Large-aperture lens functional structure processing method and large-aperture lens

Abstract

The embodiment of the invention provides a large-aperture lens functional structure processing method and a large-aperture lens, and the large-aperture lens functional structure processing method comprises the steps: carrying out the region division of a substrate of an initial lens blank, and obtaining a plurality of substrate regions; for each substrate area, setting a positioning mark at a specified position of the substrate area; and correcting the coordinate of the to-be-processed pattern based on each substrate area limited by the positioning mark, and processing in the substrate area to form the to-be-processed pattern.

Description

Technical Field

[0001] The present application relates to the field of lens processing technology, and in particular to a method for processing the functional structure of a large-aperture lens and a large-aperture lens. Background Art

[0002] Contact machining is commonly used in the fabrication of large-diameter microstructures exceeding meter-level apertures. This method suffers from drawbacks such as stress concentration and edge chipping, making it difficult to achieve the precision required for structural quality in visible or infrared wavelengths. Laser direct writing exposure is a non-contact, maskless direct writing method, but the overlay accuracy of laser direct writing equipment is insufficient to meet the precision requirements for large-diameter microstructures. Summary of the Invention

[0003] The purpose of this application is to provide a large-aperture lens functional structure processing method and a large-aperture lens, which can improve the precision and accuracy of lens processing.

[0004] In a first aspect, the present invention provides a method for processing the functional structure of a large-aperture lens, comprising: dividing the substrate of an initial lens blank into regions to obtain a plurality of substrate regions; setting a positioning mark at a specified position of each substrate region; correcting the coordinates of the to-be-processed figure based on each substrate region defined by the positioning mark, and processing the to-be-processed figure in the substrate region.

[0005] In the above implementation, the processing of a lens with a larger aperture can be divided into multiple small areas, and correction can be achieved based on the small areas, so that the processing of a lens with a larger aperture can also meet higher precision requirements.

[0006] In an optional embodiment, the coordinates of the graphics to be processed are corrected based on each substrate area defined by the positioning mark, and the graphics to be processed are formed in the substrate area, including: for the first processing layer of the large-aperture lens, according to the difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark, determining the corrected graphic processing coordinates of the graphics to be processed; with the graphic processing coordinates of the graphics to be processed as the processing position, direct writing processing is performed based on the substrate area defined by the positioning mark to form the graphics to be processed of the first processing layer in the substrate area; based on the graphics to be processed of the first processing layer, etching the graphics to be processed of the first processing layer on the substrate.

[0007] In the above-mentioned implementation method, the actual coordinates of the positioning mark can be compared with the theoretical coordinates, and the graphic processing coordinates of the to-be-processed graphics of the first processing layer can be adaptively adjusted based on the differences, so that the actual direct writing processing position can be closer to the theoretical graphic processing coordinates, and the subsequent etching graphics based on the direct writing processing graphics can be more accurate.

[0008] In an optional embodiment, the method of determining the corrected graphic processing coordinates of the graphic to be processed based on the difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark includes: measuring the positioning mark to obtain the actual coordinates of each positioning mark; comparing the actual coordinates of each positioning mark with the theoretical coordinates of the positioning mark to determine the coordinate error; and determining the graphic processing coordinates of the graphic to be processed in each substrate area based on the coordinate error and the theoretical coordinates of the graphic to be processed.

[0009] In an optional embodiment, the graphic processing coordinates of the graphic to be processed are used as the processing position, and the direct writing processing is performed on the substrate area defined by the positioning mark to form the graphic to be processed of the first processing layer in the substrate area, including: constructing a local coordinate system for the positioning mark of each of the substrate areas; under the local coordinate system, direct writing processing is performed under the graphic processing coordinates of the graphic to be processed to form the graphic to be processed of the first processing layer in the substrate area.

[0010] In the above implementation, a local coordinate system may be constructed for each substrate region, and direct writing processing may be performed based on the coordinate system, so that the graphic processing coordinates in each substrate region may be located more accurately.

[0011] In an optional embodiment, the coordinates of the pattern to be processed are corrected based on the respective substrate areas defined by the positioning marks, and the pattern to be processed is formed in the substrate areas, including: for the Nth processing layer of the large-aperture lens, based on the position of the pattern formed by the N-1th processing layer and the respective substrate areas defined by the positioning marks, the coordinates of the pattern to be processed of the Nth processing layer are corrected to determine the pattern to be processed of the Nth processing layer; wherein N is a positive integer greater than or equal to 2; based on the pattern to be processed of the Nth processing layer, etching the pattern to be processed of the Nth processing layer on the substrate.

