Wafer pre-alignment device and wafer pre-alignment method

Abstract

The application discloses a wafer pre-alignment device and a wafer pre-alignment method. The wafer pre-alignment device comprises a bearing assembly for bearing a wafer and driving the wafer to rotate around a rotation shaft of the bearing assembly; a moving assembly for driving the wafer to move in a direction perpendicular to the rotation shaft; a light source assembly located at a first side of the wafer for generating a plurality of optical fringes emitted towards the wafer, the optical fringes all intersect with a circumferential edge of the wafer; a linear array image sensor located at a second side of the wafer for receiving the optical fringes and generating a gray scale image for characterizing the circumferential edge; and a controller for determining a deviation between a center of the wafer and a center of the bearing assembly according to the gray scale image and performing corresponding compensation. According to the wafer pre-alignment device and the wafer pre-alignment method, the pre-alignment precision can be effectively improved.

Description

Technical Field

[0001] This application relates to the field of integrated circuit manufacturing technology, and more specifically to a wafer pre-alignment device and a wafer pre-alignment method. Background Technology

[0002] In wafer fabrication, the precision requirements of the fabrication process are higher than those of the wafer transport process. Therefore, before processing, the wafer must be aligned using a wafer pre-alignment device to compensate for positioning errors caused during transport. Wafer pre-alignment is a crucial step in the integrated circuit manufacturing process, and its accuracy directly affects the precision and efficiency of the entire integrated circuit manufacturing process.

[0003] Current wafer pre-alignment devices typically perform pre-alignment in the following way:

[0004] 1) Optical images of the wafer are acquired using a CCD (Charge-coupled Device) image sensor, and the wafer edges and center are calculated and fitted. This process requires complex image processing techniques and is not suitable for pre-alignment of wafers with complex edges (such as edge thinning, where a second boundary is easily detected).

[0005] 2) The notch or flat edge of the wafer is determined by fitting the waveform signal obtained by collecting the amount of light passing through the wafer edge. This method is not suitable for pre-alignment of wafers with special edges (such as edge burrs).

[0006] Therefore, improvements are needed to at least partially address the aforementioned problems. Summary of the Invention

[0007] The summary section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. The summary section of this invention is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0008] To at least partially solve the above-mentioned problems, according to a first aspect of the present invention, a wafer pre-alignment apparatus is provided, comprising:

[0009] A carrier component for carrying a wafer and driving the wafer to rotate about the rotation axis of the carrier component;

[0010] A moving component is used to move the wafer in a direction perpendicular to the rotation axis;

[0011] A light source assembly, located on a first side of the wafer, is used to generate multiple optical stripes that emit toward the wafer. The multiple optical stripes are of equal width and are arranged in parallel and equidistantly. All optical stripes intersect with the circumferential edge of the wafer.

[0012] A linear image sensor, located on the second side of the wafer, is used to receive the optical stripes and generate a grayscale image for characterizing the circumferential edge;

[0013] The controller is used to determine the deviation between the center of the wafer and the center of the carrier component based on the grayscale image, and to perform corresponding compensation.

[0014] For example, the light source assembly includes a light source and a beam splitter, the beam splitter being used to cause the light emitted by the light source to form a plurality of optical fringes through Young's interference or diffraction;

[0015] The linear image sensor is either a CCD linear image sensor or a CMOS linear image sensor.

[0016] For example, the number of optical stripes is greater than or equal to 5;

[0017] The length of the optical stripe is 1 mm to 1.25 mm;

[0018] The spacing between adjacent optical stripes is 4μm-200μm.

[0019] For example, the carrier component includes a vacuum suction cup, a first driving unit, and a second driving unit;

[0020] The vacuum chuck is used to support the wafer, the center of the support assembly is the center of the vacuum chuck, and the center of the vacuum chuck is located on the rotation axis;

[0021] The first driving unit is used to drive the vacuum chuck to rotate around the rotation axis;

[0022] The second drive unit is used to drive the vacuum suction cup to rise and fall.

[0023] The controller is also configured to locate a positioning portion on the wafer based on the grayscale image, wherein the positioning portion includes a notch or a flat edge.

[0024] For example, locating the positioning portion on the wafer based on the grayscale image includes:

[0025] The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution, so that the circumferential edge of the wafer passes between the light source component and the linear image sensor in sequence;

[0026] The position of the positioning part is determined based on the grayscale image generated by the linear image sensor during the rotation of the wafer.

[0027] The carrier component is controlled to rotate the wafer, so that the positioning part is located between the light source component and the linear image sensor.

[0028] For example, determining the position of the positioning part based on the grayscale image generated by the linear image sensor during the wafer rotation includes:

[0029] Determine whether the grayscale image generated by the linear image sensor during the wafer rotation process matches the preset grayscale image of the positioning part;

[0030] When the grayscale image matches the grayscale image of the positioning part, the position of the circumferential edge corresponding to the grayscale image that matches the grayscale image of the positioning part is determined as the position of the positioning part.

[0031] For example, locating the positioning unit based on the grayscale image further includes:

[0032] The edge contour of the positioning part is determined based on the grayscale image acquired by the linear image sensor when the positioning part is located between the light source assembly and the linear image sensor.

[0033] Based on the edge profile, the fitted circumferential edge and geometric center at the positioning portion of the wafer are determined, wherein the geometric center is the midpoint of the fitted circumferential edge.

[0034] The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution. Based on the grayscale image acquired by the linear image sensor during the wafer rotation, the distance from multiple sampling points on the circumferential edge of the wafer to the center of the carrier component is determined. The angles formed by the lines connecting adjacent sampling points to the center of the carrier component are equal, and the number of sampling points is greater than or equal to 4 and is an integer multiple of 4.

[0035] Calculate a first average distance from each of the sampling points to the center of the bearing component, and calculate the difference between the distance from each of the sampling points to the center of the bearing component and the first average distance;

[0036] Calculate the second average value of the difference corresponding to each group of relative sampling points, and take half of the second average value as the deviation value corresponding to the relative sampling points, wherein the relative sampling points are two sampling points whose line passes through the center of the bearing component;

[0037] Based on the deviation value corresponding to each sampling point, the moving component is controlled to move the wafer in a direction perpendicular to the rotation axis to compensate for the deviation value.

[0038] For example, the sampling points include some sampling points located at the positioning part, wherein the sampling points located at the positioning part are points on the fitted circumferential edge of the positioning part.

[0039] For example, the sampling points are all located on the circumferential edge of the wafer outside the positioning portion.

[0040] According to a second aspect of the present invention, a wafer pre-alignment method is provided, comprising:

[0041] A linear image sensor located on the second side of the wafer receives multiple optical fringes emitted toward the wafer from a light source assembly located on the first side of the wafer, and generates a grayscale image to characterize the circumferential edge of the wafer, wherein the multiple optical fringes are of equal width and are arranged in parallel and equidistant, and all optical fringes intersect the circumferential edge of the wafer.

[0042] Based on the grayscale image generated by the linear image sensor during the rotation of the wafer around the rotation axis of the carrier assembly, the deviation between the center of the wafer and the center of the carrier assembly is determined and compensated accordingly. The carrier assembly is used to support the wafer and drive the wafer to rotate around the rotation axis of the carrier assembly.

[0043] Exemplarily, the wafer pre-alignment method further includes:

[0044] Based on the grayscale image generated by the linear image sensor during the rotation of the wafer around the rotation axis of the carrier assembly, the positioning part on the wafer is located, wherein the positioning part includes a notch or a flat edge.

[0045] For example, the step of locating the positioning portion on the wafer based on the grayscale image generated by the linear image sensor during the wafer's rotation about a support portion for supporting the wafer includes:

[0046] The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution, so that the circumferential edge of the wafer passes between the light source component and the linear image sensor in sequence;

[0047] The position of the positioning part is determined based on the grayscale image generated by the linear image sensor during the rotation of the wafer.

[0048] The carrier component is controlled to rotate the wafer, so that the positioning part is located between the light source component and the linear image sensor.

[0049] For example, determining the position of the positioning part based on the grayscale image generated by the linear image sensor during the wafer rotation includes:

[0050] Determine whether the grayscale image generated by the linear image sensor during the wafer rotation process matches the preset grayscale image of the positioning part;

[0051] When the grayscale image matches the grayscale image of the positioning part, the position of the circumferential edge corresponding to the grayscale image that matches the grayscale image of the positioning part is determined as the position of the positioning part.

