A two-dimensional material dry transfer alignment method and system

Abstract

The embodiment of the application provides a two-dimensional material dry transfer alignment method and system, and relates to the technical field of two-dimensional material processing. The method first acquires a first topographic image of a bottom layer two-dimensional material and a second topographic image of a top layer two-dimensional material to be transferred, extracts a first position parameter in the first topographic image, and extracts a second position parameter in the second topographic image. Then, a target stacking relationship is established based on the first position parameter and the second position parameter to determine the stacking position and the stacking angle when the top layer two-dimensional material to be transferred is transferred to the bottom layer two-dimensional material. Then, a transfer path parameter is calculated according to the target stacking relationship. The method can calculate the translation, rotation and approach mode of the transfer process based on the position and topographic information of the bottom layer two-dimensional material and the top layer two-dimensional material to be transferred, so as to control the transfer platform to perform the transfer according to the calculated path, realize the automatic and repeatable alignment of the two-dimensional material, and improve the transfer efficiency.

Description

Technical Field

[0001] This application relates to the field of two-dimensional material processing technology, and in particular to a two-dimensional material dry transfer alignment method and system. Background Technology

[0002] Two-dimensional materials refer to thin sheet structures with a thickness on the scale of a single atom or a few atoms, while their length and width can form a certain area. Examples include graphene, hexagonal boron nitride (hBN), MoS2, WS2, WSe2, and black phosphorus. In two-dimensional materials, electrons are confined to a two-dimensional plane, allowing them to move freely within that plane. Their movement along the thickness direction is restricted by quantum mechanics, resulting in ultrafast response speeds and extremely low power consumption. Therefore, two-dimensional materials can be used in electronic chips, optoelectronic sensors, energy devices, and related fields.

[0003] Two-dimensional material heterojunctions can be formed by precisely stacking different two-dimensional materials. The stacking interface of two-dimensional material heterojunctions is controllable. For example, materials such as MoS2, WSe2, hBN, and graphene can be stacked in different orders to form electronic devices such as rectifier junctions, tunnel junctions, photodetectors, and field-effect transistors. The stacked structures of these two-dimensional material heterojunctions can be constructed using dry transfer technology. Dry transfer technology refers to a high-precision transfer method that utilizes the adhesive force of solid media such as polymers to peel two-dimensional materials from their growth or original substrate and attach them to a target substrate.

[0004] The dry transfer process of two-dimensional material heterostructures relies on manual observation and alignment. Operators use experience to judge the position, shape, boundaries, and target area of ​​the two-dimensional material under a microscope, and then manually adjust the platform to complete the alignment. However, because the alignment accuracy of the dry transfer process depends on human experience, the transfer repeatability is poor. Furthermore, each transfer requires manual searching, judgment, movement, and fine-tuning, which reduces transfer efficiency and is not conducive to the mass production of devices. Summary of the Invention

[0005] In view of this, embodiments of this application provide a two-dimensional material dry transfer alignment method and system to solve the problem of low efficiency in two-dimensional material dry transfer.

[0006] According to a first aspect of this application, a two-dimensional material dry transfer alignment method is provided, the method comprising: A first morphological image of the underlying two-dimensional material is obtained, wherein the first morphological image is an image acquired after the underlying two-dimensional material is transferred onto the target substrate; A first position parameter is extracted from the first topography image. The first position parameter is used to characterize the geometric relationship of the underlying two-dimensional material on the target substrate. A second morphological image of the top two-dimensional material to be transferred is obtained, and a second position parameter is extracted from the second morphological image. The second position parameter is used to characterize the geometric relationship of the top two-dimensional material to be transferred on the transfer medium. A target stacking relationship is established based on the first position parameter and the second position parameter. The target stacking relationship is used to determine the stacking position and / or stacking angle when transferring the top two-dimensional material to be transferred to the bottom two-dimensional material. The transfer path parameters are calculated based on the target stacking relationship. The transfer path parameters are used to control the transfer platform to move the top layer two-dimensional material to be transferred according to the transfer path parameters.

[0007] In some embodiments, obtaining a first morphology image of the underlying two-dimensional material includes: A set of multi-source images acquired from the underlying two-dimensional material is obtained, the set of multi-source images including at least one of optical microscopic scanning images, confocal scanning images, laser contour scanning images, white light interferometry scanning images, AFM scanning images, and machine vision imaging scanning images; Calculate the sharpness of each image in the multi-source image set; The first morphological image is selected from the multi-source image set based on the resolution, and the first morphological image is the image with the highest resolution in the multi-source image set.

[0008] In some embodiments, extracting a first position parameter from the first topography image includes: Geometric features are identified in the first topographic image, and the geometric features include at least one of the following: center point, boundary, vertex, major axis, corner identification point, and marker point; Traverse the pixel coordinates of the first topographic image; The first position parameter is calculated based on the pixel coordinates and the feature point coordinates corresponding to the geometric feature.

[0009] In some embodiments, identifying geometric features in the first topographic image includes: Call the image recognition model, which is a visual model obtained by training using sample shape images; The first morphological image is input into the image recognition model to obtain the geometric feature labels output by the image recognition model; Feature point coordinates are extracted according to the geometric feature markers, and the feature point coordinates are used to calculate the first position parameter by combining them with the pixel coordinates of the first morphology image.

[0010] In some embodiments, establishing a target stacking relationship based on the first position parameter and the second position parameter includes: Based on the first position parameter, at least two first positioning points are extracted from the first topography image; Based on the second position parameter, at least two second positioning points are extracted from the second morphology image, and the second positioning points are geometric feature points of the same type as the first positioning points. Perform a coordinate transformation on the second topographic image to align the first positioning point with the second positioning point; Extract the third position parameter from the second topography image after coordinate transformation; The target stacking relationship is calculated based on the third position parameter.

[0011] In some embodiments, calculating transfer path parameters based on the target stacking relationship includes: The target location is calculated based on the target stacking relationship and the second position parameter; Plan the optimal transfer path based on the second location parameter and the target transfer location; Obtain the current action status of the transfer platform; Based on the current action state, the optimal transfer path is decomposed into multiple decomposed paths; each decomposed path corresponds to a transfer action; the transfer action includes action type and action parameters. Using the control parameter format of the transfer platform, multiple transfer actions are recorded as transfer path parameters.

[0012] In some embodiments, the method further includes: The execution component of the transfer platform is determined according to the transfer path parameters. The execution component includes at least one of a displacement stage, a rotary stage, a Z-axis platform, and a heating stage. A set of transfer control instructions is generated according to the execution component and the transfer path parameters. The set of transfer control instructions includes at least one transfer control instruction, which is used to control the execution component to perform a transfer action. The set of transfer control commands is sent to the transfer platform so that the transfer platform moves the top-level two-dimensional material to be transferred according to the transfer path parameters.

[0013] In some embodiments, the method further includes: Acquire a calibration image, which includes a pre-contact image and / or a post-contact image when the top two-dimensional material to be transferred is aligned with the bottom two-dimensional material; The fourth position parameter is extracted from the corrected image, and the ideal position parameter is determined based on the target stacking relationship; Based on the fourth position parameter and the ideal position parameter, a correction deviation is calculated, wherein the correction deviation includes the offset of the position parameter in the fourth position parameter relative to the same type of parameter item in the ideal position parameter; The transfer path parameters are adjusted based on the correction deviation.