[0012] In an optional embodiment, the coordinates of the to-be-processed pattern of the N-1th processing layer are corrected based on the graphic position formed by the N-1th processing layer and the substrate areas defined by the positioning mark, and the to-be-processed pattern of the N-1th processing layer is determined, including: a. for the target substrate area, based on the latest coordinates of the to-be-processed pattern in the target substrate area, direct writing processing is performed on the photoresist on the substrate area defined by the positioning mark corresponding to the target substrate area to form the current processing pattern; b. processing the current overlay mark at the specified position of the target substrate area; c. determining the current processing layer based on all the current overlay marks of the current processing layer and the overlay mark of the previous processing layer of the current processing layer. overlay error; d, when the overlay error is greater than the set value, the coordinates of the graphics to be processed of the current processing layer are corrected using the overlay error; wherein the target substrate area is any one of all substrate areas; when step a is executed for the first time, the latest coordinates are the initial coordinates of the graphics to be processed, and when step a is executed for the Mth time, the latest coordinates are the coordinates of the graphics to be processed obtained by correcting the graphics to be processed by the M-1th execution of step d, and M is a positive integer greater than or equal to 2; repeat the above steps a to d; until the overlay error is no greater than the set value; use the above steps a to d to perform correction on each substrate area and then perform direct writing processing to form the graphics to be processed of the current processing layer.

[0013] In the above implementation, a cyclic method is used to correct the direct-write pattern, and etching based on the corrected pattern can make the obtained lens more precise.

[0014] In an optional embodiment, the use of the overlay error to correct the coordinates of the graphics to be processed in the current processing layer includes: correcting the positioning mark according to the overlay error to obtain an updated positioning mark; determining a deviation matrix based on the updated positioning mark and the positioning mark; and using the deviation matrix to correct the coordinates of the graphics to be processed in the current processing layer.

[0015] In the above implementation, the coordinates of the graphics to be processed are corrected based on the determined deviations of the updated positioning marks. Furthermore, because the correction standard is based on the positioning marks on the substrate, the correction standard for each layer of graphics can be relatively uniform, which can make the correction result more accurate.

[0016] In an optional embodiment, setting positioning marks at designated positions of the substrate regions includes: setting positioning marks at adjacent positions of respective substrate regions, and setting positioning marks at edge positions of respective substrate regions.

[0017] In an optional embodiment, the setting of positioning marks at adjacent positions of the respective substrate regions and the setting of positioning marks at edge positions of the respective substrate regions include: setting positioning marks at edge positions of the substrate regions.

[0018] In the above implementation, positioning marks are set at the edge of each substrate area, which can better circle the substrate area. In addition, positioning marks are set at the edge to reduce the influence of positioning marks on direct writing and etching of internal graphics in the substrate area.

[0019] In an optional embodiment, the number of positioning marks in each substrate region is not less than four.

[0020] In the above implementation, four positioning marks are set for each region, so that each substrate region can be better circled based on the positioning marks, and each substrate region can be separated more clearly.

[0021] In a second aspect, the present invention provides a large-aperture lens, comprising: a lens obtained by processing using the method described in the aforementioned embodiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A flow chart of a method for processing the functional structure of a large-aperture lens provided in an embodiment of the present application;

[0024] Figure 2a A schematic diagram of the design layout of a large-aperture lens in an example provided in an embodiment of the present application;

[0025] Figure 2b Provided in the embodiments of this application Figure 2a In the example shown, the design layout is divided into four areas;

[0026] Figure 2c Provided in the embodiments of this application Figure 2a In the example shown, the design layout is divided into 16 regions.

[0027] Figure 2d Provided in the embodiments of this application Figure 2a In the example shown, the design layout is divided into four unequal areas.

[0028] Figure 2eProvided in the embodiments of this application Figure 2a In the example shown, the design layout is divided into five non-congruent and irregular regions.

[0029] Figure 3 A schematic diagram showing a state in which the theoretical coordinates of each positioning mark provided in an example of an embodiment of the present application deviate from the actual coordinates;

[0030] Figure 4 A schematic diagram of the distribution of positioning marks in an example provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram showing the distribution of the theoretical positions of 72 positioning marks in an example provided in an embodiment of the present application;

[0032] Figure 6 A schematic diagram showing the distribution of the actual coordinates of 72 positioning marks in an example provided in an embodiment of the present application;

[0033] Figure 7 This is a schematic diagram of the processing effect of a schematic large-aperture lens functional structure processing method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0035] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0036] In the description of this application, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive products are usually placed when in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be interpreted as a limitation of this application.