[0052] For example, the positioning portion on the wafer, generated by the linear image sensor during the process of the wafer rotating about a support portion for supporting the wafer, further includes:

[0053] The edge contour of the positioning part is determined based on the grayscale image acquired by the linear image sensor when the positioning part is located between the light source assembly and the linear image sensor.

[0054] Based on the edge profile, the fitted circumferential edge and geometric center at the positioning portion of the wafer are determined, wherein the geometric center is the midpoint of the fitted circumferential edge.

[0055] For example, determining the deviation between the center of the wafer and the center of the carrier component based on the grayscale image and performing corresponding compensation includes:

[0056] The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution. Based on the grayscale image acquired by the linear image sensor during the wafer rotation, the distance from multiple sampling points on the circumferential edge of the wafer to the center of the carrier component is determined. The angles formed by the lines connecting adjacent sampling points to the center of the carrier component are equal, and the number of sampling points is greater than or equal to 4 and is an integer multiple of 4.

[0057] Calculate a first average distance from each of the sampling points to the center of the bearing component, and calculate the difference between the distance from each of the sampling points to the center of the bearing component and the first average distance;

[0058] Calculate the second average value of the difference between the corresponding sampling points in each group, and take half of the second average value as the deviation value corresponding to the corresponding sampling point, wherein the corresponding sampling point is the two sampling points whose line passes through the center of the bearing component;

[0059] Based on the deviation value corresponding to each sampling point, the moving component is controlled to move the wafer in a direction perpendicular to the rotation axis to compensate for the deviation value.

[0060] For example, the sampling points include some sampling points located at the positioning part, wherein the sampling points located at the positioning part are points on the fitted circumferential edge of the positioning part.

[0061] For example, the sampling points are all located on the circumferential edge of the wafer outside the positioning portion.

[0062] According to the wafer pre-alignment apparatus and wafer alignment method of the present invention, the deviation between the center of the wafer and the center of the supported component is determined by receiving a grayscale image generated by optical stripes emitted by a light source component on the other side of the wafer through a linear array image sensor on one side of the wafer. Based on the grayscale image, the wafer edge can be identified more accurately. It is applicable to the pre-alignment of wafers with complex edges (such as edge thinning, which are easy to detect as second boundaries) and special edges (such as edge burrs), and can effectively improve the pre-alignment accuracy. Attached Figure Description

[0063] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions, thereby explaining the apparatus and principles of the invention. In the drawings,

[0064] Figure 1 A schematic diagram of a wafer pre-alignment apparatus according to an embodiment of this application is shown;

[0065] Figure 2 From left to right, the diagram shows the positional relationship between the normal notch and the equal-width optical fringes, a schematic grayscale image of the normal notch, and a schematic diagram of the edge contour of the normal notch fitted based on the grayscale image.

[0066] Figure 3 From left to right, the diagram shows the positional relationship between the edge thinning notch and the equal-width optical stripes, a schematic grayscale image of the edge thinning notch, and a schematic diagram of the edge contour of the edge thinning notch fitted based on the grayscale image.

[0067] Figure 4 From left to right, the diagram shows the positional relationship between the film notch and the equal-width optical stripes, a schematic grayscale image of the film notch, and a schematic diagram of the edge contour of the film notch fitted based on the grayscale image.

[0068] Figure 5 From left to right, the diagram shows the positional relationship between the edge of a normal wafer and the optical fringes of equal width, a schematic grayscale image of the edge of a normal wafer, and a schematic diagram of the outline of the edge of a normal wafer fitted from the grayscale image.

[0069] Figure 6 From left to right, the diagram shows the positional relationship between the thinned wafer edge and the equal-width optical stripes, a schematic grayscale image of the thinned wafer edge, and a schematic outline of the thinned wafer edge fitted from the grayscale image.

[0070] Figure 7 From left to right, the diagram shows the positional relationship between the wafer edge with edge burrs and the equal-width optical stripes, a schematic grayscale image of the wafer edge with edge burrs, and a schematic outline of the wafer edge with edge burrs fitted based on the grayscale image.

[0071] Figure 8 A schematic diagram showing the edge contour, fitted circumferential curve, and geometric center of the positioning part according to an embodiment of this application is provided.

[0072] Figure 9 A schematic diagram of a wafer and sampling points on its circumferential edge according to an embodiment of this application is shown;

[0073] Figure 10 This diagram illustrates the positional relationship between the circumferential edge and its sampling points, fitted from grayscale images, and the center of the supporting component when the wafer is in its initial position and rotated to various angles.

[0074] Figure 11 A schematic diagram of a wafer and sampling points on its circumferential edge according to an embodiment of this application is shown.

[0075] Explanation of reference numerals in the attached figures:

[0076] 10-Wafer, 11-Positioning section, 111-Normal notch, 112-Edge thinning notch, 113-Film bonding notch, 115-Edge contour, 116-Fitted circumferential edge, 117-Geometric center, 12-Normal wafer edge, 13-Edge thinned wafer edge, 14-Wafer edge with edge burrs, 15-Edge burrs, 160, 161, 162, 163, 164, 165, 166, 167-Positioning points, 170, 171, 172, 173, 174, 175, 176, 177-Positioning points, 190-Wafer center;

[0077] 100 - Support component, 110 - Center of support component, 200 - Light source component, 210 - Optical stripe, 300 - Linear image sensor;

[0078] a - Rotation axis. Detailed Implementation

[0079] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application.

[0080] It should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions of parts and their relative dimensions may be exaggerated. The same reference numerals denote the same elements throughout.

[0081] It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or parts, these elements, components, areas, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or part from another element, component, area, layer, or part. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or part discussed below may be referred to as the second element, component, area, layer, or part.

[0082] Spatial relation terms such as "below," "under," "below," "under," "above," and "above" are used here for convenience to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of devices in use and operation.

[0083] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0084] Embodiments of the invention are described herein with reference to cross-sectional views that serve as schematic diagrams of preferred embodiments (and intermediate structures) of this application. Thus, variations in the shown shape can be anticipated due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of this application should not be limited to the specific shapes shown herein, but rather include shape deviations due to, for example, manufacturing processes.

[0085] See attached document Figure 1 An exemplary description will be given of a wafer pre-alignment apparatus according to an embodiment of the present application, which includes a carrier component 100, a moving component, a light source component 200, a linear image sensor 300, and a controller.

[0086] The carrier assembly 100 is used to carry the wafer 10 and drive the wafer 10 to rotate about the rotation axis a of the carrier assembly 100. In this embodiment, the carrier assembly 100 includes a vacuum chuck and a first driving unit. The vacuum chuck may be circular, with a diameter smaller than the diameter of the wafer 10. The vacuum chuck is used to carry the wafer 10, and it can stably hold the wafer 10 on it by vacuum adsorption. The first driving unit is used to drive the vacuum chuck to rotate about its central axis (i.e., rotation axis a), thereby driving the wafer 10 to rotate about the central axis of rotation axis a. The center (center) of the vacuum chuck is located on the central axis (i.e., rotation axis a). In some embodiments, the first driving unit may include a first motor, and the vacuum chuck is driven to the output shaft of the first motor to rotate about its central axis under the drive of the first motor. In this embodiment, the carrier assembly 100 also includes a second driving unit, which is used to drive the vacuum chuck (in the direction along its central axis) to move up and down, so as to exchange wafers with the transfer arm before and after pre-alignment. In some embodiments, the second driving unit includes a first pneumatic cylinder and a transmission rod retractably connected to the first pneumatic cylinder, with the vacuum chuck being driven by the transmission rod. In some embodiments, the second driving unit may include a second motor, which is driven by the vacuum chuck to drive the vacuum chuck to move along its central axis. In this embodiment, a positioning portion 11 is provided on the wafer 10, which may be a notch, flat edge, or other suitable positioning structure on the wafer 10. In other embodiments, the support assembly 100 may also be a rotatable and height-adjustable worktable, the surface of which is provided with a vacuum adsorption device for supporting and adsorbing the wafer 10.