[0014] In some embodiments, the first position parameter includes at least one of center coordinates, boundary contour, feature vertex coordinates, major axis direction, corner direction, edge direction, and preset marker point position; the second position parameter has the same parameter items as the first position parameter. The target stacking relationship includes at least one of the following: overlapping area, center point alignment, edge alignment, specific vertex alignment rotation angle relationship, and crystal orientation relationship; The transfer path parameters include at least one of translation compensation, rotation compensation angle, approach path, and final contact position.

[0015] According to a second aspect of this application, a two-dimensional material dry transfer alignment system is provided, the system comprising: The image acquisition module is used to acquire a first morphology image of the underlying two-dimensional material, wherein the first morphology image is an image acquired after the underlying two-dimensional material is transferred onto the target substrate; A first position extraction module is used to extract a first position parameter from the first topography image. The first position parameter is used to characterize the geometric relationship of the underlying two-dimensional material on the target substrate. The second position extraction module is used to acquire a second morphology image of the top two-dimensional material to be transferred, and to extract a second position parameter from the second morphology image. The second position parameter is used to characterize the geometric relationship of the top two-dimensional material to be transferred on the transfer medium. A stacking relationship construction module is used to establish a target stacking relationship based on the first position parameter and the second position parameter. The target stacking relationship is used to determine the stacking position and / or stacking angle when transferring the top two-dimensional material to be transferred to the bottom two-dimensional material. The path parameter calculation module is used to calculate the transfer path parameters based on the target stacking relationship. The transfer path parameters are used to control the transfer platform to move the top-level two-dimensional material to be transferred according to the transfer path parameters.

[0016] According to a third aspect of this application, a computer device is provided, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor executes the program to implement the above-described two-dimensional material dry transfer alignment method.

[0017] According to a fourth aspect of this application, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described two-dimensional material dry transfer alignment method.

[0018] By employing the above technical solutions, embodiments of this application provide a method and system for aligning two-dimensional material dry transfer. The method first acquires a first morphological image of the bottom two-dimensional material and a second morphological image of the top two-dimensional material to be transferred. A first position parameter is extracted from the first morphological image, and a second position parameter is extracted from the second morphological image. A target stacking relationship is then established based on the first and second position parameters to determine the stacking position and stacking angle when transferring the top two-dimensional material to the bottom two-dimensional material. Transfer path parameters are then calculated based on the target stacking relationship. This method can calculate the translation, rotation, and approach methods during the transfer process based on the position and morphological information of the bottom two-dimensional material and the top two-dimensional material to be transferred, thereby controlling the transfer platform to execute the transfer according to the calculated path, achieving automated and repeatable two-dimensional material alignment and transfer, and improving the efficiency of dry two-dimensional material transfer.

[0019] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A schematic diagram of the two-dimensional material dry transfer alignment method provided in the embodiments of this application; Figure 2 This is a schematic diagram of the calculation process for transfer path parameters provided in an embodiment of this application; Figure 3 This is a schematic diagram of the process of transferring two-dimensional materials according to transfer path parameters provided in an embodiment of this application; Figure 4 This is a schematic diagram illustrating the secondary correction process based on the correction deviation provided in an embodiment of this application; Figure 5 This is a schematic diagram of a two-dimensional material dry transfer process provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a two-dimensional material dry transfer alignment system provided in an embodiment of this application. Detailed Implementation

[0021] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0022] In the embodiments of this application, the two-dimensional material dry transfer alignment method and system can be used to process two-dimensional materials into two-dimensional material heterojunctions to meet specific material requirements. The two-dimensional material refers to a thin-sheet structure material with a thickness on the scale of a single atom or a few atoms, and a length and width that can form a certain area. For example, the two-dimensional material can be one or more combinations of graphene, hexagonal boron nitride (hBN), MoS2, WS2, WSe2, black phosphorus, etc.

[0023] Electrons in two-dimensional materials are confined to a two-dimensional plane, allowing them to move freely within that plane, while their movement in the thickness direction is restricted by quantum mechanics. This results in ultrafast response speeds and extremely low power consumption, making two-dimensional materials suitable for applications such as electronic chips, optoelectronic sensors, and energy devices.

[0024] Two-dimensional material heterojunctions are heterojunction structures formed by precisely stacking different two-dimensional materials. For example, materials such as MoS2, WSe2, hBN, and graphene can be stacked in different orders to form electronic devices such as rectifier junctions, tunnel junctions, photodetectors, and field-effect transistors.

[0025] The stacking interface of two-dimensional material heterojunctions is controllable, allowing for the formation of different structures through vertical stacking or in-plane splicing. Two-dimensional material heterojunctions obtained through vertical stacking are called vertical heterojunctions. These are formed by stacking different two-dimensional materials layer by layer and binding them together using van der Waals forces. Two-dimensional material heterojunctions obtained through in-plane splicing are called in-plane heterojunctions. These allow for the precise control of carrier transport paths within a single plane.

[0026] In some embodiments, a dry transfer technique can be used to construct a stacked structure of two-dimensional material heterostructures. Dry transfer technique refers to a high-precision transfer method that utilizes the adhesive force of solid media such as polymers to peel two-dimensional materials from their growth or original substrate and attach them to a target substrate.

[0027] Taking the polydimethylsiloxane-assisted transfer method as an example, a polydimethylsiloxane (PDMS) film is used as the core medium, utilizing the adhesiveness of PDMS to directly pick up and release materials. Specifically, a PDMS stamp is prepared by flatly attaching a PDMS film approximately 0.5 mm thick to one end of a glass slide, serving as a support and operating handle. The PDMS surface is then treated with ultraviolet ozone or oxygen plasma to remove impurities and enhance its adhesion.

[0028] Then, sample pickup is performed. Under a microscope, the PDMS film is brought close to the two-dimensional material that has been mechanically peeled off from the original substrate (such as SiO2 / Si). The PDMS film is pressed to ensure full contact with the two-dimensional material, and then the slide is quickly lifted. Due to the strong adhesion of PDMS during rapid peeling, the two-dimensional material is peeled off from the original substrate and adheres to the PDMS surface.

[0029] Next, flip the PDMS stamp with the sample attached so that the sample is facing down and fix it on the cantilever of the transfer stage. Under a microscope, using a precision displacement platform, align the sample with the precise position required on the target substrate. Then, slowly lower the cantilever to gently contact and press the two-dimensional material on the PDMS with the target substrate. Subsequently, lift the PDMS film upwards. At this point, because the adhesion of PDMS is weaker during slow peeling, the two-dimensional material tends to remain on the target substrate, thus achieving transfer.

[0030] The dry transfer process for two-dimensional material heterostructures relies on manual observation and alignment. Operators use experience to judge the position, shape, boundaries, and target area of ​​the two-dimensional material under a microscope, and then manually adjust the platform to complete the alignment. However, the reliance on manual experience for alignment accuracy in the dry transfer process leads to poor transfer repeatability. Furthermore, each transfer requires manual searching, judgment, movement, and fine-tuning, which reduces transfer efficiency and is detrimental to the mass production of devices.

