the present invention have the following beneficial effects: The wafer position detection device provided by the present invention includes: a carrier disk with a limiting groove, an image acquisition module installed in the limiting groove, an image processing module communicatively connected to the image acquisition module, and a main control device communicatively connected to the image processing module; the carrier disk is configured to fix the wafer, the image acquisition module is configured to acquire the position image of the wafer and output the position image to the image processing module, the image processing module is configured to calculate the actual offset of the wafer according to preset reference information and the position image, and determine the offset state information of the wafer according to the preset reference information and the actual offset, and is also used to output the offset state information to the main control device, the main control device is configured to control the wafer picking operation of the robotic arm according to the offset state information. Therefore, the wafer position detection device provided by the present invention sets a limiting groove on the wafer carrier and installs an image acquisition module in the limiting groove. Before the robotic arm performs wafer picking, the image acquisition module acquires the position image of the wafer and transmits it to the image processing module. The image processing module calculates the actual offset of the wafer and determines the offset state information of the wafer, and transmits it to the main control device to control the robotic arm's wafer picking operation. This can effectively avoid wafer breakage accidents caused by inaccurate wafer picking, thereby ensuring production safety and efficiency.

[0038] Furthermore, the image acquisition module in the wafer position detection device provided by the present invention, by adopting a shielding cover that shields the magnetic and electric fields outside the camera module and a heat dissipation substrate, enables the CMOS sensor in the camera module to have the ability to resist high temperature and strong electromagnetic fields, thereby adapting to different PVD process scenarios and further improving the applicability and reliability of the present invention.

[0039] Furthermore, the wafer position detection device provided by the present invention can redesign the structure of the carrier disk based on the existing structure. By using a method in which the end of the gas injection tube near the carrier disk surrounds the limiting groove and extends towards the groove opening to introduce process gas into the surface area of ​​the wafer, it is possible to ensure that there is enough space to install the image acquisition module while ensuring the gas output and uniformity of the gas injection tube, thereby ensuring that the gas flow effect of the gas injection tube is not affected.

[0040] Furthermore, since the wafer position detection method proposed in this invention belongs to the same inventive concept as the wafer position detection device provided in this invention, the wafer position detection method provided in this invention has at least all the advantages of the wafer position detection device provided in this invention. For details on the beneficial effects of the wafer position detection method provided in this invention, please refer to the above description of the beneficial effects of the wafer position detection device provided in this invention, which will not be repeated here. Attached Figure Description

[0041] Figure 1 This is a block diagram of a wafer position detection device provided in one embodiment of the present invention;

[0042] Figure 2 This is a simplified schematic diagram of the image acquisition module in a wafer position detection device provided in one embodiment of the present invention;

[0043] Figure 3 This is a schematic flowchart of a wafer position detection method provided in one embodiment of the present invention;

[0044] Figure 4a The offset state information determined by the wafer position detection method provided in one embodiment of the present invention is a front view of the normal offset state;

[0045] Figure 4b A top view showing the offset state information determined by the wafer position detection method provided in one embodiment of the present invention as a normal offset state;

[0046] Figure 5a A front view showing the offset state information determined by the wafer position detection method provided in one embodiment of the present invention, indicating a severely offset state;

[0047] Figure 5b A top view showing a severely offset state, determined by the wafer position detection method provided in one embodiment of the present invention.

[0048] Figure 6a The offset state information determined by the wafer position detection method provided in one embodiment of the present invention is a front view with an unknown offset state;

[0049] Figure 6b The offset state information determined by the wafer position detection method provided in one embodiment of the present invention is a top view with unknown offset state;

[0050] 1-Carrier plate, 11-Limiting groove, 2-Image acquisition module, 21-Shielding cover, 22-Camera module, 23-Heat dissipation substrate, 231-Cooling pipe, 3-Image processing module, 4-Main control device, 5-Drive shaft, 51-Hollow pipe, 6-Gas injection pipe, 7-Lift Pin. Detailed Implementation

[0051] The wafer position detection device and method proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] The core idea of ​​this invention is to provide a wafer position detection device and method. This invention sets a limiting groove on the wafer carrier and installs an image acquisition module in the limiting groove. Before the robotic arm performs wafer picking, the image acquisition module acquires the position image of the wafer and transmits it to the image processing module. The image processing module calculates the actual offset of the wafer and determines the offset state information of the wafer, and transmits it to the main control device to control the robotic arm's wafer picking operation. This can effectively avoid wafer breakage accidents caused by inaccurate wafer picking, thereby ensuring production safety and efficiency.