[0087] A moving component is used to move the wafer 10 in a direction perpendicular to the rotation axis a, thereby changing the position of the wafer 10 on the support component 100. In some embodiments, the moving component may include a second pneumatic cylinder and a vertical wall connected to the pneumatic cylinder. The second pneumatic cylinder is used to push the vertical wall to move in a direction perpendicular to the rotation axis a. The vertical wall is used to push the side of the wafer 10 when the second pneumatic cylinder is activated, causing the wafer 10 to move on the support component 100 in a direction perpendicular to the rotation axis a. In some embodiments, the moving component includes a third driving unit and a support portion connected to the third driving unit. The third driving unit is used to drive the support portion to move in a direction perpendicular to the rotation axis a. The support unit is located below the wafer 10. When it is not necessary to move the wafer 10 in a direction perpendicular to the rotation axis a via the moving component, the support unit does not contact the wafer 10. When it is necessary to move the wafer 10 in a direction perpendicular to the rotation axis a via the moving component, the second drive unit drives the vacuum chuck and the wafer 10 to descend, causing the wafer 10 to descend onto the support unit and disengage from the vacuum chuck. Then, the third drive unit drives the support unit to move in a direction perpendicular to the rotation axis a, thereby moving the wafer 10 in the same direction. After the wafer 10 moves to a predetermined position, the second drive unit drives the vacuum chuck to rise, causing the wafer 10 to contact the vacuum chuck and disengage from the support unit. Thus, the movement of the wafer 10 on the vacuum chuck is achieved. The third drive unit may include a pneumatic cylinder or a motor, which will not be described in detail here.

[0088] The light source assembly 200 is located on the first side of the wafer 10 and is used to generate a plurality of optical fringes 210 emanating towards the wafer 10. The plurality of optical fringes 210 are of equal width and arranged in parallel at equal intervals, and all of these optical fringes 210 intersect the circumferential edge of the wafer 10. It should be noted that the intersection of the optical fringes 210 with the circumferential edge of the wafer 10 means that part of the optical fringes 210 is located on the wafer 10, and part is located outside the wafer 10, with intersection points existing at the circumferential edge of the wafer 10. In this embodiment, the optical fringes 210 only intersect a portion of the circumferential edge of the wafer 10. The light source assembly 200 may include a light source and a beam splitter. The light source may be a laser light source or other suitable light source. The beam splitter is used to cause the light emitted by the light source to form a plurality of optical fringes 210 of equal width and arranged in parallel at equal intervals through Young's interference or diffraction. Specifically, the beam splitter may be a beam splitter plate with two slits, and the light emitted by the light source undergoes Young's interference through the slits to generate the aforementioned optical fringes 210. The beam splitter can be a diffractive optical element (DOE). Diffractive optical elements are typically constructed using micro-nano etching processes to form two-dimensionally distributed diffraction units. Each diffraction unit can have a specific morphology, refractive index, etc. When light emitted from the light source passes through the diffractive optical element, it produces the aforementioned optical fringes 210. The number of optical fringes 210 produced by the light source assembly 200 can be greater than or equal to 5, for example, 5-100. The spacing between adjacent optical fringes 210 can be 4μm-200μm. In some embodiments, for a 6-inch (150mm) wafer, the spacing between adjacent optical fringes 210 can be configured as 15μm-150μm; for an 8-inch (200mm) wafer, the spacing between adjacent optical fringes 210 can be configured as 10μm-200μm; and for a 12-inch (300mm) wafer, the spacing between adjacent optical fringes 210 can be configured as 6μm-150μm. It should be noted that the scope of the above embodiments is merely an example and does not constitute a limitation on this application. The spacing between adjacent optical stripes 210 can be flexibly adjusted by those skilled in the art according to the wafer size and pre-alignment accuracy requirements. The area covered by the optical stripes 210 as a whole (including the area of ​​the gap between the diameters of the relevant optical stripes 210) is larger than the area of ​​the positioning part 11. The more optical stripes there are and the smaller the spacing between adjacent optical stripes, the higher the pre-alignment accuracy, especially the θ accuracy.

[0089] A linear image sensor 300, located on the second side of wafer 10, is used to receive optical stripes 210 and generate a grayscale image characterizing the circumferential edges of wafer 10. Specifically, the linear image sensor 300 can be a CCD (Charge-coupled Device) linear image sensor or a CMOS (Complementary Metal Oxide Semiconductor) linear image sensor. After receiving the optical stripes 210, the linear image sensor 300 converts the acquired image into a grayscale image. The grayscale image can refer to an image composed of grayscale data from 0 to 255. Since the optical stripes 210 are partially located on and partially outside the wafer 10, the linear image sensor 300 receives optical stripes 210 that partially pass through the wafer 10 and partially do not. Therefore, in the grayscale image, the grayscale values ​​corresponding to these two parts will be significantly different. Thus, based on the locations where the grayscale values ​​change significantly, the position of the circumferential edge of the wafer 10 can be determined. Furthermore, based on the locations where the grayscale values ​​change significantly in the grayscale images corresponding to multiple optical stripes 210 (where the difference in grayscale values ​​on both sides of the location exceeds a set threshold), the contour of the circumferential edge of the wafer 10 can be fitted. (See Appendix) Figure 2-7 For normal notches 111, edge-thinned notches 112, film-coated notches 113, normal wafer edges 12, edge-thinned wafer edges 13, and wafer edges 14 with edge burrs 15, the corresponding grayscale images are significantly different, and the edge contours fitted based on the grayscale images are also significantly different. Therefore, based on the grayscale images acquired by the linear image sensor 300, wafer edges in these cases can be identified more accurately, and the true contours of the notches and wafer edges can be determined. In the figure, CH1-CH6 represent different positions of the linear image sensor. Normal flat edges, edge-thinned flat edges, and film-coated flat edges are similar to normal notches 111, edge-thinned notches 112, and film-coated notches 113, and will not be shown again in this application. In some embodiments, there may be multiple linear image sensors 300, each corresponding to one optical stripe 210. In some embodiments, there may be only one linear image sensor 300, which is used to receive all optical stripes 210.

[0090] In this embodiment, the controller is connected to the carrier component 100, the moving component, and the linear image sensor 300, and is used to position the positioning part 11 based on the grayscale image. The controller is also used to determine the deviation between the center of the wafer 10 and the center of the carrier component 100 (i.e., the center of the vacuum chuck) based on the grayscale image, and to perform corresponding compensation to achieve pre-alignment of the wafer 10. The controller can be a microcontroller or other suitable control device. In some embodiments, the controller can also be connected to a light source to control the light source. It should be noted that the term "controller" here can refer to one or more controllers. For example, in some embodiments, the controller may include a first controller, a second controller, and a third controller. The first controller is connected to the carrier component 100 and can be used to control the carrier component to rotate the wafer 10 according to received instructions. The second controller is connected to the moving component and can be used to control the moving component to move the wafer 10 in a direction perpendicular to the rotation axis a according to received instructions. The third controller is connected to the first and second controllers to control the actions of the carrier component and the moving component through the first and second controllers. The third controller is also connected to the linear array image sensor 300 to acquire the grayscale image generated by the linear array image sensor 300. Thus, the third controller can achieve pre-alignment of the wafer 10 through the coordinated cooperation with the first controller, the second controller, and the linear array image sensor 300.

[0091] Specifically, in this embodiment of the application, the process by which the controller locates the positioning unit 11 based on the grayscale image includes the following steps:

[0092] First, the control component 100 drives the wafer 10 to rotate around the rotation axis a once, so that the circumferential edge of the wafer 10 passes between the light source component 200 and the linear image sensor 300 in sequence. That is, the circumferential edge of the wafer 10 intersects with the optical stripes 210 generated by the light source component 200 in sequence.

[0093] Then, the position of the positioning part is determined based on the grayscale image generated by the linear image sensor 300 during the rotation of the wafer 10. Specifically, it is determined whether the grayscale image generated by the linear image sensor 300 during the rotation of the wafer 10 matches a preset grayscale image of the positioning part. When the generated grayscale image matches the preset grayscale image of the positioning part, the position of the circumferential edge corresponding to the grayscale image that matches the grayscale image of the positioning part is determined as the position of the positioning part 11. Since the dimensions of the wafer 10 and the positioning part 11 on it are relatively fixed, the grayscale image at the positioning part 11 of the wafer 10 is also fixed. Therefore, the grayscale image of the positioning part 11 can be preset, and then the grayscale image acquired during the rotation of the wafer 10 can be matched with it to determine the position of the positioning part 11. It should be noted that the matching here can refer to the similarity between the two exceeding a set threshold. The linear image sensor 300 continuously generates grayscale images at preset time intervals or preset rotation angle intervals during the rotation of the wafer 10.

