Parallel electron beam detection and adjustment device and method
By integrating a fluorescent screen, a high-resolution machine vision module, an image processing module, and a micro-displacement platform, the problem of parameter detection in parallel electron beam detection was solved, enabling rapid detection and calibration, and improving detection efficiency and accuracy.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-03-13
AI Technical Summary
Existing technologies lack the means to quickly detect parameters such as beam spot shape, positioning, focal plane, beam current, beam defects, and uniformity of parallel electron beams, which hinders the development of parallel electron beam application technology.
By integrating technologies such as fluorescent screens, high-resolution machine vision modules, image processing modules, and vacuum micro-displacement platforms, rapid detection of parallel electron beams is achieved, and the detection results are calibrated using an electron optical lens group module.
It enables rapid detection and closed-loop correction of each beam in a parallel electron beam, improving the efficiency and accuracy of parallel electron beam detection.
Smart Images
Figure CN121662685A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electron beam detection technology, and in particular to a parallel electron beam detection calibration device and method. Background Technology
[0002] Single-beam electron beams are widely used in electron microscopes (SEM) and electron beam lithography (EBL), and the maturity of single-beam electron beam detection technology has promoted the rapid development of electron beam application technology. However, parallel electron beams are severely hindered by the relatively lagging research on multi-beam electron beam detection technology and the extremely high difficulty of detection technology.
[0003] Current technologies still lack the ability to simultaneously detect the beam spot shape, positioning, focal plane, beam current, beam defects, and consistency of each electron beam in a parallel electron beam. In particular, there is a lack of technical means and methods for rapidly detecting and calibrating parallel electron beams. This shortcoming has become a major technical obstacle restricting the development and promotion of parallel electron beam application technology. Summary of the Invention
[0004] This application provides a parallel electron beam detection and calibration device and method, which can rapidly detect parameters such as beam spot shape, positioning, focal plane, beam current, beam defects, and consistency of each electron beam in a parallel electron beam by integrating technologies such as fluorescent screen, high-resolution machine vision module, image processing module, and vacuum micro-displacement platform. Based on the detection results, the parallel electron beam is rapidly calibrated through an electron optical lens group module, ultimately achieving rapid detection and closed-loop correction of each beam in the parallel electron beam.
[0005] In a first aspect, embodiments of this application provide a parallel electron beam detection and calibration apparatus, the apparatus comprising: Parallel electron beam module, used to emit parallel electron beams to the beam gate microarray; A beam gate microarray is used to control the on / off state of each beam of a parallel electron beam and to emit the passing parallel electron beam to the electron optical lens module. The electron optical lens module is used to control the deflection and focusing of the parallel electron beam, regulate the emission of the parallel electron beam and its bombardment of the fluorescent screen; perform horizontal correction of the parallel electron beam based on the detection results; and perform vertical correction of the parallel electron beam based on the focal plane position. A fluorescent screen is used to receive bombarding electrons and obtain a fluorescent spot. The machine vision module is used to acquire and process fluorescent spots to obtain fluorescent screen images and send them to the image processing module; it also acquires fluorescent screen images corresponding to various distances and sends them to the image processing module. The image processing module is used to receive and calculate the fluorescent screen image to obtain the detection result; it also receives and processes the fluorescent screen images corresponding to various distances to obtain a symmetrical double-cone beam. The micro-displacement platform is used to raise or lower the fluorescent screen and machine vision module according to multiple preset equal distances. The calculation module is used to calculate the focal plane position based on the symmetrical biconical beam.
[0006] Furthermore, the electro-optical lens module includes an electrostatic lens group, an electromagnetic lens group, or an electrostatic-electromagnetic combined lens group.
[0007] Furthermore, the machine vision module includes a large-format industrial camera and a coaxial light source industrial lens.
[0008] Furthermore, the machine vision module is specifically used for: If the coaxial light source of the industrial lens is turned on and the parallel electron beam controlled by the beam gate microarray is turned off, the first fluorescent screen image is acquired. If the coaxial light source of the industrial lens is turned off and the beam gate microarray controls the parallel electron beam to pass through, an image on the second fluorescent screen is acquired.