[0055] To achieve the above-mentioned goals, one embodiment of the present invention provides a wafer position detection device. For example, please refer to... Figure 1 and Figure 2 , Figure 1 This is a block diagram of a wafer position detection device according to one embodiment of the present invention. Figure 2 This is a simplified schematic diagram of the image acquisition module in a wafer position detection device provided in one embodiment of the present invention. Figure 1 As shown, the wafer position detection device includes: a carrier plate 1 with a limiting groove 11, an image acquisition module 2 installed in the limiting groove 11, an image processing module 3 communicatively connected to the image acquisition module 2, and a main control device 4 communicatively connected to the image processing module 3; the carrier plate 1 is configured to fix the wafer (not shown in the figure), the image acquisition module 2 is configured to acquire the position image of the wafer and output the position image to the image processing module 3, the image processing module 3 is configured to calculate the actual offset of the wafer according to preset reference information and the position image, and determine the offset state information of the wafer according to the preset reference information and the actual offset, and is also used to output the offset state information to the main control device 4, the main control device 4 is configured to control the wafer picking operation of the robotic arm according to the offset state information.

[0056] This invention provides an image acquisition module 2 by setting a limiting groove 11 on the wafer carrier 1, which provides installation space for the image acquisition module 2. Through the collaborative work of the image acquisition module 2, the image processing module 3, and the main control device 4, the position of the wafer is detected. Furthermore, by determining whether the wafer is misaligned or at risk of falling, the main control module 4 is controlled to take safety measures, effectively preventing wafer breakage accidents caused by inaccurate wafer picking. Therefore, the wafer position detection device provided by this invention, by setting a limiting groove 11 on the wafer carrier 1 and installing the image acquisition module 2 in the limiting groove 11, allows the image acquisition module 2 to acquire the position image of the wafer before the robotic arm performs wafer picking. This image is then transmitted to the image processing module 3, which calculates the actual offset of the wafer and determines the offset status information. This information is then transmitted to the main control device 4 to control the robotic arm's wafer picking operation, effectively preventing wafer breakage accidents caused by inaccurate wafer picking, thereby ensuring production safety and efficiency.

[0057] Preferably, in some exemplary embodiments, the limiting groove 11 is disposed at the center of the carrier disk 1. It is understood that when the wafer is placed on the carrier disk 1, its center usually coincides with the center of the carrier disk 1. Distributing the limiting groove 11 at the center of the carrier disk 1 can simplify the process of acquiring the position image of the wafer and the subsequent offset state detection, and further improve the accuracy of the wafer position detection.

[0058] It should be noted that the present invention does not specifically limit the shape of the limiting groove 11. It can be understood that the shape of the limiting groove 11 can be adapted to the actual process requirements. Preferably, the shape of the limiting groove 11 is cylindrical.

[0059] For example, please continue to see Figure 2 ,like Figure 2 As shown, in some exemplary embodiments, the image acquisition module 2 includes a shielding cover 21, a camera module 22 integrated within the shielding cover 21, and a heat dissipation substrate 23 placed between the shielding cover 21 and the camera module 22 and in close contact with the shielding cover 21 and the camera module 22; the shielding cover 21 is configured to protect the camera module 22 and shield magnetic and electric fields, the camera module 22 is configured to acquire position images of the wafer and output the position images to the image processing module 3, and the heat dissipation substrate 23 is configured to conduct the heat generated by the camera module 22 to the outer layer of the shielding cover 21 to achieve heat dissipation.

[0060] Therefore, by designing the shielding cover 21 outside the camera module 22, the present invention can protect the camera module 22 from process gases while also shielding magnetic and electric fields. This effectively prevents magnetic lines of force from penetrating and interfering with the camera module 22, avoiding image stripe noise or signal distortion, and blocking strong electric fields and various electrical noises generated by plasma. This provides a pure "zero potential" reference ground for the camera module 22, thereby ensuring the accuracy of the acquired wafer position image. Furthermore, by designing the heat dissipation substrate 23 and placing it tightly between the shielding cover 21 and the camera module 22, the heat generated by the camera module 22 can be efficiently conducted to the shielding cover 21, and then transferred to the carrier disk 1 body through the shielding cover 21, achieving efficient passive heat dissipation to meet the high-temperature process requirements.