[0094] Then, the control assembly 100 drives the wafer 10 to rotate around the rotation axis a, positioning the positioning part 11 between the light source assembly 200 and the linear image sensor 300. Specifically, the controller can acquire and record the rotation angle of the wafer 10 each time the linear image sensor 300 generates a grayscale image. Furthermore, based on the rotation angle corresponding to the grayscale image that matches the preset positioning part grayscale image, the controller controls the support assembly 100 to rotate the wafer 10 around the rotation axis a accordingly, positioning the positioning part 11 between the light source assembly 200 and the image sensor. When the positioning part 11 is positioned between the light source assembly 200 and the image sensor, it can be accurately identified.

[0095] Furthermore, in this embodiment, the process of the controller locating the positioning unit 11 based on the grayscale image further includes the following steps:

[0096] The edge contour of the positioning unit 11 is determined based on the grayscale image acquired by the linear array image sensor 300 when the positioning unit 11 is located between the light source assembly 200 and the linear array image sensor 300. Specifically, the edge contour of the positioning unit 11 is fitted based on the locations where significant changes in grayscale value occur on the grayscale image. That is, the edge contour of the positioning unit 11 is fitted by connecting points on the grayscale image where the same significant changes in grayscale value occur with straight lines. When multiple contours are fitted, one of them is determined as the edge contour according to a preset rule. For example, see Appendix Figure 3 When the fitted edge contours are two and approximately parallel, the positioning part 11 is the edge thinning notch 112, and the outer edge contour is determined as the edge contour of the notch. See Appendix Figure 4When there are two fitted edge contours, and the overall shape of the fitted edge contours is approximately trapezoidal, triangular, or fan-shaped, then the positioning part 11 is the film notch 113, and the inner edge contour is determined as the edge contour of the notch.

[0097] Based on the edge profile, the fitted circumferential edge and geometric center of the positioning portion 11 on wafer 10 are determined, wherein the geometric center is the midpoint of the fitted circumferential edge. Specifically, the fitted circumferential edge is used to characterize the circumferential edge of the positioning portion 11 when the positioning portion 11 is not provided. Since the dimensions of wafer 10 and the shape and dimensions of the positioning portion 11 are fixed, the correspondence between the edge profile of the positioning portion 11 and the fitted circumferential edge can be preset, and then the fitted circumferential edge of the positioning portion 11 on wafer 10 can be determined based on this correspondence, thereby determining the geometric center. See Appendix Figure 8 In this embodiment, after the edge contour 115 of the positioning part 11 is determined, the fitted circumferential edge 116 can be determined according to the size of the wafer 10 and the shape and size of the edge contour 115. After the fitted circumferential edge 116 is determined, its midpoint, i.e., the geometric center 117, is also determined accordingly, and the distance from the geometric center 117 to the center of the support component 100 is also determined accordingly.

[0098] In this embodiment, the controller determines the deviation between the center of wafer 10 and the center of the support component 100 (i.e., the center of the vacuum chuck) based on the grayscale image and performs corresponding compensation, including the following steps:

[0099] First, the carrier component 100 is controlled to drive the wafer 100 to rotate around the rotation axis a one revolution. Based on the grayscale image acquired by the linear array image sensor 300 during the wafer rotation, the distances from multiple sampling points on the circumferential edge of the wafer 10 to the center 110 of the carrier component 100 are determined. The angles formed by the lines connecting adjacent sampling points to the center of the carrier component are equal, and the number of sampling points is greater than or equal to 4 and is an integer multiple of 4 (that is, the number of sampling points can be 4, 8, 12, etc.).

[0100] Specifically, see Appendix Figure 9 , 10In this embodiment, the carrier component 100 is controlled to rotate the wafer 10 around the rotation axis a one revolution from its initial position at preset angular intervals. Based on the grayscale images generated by the linear image sensor when the wafer 10 is in its initial position and at various rotation angles, the distances from sampling points 160-167 of the wafer 10 to the center 110 of the carrier component 100 (i.e., the distances from each sampling point 160-167 to the rotation axis a) are obtained. There are 8 sampling points, and the angle formed by the lines connecting adjacent sampling points to the center 110 of the carrier component 100 is 45°. In other embodiments, the angle formed by the lines connecting adjacent sampling points to the center 110 of the carrier component 100 can be other suitable angles less than 45°, such as 30° (in which case there are 12 sampling points). The more sampling points there are, the smaller the angle formed by the lines connecting adjacent sampling points to the center 110 of the carrier component 100, resulting in a higher alignment accuracy. The initial position refers to the position of wafer 10 when the positioning part 11 is located between the light source assembly 200 and the linear image sensor 300 (i.e., Figure 9 (As shown in the diagram), the sampling point 160 when the wafer 10 is in its initial position is located at the positioning part 11, and is the geometric center 117 on the fitted circumferential edge 116 of the positioning part 11. In some other embodiments, the sampling point 160 when the wafer 10 is in its initial position can be any other point on the fitted circumferential edge of the positioning part 11. In this embodiment, the preset angle interval is 45°, which is consistent with the angle formed by the line connecting the adjacent sampling point and the center 110 of the support component 100. That is, the support component 100 is controlled to drive the wafer 10 to rotate gradually from the initial position around the rotation axis a at 45° intervals, so that the circumferential edges of the sampling points 161-167 are successively located between the light source component 200 and the linear image sensor 300, and then return to the initial position. When the wafer 10 rotates to each angle, it can stay for a preset time before rotating to the next angle, so that the linear image sensor 300 can generate a grayscale image. Furthermore, the circumferential edge of wafer 10 at various rotation angles can be fitted using the grayscale image, and the positions of sampling points 161-167 on it can be determined. The positional relationship between the circumferential edge and its sampling points 160-167 fitted using the grayscale image at various rotation angles of wafer 10 and the center 110 of the carrier component 100 is as follows: Figure 10As shown. Since the positional relationship between the linear image sensor 300 and the carrier component 100 is determined, the positional relationship between the circumferential edge (including the fitted circumferential edge) of the wafer 10 fitted with the grayscale image and the sampling points 161-167 relative to the linear image sensor 300 is also determined. Therefore, the positional relationship between the circumferential edge (including the fitted circumferential edge) of the wafer 10 fitted with the grayscale image and the sampling points 161-167 and the center 110 of the carrier component 100 is also determined. Thus, the distance between each sampling point 160-167 and the center 110 of the carrier component 100 can be obtained accordingly. In some other embodiments, the carrier component 100 can be controlled to drive the wafer 10 to rotate continuously around the rotation axis a at a uniform speed from the initial position, and grayscale images can be generated when the wafer 10 rotates 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°. Then, the distance from the sampling point 160-167 on the circumferential edge of the wafer 10 to the center 110 of the carrier component 100 can be determined based on the grayscale images.

[0101] Then, the first average distance from sampling points 160-167 to the center 110 of the bearing component 100 is calculated, and the difference between the distance from each sampling point 160-167 to the center 110 of the bearing component 100 and the first average distance is calculated.

[0102] Then, the second average value of the difference between the corresponding samples in each group of relative samples in the sampling points 160-167 is calculated, and half of the second average value is taken as the deviation value corresponding to the relative sample points. The relative sample points are two sample points whose line passes through the center 110 of the bearing component 100. That is, sample points 160 and 164 are a group of relative sample points, sample points 161 and 165 are a group of relative sample points, sample points 162 and 166 are a group of relative sample points, and sample points 163 and 167 are a group of relative sample points. In this step, the average of the difference corresponding to sampling point 160 (i.e., the difference between the distance from sampling point 160 to the center 110 of the bearing component 100 and the first average value) and the difference corresponding to sampling point 164 (i.e., the difference between the distance from sampling point 164 to the center 110 of the bearing component 100 and the first average value) is first calculated. Then, half of this average value is taken as the deviation value corresponding to sampling point 160 and sampling point 164. Then, the deviation values ​​corresponding to sampling points 161 and 165, sampling points 162 and 166, and sampling points 163 and 167 are calculated in the same way.