[0009] Furthermore, the image processing module is specifically used for: Receive fluorescent screen images and calculate to obtain a parallel electron beam target bombardment point array and a merged fluorescent screen image; Image preprocessing, contour analysis, shape and brightness analysis, and anomaly detection are performed on the merged fluorescent screen images to obtain the detection results. The detection results include the fluorescent spot contour, the fluorescent spot center coordinates, fluorescent spot missingness, and fluorescent spot brightness.
[0010] Furthermore, the electro-optical lens module is specifically used for: The horizontal deviation is calculated based on the preset target point coordinates and the detection results. The horizontal deflection angle is calculated based on the horizontal deviation. The horizontal correction of the parallel electron beam is completed based on the horizontal deflection angle.
[0011] Furthermore, the calculation module is specifically used for: The vertical deviation of the focal plane position is obtained by comparing the focal plane position with the actual focusing position of the parallel electron beam. The focal length adjustment is calculated based on the vertical deviation of the focal plane position.
[0012] Secondly, embodiments of this application provide a parallel electron beam detection and calibration method, the method comprising: The parallel electron beam module emits a parallel electron beam to the beam-gate microarray; The beam gate microarray controls the on / off state of each beam of the parallel electron beam and enables the passing parallel electron beam to be emitted to the electron optical lens module; The electron optical lens module controls the deflection and focusing of the parallel electron beam, regulates the emission of the parallel electron beam and its bombardment of the fluorescent screen; The fluorescent screen receives the bombarding electrons and produces a fluorescent spot; The machine vision module acquires and processes fluorescent spots to obtain an image of the fluorescent screen, which is then sent to the image processing module. The image processing module receives the image from the fluorescent screen and performs calculations to obtain the detection result; The micro-displacement platform raises or lowers the fluorescent screen and machine vision module according to multiple preset equal distances. The machine vision module acquires the fluorescent screen image corresponding to each distance and sends it to the image processing module. The image processing module receives and processes the fluorescent screen image corresponding to each distance to obtain a symmetrical double-cone beam. The calculation module calculates the focal plane position based on the symmetrical biconical beam. The electron optical lens module performs horizontal correction of the parallel electron beam based on the detection results and vertical correction of the parallel electron beam based on the focal plane position.
[0013] Furthermore, the electro-optical lens module includes an electrostatic lens group, an electromagnetic lens group, or an electrostatic-electromagnetic combined lens group.
[0014] Furthermore, the machine vision module includes a large-format industrial camera and a coaxial light source industrial lens.
[0015] In summary, compared with the prior art, the beneficial effects of the technical solution provided in this application include at least the following: This application provides a parallel electron beam detection and calibration device that integrates technologies such as a fluorescent screen, a high-resolution machine vision module, an image processing module, and a vacuum micro-displacement platform to rapidly detect parameters such as beam spot shape, positioning, focal plane, beam current, beam defects, and consistency of each electron beam in a parallel electron beam. Based on the detection results, the device rapidly calibrates the parallel electron beam through an electron optical lens group module, ultimately achieving rapid detection and closed-loop correction of each beam in the parallel electron beam. Attached Figure Description
[0016] Figure 1 This is a structural diagram of a parallel electron beam detection and calibration device provided as an exemplary embodiment of this application.
[0017] Figure 2 This is a schematic diagram of a clamp gate microarray control provided as an exemplary embodiment of this application.
[0018] Figure 3 This is a schematic diagram of a fluorescent screen image provided as an exemplary embodiment of this application.
[0019] Figure 4 This is a schematic diagram illustrating an image processing scenario provided as an exemplary embodiment of this application.
[0020] Figure 5This is a schematic diagram of a detection and calibration operation provided for an exemplary embodiment of this application.
[0021] Figure 6 This is a schematic diagram of a three-dimensional reconstructed symmetrical biconical beam provided as an exemplary embodiment of this application.
[0022] Figure 7 A flowchart of a parallel electron beam detection and calibration method provided as an exemplary embodiment of this application.