[0031] To address the low efficiency of dry transfer of two-dimensional materials, this application provides a two-dimensional material dry transfer alignment method in some embodiments. This method can perform two-dimensional material dry transfer alignment based on scanning positioning and coordinate mapping. Based on the position and morphology information of the bottom two-dimensional material and the top two-dimensional material to be transferred, the method calculates the translation, rotation, and approach methods during the transfer process, thereby controlling the transfer platform to execute the transfer according to the calculated path. This achieves automated and repeatable two-dimensional material alignment and transfer, improving the accuracy, repeatability, and transfer efficiency of two-dimensional material heterojunction stacking.

[0032] The transfer platform is a high-precision operating table specifically designed for the two-dimensional material transfer process. Through the coordinated operation of integrated components such as microscopic observation components, high-precision displacement components, execution components, and control equipment, it accurately completes the two-dimensional material transfer.

[0033] In some embodiments, the microscopic observation component of the transfer platform may include a high-magnification objective lens and a display screen. As a visual reference for the transfer platform, the microscopic observation component can magnify micron-sized samples hundreds or even thousands of times to clearly display the position and shape of the material and achieve precise positioning.

[0034] High-precision displacement components can include multiple sets of precision displacement stages, enabling atomically accurate transfer operations. Examples include slide stages and substrate stages. Slide stages are used to fix and manipulate slides bearing PDMS stamps, allowing for precise adjustment of their height (Z-axis) and angle to perform pick-and-place operations. Substrate stages are used to fix the target substrate (such as silicon wafers); they not only move precisely but can also rotate in a plane, which is crucial for stacking at specific angles.

[0035] The actuating components can be controlled by control commands from the control device to perform specific transfer actions. The actuating components may include a displacement stage, a rotary stage, a Z-axis platform, and a heating stage. The displacement stage may include an XY-axis displacement stage responsible for movement within the horizontal plane (XY direction). This enables wide-range sample searching and coarse positioning, allowing for rapid movement of PDMS stamps over target two-dimensional materials under a microscope, or moving stamps with samples attached to specific areas of a target substrate.

[0036] Rotary stages can be used for angle control, responsible for rotating angles in a plane (around the Z-axis) or in a specific direction to achieve angle alignment. For example, when it is necessary to stack two layers of graphene at a magic angle of about 1.1° to study superconductivity, a rotary stage can be used to precisely control the lattice angle between the two layers of material.

[0037] The Z-axis platform controls the vertical (up and down) movement of the PDMS stamp to perform the two most critical actions: placement and pickup. The downward accuracy of the Z-axis platform directly determines the quality of the contact between the 2D material and the substrate, requiring extreme smoothness and precision to avoid crushing or wrinkling of the material. It is also the actuator for implementing speed control strategies such as slow placement and fast lifting.

[0038] The heating stage can be integrated below the substrate sample stage to precisely heat the target substrate. The heating stage can utilize the temperature-dependent viscosity characteristics of PPC or PDMS polymers, allowing for the control of interfacial adhesion by setting the temperature. For example, heating the substrate to 80-120°C during sample release can cause the polymer to lose its stickiness, allowing the sample to be placed down cleanly.

[0039] The method can be applied to the control device of a transfer platform, or to an electronic device that establishes a communication connection with the control device and has data processing capabilities. The electronic device includes, but is not limited to, computers, servers, mobile terminals, smart wearable devices, and industrial control machines. For ease of description, the control device is used as the execution subject of the method in this embodiment. It should be understood that the method can also be applied to other types of execution subjects, which are not shown one by one in this embodiment. Figure 1 As shown, the method includes: S101. Obtain the first morphological image of the underlying two-dimensional material.

[0040] When performing two-dimensional material transfer, a first morphological image of the underlying two-dimensional material can be acquired first. This first morphological image is obtained after the underlying two-dimensional material has been transferred onto the target substrate. Therefore, after the underlying two-dimensional material is transferred to the target substrate, the first morphological image of the underlying two-dimensional material can be acquired using an image acquisition device.

[0041] The first morphological image can also be obtained through various scanning or imaging methods. For example, in addition to ordinary optical microscopes, the first morphological image can also be obtained through optical microscopy, confocal scanning, laser contour scanning, white light interference scanning, atomic force microscopy (AFM) scanning, and machine vision imaging scanning.

[0042] In some embodiments, when acquiring a first morphology image of the underlying two-dimensional material, a multi-source image set acquired from the underlying two-dimensional material can be acquired first. The multi-source image set includes at least one of optical microscopic scanning images, confocal scanning images, laser contour scanning images, white light interferometry scanning images, AFM scanning images, and machine vision imaging scanning images.

[0043] After obtaining the multi-source image set, the sharpness can be calculated for each image in the multi-source image set. Then, a first topographic image is selected from the multi-source image set based on the sharpness, wherein the first topographic image is the image with the highest sharpness in the multi-source image set.

[0044] For example, scanning an area of ​​graphene measuring 10 μm × 10 μm can produce optical microscopy scanning images, confocal scanning images, laser contour scanning images, white light interference scanning images, and AFM scanning images, forming a multi-source image set.

[0045] Then, sharpness evaluation functions such as the Brenner gradient function or the Tenengrad function are used to calculate the sharpness value of each image. A higher sharpness value indicates a greater grayscale difference between adjacent pixels, resulting in a sharper image. By calculating the sharpness, the sharpness values ​​are: 85.2 for the optical microscopic scan image OM_01.tif, 134.7 for the confocal scan image Confocal_02.tif, 156.3 for the laser contour scan image Laser_03.tif, 22.1 for the white light interferometry scan image WLI_04.tif, and 298.5 for the AFM scan image AFM_05.tif. Therefore, the first topographic image can be selected based on the rule of the image with the highest sharpness; that is, the AFM scan image AFM_05.tif is automatically identified as the first topographic image.

[0046] In some embodiments, comprehensive analysis can also be performed on different types of images, i.e., the first morphology image is an image sequence or superimposed image composed of multiple images. Multiple images of different types can be obtained by using the same imaging parameters (shooting distance, shooting angle, etc.) and different image acquisition devices to capture images of the same underlying two-dimensional material. Then, during subsequent location parameter extraction, different types of images can be selected for parameter extraction based on different parameters to obtain the most accurate location identification result.

[0047] S102, Extract the first position parameter from the first topography image.

[0048] After acquiring the first topographic image of the underlying two-dimensional material, image recognition can be performed on the first topographic image to extract the first position parameter. The first position parameter is used to characterize the geometric relationship of the underlying two-dimensional material on the target substrate. That is, the first position parameter is a geometric parameter extracted from the first topographic image that can be used for positioning and alignment.