[0061] It should be noted that the present invention does not specifically limit the material of the heat dissipation substrate 23. For example, the material of the heat dissipation substrate 23 includes, but is not limited to, pyrolytic graphite, molybdenum-copper alloy, and oxygen-free copper. Preferably, in one specific embodiment, the surface of the heat dissipation substrate 23 is gold-plated or nickel-plated to ensure good soldering and oxidation prevention.

[0062] Preferably, in some exemplary embodiments, at least one cooling pipe 231 is provided inside the heat dissipation substrate 23 to connect to cooling water for cooling. It can be understood that by providing a cooling pipe 231 connected to cooling water inside the heat dissipation substrate 23, the heat dissipation effect of the camera module 22 can be further improved, and the stability and reliability of the wafer position detection device provided by the present invention can be improved in high-temperature environments.

[0063] Exemplary, in some exemplary embodiments, the shielding cover 21 includes at least three shielding layers; the three shielding layers, from the inside out, are a magnetic field shielding layer, an insulating and thermally conductive layer, and an electric field shielding layer. Thus, by designing the magnetic field shielding layer in the shielding cover 21, the present invention can guide magnetic field lines through itself, reducing the impact of the magnetic field on the camera module 22; the insulating and thermally conductive layer enables electrical isolation and heat dissipation; and the good electrical and thermal connection between the electric field shielding layer and the carrier plate 1 ensures good grounding, thereby dissipating charge.

[0064] It should be noted that the present invention does not limit the specific materials of each functional layer of the three-layer shielding structure. Preferably, in one specific embodiment, the magnetic field shielding layer is preferably made of a high magnetic permeability material; the insulating and thermally conductive layer is preferably made of thermally conductive silicone or ceramic sheet; and the electric field shielding layer is preferably made of a metal material with both high electrical conductivity and high thermal conductivity, such as aluminum alloy or copper alloy. The three-layer shielding structure achieves efficient electromagnetic shielding while ensuring effective dissipation of the heat generated by the camera module 22 through the synergistic effect of the materials of each functional layer.

[0065] Exemplary, in some exemplary embodiments, the shield 21 is a sealed housing, the camera module 22 includes a CMOS sensor, a lens mount electrically connected to the CMOS sensor, and a signal processing component; the CMOS sensor is configured to acquire image data of the wafer captured by the lens mount, the signal processing component is configured to process the image data to obtain the position image and output the position image to the image processing module 3, and the shield 21 has a transparent window on the side facing the lens mount.

[0066] Therefore, by constructing the shielding cover 21 as an electromagnetically sealed housing, the present invention provides effective physical protection and electromagnetic shielding for the camera module 22 embedded therein. A transparent window is provided on the side of the shielding cover 21 facing the lens mount, allowing the lens mount to capture an image of the wafer's position through the transparent window. Simultaneously, the camera module 22 employs a high-performance CMOS sensor, which features low power consumption, high integration, high speed, and high quality, enabling rapid and accurate image acquisition, thereby significantly improving the accuracy of wafer position determination and the overall reliability of the device.

[0067] It should be noted that the present invention does not specifically limit the type of CMOS sensor. As a preferred embodiment, the CMOS sensor is selected from chips that support global shutter mode and meet high-temperature requirements. This configuration ensures that the CMOS sensor can operate stably for a long time in an environment temperature greater than 85°C, and utilizes global shutter technology to avoid distortion when capturing high-speed motion (specifically, such as the process of a robotic arm grasping the wafer), thereby ensuring that the acquired position image of the wafer has high clarity, providing an accurate data basis for the subsequent image processing module 3 to calculate the actual offset of the wafer.

[0068] It should be noted that the present invention does not limit the specific type of the lens mount. As a preferred embodiment, the lens mount employs a small-sized, large-aperture, and wide-angle fixed-focus lens to meet the image acquisition requirements of achieving sufficient field-of-view coverage (specifically, such as the edge of the wafer) within a limited installation space. Furthermore, the lens mount utilizes an all-metal lens barrel structure and high-temperature resistant optical glass lenses to suppress the risk of thermal deformation of the lens barrel and lens delamination caused by changes in ambient temperature, thereby ensuring focal length stability and image acquisition quality under high-temperature conditions.