[0023] Explanation of reference numerals in the attached figures: 1: Parallel electron beam module; 11: Parallel electron beam; 2: Beam gate microarray; 3: Electro-optical lens group module; 4: Fluorescent screen; 5: Vacuum cavity; 61: Industrial camera; 62: Industrial lens; 63: Coaxial light source; 64: Object-side field of view; 71: Lifting motor; 72: Lifting rod. Detailed Implementation
[0024] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.
[0025] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0026] Please see Figure 1 This application provides a parallel electron beam detection and calibration device, which specifically includes: Parallel electron beam module, used to emit parallel electron beams to beam gate microarray.
[0027] The parallel electron beam module can be an electron source array or a parallel electron beam source obtained by splitting a single source; the parallel electron beam is emitted by the parallel electron beam module excited by a precision power supply.
[0028] Simultaneously, the beam gate microarray controls the on / off state of each beam of the parallel electron beam and enables the passing parallel electron beam to be emitted to the electron optical lens module.
[0029] Please see Figure 2 In some embodiments, the parallel electron beams can be 3×3=9 beams, which sequentially correspond to the 9 control channels of the beam gate microarray and the 9 exposure regions of the wafer. For example, when regions ①, ②, ⑤, ⑦, ⑧, and ⑨ of the wafer need exposure, while regions ③, ④, and ⑥ do not need exposure, then channels ①, ②, ⑤, ⑦, ⑧, and ⑨ of the beam gate microarray are controlled to be on, while channels ③, ④, and ⑥ are controlled to be off.
[0030] The electron optical lens module controls the deflection and focusing of the parallel electron beam, regulates the emission of the parallel electron beam, and bombards the fluorescent screen.
[0031] In some embodiments, the electro-optical lens group module includes an electrostatic lens group, an electromagnetic lens group, or an electrostatic-electromagnetic combined lens group.
[0032] Specifically, the electron optical lens module changes the electrostatic force (Coulomb force) and Lorentz force on the parallel electron beam by changing the intensity of the electric and magnetic fields, thereby achieving the deflection and focusing of each beam of the parallel electron beam.
[0033] A fluorescent screen is used to receive bombarding electron beams and obtain fluorescent spots.
[0034] The fluorescent screen can be a transmissive fluorescent screen. Parallel electron beams bombard the transmissive fluorescent screen, using the principle of electron emission to bombard phosphors and emit light. The emission of each beam of the parallel electron beam is then positioned to obtain the corresponding fluorescent spot.
[0035] The machine vision module is used to acquire and process fluorescent spots, obtain images of the fluorescent screen, and send them to the image processing module.
[0036] In some embodiments, the machine vision module includes a large-format industrial camera and a coaxial light source industrial lens, i.e., it includes... Figure 1 The components include: 61 industrial camera, 62 industrial lens, 63 coaxial light source, and 64 object-side field of view.
[0037] In some embodiments, the machine vision module is specifically used for: If the coaxial light source of the industrial lens is turned on and the parallel electron beam controlled by the beam gate microarray is turned off, the first fluorescent screen image is acquired. If the coaxial light source of the industrial lens is turned off and the beam gate microarray controls the parallel electron beam to pass through, an image on the second fluorescent screen is acquired.
[0038] The first screen image is image 41, and the second screen image is image 42.
[0039] Please see Figure 3 Among them, 41 is a fluorescent screen image with clear markers but no parallel electron beam bombardment; 411 is a marker; 42 is a fluorescent screen image with fluorescent spots appearing but no clear markers when bombarded by parallel electron beams; and 421 is an electron beam laser fluorescent spot.
[0040] The coaxial light source illuminates the marker points on the fluorescent screen, and a beam-gate microarray controls the on / off state of each parallel electron beam. To acquire a fluorescent screen image with clear marker points and avoid reducing the contrast of the fluorescent spot when the coaxial light source is on, this application employs a time-division imaging method. When the coaxial light source is on and the parallel electron beam is turned off using the beam-gate microarray, the machine vision module acquires the fluorescent screen image, resulting in a fluorescent screen image 41 with clear marker points but no parallel electron beam bombardment. When the coaxial light source is off and the parallel electron beam is controlled to pass through using the beam-gate microarray, the machine vision module acquires the fluorescent screen image, resulting in a fluorescent screen image 42 with fluorescent spots appearing but no clear marker points due to parallel electron beam bombardment.