[0049] In some embodiments, the first position parameter includes at least one of center coordinates, boundary contour, feature vertex coordinates, major axis direction, corner direction, edge direction, and preset marker point position. Here, center coordinates refer to the (X, Y) position of the geometric center point of the two-dimensional material shape in the image coordinate system or sample stage coordinate system, such as centroid coordinates. Boundary contour is the outer boundary line of the two-dimensional material sheet extracted by image processing methods such as edge detection. The boundary contour is a set of pixels consisting of a series of continuous boundary pixels. Feature vertex coordinates are the sharp corner points on the boundary contour, such as the corner points of polygons like triangles, hexagons, and parallelograms. Major axis direction refers to the angle between the direction of the longest axis in the image that can cover the material shape and the reference axis. For example, if the longest axis is the long side of the smallest bounding rectangle of the bottom two-dimensional material region, and the reference axis is the horizontal reference axis, i.e., the X-axis, then the major axis direction is the angle between the long side of the smallest bounding rectangle of the bottom two-dimensional material region and the X-axis.

[0050] The rotation direction is a relative value, referring to the relative rotation angle between the long axis or specific crystal orientation of the current material and the alignment mark on another layer of material or substrate. The edge direction refers to the angle between the extension direction of a straight edge on the boundary profile of a two-dimensional material and a reference axis such as the X-axis. The preset marker point position refers to the coordinates of a marker point that has been pre-marked on the image or sample substrate, such as the center coordinates of a crosshair mark or the edge of a gold electrode.

[0051] Image recognition algorithms can be used to extract the first positional parameters of the underlying two-dimensional material, such as the center coordinates, boundary contours, feature vertex coordinates, major axis direction, corner direction, edge direction, and the position of preset marker points, based on the first morphology image.

[0052] In order to extract the first position parameter, in some embodiments, when extracting the first position parameter from the first topography image, geometric features can be identified in the first topography image first, wherein the geometric features include at least one of center point, boundary, vertex, major axis, corner identification point and marker point.

[0053] Geometric features can be determined by analyzing specific shapes, colors, variation patterns, and quantities of pixels in the first topographic image using an image recognition model. Therefore, when identifying geometric features in the first topographic image, a pre-trained image recognition model can be invoked. This image recognition model is a visual model trained using sample topographic images. The first topographic image is then input into the image recognition model to obtain geometric feature labels output by the model, and feature point coordinates are extracted according to these labels.

[0054] The feature point coordinates are used in conjunction with the pixel coordinates of the first topographic image to calculate the first position parameter. Therefore, after recognizing the geometric features, the control device can traverse the pixel coordinates of the first topographic image and then calculate the first position parameter based on the pixel coordinates and the feature point coordinates corresponding to the geometric features.

[0055] For example, to extract the geometric features of a monolayer molybdenum disulfide (MoS2) sheet from a first morphology image such as an AFM scan image to calculate its center coordinates, major axis direction, and edge direction, an AFM scan image AFM_05.tif can be used as the input image. The input image includes a triangular MoS2 single crystal with a side length of approximately 15 μm located on a SiO2 / Si substrate.

[0056] The control device can first call an image recognition model based on U-Net or Mask R-CNN semantic segmentation to identify geometric features such as boundaries and vertices of the two-dimensional material. Then, AFM_05.tif is input into the pre-trained image recognition model. The image recognition model can then output geometric feature labels, such as a set of boundary pixels B = {(x1, y1), (x2, y2), ..., (x...}. n y n Vertex coordinates V1 = (120, 340), V2 = (580, 120), V3 = (680, 560); Center point coordinates C = (460, 340); Major axis direction angle θ_major axis = 15.3° relative to the horizontal X-axis of the image; Marker point coordinates M1 = (50, 50), M2 = (900, 50), M3 = (50, 700), etc.

[0057] The geometric feature markers output by the model are then directly converted into specific feature point coordinates. Furthermore, the control device can store these feature point coordinates as structured parameters. Next, the pixel coordinates of the entire AFM_05.tif image are traversed. Assuming the AFM_05.tif image size is 1024×1024 pixels, the first position parameters can be obtained through geometric calculations by combining the feature point coordinates extracted in the previous step. The center coordinates can then be directly output by the model without additional calculation. For vertex coordinates, the boundary can be verified through pixel traversal; that is, by traversing the boundary pixel set B, it can be verified whether the three vertices output by the model are indeed located on the boundary and whether the edges between them are straight lines.

[0058] For the major axis direction, the precise major axis direction can be calculated through pixel traversal optimization. That is, after the image recognition model provides an initial major axis direction (15.3°), the control device further traverses all boundary points, calculates the distance between each pair of boundary points, finds the direction corresponding to the maximum distance, and performs refined verification of the model output. For example, traversing boundary pixel point B (a total of 1580 points), the maximum distance point pairs are: P1 = (130, 335), P2 = (675, 565). Therefore, the direction angle can be calculated as: θ = arctan((565-335) / (675-130)) = arctan(230 / 545) ≈ 22.9°, which deviates from the model output (15.3°) by 7.6°. After confidence-weighted fusion, the final result using the high-confidence traversal calculation is adopted, i.e., the major axis direction relative to the horizontal X-axis of the image is 22.9°.

[0059] Similarly, when calculating edge directions, the three sides of the triangle can be determined based on the vertex and boundary coordinates to correspond to the three edge directions. For example, for edge V1-V2, dx=580-120=460, dy=120-340=-220, then the direction angle = arctan(-220 / 460) = -25.6°-154.4°. For edge V2-V3, dx=680-580=100, dy=560-120=440; the direction angle = arctan(440 / 100) = 77.2°. For edge V3→V1, dx=120-680=-560, dy=340-560=-220; the direction angle = arctan((-220) / (-560)) = 21.5°-201.5°-21.5°. Therefore, the edge directions relative to the horizontal X-axis of the image are: 154.4°, 77.2°, 21.5°.

[0060] For the direction of the turn, the center point and at least one geometric feature that does not completely coincide with the center point can be extracted from the first topography image, and then compared with the center point and similar geometric features in the standard topography image without the turn. Based on the difference between the geometric features in the first topography image and the geometric features in the standard topography image without the turn, the direction of the turn and the angle of the turn can be determined.

[0061] For example, by aligning the first topographic image of the MoS2 sheet with a non-rotated image of the MoS2 sheet, we can determine how many degrees the reference direction of the current MoS2 needs to be rotated to achieve the target angle, such as 21.5° at the edge. Therefore, the target alignment angle is 0°, i.e., a non-rotated MoS2 sheet. Taking the first edge direction of the MoS2 sheet as the underlying two-dimensional material, we can determine that the current material reference direction is 21.5°. The rotation direction is then the difference between the edge direction of the MoS2 sheet and the target alignment angle, i.e., -21.5°, indicating a clockwise rotation of 21.5°.

[0062] S103. Obtain a second morphological image of the top-layer two-dimensional material to be transferred, and extract a second position parameter from the second morphological image.

[0063] Similar to the underlying two-dimensional material, image acquisition and position parameter extraction can also be performed on the top two-dimensional material to be transferred. This involves obtaining a second morphological image of the top two-dimensional material and extracting a second position parameter from the second morphological image. The second position parameter characterizes the geometric relationship of the top two-dimensional material on the transfer medium.

[0064] Similar to the scanning method of the first morphology image, the second morphology image can also be obtained using various scanning or imaging methods. For example, the second morphology image can be obtained by scanning with a conventional optical microscope. In addition to conventional optical microscopes, the second morphology image can also be obtained by scanning methods such as optical microscopy, confocal scanning, laser contour scanning, white light interferometry, atomic force microscopy (AFM) scanning, and machine vision imaging scanning.