[0037] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0038] Large-aperture planar imaging systems are of great value in fields such as national defense, remote sensing, terrain scanning, and weather forecasting. With the advancement of detection technology, higher requirements are being placed on the resolution of imaging systems, and increasing the system aperture is an inevitable path to improving imaging resolution. To improve imaging quality, higher requirements are placed on the diffraction efficiency of large-aperture planar imaging systems, and increasing the number of structural layers can improve diffraction efficiency. Taking the Fresnel lens as an example, its diffraction efficiency is closely related to the number of microstructure layers. For example, the theoretical diffraction efficiency of a 2-step Fresnel lens is approximately 40%, that of a 4-step Fresnel lens is approximately 81%, and that of an 8-step Fresnel lens is approximately 95%. Therefore, by achieving high-precision processing of large-aperture multi-layer structures, the performance indicators of large-aperture planar optical imaging systems can be improved.

[0039] Currently, the methods for processing large-caliber microstructures include laser ablation, CNC machine tool processing, and laser direct writing exposure processing. Laser ablation uses high-energy laser subtraction to achieve functional structure patterning. Its processing aperture exceeds the meter level, and it has good material adaptability. However, it suffers from disadvantages such as high surface roughness, high sputtering, and significant thermal effects, making it difficult to meet the structural quality requirements of the visible light band. CNC machine tool processing achieves functional structure processing through turning or milling. Its processing aperture exceeds the meter level, and it is a contact processing method with disadvantages such as stress concentration and easy edge collapse. Furthermore, since the processing process inevitably causes wear on the tool head, it is difficult to ensure the consistency of microstructure processing. Laser direct writing exposure is a non-contact, maskless direct writing method with advantages such as no stress concentration and high processing precision. However, the overlay accuracy of current laser direct writing equipment is greater than 500nm, and there is no method that can meet the overlay accuracy of meter-level multi-layer structures better than 500nm.

[0040] Based on the above research, this application provides a method for processing the functional structure of a large-aperture lens and a large-aperture lens. By dividing the substrate into regions, the processing of the large-aperture lens is converted into processing corrections in smaller regions, thereby improving the processing accuracy of the large-aperture lens. The following describes the method for processing the functional structure of a large-aperture lens and the large-aperture lens provided by this application through several embodiments.

[0041] Figure 1This is a flow chart of the method for processing the functional structure of a large-aperture lens provided in an embodiment of the present application. Figure 1 As shown, the method for processing the functional structure of a large-aperture lens includes the following steps.

[0042] Step 110 , dividing the substrate of the initial mirror blank into regions to obtain a plurality of substrate regions.

[0043] The number of substrate regions can be set as needed. For example, if the initial mirror blank is relatively large, a larger number of substrate regions can be divided; if the initial mirror blank is relatively small, a smaller number of substrate regions can be divided.

[0044] For example, the shape of the substrate region can be set as needed. Each substrate region can have a regular shape, an irregular shape, or other shapes. The substrate regions can have congruent shapes or random shapes. For example, the shape of the substrate region can be a regular shape such as a rectangle, a parallelogram, a pentagon, or a triangle. For another example, the shape of the substrate region can also be a circle, a combination of irregular shapes connected to a circle, or a combination of various shapes such as a rectangle and a trapezoid.

[0045] like Figures 2a to 2e As shown, Figure 2a A schematic diagram of the design layout of a large-aperture lens in an example is shown; Figure 2b Shows a schematic diagram of dividing the design layout into 4 areas; Figure 2c Shows a schematic diagram of dividing the design layout into 16 areas; Figure 2d A schematic diagram showing the division of the design layout into four unequal areas is shown; Figure 2e A schematic diagram showing the division of the design layout into five non-congruent and irregular areas is shown.

[0046] Step 120 : For each substrate region, a positioning mark is set at a designated position of the substrate region.

[0047] To reduce the impact of the positioning mark on various processing operations within the substrate region, the positioning mark can be set at the edge of each substrate region or at the boundary between two adjacent substrate regions. The designated position can be the edge of each substrate region, the boundary between two adjacent substrate regions, etc.