[0041] Among them, the use of time-division image acquisition can avoid the situation where the coaxial light of the industrial lens and the image on the fluorescent screen interfere with each other, resulting in unclear image acquisition.
[0042] The image processing module is used to receive images from the fluorescent screen and perform calculations to obtain detection results.
[0043] Please see Figure 4 Among them, 43 is a fluorescent screen image with an electron beam target bombardment coordinate point array, 431 is a parallel electron beam target bombardment coordinate point array, and 44 is a merged image obtained from multiple image processing.
[0044] In some embodiments, the image processing module is specifically used for: Receive fluorescent screen images and calculate to obtain a parallel electron beam target bombardment point array and a merged fluorescent screen image; Image preprocessing, contour analysis, shape and brightness analysis, and anomaly detection are performed on the merged fluorescent screen images to obtain the detection results. The detection results include the fluorescent spot contour, the fluorescent spot center coordinates, fluorescent spot missingness, and fluorescent spot brightness.
[0045] The image processing module first processes the fluorescent screen image 41 to calculate the parallel electron beam target bombardment coordinate point array. Then, the image 43 and the original image 42 are processed by the image algorithm to obtain the merged fluorescent screen image 44. The image 44 is then processed and analyzed to obtain the actual detection results such as the fluorescent spot contour, the fluorescent spot center coordinates, the fluorescent spot missingness, and the fluorescent spot brightness. The fluorescent spot contour represents the shape of the electron beam spot, the fluorescent spot center coordinates represent the measured corresponding electron beam bombardment point coordinates, the fluorescent spot missingness represents the electron beam missingness, and the fluorescent spot brightness indirectly represents the electron beam current magnitude.
[0046] In some embodiments, the image processing module of this application may employ the following image processing algorithms: edge detection algorithms, used to extract the contour of the fluorescent spot, such as the Canny edge detection algorithm, the Sobel operator, or the Laplacian operator; these algorithms can effectively identify edges in the image, help extract the outer contour of the spot, and thus determine the focusing quality of the electron beam.
[0047] Image segmentation algorithms are used to separate fluorescent spot regions from fluorescent screen images. Common image segmentation algorithms include thresholding, K-means clustering, and Otsu's algorithm, which can effectively separate the spot from the background based on differences in brightness or color. Feature point detection and matching algorithms, such as SIFT (Scale Invariant Feature Transform) and SURF (Speed Robust Feature Transform), can be used to accurately locate the center of the spot, helping to calculate the accurate bombardment point coordinates of parallel electron beams.
[0048] Morphological operations, including dilation, erosion, opening and closing operations, can be used to improve image quality, fill gaps in light spots, or remove noise, making subsequent analysis more accurate.
[0049] Template matching algorithm, which can be used to match the spot in the actual image with the known fluorescent spot template, so as to obtain accurate information such as spot position, shape and brightness.
[0050] Deep learning algorithms can also be used for complex image analysis tasks, such as automatic image classification and feature extraction using convolutional neural networks, which are especially suitable for scenarios with high complexity or requiring high-precision positioning. By training neural networks, the features of fluorescent spots can be automatically identified and analyzed in multiple dimensions.
[0051] In some embodiments, the image processing procedure of this application can be implemented as follows: Image preprocessing: Before contour extraction, the image is first preprocessed, including: Denoising: Using methods such as Gaussian blur and mean filtering to remove noise from the image to ensure the accuracy of subsequent analysis. Contrast enhancement: Enhancing the contrast of the image through methods such as histogram equalization or adaptive histogram equalization to make the fluorescent spots more obvious and easier to extract.
[0052] Thresholding segmentation uses thresholding algorithms to separate bright areas from the background in an image. Common methods include: Otsu's algorithm: automatically selects the optimal threshold for the image to separate the bright areas from the background; and adaptive thresholding: dynamically adjusts the threshold based on the brightness information of local areas to adapt to bright area extraction under different lighting conditions.
[0053] Contour extraction uses edge detection algorithms (such as Canny edge detection and Sobel operator) to extract the contour of the fluorescent spot. These algorithms help determine the outer boundary of the fluorescent spot by identifying edges and brightness variations in the image.