[0069] Preferably, in one specific embodiment, the transparent window is made of quartz glass with an indium tin oxide (ITO) conductive film coated on its surface. Thus, using quartz glass as the substrate provides excellent high-temperature stability and light transmittance, while the ITO film ensures high optical transmittance while providing good surface conductivity. This structural design not only ensures the functional integrity of the optical observation channel but also effectively maintains the high-frequency electrical continuity of the shield 21 in the window area, thereby significantly suppressing external electromagnetic fields from coupling into the sensitive circuitry of the camera module 22 through the window.

[0070] Preferably, in some exemplary embodiments, the signal processing component can be a miniaturized multilayer PCB based on rigid-flex PCB technology to accommodate the compact spatial layout inside the image acquisition module 2; the substrate of the PCB is made of high-temperature resistant material, including but not limited to high-temperature FR-5 or polyimide board, and the operating temperature range of the electronic components mounted on its surface covers -40°C to 125°C, thereby ensuring that the signal processing component can maintain stable electrical performance and structural reliability under high-temperature process environments.

[0071] Preferably, in one specific embodiment, the signal processing component further includes a filtering unit and a differential signal transmission unit. The filtering unit includes a filtering capacitor and a filtering inductor, used to filter high-frequency interference and block high-frequency noise generated by external electromagnetic fields from entering the sensitive circuit of the signal processing component; simultaneously, the signal processing component effectively suppresses common-mode interference through the differential signal transmission unit using a differential signal transmission method. It should be noted that for more detailed information regarding the filtering unit and the differential signal transmission method, please refer to relevant technologies known to those skilled in the art; due to space limitations, this invention will not elaborate further.

[0072] Exemplary examples, in some exemplary embodiments, the image acquisition module 2 is integrated into a housing, which is detachably mounted within the limiting groove 11. Thus, by providing a housing around the image acquisition module 2, the present invention avoids damage to the shielding cover 21 during installation and manufacturing processes. Furthermore, the housing's mounting within the limiting groove 11 ensures reliable fixation of the image acquisition module 2. The detachable design simplifies the installation process and facilitates maintenance. It should be noted that the present invention does not specifically limit the material of the housing. Preferably, the housing is made of stainless steel, taking advantage of its high strength, corrosion resistance, and weak magnetism to further enhance the stability and reliability of the image acquisition module 2.

[0073] Preferably, in one specific embodiment, the image acquisition module 2 is integrated into the housing to form a robust unit with a mounting flange and a connector. In this way, the housing is detachably fixed in the limiting groove 11 by the mounting flange, and a connector is provided on the housing to provide a line connection interface between the image acquisition module 2 and the image processing module 3.

[0074] For example, please continue to see Figure 1In some exemplary embodiments, the detection device further includes a gas injection pipe 6 and a drive shaft 5 supporting the support plate 1; the drive shaft 5 has a hollow conduit 51; the gas injection pipe 6 passes through the hollow conduit 51 and extends towards the opening of the groove after surrounding the limiting groove 11 at one end near the support plate 1. Figure 1 (The gray shading lines on both sides and bottom of the limiting groove 11 are used to indicate this). The process gas is introduced into the surface area of ​​the wafer. The transmission line between the image acquisition module 2 and the image processing module 3 passes through the hollow pipe 51. Therefore, this invention introduces the process gas into the surface area of ​​the wafer by surrounding the limiting groove 11 with one end of the gas injection pipe 6 near the support plate 1 and extending towards the groove opening. This ensures the output volume and uniformity of the gas injection pipe 6, preventing any impact on the gas flow effect and ensuring that the device does not affect the original process flow during use. By reserving a hollow pipe 51 in the drive shaft 5 for the transmission line routing, space utilization and structural integration are optimized, providing a convenient installation and maintenance path for the transmission line, while ensuring signal transmission stability and reducing interference.

[0075] Preferably, in some exemplary embodiments, at least one hole (not shown in the figure) is formed in the limiting groove 11. This arrangement allows the hole to form a wind-cooling effect with the body of the gas injection pipe 6 and / or the injection sub-pipe, thereby reducing the operating temperature of the image acquisition module 2 and further achieving a heat dissipation effect.

[0076] Preferably, in some exemplary embodiments, all components of the image acquisition module 2 are made of high-temperature resistant materials, thereby ensuring that the image acquisition module 2 can maintain good structural stability and mechanical strength in high-temperature environments.

