A silicon carbide wafer surface defect detection mechanism

Abstract

The utility model discloses a kind of silicon carbide wafer surface defect detection mechanisms, including platform, area light source and visual detection device, the platform is equipped with first X-axis moving device and is equipped in the first Y-axis moving device of first X-axis moving device, the first Y-axis moving device is equipped with carrier to place silicon carbide wafer, the first X-axis moving device and first Y-axis moving device are used to drive silicon carbide wafer and move along X-axis and Y-axis direction, the platform is equipped with second X-axis moving device and is equipped in the second Y-axis moving device of second X-axis moving device, the second Y-axis moving device is equipped with rotating device, the area light source is located on rotating device to adjust the relative position and relative inclination angle between irradiation surface and silicon carbide wafer, the visual detection device includes industrial camera and is equipped with FA lens below industrial camera;The visual detection device is used to obtain the image when area light source is located at different positions of silicon carbide wafer.

Description

Technical Field

[0001] This utility model relates to the field of visual inspection mechanisms, and in particular to a silicon carbide wafer surface defect inspection mechanism. Background Technology

[0002] Silicon carbide (SiC), as a third-generation semiconductor material, possesses characteristics such as a wide bandgap (3.2 eV), high thermal conductivity, and a high breakdown electric field (10 times that of silicon), making it suitable for high-temperature, high-voltage, and high-frequency applications. Silicon carbide has a withstand voltage of tens of thousands of volts and its thermal conductivity is three times that of silicon, which can significantly reduce device power consumption and size.

[0003] The common method for detecting surface defects on silicon carbide wafers in the market is to combine deep learning algorithms with automated optical inspection equipment.

[0004] 1. Lighting tests were conducted by placing dome light sources, ring light sources, coaxial light sources, and strip light sources directly above the silicon carbide wafer;

[0005] 2. However, the existing multiple light sources, after testing, do not show a significant difference in grayscale between defects and normal areas on the silicon carbide wafer surface. Moreover, the images acquired by these light sources show a cluttered background on the silicon carbide surface, which is not conducive to the detection and recognition of algorithms. Utility Model Content

[0006] The main objective of this invention is to propose a silicon carbide wafer surface defect detection mechanism, which aims to improve the coordination between existing light sources and visual inspection mechanisms, thereby enhancing the grayscale difference between silicon carbide wafer surface defects and normal areas on the silicon carbide surface, improving detection contrast while reducing the computing power of the recognition system and increasing detection efficiency.

[0007] To achieve the above objectives, this utility model proposes a silicon carbide wafer surface defect detection mechanism, comprising:

[0008] The platform includes a first X-axis moving device and a first Y-axis moving device disposed on the first X-axis moving device. The first Y-axis moving device is equipped with a carrier for placing silicon carbide wafers.

[0009] The first X-axis moving device and the first Y-axis moving device are used to drive the silicon carbide wafer to move along the X-axis and Y-axis directions;

[0010] The platform includes a surface light source, a second X-axis moving device, and a second Y-axis moving device located on the second X-axis moving device. The second Y-axis moving device is equipped with a rotating device.

[0011] The surface light source is mounted on a rotating device to adjust the relative position and relative tilt angle between the irradiation surface and the silicon carbide wafer.

[0012] A visual inspection device, comprising an industrial camera and a FA lens disposed below the industrial camera;

[0013] The visual inspection device is used to acquire images when the surface light source is located at different positions on the silicon carbide wafer.

[0014] In the actual design, the object under test is moved by the first X-axis moving device and the first Y-axis moving device. The human eye observes the left side of the silicon carbide wafer. After the image is good, the industrial color camera is controlled by the industrial color camera software to take the first picture.

[0015] Then, the object under test is moved by the first X-axis moving device and the first Y-axis moving device. The human eye observes the center of the silicon carbide wafer. After the image is well formed, the industrial color camera software is used to control the industrial color camera to take a second picture.

[0016] Finally, the object under test is moved by the first X-axis moving device and the first Y-axis moving device. The right side of the silicon carbide wafer is observed by the human eye. After the image is well formed, the industrial color camera is controlled by the industrial color camera software to take a third picture.

[0017] By combining the synthesized image with existing algorithms, three images are used to extract regions suitable for defect detection. These regions are then combined to create a complete image showing the defect location. This method can effectively detect defects on the entire silicon carbide wafer surface, avoiding the instability caused by using other light sources.