[0054] After contour extraction, morphological operations (such as dilation and erosion) may be needed to repair the contour of the light spot, fill small holes in the contour, or remove unnecessary noise to ensure a clear contour.
[0055] Contour analysis begins with calculating contour features: by analyzing the geometry of the contour, the area, aspect ratio, and roundness of the spot are calculated. These features help determine the focusing state of the electron beam. Next, center positioning is performed: by calculating the centroid of the contour, the center position of the spot is determined. This position corresponds to the coordinates of the electron beam bombardment point.
[0056] Shape and brightness analysis; Spot shape: Based on the geometry of the outline, analyze the circularity, symmetry, and other indicators of the spot to help determine whether the electron beam is well focused. Spot brightness: Calculate the average or maximum brightness of the spot area, indirectly reflecting the beam current intensity of the electron beam.
[0057] Anomaly detection involves determining, based on the analysis results, whether there are missing or unexpected spot characteristics. For example, missing outlines or abnormal spot brightness may indicate a problem with the electron beam (such as beam instability or focus shift).
[0058] In some embodiments, the center position of the fluorescent spot and the position of the electron beam bombardment point correspond through the geometric relationship formed by the spot. We can assume that the center of the fluorescent spot and the bombardment point of the electron beam are directly corresponding, that is, the position of the electron beam on the fluorescent screen corresponds one-to-one with the position of the fluorescent spot. In practical applications, the electron beam bombards the phosphor and produces a spot, and the center of the spot is the bombardment point of the electron beam. The calculated coordinates of the fluorescent spot center are actually the coordinates of the actual bombardment point of the electron beam on the fluorescent screen.
[0059] To further improve accuracy, coordinate system calibration can be performed, converting the image coordinates of the fluorescence spot into actual physical coordinates. This can be achieved using known coordinate transformation relationships, specifically by using known reference points (such as calibration points on a calibration plate) for coordinate mapping. For example, using a calibration point at a known location, the position of that point in the image is measured, and coordinate calibration is performed using the known relationship between that point and the actual physical coordinates. In this way, the center coordinates of the fluorescence spot in the image can be accurately mapped to the coordinates of the electron beam bombardment point in physical space.
[0060] In actual measurements, errors may occur due to factors such as optical system distortion and image noise. Therefore, some error correction methods, such as the least squares method or the weighted average method, can be used to further correct the coordinates of the spot center to ensure that the obtained electron beam bombardment point coordinates are more accurate.
[0061] The electron optical lens module is used to perform parallel electron beam horizontal correction based on the detection results.
[0062] Please see Figure 5 Among them, 45 is the fluorescent screen image after detection and calibration, and 451 is the case where the measured point of the electron beam coincides with the target point.
[0063] In some embodiments, the electro-optical lens group module is specifically used for: The horizontal deviation is calculated based on the preset target point coordinates and the detection results. The horizontal deflection angle is calculated based on the horizontal deviation. The horizontal correction of the parallel electron beam is completed based on the horizontal deflection angle.
[0064] Specifically, the actual bombardment point coordinates of each electron beam (i.e., the center coordinates of the fluorescence spot) were obtained through the aforementioned operations and compared with the preset target point coordinates. Assuming the target point coordinates are (X_target, Y_target) and the actual bombardment point coordinates are (X_actual, Y_actual), then the horizontal deviation ΔX (in the X-axis direction) is: ΔX = X_actual - X_target, and the horizontal deviation ΔY (in the Y-axis direction) is: ΔY = Y_actual - Y_target. The horizontal deviation represents the displacement of each electron beam in the horizontal plane (X-axis and Y-axis directions).