[0048] The shape of the positioning mark can be set as needed, for example, the positioning mark can be a plus sign, square, field shape, circle, black dot, asterisk, rectangle, etc. Of course, the shape of the positioning mark can also be other shapes except the above shapes.

[0049] In step 130 , the coordinates of the pattern to be processed are corrected based on each substrate area defined by the positioning mark, and the pattern to be processed is formed in the substrate area.

[0050] In this embodiment, each substrate region may be positioned based on each positioning mark to determine whether the coordinates of the graphics to be processed in each substrate region are aligned in a standard manner in the substrate region.

[0051] For example, the correction may be performed based on the deviation between the actual coordinates of the pattern to be processed in the substrate region and the theoretical coordinates.

[0052] Optionally, direct writing processing can be first performed on the substrate area to produce the pattern to be processed, and based on the relative position of the pattern formed by the direct writing processing and the positioning mark of the substrate area, it can be determined whether there is a deviation in the pattern to be processed; if there is a deviation, the coordinates of the pattern to be processed can be corrected, and then the direct writing processing of the pattern to be processed can be washed off, and direct writing processing can be performed again in the substrate area, so that the position of the direct writing processing pattern can be made more accurate through one or more corrections of the direct writing processing pattern, and further the position of the etched pattern can be made more accurate, and the precision of the processed lens will be higher.

[0053] Through the above implementation method, the processing of a large-aperture lens can be converted into multiple small areas to achieve more precise processing.

[0054] The large-aperture lens to be processed may have one or more layers of micro-nano structures. The correction and processing methods for different layers of micro-nano structures may be different. The following describes the correction of the coordinates of the to-be-processed graphics and the formation of the to-be-processed graphics in conjunction with the actual processed layers.

[0055] In an optional embodiment, for processing the first layer of graphics to be processed, the above step 130 may include the following steps 131 to 133.

[0056] Step 131 : for the first processing layer of the large-diameter lens, according to the difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark, determine the corrected graphic processing coordinates of the to-be-processed graphic.

[0057] The actual coordinates of the positioning mark may be coordinates obtained by actually measuring the position of the positioning mark after the positioning mark is processed at a designated position in the substrate region.

[0058] For example, the original graphic processing coordinates of the graphic to be processed can be obtained first, and the original graphic processing coordinates of the graphic to be processed can be corrected based on the difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark, so as to obtain the corrected graphic processing coordinates of the graphic to be processed.

[0059] For example, the actual coordinates of the positioning mark can be expressed as (X' 1,1 ,Y' 1,1 )、(X' 1,2 ,

[0060] Y' 1,2 )、(X' 1,3 ,Y' 1,3 ),…,(X' 2,1 ,Y' 2,1 )、(X' 2,2 ,Y' 2,2 ),…,(X' i,j ,Y' i,j ),…, the actual coordinates of each positioning mark can be expressed as a matrix: The theoretical coordinates of each positioning mark can be expressed as (X 1,1 ,Y 1,1 )、(X 1,2 ,Y 1,2 )、(X 1,3 ,Y 1,3 ),…,(X 2,1 ,Y 2,1 )、(X 2,2 ,Y 2,2 ),…,(X i,j ,Y i,j ),…, the theoretical coordinates of each positioning mark can be expressed as a matrix: Where i represents the i-th row and j represents the j-th column. Figure 3 As shown in the figure, it is a schematic diagram showing the deviation between the theoretical coordinates and the actual coordinates of each positioning mark. Figure 3 In the example shown, a total of i*j positioning marks are included, and the theoretical coordinates of each positioning mark are located at the intersection of the dotted lines, while the actual coordinates of each positioning mark are offset from the intersection of the dotted lines.

[0061] The difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark can be the difference between the two matrices mentioned above. For example, the difference can be expressed as the matrix K i，j and matrix K′ i，j The position deviation matrix between can be expressed as: K i，j =M i，j K′ i，j Among them, M i,j The position deviation matrix can be expressed.

[0062] In this embodiment, the graphics processing coordinates of the graphics to be processed may be corrected based on the difference between the determined actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark.

[0063] Exemplarily, the above-mentioned position deviation matrix can be used to correct the original graphics processing coordinates of the graphics to be processed, and the corrected graphics processing coordinates of the graphics to be processed can be obtained. The corrected graphics processing coordinates of the graphics to be processed are used as the processing coordinates when processing the graphics to be processed.