[0077] Based on the same inventive concept, this invention also proposes a method for detecting wafer position; please refer to [link to related document]. Figures 1-6b ,in, Figure 3 This is a schematic flowchart of a wafer position detection method provided in one embodiment of the present invention. Figure 4a The offset state information determined by the wafer position detection method provided in one embodiment of the present invention is a front view of a normal offset state. Figure 4b A top view showing the wafer position detection method provided in one embodiment of the present invention, where the offset state information is determined to be in a normal offset state. Figure 5a A front view showing a severely offset state determined by the wafer position detection method provided in one embodiment of the present invention. Figure 5bA top view showing a severely offset state, determined by the wafer position detection method provided in one embodiment of the present invention. Figure 6a The offset state information determined by the wafer position detection method provided in one embodiment of the present invention is a front view with an unknown offset state. Figure 6b The offset state information determined by the wafer position detection method provided in one embodiment of the present invention is a top view with an unknown offset state.

[0078] like Figure 1 and Figure 3 As shown, the wafer position detection method uses the wafer position detection device described above. Before performing the wafer pick-up operation on the wafer placed on the carrier disk 1, the detection method performs the following steps:

[0079] S100: The image acquisition module 2 acquires a position image of the wafer and outputs the position image to the image processing module 3;

[0080] S200: The image processing module 3 calculates the actual offset of the wafer based on the preset reference information and the position image, determines the offset status information of the wafer based on the preset reference information and the actual offset, and outputs the offset status information to the main control device 4.

[0081] S300: The main control device 4 controls the robotic arm to pick up the piece according to the received offset status information.

[0082] Preferably, in some exemplary embodiments, the step of acquiring the position image of the wafer through the image acquisition module 2 and outputting the position image to the image processing module 3 includes: establishing a distortion model and pre-obtaining the intrinsic parameter matrix and distortion coefficients; inputting the acquired position image, intrinsic parameter matrix, and distortion coefficients into the distortion model to obtain a distortion-processed position image. Thus, this invention describes the distortion caused by the lens by establishing a distortion model and eliminates the deformation caused by distortion by repositioning and calculating each pixel in the image, thereby ensuring the high definition of the acquired position image of the wafer and thus ensuring the accuracy of the wafer's position determination. It should be noted that for more detailed information on how to use a distortion model for image distortion correction, please refer to relevant technologies known to those skilled in the art; due to space limitations, this invention will not elaborate further.

[0083] Exemplary, in some exemplary embodiments, the preset reference information includes the standard center coordinates, pixel equivalent, edge point number threshold, and maximum allowable offset of the carrier disk 1; the offset status information includes unknown offset status, severe offset status, and normal offset status; the image processing module 3 calculates the actual offset of the wafer based on the preset reference information and the position image, and determines the offset status information of the wafer based on the preset reference information and the actual offset, including: preprocessing and feature extraction of the position image to obtain the set of edge point coordinates and the number of edge points in the position image; determining whether the number of edge points is less than the edge point number threshold: if yes, the offset status information is unknown offset status; if no, the following steps are performed:

[0084] Based on the set of edge point coordinates of the location image, the center coordinates of the location image are obtained by random sampling; and the actual offset of the wafer is calculated based on the center coordinates, the standard center coordinates, and the pixel equivalent; and the offset status information is determined based on the maximum allowable offset and the actual offset.

[0085] Preferably, in some exemplary embodiments, please refer to Figure 4a , Figure 5a and Figure 6a The standard center coordinates and pixel equivalent of the carrier disk 1 in the preset reference information are obtained by: setting the center coordinates of the triangle formed by the three Lift Pins 7 on the carrier disk 1 as the standard center coordinates; and taking a piece of known precise physical size (specifically, such as diameter) as the reference information. A calibration object (300 mm in diameter) is placed on the carrier plate 1 and photographed. The number of pixels occupied by its diameter is measured in the corrected image. The pixel equivalent (For example, if the unit is micrometers / pixel) it can be calculated using the following formula:

[0086]

[0087] It should be noted that the present invention does not limit the specific value of the edge point number threshold, and the specific value of the edge point number threshold can be set and adjusted by those skilled in the art according to actual application needs. For example, in an exemplary embodiment, the edge point number threshold is set to 200.

[0088] For example, in some exemplary embodiments, preprocessing and feature extraction of the location image to obtain the set of edge point coordinates and the number of edge points of the location image includes: converting the location image into a grayscale image, performing Gaussian filtering for noise reduction and edge detection on the grayscale image to obtain the set of edge point coordinates of the location image; and determining the number of edge points based on the set of edge point coordinates of the location image.