[0065] The deflection angle is closely related to the electron beam deviation and the geometric parameters of the electron optical system (electro-optical lens module), such as the focal length of the electron optical lens group and the incident angle of the beam. For electrostatic or electromagnetic lenses, the required horizontal X-axis offset angle θX can be calculated using the following formula: θX = ΔX / f; where ΔX is the horizontal X-axis deviation and f is the focal length of the electron optical system. The formula for the horizontal Y-axis offset angle is similar: θY = ΔY / f; where ΔY is the horizontal Y-axis deviation and f is the focal length of the electron optical system. Based on the horizontal offset angles θX and θY, the required deflection adjustment ΔV or ΔA is calculated using the deflection formula of the electron optical system. Fine-tuning of the deflection angle can be achieved by adjusting the voltage V (for electrostatic lenses) or current A (for electromagnetic lenses) of the electron optical lens module. Completing the horizontal correction means ensuring that the actual bombardment points of each parallel electron beam coincide with the target point.
[0066] The micro-displacement platform is used to raise or lower the fluorescent screen and the machine vision module according to multiple preset equal distances. The machine vision module acquires the fluorescent screen images corresponding to each distance and sends them to the image processing module. The image processing module receives and processes the fluorescent screen images corresponding to each distance to obtain a symmetrical double-cone beam.
[0067] The micro-displacement platform includes 71 lifting motors and 72 lifting rods. It employs at least a 4-dimensional micro-displacement platform, comprising X, Y, Z, and rotation dimensions. The micro-displacement platform can also initially move the fluorescent screen to the target detection position, enabling fine-tuning and accurate positioning of the screen in conjunction with the machine vision module.
[0068] Please see Figure 6 , where 461 is the layer-by-layer fluorescent screen image, 462 is the focal plane (with the cone point as the focal point) position, and d is a preset set of multiple equal distances.
[0069] The fluorescent screen and machine vision system are fixed on the lifting guide rail of the micro-displacement platform. The micro-displacement platform lifts and lowers the fluorescent screen and vision system according to multiple preset equal distances d, and sequentially acquires the fluorescent screen's luminous images. At the same time, the image algorithm processes the images to obtain the corresponding layer-by-layer fluorescent screen images of each beam of the parallel electron beam.
[0070] Specifically, the fluorescent screen images for each layer have been obtained, and these images correspond to the bombardment effect of the parallel electron beam at different vertical positions. Each layer's fluorescent screen image contains two-dimensional information about the light spot, such as its position, shape, and brightness. The acquisition position of each layer's fluorescent screen image can be represented by a vertical displacement value Zi, forming an image dataset I: I(x,y,Zi); where i is the position at the i-th layer, and Zi is the displacement value corresponding to the acquired fluorescent screen image.
[0071] Image processing algorithms (such as centroid calculation or edge detection) are applied to each fluorescent screen image to extract the center coordinates (xi, yi) and geometric features (such as radius and shape) of the light spot. These features represent the distribution of the light spot on a two-dimensional plane. Using the spatial location information of each fluorescent screen image (i.e., the Zi value of each image layer) and the center coordinates (xi, yi) of the light spot, the two-dimensional coordinates of each light spot can be mapped to three-dimensional space: Pi = (xi, yi, Zi). Here, Pi represents the three-dimensional spatial coordinates corresponding to the i-th image layer.
[0072] Subsequently, the spot data from each layer are synthesized. Common 3D reconstruction algorithms include: interpolation methods, where interpolation methods (such as cubic interpolation or spline interpolation) are used to insert data points between each layer for discrete spot coordinates, thereby smoothly reconstructing a continuous 3D structure; and voxel reconstruction methods, which map each layer of spot image onto a 3D mesh (voxels), reconstructing the 3D distribution of the light beam through voxelization techniques. The voxel value of each spot region can be assigned based on the spot brightness value.
[0073] The spatial distribution pattern of the beam is generated and visualized using the reconstructed 3D data. Based on the position and shape of the beam spots at different levels, a symmetrical biconical beam can ultimately be obtained. This 3D reconstruction reflects the spatial distribution of the parallel electron beam, helping to analyze its focusing state and distribution.
[0074] The calculation module is used to calculate the focal plane position based on the symmetrical biconical beam.
[0075] The electron optical lens module is used to perform vertical correction of the parallel electron beam based on the focal plane position.
[0076] In some embodiments, the computing module is specifically used for: The vertical deviation of the focal plane position is obtained by comparing the focal plane position with the actual focusing position of the parallel electron beam. The focal length adjustment is calculated based on the vertical deviation of the focal plane position.