[0018] Of course, the number of times the image is acquired can be more than 3 or less than 3, such as 2, 4, 5, 6 to 20 times, which can be set according to the actual product size and product parameters.

[0019] The additional second X-axis moving device, second Y-axis moving device, and rotating device can adjust the relative position of the surface light source according to actual needs, thereby improving the applicability of the product.

[0020] The mechanism of this technical solution is simple to operate and has good stability. By tilting the surface light source and using the principle of mirror reflection, the gray scale of the silicon carbide wafer surface can be made relatively uniform and the defects are very prominent. It can effectively detect defects on the entire surface of the silicon carbide wafer, which can reduce the pressure of subsequent image algorithm detection and improve the stability of defect detection. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of the present utility model. Figure 1 ;

[0022] Figure 2 This is a cross-sectional view of the present invention;

[0023] Figure 3This refers to the process of acquiring product images.

[0024] In the picture,

[0025] 1 is the platform, 11 is the first X-axis moving device, 12 is the first Y-axis moving device, and 13 is the vehicle.

[0026] 2 is a surface light source, 21 is a second X-axis moving device, 22 is a second Y-axis moving device, and 23 is a rotating device.

[0027] 3 represents a vision inspection device, 31 represents an industrial camera, and 32 represents a FA lens.

[0028] 100 represents silicon carbide wafers. Detailed Implementation

[0029] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0030] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, inside, outside, vertical, horizontal, longitudinal, counterclockwise, clockwise, circumferential, radial, axial, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0031] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0032] like Figures 1 to 3 As shown, a silicon carbide wafer surface defect detection mechanism includes:

[0033] Platform 1, wherein the platform 1 is provided with a first X-axis moving device 11 and a first Y-axis moving device 12 provided on the first X-axis moving device 11, and the first Y-axis moving device 12 is provided with a carrier 13 for placing silicon carbide wafers 100.

[0034] The first X-axis moving device 11 and the first Y-axis moving device 12 are used to drive the silicon carbide wafer 100 to move along the X-axis and Y-axis directions;

[0035] The surface light source 2, the platform 1 is provided with a second X-axis moving device 21 and a second Y-axis moving device 22 provided on the second X-axis moving device 21, the second Y-axis moving device 22 is provided with a rotating device 23.

[0036] The surface light source 2 is mounted on the rotating device 23 to adjust the relative position and relative tilt angle between the irradiation surface and the silicon carbide wafer 100.

[0037] The visual inspection device 3 includes an industrial camera 31 and an FA lens 32 disposed below the industrial camera 31.

[0038] The visual inspection device 3 is used to acquire images of the surface light source 2 at different positions on the silicon carbide wafer 100.

[0039] In the actual design, the object under test is moved by the first X-axis moving device 11 and the first Y-axis moving device 12. The human eye observes the left side of the silicon carbide wafer 100. After the image is good, the industrial color camera is controlled by the industrial color camera software to take the first picture.

[0040] Then, the object under test is moved by the first X-axis moving device 11 and the first Y-axis moving device 12. The human eye observes the center of the silicon carbide wafer 100. After the image is well formed, the industrial color camera software is used to control the industrial color camera to take a second picture.

[0041] Finally, the object under test is moved by the first X-axis moving device 11 and the first Y-axis moving device 12. The right side of the silicon carbide wafer 100 is observed by the human eye. After the image is well formed, the industrial color camera is controlled by the industrial color camera software to take a third picture.

[0042] By combining the synthesized image with existing algorithms, three images are used to extract regions suitable for defect detection. These regions are then combined to create a complete image showing the defect location. This method can effectively detect defects on the entire silicon carbide wafer surface, avoiding the instability caused by using other light sources.

[0043] Of course, the number of times the image is acquired can be more than 3 or less than 3, such as 2, 4, 5, 6 to 20 times, which can be set according to the actual product size and product parameters.

[0044] The other second X-axis moving device 21, second Y-axis moving device 22 and rotating device 23 can adjust the relative position of the surface light source 2 according to actual needs, thereby improving the applicability of the product.