[0089] For example, in one specific implementation, if the number of edge points is less than the edge point number threshold, the offset status information is "offset status unknown." When the main control device 4 receives this offset status information, it controls the robotic arm to stop the wafer picking operation and issues an alarm to facilitate timely equipment maintenance and minimize losses. In some implementations, the "offset status unknown" includes, for example,... Figure 6a and Figure 6b The detected actual offset of the wafer shown far exceeds the maximum allowable offset; in other embodiments, the unknown offset state may also mean that the actual offset of the wafer cannot be obtained.

[0090] For example, in some exemplary embodiments, the preset reference information further includes a minimum point distance preset value and a maximum point distance preset value for the location image; the step of obtaining the center coordinates of the location image by random sampling based on the set of edge point coordinates of the location image includes: randomly selecting edge points in the set of edge point coordinates whose point distances are between the minimum point distance preset value and the maximum point distance preset value to form edge point pairs, and constructing the perpendicular bisector equation of the edge point pairs; and fitting and calculating the center coordinates of the location image based on the perpendicular bisector equation.

[0091] Preferably, in one specific embodiment, the minimum and maximum point distance preset values ​​of the position image are preset using the following formulas:

[0092]

[0093] in, This indicates the preset minimum point distance. This indicates the preset maximum point spacing. This indicates the radius of the wafer.

[0094] It should be noted that the present invention does not specifically limit the values ​​of the first ratio and the second ratio. However, as a preferred embodiment, the first ratio should be much smaller than the second ratio. For example, the first ratio is 0.2 and the second ratio is 1.6, to avoid selecting points that are too close or at the ends of the diameter, which could lead to excessive errors.

[0095] Preferably, in some exemplary embodiments, the perpendicular bisector equation of the edge point pair is constructed by the following method:

[0096] For any two edge points and ,in ,from arrive The direction vector is: This vector v and the line segment Parallel, the normal vector of vector v is edge point and midpoint coordinates for:

[0097]

[0098] Two edge points and The general form of the equation for the generated perpendicular bisector is:

[0099]

[0100] in: , , .

[0101] Furthermore, the equation for the perpendicular bisector is normalized:

[0102]

[0103] The normalized equation of the perpendicular bisector is obtained:

[0104]

[0105] Preferably, in some exemplary embodiments, the preset reference information further includes the number of selected edge point pairs. Calculating the center coordinates of the position image based on the perpendicular bisector equation includes: calculating the center coordinates of the position image based on the number of selected edge point pairs (e.g., the number of selected edge point pairs). The perpendicular bisector equation of the edge point pair is obtained by the method described above. Find the equations of the perpendicular bisectors and construct the following system of linear equations:

[0106]

[0107] The system of linear equations can be expressed in matrix form as follows: ,in:

[0108]

[0109] The center coordinates of the circle in the position image are calculated using least squares fitting. for:

[0110]

[0111] It should be noted that the present invention does not limit the specific number of edge point pairs selected. Preferably, the number of edge point pairs selected ranges from 50 to 200.

[0112] For example, in some exemplary embodiments, the step of calculating the actual offset of the wafer based on the center coordinates, the standard center coordinates, and the pixel equivalent, and determining the offset state information based on the maximum allowable offset and the actual offset, includes: calculating the pixel offset of the wafer based on the center coordinates and the standard center coordinates, and calculating the actual offset of the wafer based on the pixel offset and the pixel equivalent; determining whether the actual offset is greater than the maximum allowable offset: if yes, the offset state information is a severe offset state; if no, the offset state information is a normal offset state, the normal offset state including the actual offset.

[0113] Preferably, in some exemplary embodiments, the pixel offset of the wafer is calculated based on the center coordinates and the standard center coordinates using the following formula:

[0114]

[0115] in, This represents the pixel offset (in pixels). Indicates the coordinates of the center of the circle. This represents the coordinates of the standard circle center.

[0116] The actual offset of the wafer is calculated using the following formula based on the pixel offset and the pixel equivalent:

[0117]

[0118] in, This indicates the actual offset (in micrometers).

[0119] For example, in one exemplary embodiment, please refer to Figures 4a-5b The maximum allowable offset of the wafer is preset to be (For example, such as) Figure 4b , Figure 5b and Figure 6b The range shown by the red dashed line in the middle), the actual offset amount and Compare and determine the actual offset. Is it greater than the maximum allowable offset? If (for example, such as) Figure 5a and Figure 5b If the offset status information is as shown, then the offset status is a severe offset status; otherwise (for example, as shown in the figure), the offset status information is a severe offset status. Figure 4a and Figure 4b (As shown), then the offset status information is a normal offset status.