[0103] Subsequently, based on the deviation values ​​corresponding to each sampling point 160-167, the moving component is controlled to move the wafer 10 in a direction perpendicular to the rotation axis a to compensate for the deviation value. Specifically, in this embodiment, the moving component is configured to only move the wafer 10 along the line connecting the sampling point 160 and the center 110 of the carrier component 100 when the wafer 10 is in the initial position (including movement towards the center 110 of the carrier component 100 and movement away from the center 110 of the carrier component 100). Therefore, it is necessary to control the carrier component 100 to rotate the wafer 10 around the rotation axis a one revolution again from the initial position at preset angular intervals (the angle formed by the lines connecting adjacent sampling points and the center 110 of the carrier component 100). When the wafer 10 is in the initial position and rotates to each angle (i.e., when the wafer 10 rotates 0°, 45°, 90°, 135°, 1...), the wafer 10 rotates one revolution around the rotation axis a one revolution again from the initial position. At 80°, 225°, 270°, and 315°, the moving component is controlled to move the wafer 10 in a direction perpendicular to the rotation axis a, along the line connecting the sampling point 160 and the center 110 of the carrier component 100 when the wafer 10 is in its initial position, based on the deviation value corresponding to each sampling point 160-167. Specifically, when the distance from the sampling point to the center 110 of the carrier component 100 is less than the first average value, the sampling point is moved away from the center 110 of the carrier component 100 by the corresponding deviation value; when the distance from the sampling point to the center 110 of the carrier component 100 is greater than the first average value, the sampling point is moved towards the center 110 of the carrier component 100 by the corresponding deviation value. After wafer 10 rotates one revolution, the distance from each sampling point 160-167 on wafer 10 to the center 110 of carrier assembly 100 is equal to or very close to the first average value. The center 190 of wafer 10 coincides with or substantially coincides with the center 110 of carrier assembly 100, thus completing the pre-alignment, and the edge contour 116 and geometric center 117 of positioning part 11 are determined. If it is necessary to rotate positioning part 11 to face a specific direction at this time, wafer 10 can be rotated by carrier assembly 100 to make the geometric center 117 of positioning part 11 face that direction. In some embodiments, the moving component can be configured to move the wafer 10 arbitrarily in a direction perpendicular to the rotation axis a. In this case, there is no need to control the carrier component 100 to rotate the wafer 10 around the rotation axis a again. Instead, the moving component can be directly controlled to move the wafer 10 in a direction perpendicular to the rotation axis a according to the deviation value corresponding to each sampling point 160-167. The wafer 10 moves along the line connecting the center 110 of the carrier component 100 and the line connecting the sampling point 160 and the center 110 of the carrier component 100 at 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° respectively.

[0104] See appendix Figure 11In another embodiment of this application, sampling points 170-177 on the circumferential edge of wafer 10 are all located on the circumferential edge of the wafer outside the positioning part 11, that is, avoiding the positioning part 11. This allows for more precise alignment compared to using sampling points on the fitted circumferential edge. For sampling points 170-177, the number of sampling points is 8, and the angle formed by the lines connecting adjacent sampling points to the center 110 of the carrier component 100 is 45°. In some other embodiments, the angle formed by the lines connecting adjacent sampling points to the center 110 of the carrier component 100 can be other suitable angles less than 45°, such as 30° (in which case the number of sampling points is 12). Accordingly, determining the deviation between the center 190 of wafer 10 and the center 110 of carrier component 100 (i.e., the center of the vacuum chuck) based on the grayscale image and performing corresponding compensation can include the following steps:

[0105] First, the control support component 100 rotates the wafer 10 22.5° from its initial position. This initial position refers to the position of the wafer 10 when the positioning part 11 is located between the light source component 200 and the linear image sensor 300 (i.e., Figure 11 (The location shown in the image). After the carrier component 100 rotates the wafer 10 by 22.5° from its initial position, the positioning part 11 is no longer located between the light source component 200 and the linear image sensor 300. The sampling point 170 is the intersection of a line passing through the center 110 of the carrier component 100 and forming a 22.5° angle with the line connecting the geometric center 117 of the positioning part 110 and the center of the carrier component 100, and the circumferential edge of the wafer 10. That is, after the wafer 10 rotates by 22.5° from its initial position, the sampling point 170 moves to the position where the geometric center 117 of the positioning part 11 was when the wafer 10 was in its initial position. In some other embodiments, after the wafer 10 rotates by 22.5° from its initial position, any point on the circumferential edge determined according to the generated grayscale image can be used as the sampling point 170. The carrier component 100 is then controlled to rotate the wafer 10 from its initial position around the rotation axis a at 45° intervals, so that the circumferential edges of sampling points 171-177 are successively positioned between the light source component 200 and the linear image sensor 300. The carrier component 100 is then controlled to rotate the wafer 10 around the rotation axis a by 22.5° back to its initial position. The wafer 10 can pause for a preset time at each angle before rotating to the next angle, allowing the linear image sensor 300 to generate a grayscale image. The circumferential edges of the wafer 10 at each angle can then be fitted based on the grayscale image, and the positions of sampling points 170-177 on them can be determined, along with the distance from sampling points 170-177 to the center 110 of the carrier component 100.

[0106] Then, calculate the first average value of the distance from each sampling point 170-177 to the center 110 of the bearing component 100, and calculate the difference between the distance from each sampling point 170-177 to the center 110 of the bearing component 100 and the first average value.

[0107] Then, the second average value of the difference between the corresponding relative sampling points in each group of sampling points 170-177 is calculated, and half of the second average value is taken as the deviation value corresponding to the relative sampling point. The relative sampling point is the two sampling points whose line passes through the center 110 of the bearing component 100. That is, sampling point 170 and sampling point 174 are a group of relative sampling points, sampling point 171 and sampling point 175 are a group of relative sampling points, sampling point 172 and sampling point 176 are a group of relative sampling points, and sampling point 173 and sampling point 177 are a group of relative sampling points. In this step, the average of the difference corresponding to sampling point 170 (i.e., the difference between the distance from sampling point 170 to the center 110 of the bearing component 100 and the first average value) and the difference corresponding to sampling point 174 (i.e., the difference between the distance from sampling point 174 to the center 110 of the bearing component 100 and the first average value) is first calculated. Then, half of this average value is taken as the deviation value corresponding to sampling point 170 and sampling point 174. Then, the deviation values ​​corresponding to sampling points 171 and 175, 172 and 176, and 173 and 177 are calculated in the same way.

[0108] Furthermore, based on the deviation values ​​corresponding to each sampling point 170-177, the moving component is controlled to move wafer 10 accordingly in the direction perpendicular to the rotation axis a, in order to compensate for the deviation value. This process is consistent with the attached... Figure 9 , 10 The embodiments shown are basically the same, and will not be repeated here.

[0109] This application also provides a wafer pre-alignment method, which can be based on the pre-alignment device described above, and includes the following steps:

[0110] S100: A linear image sensor 300 located on the second side of the wafer 10 receives a plurality of optical stripes 210 emitted toward the wafer 10 from a light source assembly 200 located on the first side of the wafer 10, and generates a grayscale image for characterizing the circumferential edge of the wafer 10. The plurality of optical stripes 210 are of equal width and arranged in parallel at equal intervals, and all optical stripes 210 intersect the circumferential edge of the wafer 10.

[0111] S200: Based on the grayscale image generated by the linear image sensor 300 during the rotation of the wafer 10 around the rotation axis a of the carrier assembly 100, the positioning part 11 on the wafer 10 is positioned. The positioning part 11 may be a notch, a flat edge, or other suitable positioning structure.

[0112] S300: Based on the grayscale image generated by the linear array image sensor 300 during the rotation of the wafer 10 around the rotation axis a of the carrier component 100, the deviation between the wafer center and the chuck center a is determined and corresponding compensation is performed.

[0113] In some embodiments, step S300 can be performed directly after step S100 without performing step S200.