[0064] Step 132 , using the graphics processing coordinates of the graphics to be processed as the processing position, and performing direct writing processing based on the substrate area defined by the positioning mark to form the graphics to be processed of the first processing layer in the substrate area.

[0065] For example, photoresist can be coated on the optical surface of each substrate area, and then the photoresist can be exposed according to the determined graphic processing coordinates of the pattern to be processed using laser direct writing technology; finally, the exposed photoresist is developed using development technology to form the photoresist pattern to be processed.

[0066] In order to improve the accuracy of the position of each layer of the graphics to be processed. If it is necessary to realize the processing of a multi-layer structure, an overprint mark can be formed on the graphics to be processed during the direct writing processing of the graphics to be processed. The overprint mark can be used as a reference standard for the direct writing processing of the next layer of graphics to be processed. The position of the overprint mark can be a position near the positioning mark. For example, if the substrate area is rectangular, the positioning mark can be set at the vertex position of the rectangle. The overprint mark can be set on one of the sides where the vertex of the substrate area is located, and close to the position of the positioning mark.

[0067] Step 133 : Based on the pattern to be processed of the first processing layer, etching is performed on the substrate to form the pattern to be processed of the first processing layer.

[0068] Illustratively, a dry etching technique may be used to transfer the pattern to be processed of the photoresist to the pattern to be processed, thereby forming the pattern to be processed in each substrate region.

[0069] In this embodiment, if a single-layer structure is required, the processing of the large-diameter lens can be completed after the processing of the first layer of micro-nanostructures is completed. If a multi-layer structure is required, the processing of the deeper micro-nanostructures can be continued after the processing of the first layer of micro-nanostructures is completed.

[0070] By combining the positioning marks of each substrate area to realize the correction of the coordinates of the processed graphics, the position of the graphics obtained by processing the first layer of graphics can be made more accurate, which can also make the precision of the structure of the large-diameter lens processed and formed higher.

[0071] Optionally, the above step 131 may include the following steps 1311 to 1313.

[0072] Step 1311: measure the positioning marks to obtain the actual coordinates of each positioning mark.

[0073] Optionally, the position of the positioning mark may be measured manually, and the data obtained by the measurement are the actual coordinates of the positioning mark.

[0074] Optionally, the position of the positioning mark may be measured by image recognition.

[0075] Step 1312 : Compare the actual coordinates of each positioning mark with the theoretical coordinates of the positioning mark to determine the coordinate error.

[0076] Optionally, the actual coordinates of the positioning mark may be directly subtracted from the theoretical coordinates of the positioning mark to determine the coordinate error between the actual coordinates and the theoretical coordinates.

[0077] Optionally, the coordinate error may be multiplied by the actual coordinate to obtain the theoretical coordinate, thereby calculating the coordinate error.

[0078] In this embodiment, when it is determined that there is an error between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark, the positioning mark may be calibrated.

[0079] The coordinate error can be represented by a position deviation matrix.

[0080] Step 1313 , determining the graphic processing coordinates of the graphic to be processed in each substrate region according to the coordinate error and the theoretical coordinates of the graphic to be processed.

[0081] In this embodiment, the theoretical coordinates of the to-be-processed pattern can be obtained based on the determined substrate and processing pattern after the design processing pattern is determined and the substrate of the processed carrier is determined.

[0082] For example, the graphics processing coordinates of the graphics to be processed can be expressed as:

[0083] ψ' n (X,Y)=M i,j ·ψ n (X,Y), where ψ n (X, Y) represents the theoretical coordinates of the graphics to be processed; ψ' n (X, Y) can represent the graphics processing coordinates of the graphics to be processed after correction.

[0084] In this embodiment, if multiple layers of graphics to be processed need to be processed, the coordinates of each layer of the graphics to be processed may be preliminarily calibrated using the above method to obtain the graphics processing coordinates of each layer of the graphics to be processed.

[0085] In each of the above steps, the coordinates of the graphics to be processed can be corrected in combination with the errors of the positioning marks, and the corrected coordinates can be used as the graphics processing coordinates of the graphics to be processed, which can better improve the errors caused by processing and improve the accuracy of the position of the graphics to be processed.

[0086] In this embodiment, the above step 131 may include: constructing a local coordinate system for the positioning marks of each substrate area respectively; in the local coordinate system, performing direct writing processing under the graphic processing coordinates of the to-be-processed graphic to form the to-be-processed graphic of the first processing layer in the substrate area.