[0120] It should be noted that this invention does not limit the specific value of the maximum permissible offset. Those skilled in the art can adaptively adjust and optimize this parameter based on actual process conditions, equipment accuracy, and production requirements.

[0121] For example, in some exemplary embodiments, the master control device controls the robotic arm's wafer-picking operation based on the received offset status information, including: when the offset status information is the offset status unknown or the severe offset status, controlling the robotic arm to stop the wafer-picking operation and triggering an alarm; when the status judgment parameter is the normal offset status, controlling the robotic arm to pick up the wafer normally and perform offset calibration based on the actual offset amount.

[0122] Compared with the prior art, the wafer position detection device and method provided by the present invention have the following beneficial effects: The wafer position detection device provided by the present invention includes: a carrier disk with a limiting groove, an image acquisition module installed in the limiting groove, an image processing module communicatively connected to the image acquisition module, and a main control device communicatively connected to the image processing module; the carrier disk is configured to fix the wafer, the image acquisition module is configured to acquire the position image of the wafer and output the position image to the image processing module, the image processing module is configured to calculate the actual offset of the wafer according to preset reference information and the position image, and determine the offset state information of the wafer according to the preset reference information and the actual offset, and is also used to output the offset state information to the main control device, the main control device is configured to control the wafer picking operation of the robotic arm according to the offset state information.

[0123] Therefore, the wafer position detection device provided by the present invention sets a limiting groove on the wafer carrier and installs an image acquisition module in the limiting groove. Before the robotic arm performs wafer picking, the image acquisition module acquires the position image of the wafer and transmits it to the image processing module. The image processing module calculates the actual offset of the wafer and determines the offset state information of the wafer, and transmits it to the main control device to control the robotic arm's wafer picking operation. This can effectively avoid wafer breakage accidents caused by inaccurate wafer picking, thereby ensuring production safety and efficiency.

[0124] Furthermore, the image acquisition module in the wafer position detection device provided by the present invention, by adopting a shielding cover that shields the magnetic and electric fields outside the camera module and a heat dissipation substrate, enables the CMOS sensor in the camera module to have the ability to resist high temperature and strong electromagnetic fields, thereby adapting to different PVD process scenarios and further improving the applicability and reliability of the present invention.

[0125] Furthermore, the wafer position detection device provided by the present invention can redesign the structure of the carrier disk based on the existing structure. By using a method in which the end of the gas injection tube near the carrier disk surrounds the limiting groove and extends towards the groove opening to introduce process gas into the surface area of ​​the wafer, it is possible to ensure that there is enough space to install the image acquisition module while ensuring the gas output and uniformity of the gas injection tube, thereby ensuring that the gas flow effect of the gas injection tube is not affected.

[0126] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," or "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0127] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A wafer position detection device, characterized in that, The wafer position detection device includes: A carrier plate with a limiting groove is provided, an image acquisition module is installed in the limiting groove, an image processing module is communicatively connected to the image acquisition module, and a main control device is communicatively connected to the image processing module. The carrier disk is configured to fix the wafer. The image acquisition module is configured to acquire the position image of the wafer and output the position image to the image processing module. The image processing module is configured to calculate the actual offset of the wafer based on preset reference information and the position image, and determine the offset state information of the wafer based on the preset reference information and the actual offset. It is also configured to output the offset state information to the main control device. The main control device is configured to control the wafer picking operation of the robotic arm based on the offset state information.

2. The wafer position detection device as described in claim 1, characterized in that, The image acquisition module includes a shielding cover, a camera module integrated within the shielding cover, and a heat dissipation substrate placed between the shielding cover and the camera module and in close contact with the shielding cover and the camera module; The shielding cover is configured to protect the camera module and shield magnetic and electric fields. The camera module is configured to acquire position images of the wafer and output the position images to the image processing module. The heat dissipation substrate is configured to conduct the heat generated by the camera module to the outer layer of the shielding cover to achieve heat dissipation.

3. The wafer position detection device as described in claim 2, characterized in that, The shielding cover includes at least three shielding structures; the three shielding structures, from the inside out, are a magnetic field shielding layer, an insulating and heat-conducting layer, and an electric field shielding layer.