[0114] In this embodiment of the application, step S200 specifically includes the following steps:

[0115] S210: Control the carrier component 100 to drive the wafer 10 to rotate around the rotation axis a one revolution, so that the circumferential edge of the wafer 10 passes between the light source component 200 and the linear image sensor 300 in sequence, that is, so that the circumferential edge of the wafer 10 intersects with the optical stripe 210 generated by the light source component 200 in sequence.

[0116] S211: Determine the position of the positioning part 11 based on the grayscale image generated by the linear array image sensor 300 during the rotation of the wafer 10.

[0117] Specifically, it is determined whether the grayscale image generated by the linear image sensor 300 during the rotation of the wafer 10 matches a preset grayscale image of the positioning part. When the generated grayscale image matches the preset grayscale image of the positioning part, the position of the circumferential edge corresponding to the grayscale image matching the positioning part is determined as the position of the positioning part 11. Since the dimensions of the wafer 10 and the positioning part 11 on it are relatively fixed, the grayscale image at the positioning part 11 of the wafer 10 is also fixed. Therefore, the grayscale image of the positioning part 11 can be preset, and then the grayscale image acquired during the rotation of the wafer 10 can be matched with it to determine the position of the positioning part 11. It should be noted that matching here can refer to the similarity between the two exceeding a set threshold. The linear image sensor 300 continuously generates grayscale images at preset time intervals or preset rotation angle intervals during the rotation of the wafer 10.

[0118] S212: Control the carrier component 100 to drive the wafer 10 to rotate around the rotation axis a, so that the positioning part 11 is located between the light source component 200 and the linear image sensor 300.

[0119] Specifically, the controller can acquire and record the rotation angle of the wafer 10 each time the linear image sensor 300 generates a grayscale image. Then, based on the rotation angle corresponding to the grayscale image matched with the preset positioning grayscale image, the controller can control the support assembly 100 to rotate the wafer 10 around the rotation axis a accordingly, so that the positioning part 11 is positioned between the light source assembly 200 and the image sensor. When the positioning part 11 is positioned between the light source assembly 200 and the image sensor, it can be accurately identified.

[0120] Further, in step S200, the positioning part 11 is positioned based on the grayscale image generated by the linear image sensor 300 during the rotation of the wafer 10 around the rotation axis a of the support portion for supporting the wafer 10, and the following steps are also included:

[0121] S213: Determine the edge contour of the positioning part 11 based on the grayscale image acquired by the linear array image sensor 300 when the positioning part 11 is located between the light source assembly 200 and the linear array image sensor 300.

[0122] Specifically, the edge contour of the positioning unit 11 is fitted based on the locations where significant changes in grayscale value occur on the grayscale image. That is, the edge contour of the positioning unit 11 is fitted by connecting points on the grayscale image where the same significant changes in grayscale value occur with straight lines. When multiple contours are fitted, one of them is determined as the edge contour according to a preset rule. For example, see Appendix Figure 3 When the fitted edge contours are two and approximately parallel, the positioning part 11 is the edge thinning notch 112, and the outer edge contour is determined as the edge contour of the notch. See Appendix Figure 4 When there are two fitted edge contours, and the overall shape of the fitted edge contours is approximately trapezoidal, triangular, or fan-shaped, then the positioning part 11 is the film notch 113, and the inner edge contour is determined as the edge contour of the notch.

[0123] S214: Based on the edge profile, determine the fitted circumferential edge and geometric center at the positioning part 11 of the wafer 10, wherein the geometric center is the midpoint of the fitted circumferential edge.

[0124] Specifically, the fitted circumferential edge is used to characterize the circumferential edge at the positioning part 11 when the positioning part 11 is not provided. Since the size of the wafer 10 and the shape of the positioning part 11 are both fixed, the correspondence between the edge contour at the positioning part 11 and the fitted circumferential edge can be preset, and then the fitted circumferential edge at the positioning part 11 of the wafer 10 can be determined according to this correspondence, thereby determining the geometric center. See Appendix Figure 8In this embodiment, after the edge contour 115 of the positioning part 11 is determined, the fitted circumferential edge 116 can be determined according to the size of the wafer 10 and the shape and size of the edge contour 115. After the fitted circumferential edge 116 is determined, its midpoint, i.e., the geometric center 117, is also determined accordingly, and the distance from the geometric center 117 to the center of the support component 100 is also determined accordingly.

[0125] See appendix Figure 9 , 10 In this embodiment of the application, step S300 includes the following steps:

[0126] S310: Control the carrier component 100 to drive the wafer 100 to rotate one revolution around the rotation axis a. Based on the grayscale image acquired by the linear array image sensor 300 during the wafer rotation, determine the distance from the sampling points 160-167 on the circumferential edge of the wafer 10 to the center 110 of the carrier component 100. The number of sampling points is 8, and the angles formed by the lines connecting adjacent sampling points to the center 110 of the carrier component 100 are equal, all being 45°. In some other embodiments, the number of sampling points can be any number greater than or equal to 4 and an integer multiple of 4 (i.e., the number of sampling points can be 4, 12, etc.).

[0127] Specifically, in step S310, the control component 100 drives the wafer 10 to rotate gradually from its initial position around the rotation axis a at 45° intervals, so that the circumferential edges of sampling points 161-167 are successively positioned between the light source component 200 and the linear image sensor 300, and then return to the initial position. The wafer 10 can pause for a preset time at each angle before rotating to the next angle, so that the linear image sensor 300 can generate a grayscale image. The initial position refers to the position of the wafer 10 when the positioning part 11 is located between the light source component 200 and the linear image sensor 300 (i.e.,...). Figure 9 As shown in the figure, the sampling point 160 when the wafer 10 is in its initial position is located at the positioning part 11, which is the geometric center 117 on the fitted circumferential edge 116 at the positioning part 11. In some other embodiments, the sampling point 160 when the wafer 10 is in its initial position can be any other point on the fitted circumferential edge 116 at the positioning part 11. The circumferential edge of the wafer 10 when rotated to various angles can then be fitted based on the grayscale image, and the positions of the sampling points 161-167 thereon can be determined. The positional relationship between the circumferential edge and the sampling points 160-167 thereon when the wafer 10 is rotated to various angles, fitted based on the grayscale image, and the center 110 of the carrier component 100 is as follows: Figure 10As shown. Since the positional relationship between the linear image sensor 300 and the carrier component 100 and the wafer 10 is determined, the positional relationship between the circumferential edge (including the fitted circumferential edge 116) of the wafer 10 and the sampling points 160-167 relative to the linear image sensor 300, as fitted based on the grayscale image, is also determined. Therefore, the positional relationship between the circumferential edge (including the fitted circumferential edge 116) of the wafer 10 and the center 110 of the carrier component 100, as fitted based on the grayscale image, is also determined. Thus, the distance between each sampling point 160-167 and the center 110 of the carrier component 100 can be obtained accordingly. In other embodiments, the carrier component 100 can be controlled to drive the wafer 10 to rotate continuously around the rotation axis a at a uniform speed from its initial position, generating grayscale images at 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° rotations. The distance from the sampling points 160-167 on the circumferential edge of the wafer 10 to the center 110 of the carrier component 100 can then be determined based on the grayscale images. The initial position refers to the position of the wafer 10 when the positioning part 11 is located between the light source component 200 and the linear image sensor 300 (i.e.,...). Figure 9 (As shown in the figure), the sampling point 160 when the wafer 10 is in the initial position is located at the positioning part 11, which is the geometric center 117 on the fitting circumferential edge 116 of the positioning part 11. In some other embodiments, the sampling point 160 when the wafer 10 is in the initial position can be any other point on the fitting circumferential edge 116 of the positioning part 11.

[0128] S311: Calculate the first average value of the distance from each sampling point 160-167 to the center 110 of the bearing component 100, and calculate the difference between the distance from each sampling point 160-167 to the center 110 of the bearing component 100 and the first average value.

[0129] S312: Calculate the second average value of the difference between the corresponding pairs of sampling points in each group of relative sampling points in sampling points 160-167, and take half of the second average value as the deviation value corresponding to the relative sampling points. The relative sampling points are two sampling points whose connecting line passes through the center 110 of the bearing component 100. That is, sampling points 160 and 164 are a pair of relative sampling points, sampling points 161 and 165 are a pair of relative sampling points, sampling points 162 and 166 are a pair of relative sampling points, and sampling points 163 and 167 are a pair of relative sampling points.