[0065] In some embodiments, the second position parameter includes at least one of the following: center coordinates, boundary contour, feature vertex coordinates, major axis direction, corner direction, edge direction, and preset marker point position, and the second position parameter has the same parameter items as the first position parameter. Therefore, when acquiring the second morphology image of the top-layer two-dimensional material to be transferred and extracting the second position parameter of the top-layer two-dimensional material to be transferred, the position, contour, orientation, and feature points of the top-layer material to be transferred on the transfer medium can be identified.

[0066] The extraction method for the second position parameter can be the same as that for the first position parameter. For example, when extracting the second position parameter from the second topography image, an image recognition model can be called to identify geometric features in the second topography image. These geometric features include at least one of the following: center point, boundary, vertex, major axis, corner recognition point, and marker point. Then, the second position parameter is calculated by traversing the pixel coordinates of the second topography image and using the pixel coordinates and the feature point coordinates corresponding to the geometric features.

[0067] S104. Establish the target stacking relationship based on the first position parameter and the second position parameter.

[0068] After extracting the first and second position parameters through image recognition, a target stacking relationship can be established based on the first and second position parameters. This target stacking relationship is used to determine the stacking position and / or stacking angle when transferring the top-layer 2D material to the bottom-layer 2D material.

[0069] Based on the first position parameters of the bottom material and the second position parameters of the top material, a target stacking position and stacking angle relationship between the bottom and top materials can be established. This target stacking position and stacking angle relationship can indicate that the two two-dimensional materials need to overlap, or it can indicate the overlap area, center point alignment, edge alignment, specific vertex alignment, rotation angle, or crystal orientation relationship of the two-dimensional materials. Therefore, in some embodiments, the target stacking relationship includes at least one of the following: overlap area, center point alignment, edge alignment, specific vertex alignment, rotation angle relationship, and crystal orientation relationship.

[0070] The overlapping area refers to the specific area and size of the top layer material covering the bottom layer material. For example, in order to make an electrode with edge contact, the top layer can be set to cover only half of the bottom layer area, forming a stepped structure.

[0071] Center-point alignment refers to aligning the geometric centers of two layers of material vertically. Center-point alignment offers a high degree of symmetry in stacking. If the two layers have the same shape, such as being circular or square, center alignment can ensure complete overlap.

[0072] Edge alignment can refer to the alignment of edge regions when two materials are stacked. For 2D material transfer in in-plane joins, edge alignment means aligning a specific edge of the two layers of material in the vertical direction. Edge alignment can be applied to polygonal materials, such as aligning one edge of two triangles to form a larger rhombus or parallelogram structure. Edge alignment can be used to construct atomically smooth in-plane connections, thereby creating in-plane heterostructures.

[0073] Specific vertex alignment refers to the vertical alignment of two layers of material with a specific corner point aligned. Specific vertex alignment is a high-precision positioning method that can be used in applications requiring precise anchoring to a specific electrode or contact point. For example, it may be necessary for a corner of the top layer material to fall precisely on a corner of the bottom layer material, forming a nanoscale L-shaped contact to achieve accurate local electrical measurements.

[0074] Rotation angle, or crystal orientation relationship, is a core element in constructing functional heterostructures, referring to the relative rotation angle between the lattice orientations of two layers of materials. When no rotation is needed (angle 0°), the atomic arrangement of the two layers is completely aligned, forming a simple AA stack. When a specific angle is introduced, such as the 1.1° magic angle of graphene, the atomic arrangement of the two layers will generate a moiré superlattice due to periodic misalignment. The moiré superlattice alters the electronic behavior of the material, producing functionalities such as superconductivity or strongly correlated electronic states.

[0075] In order to establish the target stacking relationship, in some embodiments, when establishing the target stacking relationship based on the first position parameter and the second position parameter, at least two first positioning points can be extracted from the first topography image according to the first position parameter, and at least two second positioning points can be extracted from the second topography image according to the second position parameter, wherein the second positioning points are geometric feature points of the same type as the first positioning points.

[0076] Then, a coordinate transformation is performed on the second topography image to align the first positioning point with the second positioning point, and a third position parameter is extracted from the second topography image after the coordinate transformation, and the target stacking relationship is calculated based on the third position parameter.

[0077] For example, to precisely stack a top layer of MoS2 (molybdenum disulfide) triangular sheets onto a bottom layer of WSe2 (tungsten diselenide) triangular sheets, specific vertices of the two layers must be aligned, and their edges must be parallel (rotation angle of 0°) to form an atomically flat van der Waals heterojunction. Therefore, for the first AFM topography image (AFM_Bottom.tif) of the bottom WSe2 and the second AFM topography image (AFM_Top.tif) of the top MoS2, the geometric parameters of the bottom WSe2 and the top MoS2, respectively, can be extracted, namely the first position parameter and the second position parameter.

[0078] When constructing the target stacking relationship, positioning points can be extracted first, that is, geometric feature points of the same type can be extracted from the images of the two layers of material as positioning points. For example, at least two vertices of a triangle can be selected as positioning points. Then, the first positioning point in the first topography image (bottom layer WSe2) can be extracted from the first position parameters to extract two positioning points A1 and B1 of the triangle vertex, and the corresponding positioning point coordinates in the image coordinate system are (200, 350) and (600, 150).

[0079] Similarly, for the second positioning point in the second topographic image (top layer MoS2), the coordinates of the two positioning points A2 and B2 in the image coordinate system can be extracted from the second position parameters as (300, 400) and (700, 200).

[0080] Then, by visualizing the current state, the current relative positions of the two material layers in the image coordinate system are shown in Table 1: Table 1 Current relative position;

[0081] The two layers of material have the same side length (both 447.2 pixels) and the same orientation angle (-26.565°), indicating that they are the same size and orientation in the image, but their positions are offset.

[0082] Therefore, to achieve the target stacking, a coordinate transformation can be performed on the second topographic image to align vertex A2 with A1 and B2 with B1. This requires a coordinate transformation of the top-level MoS2 image and all its geometric features. For example, when calculating the translation vector and rotation, the positioning point A2 (300, 400) of the top-level MoS2 can be moved to coincide with the positioning point A1 (200, 350) of the bottom-level WSe2. Then, the translation vector T = A1 - A2 = (200 - 300, 350 - 400) = (-100, -50) pixels.

[0083] Next, determine whether rotation is needed. This is done by comparing the orientation angles of the two layers: bottom layer orientation angle: -26.565°; top layer orientation angle: -26.565°. The angle difference is 0°, meaning no rotation is needed. Therefore, only a translation transformation needs to be performed on the second topography image.

[0084] Then, a coordinate transformation is performed. The vertices, boundaries, and center points on the top-level MoS2 are all transformed using a translation vector T(-100, -50). For example, the original coordinates of point A2 (300, 400) and point B2 (700, 200) are transformed into (200, 350) and (600, 150) respectively, making A2 coincide with A1 and B2 coincide with B1. Similarly, the third vertex C2 (600, 600) is transformed to (500, 550), and the center point (533, 400) is transformed to (433, 350), ensuring that the transformed A2 and B2 of the top-level MoS2 are perfectly aligned with the A1 and B1 of the bottom-level WSe2.