[0077] The above processing yields an ideal focal plane position (xf, yf, zf), at which the focusing point of the parallel electron beam should be located. This focal plane position can be compared with the actual electron beam focusing position to calculate the vertical deviation of the focal plane position ΔZ = zf - Z_actual; where Z_actual is the actual bombardment point position.
[0078] Based on the focal plane position deviation ΔZ, the required focal length adjustment Δf is calculated using the focusing formula of the electro-optical system. For example, if the focal plane position shifts upward or downward, fine-tuning of the focal length can be achieved by adjusting the voltage V (electrostatic lens) or current A (electromagnetic lens) of the electro-optical lens group.
[0079] Based on the calculated focal length adjustment, the focal length of the lens (such as an electrostatic lens or an electromagnetic lens) in the electro-optical system is adjusted. This is typically achieved by changing the voltage V (for an electrostatic lens) or the current A (for an electromagnetic lens). The adjustment of the focal length directly affects the focusing of the electron beam, ensuring that its focal point coincides with the target focal plane.
[0080] The parallel electron beam detection and calibration device provided in the above embodiments can quickly detect parameters such as beam spot shape, positioning, focal plane, beam current, missing beams, and consistency of each electron beam in a parallel electron beam by integrating technologies such as fluorescent screen, high-resolution machine vision module, image processing module, and vacuum micro-displacement platform. Based on the detection results, the parallel electron beam is quickly calibrated through an electron optical lens group module, ultimately achieving rapid detection and closed-loop correction of each beam in the parallel electron beam.
[0081] Please see Figure 7 Another embodiment of this application provides a parallel electron beam detection calibration method, the method comprising: Step S1: The parallel electron beam module emits a parallel electron beam to the beam gate microarray.
[0082] In step S2, the beam gate microarray controls the on / off state of each beam of the parallel electron beam and causes the passing parallel electron beam to be emitted to the electron optical lens group module.
[0083] In step S3, the electron optical lens module controls the deflection and focusing of the parallel electron beam, regulates the emission of the parallel electron beam and bombards the fluorescent screen.
[0084] In step S4, the fluorescent screen receives the bombarding electron beam to obtain a fluorescent spot.
[0085] In step S5, the machine vision module acquires and processes the fluorescent spot to obtain the fluorescent screen image and sends it to the image processing module.
[0086] In step S6, the image processing module receives the image from the fluorescent screen and performs calculations to obtain the detection result.
[0087] In step S7, the micro-displacement platform raises or lowers the fluorescent screen and the machine vision module according to multiple preset equal distances. The machine vision module acquires the fluorescent screen images corresponding to each distance and sends them to the image processing module. The image processing module receives and processes the fluorescent screen images corresponding to each distance to obtain a symmetrical double-cone beam.
[0088] In step S8, the calculation module calculates the focal plane position based on the symmetrical double-cone beam.
[0089] In step S9, the electron optical lens module completes the horizontal correction of the parallel electron beam based on the detection results, and completes the vertical correction of the parallel electron beam based on the focal plane position.
[0090] In some embodiments, the electro-optical lens group module includes an electrostatic lens group, an electromagnetic lens group, or an electrostatic-electromagnetic combined lens group.
[0091] In some embodiments, the machine vision module includes a large-format industrial camera and a coaxial light source industrial lens.
[0092] The specific limitations of the parallel electron beam detection and calibration method provided in this embodiment can be found in the embodiment of the parallel electron beam detection and calibration device described above, and will not be repeated here. Each module in the above-described parallel electron beam detection and calibration method can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.
[0093] 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.
[0094] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. 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 all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.