[0130] Specifically, in this step, the average of the difference corresponding to sampling point 160 (i.e., the difference between the distance from sampling point 160 to the center 110 of the bearing component 100 and the first average value) and the difference corresponding to sampling point 164 (i.e., the difference between the distance from sampling point 164 to the center 110 of the bearing component 100 and the first average value) is first calculated. Then, half of this average value is taken as the deviation value corresponding to sampling point 160 and sampling point 164. Then, the deviation values ​​corresponding to sampling points 161 and 165, sampling points 162 and 166, and sampling points 163 and 167 are calculated in the same way.

[0131] S313: Based on the deviation value corresponding to each sampling point 160-167, control the moving component to drive the wafer 10 to move accordingly in the direction perpendicular to the rotation axis a, so as to compensate for the deviation value.

[0132] Specifically, in this embodiment, the moving component is configured to only move the wafer 10 along the line connecting the sampling point 160 and the center 110 of the carrier component 100 when the wafer 10 is in its initial position (including movement towards the center 110 of the carrier component 100 and movement away from the center 110 of the carrier component 100). Therefore, it is necessary to control the carrier component 100 to drive the wafer 10 to rotate around the rotation axis a one revolution from the initial position at preset angular intervals (the angle formed by the lines connecting adjacent sampling points and the center 110 of the carrier component 100). When the wafer 10 is in its initial position and rotates to each angle (i.e., when the wafer 10 rotates to 0°, 45°, 90°, 135°, 1...), the wafer 10 rotates one revolution around the rotation axis a one revolution from the initial position. (80°, 225°, 270°, 315°), respectively, based on the deviation value corresponding to each sampling point 160-167, control the moving component to drive the wafer 10 to move in a direction perpendicular to the rotation axis a along the line connecting the sampling point 160 and the center 110 of the carrier component 100 when the wafer 10 is in the initial position. Specifically, when the distance from the sampling point to the center 110 of the carrier component 100 is less than the first average value, the sampling point is moved away from the center 110 of the carrier component 100 by the deviation value corresponding to that sampling point; when the distance from the sampling point to the center 110 of the carrier component 100 is greater than the first average value, the sampling point is moved towards the center 110 of the carrier component 100 by the deviation value corresponding to that sampling point. After wafer 10 rotates one revolution, the distance from each sampling point 160-167 on the wafer to the center 110 of the carrier assembly 100 is equal to or very close to the first average value. The center 190 of wafer 10 coincides with or substantially coincides with the center 110 of the carrier assembly 100, thus completing the pre-alignment, and the edge contour 116 and geometric center 117 of the positioning part 11 are determined. If it is necessary to rotate the positioning part 11 to face a specific direction at this time, the wafer 10 can be rotated by the carrier assembly 100 so that the geometric center 117 of the positioning part 11 faces that direction. In some embodiments, the moving component can be configured to move the wafer 10 arbitrarily in a direction perpendicular to the rotation axis a. In this case, there is no need to control the carrier component 100 to rotate the wafer 10 around the rotation axis a again. Instead, the moving component can be directly controlled to move the wafer 10 in a direction perpendicular to the rotation axis a according to the deviation value corresponding to each sampling point 160-167. The wafer 10 moves along the line connecting the center 110 of the carrier component 100 and the line connecting the sampling point 160 and the center 110 of the carrier component 100 at 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° respectively.

[0133] See appendix Figure 11 In another embodiment of this application, step S300 includes the following steps:

[0134] S320: Control the carrier component 100 to drive the wafer 100 to rotate around the rotation axis a one revolution. Based on the grayscale image acquired by the linear array image sensor 300 during the wafer rotation, determine the distance from the sampling points 170-177 on the circumferential edge of the wafer 100 to the center 110 of the carrier component 100. The number of sampling points is 8, and the angles formed by the lines connecting adjacent sampling points to the center of the carrier component are equal, all being 45°. In some other embodiments, the number of sampling points can be any number greater than or equal to 4 and an integer multiple of 4 (i.e., the number of sampling points can be 4, 12, etc.).

[0135] Specifically, sampling points 170-177 on the circumferential edge of wafer 10 are all located on the circumferential edge of the wafer outside the positioning part 11, that is, avoiding the positioning part 11. This allows for more precise alignment compared to using sampling points on the fitted circumferential edge 116. In step S220, the control support assembly 100 drives wafer 10 to rotate 22.5° from its initial position. This initial position refers to the position of wafer 10 when the positioning part 11 is located between the light source assembly 200 and the linear image sensor 300 (i.e., Figure 11 (The location shown in the image). After the carrier component 100 rotates the wafer 10 by 22.5° from its initial position, the positioning part 11 is no longer located between the light source component 200 and the linear image sensor 300. The sampling point 170 is the intersection of a line passing through the center 110 of the carrier component 100 and forming a 22.5° angle with the line connecting the geometric center 117 of the positioning part 110 and the center of the carrier component 100, and the circumferential edge of the wafer 10. That is, after the wafer 10 rotates by 22.5° from its initial position, the sampling point 170 moves to the position where the geometric center 117 of the positioning part 11 was when the wafer 10 was in its initial position. In some other embodiments, after the wafer 10 rotates by 22.5° from its initial position, any point on the circumferential edge determined according to the generated grayscale image can be used as the sampling point 170. The carrier component 100 is then controlled to rotate the wafer 10 from its initial position around the rotation axis a at 45° intervals, so that the circumferential edges of sampling points 171-177 are successively positioned between the light source component 200 and the linear image sensor 300. The carrier component 100 is then controlled to rotate the wafer 10 around the rotation axis a by 22.5° back to its initial position. The wafer 10 can pause for a preset time at each angle before rotating to the next angle, allowing the linear image sensor 300 to generate a grayscale image. The circumferential edges of the wafer 10 at each angle can then be fitted based on the grayscale image, and the positions of sampling points 170-177 on them can be determined, along with the distance from sampling points 170-177 to the center 110 of the carrier component 100.

[0136] S321: Calculate the first average value of the distance from each sampling point 170-177 to the center 110 of the bearing component 100, and calculate the difference between the distance from each sampling point 170-177 to the center 110 of the bearing component 100 and the first average value.

[0137] S322: Calculate the second average value of the difference between the corresponding pairs of sampling points in each group of relative sampling points in sampling points 170-177 respectively, and take half of the second average value as the deviation value corresponding to the relative sampling points. The relative sampling points are two sampling points whose connecting line passes through the center 110 of the bearing component 100. That is, sampling points 170 and 174 are a pair of relative sampling points, sampling points 171 and 175 are a pair of relative sampling points, sampling points 172 and 176 are a pair of relative sampling points, and sampling points 173 and 177 are a pair of relative sampling points.

[0138] Specifically, in this step, the average of the difference corresponding to sampling point 170 (i.e., the difference between the distance from sampling point 170 to the center 110 of the bearing component 100 and the first average value) and the difference corresponding to sampling point 174 (i.e., the difference between the distance from sampling point 174 to the center 110 of the bearing component 100 and the first average value) is first calculated. Then, half of this average value is used as the deviation value corresponding to sampling point 160 and sampling point 164. Then, the deviation values ​​corresponding to sampling points 161 and 165, 162 and 166, and 163 and 167 are calculated in the same way.

[0139] S323: Based on the deviation values ​​corresponding to each sampling point 170-177, control the moving component to move wafer 10 accordingly in the direction perpendicular to the rotation axis a, in order to compensate for the deviation value. Step S323 is basically the same as step S313, and will not be described again here.

[0140] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0141] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0142] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of this application may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0143] Similarly, it should be understood that, in order to streamline this application and aid in understanding one or more of the various inventive aspects, features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with features fewer than all features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0144] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed can be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature serving the same, equivalent, or similar purpose.

[0145] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0146] It should be noted that the above embodiments are illustrative of this application and not restrictive of this application, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims.