[0085] Then, the third positional parameter is extracted from the second topographic image after coordinate transformation. That is, after coordinate transformation, the geometric coordinates of the top layer MoS2 change, and the control device re-extracts the positional parameters of the top layer material from the transformed image or transformed coordinate data; these are the third positional parameters, including vertex coordinates (200, 350), (600, 150), (500, 550); center point coordinates (433, 350); side length 447.2 pixels; and orientation angle -26.565°. Essentially, the third positional parameter is the new position of the top layer MoS2 in the same coordinate system shared with the bottom layer WSe2 after coordinate transformation.

[0086] Then, the target stacking relationship is calculated based on the third position parameter, that is, all feature points of the top layer MoS2 are aligned with the feature points of the bottom layer WSe2 in the same coordinate system. For example, the complete target stacking relationship calculated based on the third position parameter includes: two layers of triangles with the same side length and direction completely overlap, then the overlap area is 100%; the center point alignment is that the bottom center (433, 350) and the top center (433, 350) completely overlap; the edge alignment is that the bottom edge AB (200, 350-600, 150) and the top edge AB (200, 350-600, 150) are completely parallel and overlap; the specific vertex alignment is that A1 (200, 350) = A2 (200, 350), B1 (600, 150) = B2 (600, 150), that is, vertices A and B overlap respectively; the rotation angle / crystal orientation relationship is that the bottom orientation angle is -26.565° and the top orientation angle is -26.565°, and the 0° crystal orientation is parallel.

[0087] S105. Calculate the transfer path parameters based on the target stacking relationship.

[0088] After constructing the target stacking relationship, the transfer path parameters can be calculated based on the target stacking relationship, such as... Figure 2 As shown, transfer path parameters are calculated based on the target stacking position / angle relationship. These transfer path parameters are used to control the transfer platform to move the top-layer two-dimensional material to be transferred according to the transfer path parameters. In some embodiments, the transfer path parameters include at least one of translation compensation, rotation compensation angle, approach path, and final contact position.

[0089] The transfer path parameters can include X-direction translation compensation, Y-direction translation compensation, rotation compensation angle, Z-direction approach path, and final contact position. The transfer path control device can be used to set the transfer platform's action values, such as how much the top layer material should move left or right; how much forward or backward; the required rotation angle; the height and path at which it gradually approaches the bottom layer material; and the final contact position.

[0090] In some embodiments, when calculating transfer path parameters based on the target stacking relationship, the target transfer position can be calculated first based on the target stacking relationship and the second position parameter, and then the optimal transfer path can be planned based on the second position parameter and the target transfer position. Then, the current action state of the transfer platform is obtained, and the optimal transfer path is decomposed into multiple decomposed paths according to the current action state. Each decomposed path corresponds to one transfer action; the transfer action includes an action type and action parameters. Then, using the control parameter format of the transfer platform, the multiple transfer actions are recorded as transfer path parameters.

[0091] For example, after establishing the target stacking relationship, the target position that the top layer MoS2 needs to move to can be calculated based on the target stacking relationship, and the transfer path parameters can be calculated by combining the geometric parameters of the top layer MoS2 in the current coordinate system.

[0092] Therefore, the target transfer position can be calculated based on the target stacking relationship and the second position parameter. The geometric constraints in the target stacking relationship can be converted into the target pose that the top layer material needs to reach in the physical coordinate system, such as the target position and the target angle. When calculating the target transfer position, the top layer material needs to move from its current position so that its vertex A reaches the target position (2.00μm, 3.50μm). Since the orientation of the material is already consistent with the target (no rotation is needed), only the translation amount needs to be calculated, that is, translation amount = target vertex A position - current vertex A position, i.e. (2.00-3.00, 3.50-4.50) = (-1.00μm, -1.00μm).

[0093] Then, based on the second position parameter and the target position, the optimal transfer path is planned. This means the control device plans an optimal transfer path between the current position P_current and the target position P_target. When planning the optimal transfer path, it's necessary to consider the shortest path to reduce transfer time, avoid electrodes, markers, or other materials on the substrate, and ensure smooth operation, avoiding sudden stops and starts that could cause material wrinkling or displacement. The path planning result is obtained, where the displacement vector from the current position to the target position is (-1.00μm, -1.00μm), and the rotation is 0°. For example, the planned optimal transfer path might consist of three segments: a first segment of Z-axis lifting, a second segment of XY horizontal movement, and a third segment of Z-axis descent.

[0094] The first Z-axis lifting path starts at (5.00, 4.00, Z_current) and ends at (5.00, 4.00, Z_safe), used to vertically lift the PDMS stamp to a safe height to avoid scratching the substrate during horizontal movement. The second XY horizontal movement, starting at (5.00, 4.00, Z_safe) and ending at (4.00, 3.00, Z_safe), is used to move the stamp horizontally to directly above the target position at the safe height. The third Z-axis descent path, starting at (4.00, 3.00, Z_safe) and ending at (4.00, 3.00, Z_target), is used to vertically descend to the target position to complete the placement.

[0095] Then, the optimal transfer path is represented by path parameterization. Taking path segment 2 (XY horizontal movement) as an example, it can be represented by a parameterized curve: P(t) = P_current + t × (P_target - P_current), t∈[0,1]. Then, at t=0.5, the top material is located at (4.50μm, 3.50μm, Z_safe).

[0096] Next, the current motion state of the transfer platform is acquired and the path is decomposed. By reading the current motion state of the transfer platform, i.e., the current position, velocity, acceleration, etc. of each axis of the transfer platform, the optimal transfer path is decomposed into multiple decomposed paths, each decomposed path corresponding to a transfer action. That is, based on the kinematic constraints (maximum velocity, acceleration) and safety requirements of the platform, the path is decomposed into three consecutive decomposed paths, namely the first segment of Z-axis lifting, the second segment of XY horizontal movement, and the third segment of Z-axis descent.

[0097] By converting decomposition paths into transfer actions, each decomposition path is transformed into an independent transfer action, which includes action type and action parameters. For example, the relationship between decomposition paths and transfer actions can include: if the action type corresponding to decomposition path 1 is MOVE_ABS, then action parameters in JSON format such as {"axis":"Z", "target":100.0, "velocity":1.0} can be set, indicating that the Z-axis is moved absolutely 100μm at a speed of 1.0μm / s.

[0098] Similarly, the action type corresponding to decomposition path 2 is MOVE_ABS, with action parameters {"axis":"XY", "target_x":4.0, "target_y":3.0, "velocity_x":1.0, "velocity_y":1.0}, indicating that the X and Y axes move simultaneously to (4.0, 3.0) at a speed of 1.0 μm / s. The action type corresponding to decomposition path 3 is MOVE_ABS, with action parameters {"axis":"Z", "target":0.0, "velocity":0.2}, indicating that the Z axis moves absolutely to 0 μm (contact) at a speed of 0.2 μm / s (slow).