Claims
1. A parallel electron beam detection and calibration device, characterized in that, The device includes: Parallel electron beam module, used to emit parallel electron beams to the beam gate microarray; A beam gate microarray is used to control the on / off state of each beam of a parallel electron beam and to emit the passing parallel electron beam to the electron optical lens module. The electron optical lens module is used to control the deflection and focusing of the parallel electron beam, regulate the emission of the parallel electron beam and its bombardment of the fluorescent screen; perform horizontal correction of the parallel electron beam based on the detection results; and perform vertical correction of the parallel electron beam based on the focal plane position. A fluorescent screen is used to receive bombarding electron beams and obtain fluorescent spots. The machine vision module is used to acquire and process the fluorescent spot to obtain a fluorescent screen image and send it to the image processing module; it also acquires fluorescent screen images corresponding to various distances and sends them to the image processing module. The image processing module is used to receive the fluorescent screen image and calculate to obtain the detection result; receive and process the fluorescent screen images corresponding to each distance to obtain a symmetrical double-cone beam; A micro-displacement platform is used to raise or lower the fluorescent screen and machine vision module according to multiple preset equal distances. The calculation module is used to calculate the focal plane position based on the symmetrical biconical beam.
2. The parallel electron beam detection and calibration device according to claim 1, characterized in that, The electro-optical lens module includes an electrostatic lens group, an electromagnetic lens group, or an electrostatic-electromagnetic combined lens group.
3. The parallel electron beam detection and calibration device according to claim 2, characterized in that, The machine vision module includes a large-format industrial camera and a coaxial light source industrial lens.
4. The parallel electron beam detection and calibration device according to claim 3, characterized in that, The machine vision module is specifically used for: If the coaxial light source of the industrial lens is turned on and the parallel electron beam controlled by the beam gate microarray is turned off, the first fluorescent screen image is acquired. If the coaxial light source of the industrial lens is turned off and the beam gate microarray controls the parallel electron beam to pass through, an image on the second fluorescent screen is acquired.
5. The parallel electron beam detection and calibration device according to claim 4, characterized in that, The image processing module is specifically used for: The fluorescent screen image is received and calculated to obtain a parallel electron beam target bombardment point array and a merged fluorescent screen image; The merged fluorescent screen image is subjected to image preprocessing, contour analysis, shape and brightness analysis, and anomaly detection to obtain detection results; the detection results include fluorescent spot contour, fluorescent spot center coordinates, fluorescent spot missingness, and fluorescent spot brightness.
6. The parallel electron beam detection and calibration device according to claim 5, characterized in that, The electron optical lens module is specifically used for: The horizontal deviation is calculated based on the preset target point coordinates and the detection results; The horizontal deflection angle is calculated based on the horizontal deviation. The horizontal correction of the parallel electron beam is completed based on the horizontal deflection angle.
7. The parallel electron beam detection and calibration device according to claim 6, characterized in that, The calculation module is specifically used for: The vertical deviation of the focal plane position is obtained by comparing the focal plane position with the actual focusing position of the parallel electron beam. The focal length adjustment is calculated based on the vertical deviation of the focal plane position.
8. A parallel electron beam detection and calibration method, characterized in that, The method includes: The parallel electron beam module emits a parallel electron beam to the beam-gate microarray; The beam gate microarray controls the on / off state of each beam of the parallel electron beam and enables the passing parallel electron beam to be emitted to the electron optical lens module; The electron optical lens module controls the deflection and focusing of the parallel electron beam, regulates the emission of the parallel electron beam and its bombardment of the fluorescent screen; A fluorescent screen receives the bombarding electron beam, resulting in a fluorescent spot; The machine vision module acquires and processes the fluorescent spot to obtain an image of the fluorescent screen, which is then sent to the image processing module. The image processing module receives the fluorescent screen image and calculates to obtain the detection result; The micro-displacement platform raises or lowers the fluorescent screen and machine vision module according to multiple preset equal distances. The machine vision module acquires the fluorescent screen image corresponding to each distance and sends it to the image processing module. The image processing module receives and processes the fluorescent screen image corresponding to each distance to obtain a symmetrical double-cone beam. The calculation module calculates the focal plane position based on the symmetrical biconical beam. The electron optical lens module performs parallel electron beam horizontal correction based on the detection results and parallel electron beam vertical correction based on the focal plane position.
9. The parallel electron beam detection and calibration method according to claim 8, characterized in that, The electro-optical lens module includes an electrostatic lens group, an electromagnetic lens group, or an electrostatic-electromagnetic combined lens group.
10. The parallel electron beam detection and calibration method according to claim 9, characterized in that, The machine vision module includes a large-format industrial camera and a coaxial light source industrial lens.