Claims

1. A wafer pre-alignment device, characterized in that, include: A carrier component for carrying a wafer and driving the wafer to rotate about the rotation axis of the carrier component; A moving component is used to move the wafer in a direction perpendicular to the rotation axis; A light source assembly, located on a first side of the wafer, is used to generate multiple optical stripes that emit toward the wafer. The multiple optical stripes are of equal width and are arranged in parallel and equidistantly. All optical stripes intersect with the circumferential edge of the wafer. A linear image sensor, located on the second side of the wafer, is used to receive the optical stripes and generate a grayscale image for characterizing the circumferential edge; The controller is used to determine the deviation between the center of the wafer and the center of the carrier component based on the grayscale image, and to perform corresponding compensation.

2. The wafer pre-alignment apparatus according to claim 1, characterized in that, The light source assembly includes a light source and a beam splitter, wherein the beam splitter is used to cause the light emitted by the light source to form multiple optical fringes through Young's interference or diffraction. The linear image sensor is either a CCD linear image sensor or a CMOS linear image sensor.

3. The wafer pre-alignment apparatus according to claim 1, characterized in that, The number of optical stripes is greater than or equal to 5; The spacing between adjacent optical stripes is 4 μm - 200 μm.

4. The wafer pre-alignment apparatus according to claim 1, characterized in that, The load-bearing component includes a vacuum suction cup, a first driving unit, and a second driving unit; The vacuum chuck is used to support the wafer, the center of the support assembly is the center of the vacuum chuck, and the center of the vacuum chuck is located on the rotation axis; The first driving unit is used to drive the vacuum chuck to rotate around the rotation axis; The second drive unit is used to drive the vacuum suction cup to rise and fall.

5. The wafer pre-alignment apparatus according to claim 1, characterized in that, The controller is also configured to locate a positioning portion on the wafer based on the grayscale image, wherein the positioning portion includes a notch or a flat edge.

6. The wafer pre-alignment apparatus according to claim 5, characterized in that, The step of locating the positioning portion on the wafer based on the grayscale image includes: The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution, so that the circumferential edge of the wafer passes between the light source component and the linear image sensor in sequence; The position of the positioning part is determined based on the grayscale image generated by the linear image sensor during the rotation of the wafer. The carrier component is controlled to rotate the wafer, so that the positioning part is located between the light source component and the linear image sensor.

7. The wafer pre-alignment apparatus according to claim 6, characterized in that, Determining the position of the positioning part based on the grayscale image generated by the linear image sensor during wafer rotation includes: Determine whether the grayscale image generated by the linear image sensor during the wafer rotation process matches the preset grayscale image of the positioning part; When the grayscale image matches the grayscale image of the positioning part, the position of the circumferential edge corresponding to the grayscale image that matches the grayscale image of the positioning part is determined as the position of the positioning part.

8. The wafer pre-alignment apparatus according to claim 6, characterized in that, The step of locating the positioning portion on the wafer based on the grayscale image further includes: The edge contour of the positioning part is determined based on the grayscale image acquired by the linear image sensor when the positioning part is located between the light source assembly and the linear image sensor. Based on the edge profile, the fitted circumferential edge and geometric center at the positioning portion of the wafer are determined, wherein the geometric center is the midpoint of the fitted circumferential edge.

9. The wafer pre-alignment apparatus according to claim 5, characterized in that, The step of determining the deviation between the center of the wafer and the center of the carrier component based on the grayscale image and performing corresponding compensation includes: The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution. Based on the grayscale image acquired by the linear image sensor during the wafer rotation, the distance from multiple sampling points on the circumferential edge of the wafer to the center of the carrier component is determined. The angles formed by the lines connecting adjacent sampling points to the center of the carrier component are equal, and the number of sampling points is greater than or equal to 4 and is an integer multiple of 4. Calculate a first average distance from each of the sampling points to the center of the bearing component, and calculate the difference between the distance from each of the sampling points to the center of the bearing component and the first average distance; Calculate the second average value of the difference corresponding to each group of relative sampling points, and take half of the second average value as the deviation value corresponding to the relative sampling points, wherein the relative sampling points are two sampling points whose line passes through the center of the bearing component; Based on the deviation value corresponding to each sampling point, the moving component is controlled to move the wafer in a direction perpendicular to the rotation axis to compensate for the deviation value.

10. The wafer pre-alignment apparatus according to claim 9, characterized in that, The sampling points include some sampling points located at the positioning part, wherein the sampling points located at the positioning part are points on the edge of the fitted circle at the positioning part.

11. The wafer pre-alignment apparatus according to claim 9, characterized in that, The sampling points are all located on the circumferential edge of the wafer outside the positioning part.

12. A wafer pre-alignment method, characterized in that, include: A linear image sensor located on the second side of the wafer receives multiple optical fringes emitted toward the wafer from a light source assembly located on the first side of the wafer, and generates a grayscale image to characterize the circumferential edge of the wafer, wherein the multiple optical fringes are of equal width and are arranged in parallel and equidistant, and all optical fringes intersect the circumferential edge of the wafer. Based on the grayscale image generated by the linear image sensor during the rotation of the wafer around the rotation axis of the carrier assembly, the deviation between the center of the wafer and the center of the carrier assembly is determined and compensated accordingly. The carrier assembly is used to support the wafer and drive the wafer to rotate around the rotation axis of the carrier assembly.

13. The wafer pre-alignment method according to claim 12, characterized in that, The wafer pre-alignment method further includes: Based on the grayscale image generated by the linear image sensor during the rotation of the wafer around the rotation axis of the carrier assembly, the positioning part on the wafer is located, wherein the positioning part includes a notch or a flat edge.

14. The wafer pre-alignment method according to claim 13, characterized in that, The step of locating the positioning portion on the wafer based on the grayscale image generated by the linear image sensor during the process of the wafer rotating about the rotation axis of the support portion for supporting the wafer includes: The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution, so that the circumferential edge of the wafer passes between the light source component and the linear image sensor in sequence; The position of the positioning part is determined based on the grayscale image generated by the linear image sensor during the rotation of the wafer. The carrier component is controlled to rotate the wafer, so that the positioning part is located between the light source component and the linear image sensor.

15. The wafer pre-alignment method according to claim 14, characterized in that, Determining the position of the positioning part based on the grayscale image generated by the linear image sensor during wafer rotation includes: Determine whether the grayscale image generated by the linear image sensor during the wafer rotation process matches the preset grayscale image of the positioning part; When the grayscale image matches the grayscale image of the positioning part, the position of the circumferential edge corresponding to the grayscale image that matches the grayscale image of the positioning part is determined as the position of the positioning part.

16. The wafer pre-alignment method according to claim 14, characterized in that, The step of locating the positioning portion on the wafer based on the grayscale image generated by the linear image sensor during the process of the wafer rotating about the rotation axis of the support portion for supporting the wafer further includes: The edge contour of the positioning part is determined based on the grayscale image acquired by the linear image sensor when the positioning part is located between the light source assembly and the linear image sensor. Based on the edge profile, the fitted circumferential edge and geometric center at the positioning portion of the wafer are determined, wherein the geometric center is the midpoint of the fitted circumferential edge.

17. The wafer pre-alignment method according to claim 13, characterized in that, The step of determining the deviation between the center of the wafer and the center of the carrier component based on the grayscale image and performing corresponding compensation includes: The carrier component is controlled to drive the wafer to rotate around the rotation axis for one revolution. Based on the grayscale image acquired by the linear image sensor during the wafer rotation, the distance from multiple sampling points on the circumferential edge of the wafer to the center of the carrier component is determined. The angles formed by the lines connecting adjacent sampling points to the center of the carrier component are equal, and the number of sampling points is greater than or equal to 4 and is an integer multiple of 4. Calculate a first average distance from each of the sampling points to the center of the bearing component, and calculate the difference between the distance from each of the sampling points to the center of the bearing component and the first average distance; Calculate the second average value of the difference corresponding to each group of relative sampling points, and take half of the second average value as the deviation value corresponding to the relative sampling points, wherein the relative sampling points are two sampling points whose line passes through the center of the bearing component; Based on the deviation value corresponding to each sampling point, the moving component is controlled to move the wafer in a direction perpendicular to the rotation axis to compensate for the deviation value.

18. The wafer pre-alignment method according to claim 17, characterized in that, The sampling points include some sampling points located at the positioning part, wherein the sampling points located at the positioning part are points on the edge of the fitted circle at the positioning part.

19. The wafer pre-alignment method according to claim 17, characterized in that, The sampling points are all located on the circumferential edge of the wafer outside the positioning part.

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