[0045] The mechanism of this technical solution is simple to operate and has good stability. By tilting the surface light source 2 and using the principle of mirror reflection, the gray scale of the silicon carbide wafer surface can be made relatively uniform and the defects are very prominent. It can effectively detect defects on the entire surface of the silicon carbide wafer, which can reduce the pressure of subsequent image algorithm detection and improve the stability of defect detection.

[0046] The FA lens 32 is a manual focus lens, which is existing technology.

[0047] Specifically, the positions of the X-axis moving device and the Y-axis moving device can be interchanged to meet different needs.

[0048] Specifically, the first X-axis moving device 11 and the first Y-axis moving device 12 are manual adjustment rod devices or linear motors. Depending on the actual needs, they can be set as manual adjustment devices as shown in the figure, or the two linear motors can be used in conjunction to achieve the position adjustment of the surface light source.

[0049] Specifically, the second X-axis moving device 21 and the second Y-axis moving device 22 are manual adjustment rod devices or linear motors. Depending on the actual needs, they can be set as manual adjustment devices as shown in the figure, or the two linear motors can be used in conjunction to achieve the position adjustment of the surface light source.

[0050] Specifically, the industrial camera 31 is a color industrial camera, which can improve the distinction between bright and dark areas, thereby improving the detection contrast.

[0051] Specifically, the extension of the line connecting the center point of the bottom surface and the center point of the top surface of the surface light source 2 intersects the optical axis of the FA lens 32.

[0052] Specifically, the angle α between the surface light source 2 and the horizontal plane is 30°.

[0053] Specifically, the distance between the FA lens 32 and the silicon carbide wafer is 260mm.

[0054] Specifically, the exposure parameter of the industrial color camera 31 is 40ms.

[0055] Specifically, the length and width of the light-emitting surface of the surface light source 2 are both 200mm.

[0056] Of course, the specific parameters are set according to the different products, and are not limited to specific dimensions.

[0057] The visual inspection device is mounted on a gantry frame.

[0058] The gantry frame is equipped with a vertical moving device, the vertical moving device is equipped with a horizontal moving device, and the visual inspection device is mounted on the horizontal moving device.

[0059] Specifically, the vertical moving device is a worm gear drive structure, and the horizontal moving device can be a linear motor.

[0060] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A silicon carbide wafer surface defect detection mechanism, characterized by, include: The platform includes a first X-axis moving device and a first Y-axis moving device disposed on the first X-axis moving device. The first Y-axis moving device is equipped with a carrier for placing silicon carbide wafers. The first X-axis moving device and the first Y-axis moving device are used to drive the silicon carbide wafer to move along the X-axis and Y-axis directions; The platform includes a surface light source, a second X-axis moving device, and a second Y-axis moving device located on the second X-axis moving device. The second Y-axis moving device is equipped with a rotating device. The surface light source is mounted on a rotating device to adjust the relative position and relative tilt angle between the irradiation surface and the silicon carbide wafer. A visual inspection device, comprising an industrial camera and a FA lens disposed below the industrial camera; The visual inspection device is used to acquire images when the surface light source is located at different positions on the silicon carbide wafer.

2. The silicon carbide wafer surface defect inspection mechanism of claim 1, wherein: The first X-axis moving device and the first Y-axis moving device are manual adjustment rod devices or linear motors.

3. The silicon carbide wafer surface defect inspection mechanism of claim 1, wherein: The second X-axis moving device and the second Y-axis moving device are manual adjustment rod devices or linear motors.

4. The silicon carbide wafer surface defect inspection mechanism of claim 1, wherein: The industrial camera mentioned is a color industrial camera.

5. The silicon carbide wafer surface defect detection mechanism of claim 1, wherein: The angle between the surface light source and the horizontal plane is 30°.

6. The silicon carbide wafer surface defect detection mechanism of claim 1, wherein: The distance between the FA lens and the silicon carbide wafer is 260mm.

7. The silicon carbide wafer surface defect detection mechanism of claim 4, wherein: The exposure parameter of the industrial color camera is 40ms.

8. The silicon carbide wafer surface defect inspection mechanism of claim 1, wherein: The length and width of the light-emitting surface of the surface light source are both 200mm.

9. The silicon carbide wafer surface defect inspection mechanism of claim 1, wherein: The visual inspection device is mounted on a gantry frame, which is equipped with a vertical moving device and a horizontal moving device. The visual inspection device is mounted on the horizontal moving device.

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