[0099] The transfer path parameters are then recorded using the control parameter format of the transfer platform. In other words, the control device converts all the aforementioned transfer actions into a standardized instruction format that the transfer platform controller can parse. For example, the transfer platform's control protocol may be an extended instruction set based on G-code (CNC standard instruction set).

[0100] By applying the technical solutions of the above embodiments, the two-dimensional material dry transfer alignment method described in the above embodiments can first acquire a first morphological image of the bottom two-dimensional material and a second morphological image of the top two-dimensional material to be transferred, and extract a first position parameter from the first morphological image and a second position parameter from the second morphological image. Then, based on the first and second position parameters, a target stacking relationship is established to determine the stacking position and stacking angle when transferring the top two-dimensional material to be transferred to the bottom two-dimensional material. Finally, transfer path parameters are calculated according to the target stacking relationship. This method can calculate the translation, rotation, and approach methods of the transfer process based on the position and morphological information of the bottom two-dimensional material and the top two-dimensional material to be transferred, thereby controlling the transfer platform to execute the transfer according to the calculated path, realizing automated and repeatable two-dimensional material alignment transfer, and improving the transfer efficiency of two-dimensional material dry transfer.

[0101] In some embodiments, as a refinement and extension of the specific implementation of the above embodiments, and to fully illustrate the specific implementation process of this embodiment, some embodiments of this application also provide a two-dimensional material dry transfer alignment method. The difference between this method and the above embodiments is that it can control the transfer platform to move the top-layer two-dimensional material according to transfer path parameters, such as... Figure 3 As shown, the method includes: S201. Determine the execution component of the transfer platform based on the transfer path parameters; S202. Generate a set of transfer control instructions according to the execution unit and transfer path parameters; S203. Send the set of transfer control commands to the transfer platform so that the transfer platform moves the top-level two-dimensional material to be transferred according to the transfer path parameters.

[0102] To control the transfer platform, after calculating and obtaining the transfer path parameters, the control device can first determine the execution components of the transfer platform based on the transfer path parameters. The execution components include at least one of a displacement stage, a rotary stage, a Z-axis platform, and a heating stage.

[0103] A set of transfer control instructions is then generated based on the execution component and transfer path parameters. This set includes at least one transfer control instruction, which controls the execution component to perform the transfer action. The set of transfer control instructions is then sent to the transfer platform, causing the platform to move the top-level two-dimensional material to be transferred according to the transfer path parameters.

[0104] The control equipment can control the transfer platform to move the top two-dimensional material according to the transfer path parameters, so that the top two-dimensional material and the bottom two-dimensional material reach a preset alignment state, and convert the algorithm calculation results into the actual actions of the displacement stage, rotary stage, Z-axis platform and heating stage.

[0105] In some embodiments, as a refinement and extension of the specific implementation of the above embodiments, and to fully illustrate the specific implementation process of this embodiment, some embodiments of this application also provide a two-dimensional material dry transfer alignment method. The difference between this method and the above embodiments is that it can perform secondary correction based on the correction deviation. For example... Figure 4 As shown, the method includes: S301. Obtain the corrected image; S302, Extract the fourth position parameter from the corrected image, and determine the ideal position parameter based on the target stacking relationship; S303. Calculate the correction deviation based on the fourth position parameter and the ideal position parameter; S304. Adjust the transfer path parameters according to the correction deviation.

[0106] During the secondary correction, a correction image can be acquired first. This correction image includes at least one of a pre-contact image and a post-contact image when the top-layer 2D material to be transferred is aligned with the bottom-layer 2D material. Then, a fourth position parameter is extracted from the correction image, and an ideal position parameter is determined based on the target stacking relationship.

[0107] Then, based on the fourth position parameter and the ideal position parameter, a correction deviation is calculated. This correction deviation includes the offset of the position parameter in the fourth position parameter relative to the same type of parameter in the ideal position parameter. The transfer path parameters are then adjusted according to the correction deviation.

[0108] For example, such as Figure 5 As shown, a calibrated image can be acquired before or after the top and bottom materials come into contact, and secondary corrections can be made based on the calibration deviation. Since slight slippage, positional changes due to thermal release, or minor material shifts may occur during the actual transfer process, secondary imaging and correction can further improve the final alignment accuracy, complete the release of the top two-dimensional material, and thus form a two-dimensional material heterostructure.

[0109] By applying the technical solutions of the above embodiments, the two-dimensional material dry transfer alignment method described in the above embodiments can first obtain the position and morphology information of the bottom two-dimensional material, and then obtain the position and morphology information of the top two-dimensional material to be transferred. Then, an algorithm calculates how the two materials should translate, rotate, and approach each other. Finally, the transfer platform is controlled to execute the transfer according to the calculated path, and corrections are performed before and after contact. This method can achieve more automated and repeatable two-dimensional material alignment and transfer through scanning imaging, image recognition, feature extraction, coordinate mapping, and platform control.

[0110] In some embodiments, as a specific implementation of the two-dimensional material dry transfer alignment method described in the above embodiments, some embodiments of this application also provide a two-dimensional material dry transfer alignment system, such as... Figure 6 As shown, the system includes: The image acquisition module is used to acquire a first morphology image of the underlying two-dimensional material, wherein the first morphology image is an image acquired after the underlying two-dimensional material is transferred onto the target substrate; A first position extraction module is used to extract a first position parameter from the first topography image. The first position parameter is used to characterize the geometric relationship of the underlying two-dimensional material on the target substrate. The second position extraction module is used to acquire a second morphology image of the top two-dimensional material to be transferred, and to extract a second position parameter from the second morphology image. The second position parameter is used to characterize the geometric relationship of the top two-dimensional material to be transferred on the transfer medium. A stacking relationship construction module is used to establish a target stacking relationship based on the first position parameter and the second position parameter. The target stacking relationship is used to determine the stacking position and / or stacking angle when transferring the top two-dimensional material to be transferred to the bottom two-dimensional material. The path parameter calculation module is used to calculate the transfer path parameters based on the target stacking relationship. The transfer path parameters are used to control the transfer platform to move the top-level two-dimensional material to be transferred according to the transfer path parameters.

[0111] It should be noted that other corresponding descriptions of the functional units involved in the two-dimensional material dry transfer alignment system provided in the embodiments of this application can be found in the corresponding descriptions in the two-dimensional material dry transfer alignment method provided in the above embodiments, and will not be repeated here.

[0112] By applying the technical solutions of the above embodiments, the two-dimensional material dry transfer alignment system described in the above embodiments can acquire a first morphological image of the bottom two-dimensional material and a second morphological image of the top two-dimensional material to be transferred through an image acquisition module. Then, a first position extraction module extracts a first position parameter from the first morphological image, and a second position extraction module extracts a second position parameter from the second morphological image. A stacking relationship construction module then establishes a target stacking relationship based on the first and second position parameters, determining the stacking position and stacking angle when transferring the top two-dimensional material to the bottom two-dimensional material. Finally, a path parameter calculation module calculates the transfer path parameters based on the target stacking relationship. The system can calculate the translation, rotation, and approach methods of the transfer process based on the position and morphological information of the bottom two-dimensional material and the top two-dimensional material to be transferred, thereby controlling the transfer platform to execute the transfer according to the calculated path, achieving automated and repeatable two-dimensional material alignment and transfer, and improving the efficiency of dry two-dimensional material transfer.