[0087] Optionally, in order to improve the accuracy of the graphics to be processed, when there is an error between the actual coordinates of the positioning mark and the theoretical coordinates, the positioning mark can be corrected, and the local coordinate system can be constructed with the coordinates of the corrected positioning mark.

[0088] The local coordinate system can be used as a processing reference to perform direct writing processing on the image to be processed. For example, the graphics processing coordinates of the graphics to be processed can be the coordinates in the local coordinate system, and the first layer of graphics to be processed on the substrate is processed at the graphics processing coordinates of the graphics to be processed based on the local coordinate system.

[0089] In the above implementation, by directly writing the pattern to be processed in combination with the local coordinate system, the position of the pattern to be processed on the substrate can be made more accurate.

[0090] In an optional embodiment, for processing the Nth layer of graphics to be processed, the above step 130 may include the following steps 134 to 135.

[0091] Step 134 , for the Nth processed layer of the large-aperture lens, based on the position of the pattern formed on the N-1th processed layer and the substrate areas defined by the positioning marks, the coordinates of the pattern to be processed on the Nth processed layer are corrected to determine the pattern to be processed on the Nth processed layer.

[0092] Wherein, N is a positive integer greater than or equal to 2.

[0093] For example, the coordinates of the pattern to be processed in the Nth processing layer can be adjusted in combination with the position of the pattern formed in the N-1th processing layer, and the pattern to be processed in the Nth processing layer can be directly written based on the corrected coordinates of the pattern to be processed in the Nth processing layer.

[0094] Step 135 , based on the pattern to be processed of the Nth processing layer, etching to form the pattern to be processed of the Nth processing layer on the substrate.

[0095] Optionally, the above step 134 may be implemented by cyclic multiple calibration, and the step 134 includes the following steps.

[0096] a. For the target substrate area, based on the latest coordinates of the to-be-processed pattern in the target substrate area, direct-write processing is performed on the photoresist on the substrate area defined by the positioning mark corresponding to the target substrate area to form the current processing pattern.

[0097] In this embodiment, when step a is performed for the first time, the latest coordinates of the figure to be processed may be the initial coordinates of the figure to be processed, or the coordinates of the figure to be processed after correction using the position deviation matrix used to correct the positioning mark; when step a is performed for the Mth time, the latest coordinates of the figure to be processed may be the coordinates obtained after the coordinates of the figure to be processed are corrected for the M-1th time through step d. M is a positive integer greater than or equal to 2.

[0098] In this embodiment, the current processing pattern is formed in the same manner as the pattern to be processed in the first processing layer in step 132 . For details, please refer to the description of step 132 , which will not be repeated here.

[0099] b. Process the current overlay mark at the specified location in the target substrate area.

[0100] Optionally, the overlay mark may be formed on the photoresist by direct writing.

[0101] The designated position can be pre-designed. For example, the designated position can be a position adjacent to the positioning mark, a representative position on the edge of the target substrate area, or a position superimposed on the positioning mark.

[0102] c. Determine the overlay error of the current processing layer based on all the current overlay marks of the current processing layer and the overlay marks of the previous processing layer of the current processing layer.

[0103] For example, the overlay mark of the current processing layer can be expressed as D B , the overlay mark of the previous processing layer can be expressed as C A Each layer can contain multiple overlay marks. The current processing layer has multiple overlay marks D B , the previous processing layer also has multiple overlay marks C A .

[0104] For example, the position of each overlay mark of the current processing layer can be compared with the position of the corresponding overlay mark of the previous processing layer to determine the overlay error. Taking the overlay mark of the i-th row and j-th column as an example, the overlay mark D of the i-th row and j-th column of the current processing layer is Bij Overlay mark C of row i and column j of the previous processing layer AijThe distance between them can be regarded as the overlay error of row i and column j. The overlay error of the current processing layer can be expressed as a matrix of overlay errors at each position.