4. The wafer position detection device as described in claim 2, characterized in that, The shield is a sealed housing. The camera module includes a CMOS sensor, a lens mount electrically connected to the CMOS sensor, and a signal processing component. The CMOS sensor is configured to acquire image data of the wafer captured by the lens mount. The signal processing component is configured to process the image data to obtain the position image and output the position image to the image processing module. A transparent window is provided on the side of the shield facing the lens mount.

5. The wafer position detection device as described in claim 1, characterized in that, The image acquisition module is integrated into a housing, which is detachably installed within the limiting groove.

6. The wafer position detection device as described in claim 1, characterized in that, The detection device further includes a gas injection pipe and a drive shaft that carries the support disk; the drive shaft has a hollow pipe; the gas injection pipe passes through the hollow pipe and extends towards the groove after surrounding the limiting groove at one end near the support disk, so as to introduce process gas into the surface area of ​​the wafer; the transmission line between the image acquisition module and the image processing module passes through the hollow pipe.

7. A method for detecting wafer position, characterized in that, The wafer position detection method uses the wafer position detection device as described in any one of claims 1-6. Before performing a wafer pick-up operation on the wafer placed on the carrier disk, the detection method performs the following steps: The image acquisition module acquires a position image of the wafer and outputs the position image to the image processing module; The image processing module calculates the actual offset of the wafer based on the preset reference information and the position image, determines the offset status information of the wafer based on the preset reference information and the actual offset, and outputs the offset status information to the main control device. The main control device controls the robotic arm's chip-picking operation based on the received offset status information.

8. The wafer position detection method as described in claim 7, characterized in that, The preset reference information includes the standard center coordinates of the carrier disk, pixel equivalent, edge point number threshold, and maximum allowable offset; the offset status information includes unknown offset status, severe offset status, and normal offset status; the image processing module calculates the actual offset of the wafer based on the preset reference information and the position image, and determines the offset status information of the wafer based on the preset reference information and the actual offset, including: The location image is preprocessed and features are extracted to obtain the set of edge point coordinates and the number of edge points in the location image; Determine whether the number of edge points is less than the edge point number threshold: if yes, the offset status information is "offset status unknown"; if no, perform the following steps: Based on the set of edge point coordinates of the location image, the center coordinates of the location image are obtained by random sampling; and the actual offset of the wafer is calculated based on the center coordinates, the standard center coordinates, and the pixel equivalent; and the offset status information is determined based on the maximum allowable offset and the actual offset.

9. The wafer position detection method as described in claim 8, characterized in that, The location image is preprocessed and its features are extracted to obtain the set of edge point coordinates and the number of edge points in the location image, including: The location image is converted into a grayscale image, and Gaussian filtering and edge detection are performed on the grayscale image to obtain a set of edge point coordinates of the location image; The number of edge points is determined based on the set of edge point coordinates of the location image.

10. The wafer position detection method as described in claim 9, characterized in that, The preset reference information also includes a minimum point distance preset value and a maximum point distance preset value for the location image; the step of obtaining the center coordinates of the location image using a random sampling method based on the set of edge point coordinates of the location image includes: Randomly select edge points from the set of edge point coordinates that are between the minimum and maximum preset point distance values ​​to form edge point pairs, and construct the equation of the perpendicular bisector of the edge point pairs. The center coordinates of the position image are calculated by fitting the perpendicular bisector equation.

11. The wafer position detection method as described in claim 10, characterized in that, The step of calculating the actual offset of the wafer based on the center coordinates, the standard center coordinates, and the pixel equivalent, and determining the offset status information based on the maximum allowable offset and the actual offset, includes: The pixel offset of the wafer is calculated based on the center coordinates of the circle and the standard center coordinates of the circle, and the actual offset of the wafer is calculated based on the pixel offset and the pixel equivalent. Determine whether the actual offset is greater than the maximum allowable offset: If yes, the offset status information is a severe offset state; if no, the offset status information is a normal offset state, and the normal offset state includes the actual offset amount.

12. The wafer position detection method as described in claim 11, characterized in that, The main control device controls the robotic arm's wafer-picking operation based on the received offset status information, including: When the offset status information indicates an unknown offset status or a severe offset status, the robotic arm is controlled to stop the wafer picking operation and an alarm is triggered; when the status judgment parameter indicates a normal offset status, the robotic arm is controlled to pick up the wafer normally and perform offset calibration based on the actual offset amount.

Images