[0113] This application also provides a computer device, specifically a personal computer, server, network device, etc. The computer device includes a bus, processor, memory, and communication interface, and may also include input / output interfaces and a display device. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device stores location information. The network interface of the computer device is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the steps in the various method embodiments.

[0114] Those skilled in the art will understand that the structure of the computer device described above is only a partial structure related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. A specific computer device may include more or fewer components, or combine certain components, or have different component arrangements.

[0115] In one embodiment, a computer-readable storage medium is also provided, which may be non-volatile or volatile, and a computer program is stored thereon, which, when executed by a processor, implements the steps in the above method embodiments.

[0116] In one embodiment, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in the above method embodiments.

[0117] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0118] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods.

[0119] Any references to memory, database, or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc.

[0120] Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take many forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0121] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchain. The processors involved in the embodiments provided in this application may be, but are not limited to, general-purpose processors, graphics processors, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0123] The embodiments described above are merely examples of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application.

Claims

1. A method for dry transfer and alignment of two-dimensional materials, characterized in that, The method includes: A first morphological image of the underlying two-dimensional material is obtained, wherein the first morphological image is an image acquired after the underlying two-dimensional material is transferred onto the target substrate; A first position parameter is extracted from the first topography image. The first position parameter is used to characterize the geometric relationship of the underlying two-dimensional material on the target substrate. A second morphological image of the top two-dimensional material to be transferred is obtained, and a second position parameter is extracted from the second morphological image. The second position parameter is used to characterize the geometric relationship of the top two-dimensional material to be transferred on the transfer medium. A target stacking relationship is established based on the first position parameter and the second position parameter. The target stacking relationship is used to determine the stacking position and / or stacking angle when transferring the top two-dimensional material to be transferred to the bottom two-dimensional material. The transfer path parameters are calculated based on the target stacking relationship. The transfer path parameters are used to control the transfer platform to move the top layer two-dimensional material to be transferred according to the transfer path parameters.

2. The method according to claim 1, characterized in that, Obtain the first morphological image of the underlying two-dimensional material, including: A set of multi-source images acquired from the underlying two-dimensional material is obtained, the set of multi-source images including at least one of optical microscopic scanning images, confocal scanning images, laser contour scanning images, white light interferometry scanning images, AFM scanning images, and machine vision imaging scanning images; Calculate the sharpness of each image in the multi-source image set; The first morphological image is selected from the multi-source image set based on the resolution, and the first morphological image is the image with the highest resolution in the multi-source image set.

3. The method according to claim 1, characterized in that, Extracting the first position parameter from the first topographic image includes: Geometric features are identified in the first topographic image, and the geometric features include at least one of the following: center point, boundary, vertex, major axis, corner identification point, and marker point; Traverse the pixel coordinates of the first topographic image; The first position parameter is calculated based on the pixel coordinates and the feature point coordinates corresponding to the geometric feature.

4. The method according to claim 3, characterized in that, Identifying geometric features in the first topographic image includes: Call the image recognition model, which is a visual model obtained by training using sample shape images; The first morphological image is input into the image recognition model to obtain the geometric feature labels output by the image recognition model; Feature point coordinates are extracted according to the geometric feature markers, and the feature point coordinates are used to calculate the first position parameter by combining them with the pixel coordinates of the first morphology image.

5. The method according to claim 1, characterized in that, Establishing the target stacking relationship based on the first position parameter and the second position parameter includes: Based on the first position parameter, at least two first positioning points are extracted from the first topography image; Based on the second position parameter, at least two second positioning points are extracted from the second morphology image, and the second positioning points are geometric feature points of the same type as the first positioning points. Perform a coordinate transformation on the second topographic image to align the first positioning point with the second positioning point; Extract the third position parameter from the second topography image after coordinate transformation; The target stacking relationship is calculated based on the third position parameter.

6. The method according to claim 1, characterized in that, The transfer path parameters are calculated based on the target stacking relationship, including: The target location is calculated based on the target stacking relationship and the second position parameter; Plan the optimal transfer path based on the second location parameter and the target transfer location; Obtain the current action status of the transfer platform; Based on the current action state, the optimal transfer path is decomposed into multiple decomposed paths; each decomposed path corresponds to a transfer action; the transfer action includes action type and action parameters. Using the control parameter format of the transfer platform, multiple transfer actions are recorded as transfer path parameters.

7. The method according to claim 1, characterized in that, The method further includes: The execution component of the transfer platform is determined according to the transfer path parameters. The execution component includes at least one of a displacement stage, a rotary stage, a Z-axis platform, and a heating stage. A set of transfer control instructions is generated according to the execution component and the transfer path parameters. The set of transfer control instructions includes at least one transfer control instruction, which is used to control the execution component to perform a transfer action. The set of transfer control commands is sent to the transfer platform so that the transfer platform moves the top-level two-dimensional material to be transferred according to the transfer path parameters.

8. The method according to claim 1, characterized in that, The method further includes: Acquire a calibration image, which includes a pre-contact image and / or a post-contact image when the top two-dimensional material to be transferred is aligned with the bottom two-dimensional material; The fourth position parameter is extracted from the corrected image, and the ideal position parameter is determined based on the target stacking relationship; Based on the fourth position parameter and the ideal position parameter, a correction deviation is calculated, wherein the correction deviation includes the offset of the position parameter in the fourth position parameter relative to the same type of position parameter in the ideal position parameter; The transfer path parameters are adjusted based on the correction deviation.

9. The method according to claim 1, characterized in that, The first position parameter includes at least one of the following: center coordinates, boundary contour, feature vertex coordinates, major axis direction, corner direction, edge direction, and preset marker point position; the second position parameter has the same parameter items as the first position parameter. The target stacking relationship includes at least one of the following: overlapping area, center point alignment, edge alignment, specific vertex alignment rotation angle relationship, and crystal orientation relationship; The transfer path parameters include at least one of translation compensation, rotation compensation angle, approach path, and final contact position.

10. A two-dimensional material dry transfer alignment system, characterized in that, The system includes: The image acquisition module is used to acquire a first morphology image of the underlying two-dimensional material, wherein the first morphology image is an image acquired after the underlying two-dimensional material is transferred onto the target substrate; A first position extraction module is used to extract a first position parameter from the first topography image. The first position parameter is used to characterize the geometric relationship of the underlying two-dimensional material on the target substrate. The second position extraction module is used to acquire a second morphology image of the top two-dimensional material to be transferred, and to extract a second position parameter from the second morphology image. The second position parameter is used to characterize the geometric relationship of the top two-dimensional material to be transferred on the transfer medium. A stacking relationship construction module is used to establish a target stacking relationship based on the first position parameter and the second position parameter. The target stacking relationship is used to determine the stacking position and / or stacking angle when transferring the top two-dimensional material to be transferred to the bottom two-dimensional material. The path parameter calculation module is used to calculate the transfer path parameters based on the target stacking relationship. The transfer path parameters are used to control the transfer platform to move the top-level two-dimensional material to be transferred according to the transfer path parameters.

Images