[0105] For example, the overlay mark of each substrate region can also be compared to determine the overlay error of each substrate region. For example, the overlay mark C at the substrate region (i, j) of the previous processing layer can be measured. A The center coordinates (X C ,Y C ) and the currently processed overlay mark D B The center coordinates (X D ,Y D ), then the overlay error measured at the kth positioning mark in the substrate area is δ in the X direction i,j x k =X C,k -X D,k , Y direction δ i,j y k =Y C,k -Y D,k , if the substrate region (i, j) corresponds to k overlay marks, the average overlay error of the substrate region (i, j) can be expressed as:

[0106] Using the above calculation method, the average overlay error can be obtained for each substrate area. The overlay error of the current processing layer can be expressed as a matrix of the average overlay error of each substrate area. The overlay error of the current processing layer can be expressed as a matrix En:

[0107] In the above example, the overlay mark C A The overlay error can be calculated based on the center coordinates of the overlay mark. In actual use, it can also adapt to changes. For example, if the overlay mark is a rectangle, the overlay mark C A The overlay error can also be calculated by using the overlay mark C A The coordinates of the midpoint on one of the sides and the coordinates of the other points are used to calculate the overlay error. It is understood that the embodiment of the present application is not limited to the overlay mark position points used to calculate the overlay error.

[0108] d. When the overlay error is greater than the set value, the coordinates of the graphics to be processed in the current processing layer are corrected using the overlay error.

[0109] The target substrate region is any one of all substrate regions.

[0110] Repeat steps a to d above until the overlay error is no greater than the set value; perform correction using steps a to d above for each substrate area and then perform direct writing processing to form the pattern to be processed in the current processing layer.

[0111] For example, the set value can be set based on actual accuracy or correction speed requirements. For example, if the accuracy requirement is relatively high, the set value can be set to a smaller value; if the correction speed is required to be relatively faster, the set value can be set to a relatively larger value while meeting the accuracy requirement.

[0112] In the above steps, each round of execution can form the graphics to be processed of the current processing layer and the overlay mark of the current processing layer. After the above cycle is completed, the graphics to be processed of the current processing layer and the overlay mark of the current processing layer can be obtained.

[0113] In this embodiment, after the correction in step 134 is completed, etching can be performed in step 135 based on the obtained pattern to be processed of the current processing layer and the overlay mark of the current processing layer.

[0114] Through the above implementation, a deep-layer pattern to be processed is formed by performing multiple correction cycles, so that the formed pattern to be processed can be more accurate.

[0115] In this embodiment, the above step d may include the following steps.

[0116] Step d1, correcting the positioning mark according to the overlay error to obtain an updated positioning mark.

[0117] For the current processing layer, it can be determined that based on the above-mentioned overlay deviation, the updated positioning mark corrected under the influence of the error of the current processing layer can be expressed as K" i,j , the updated positioning mark can satisfy K" i,j =K' i,j -E n Among them, the K' i,j Indicates the actual coordinates of the positioning marker.

[0118] Step d2: determining a deviation matrix based on the updated positioning mark and the positioning mark.

[0119] A deviation matrix is determined based on the actual coordinates of the positioning markers and the updated positioning markers.

[0120] The product of the deviation matrix and the actual coordinates of the positioning mark can be equal to the updated positioning mark. The deviation matrix can be expressed as N i,j , where K” i,j =N i,j ·K' i,j .

[0121] Step d3: using the deviation matrix, correct the coordinates of the graphics to be processed in the current processing layer.

[0122] The deviation matrix can be directly multiplied with the latest coordinates of the graphics to be processed in the current processing layer to obtain the updated coordinates of the graphics to be processed in the current processing layer. For example, it can be expressed as: ψ' n,B (X,Y)=N i,j ·ψ n,B (X, Y). When this step is performed for the first time, the latest coordinates of the figure to be processed here may be the initial coordinates of the figure to be processed; when this step is performed for the Mth time, the latest coordinates of the figure to be processed here may be the coordinates obtained after the coordinates of the figure to be processed are corrected for the M-1th time through step d.

[0123] In this embodiment, i,j x and δ i,j If y is less than the design value, the correction process ends.

[0124] Through the above-mentioned implementation method, during correction, the deviation can be realized by combining the overlay marks of two adjacent layers to determine the possible deviation of the positioning mark, so that the coordinates of the graphics to be processed in each substrate area can be corrected based on the possible deviation of the positioning mark. Since the overlay error of each substrate area is taken into account in the correction, the correction result can obtain a better correction effect in each substrate area, so that the coordinates of the graphics to be processed after correction can be more accurate.

[0125] In one embodiment, the above-mentioned step 120 includes: setting positioning marks at adjacent positions of each substrate region, and setting positioning marks at edge positions of each substrate region.

[0126] The substrate area may be a rectangular substrate area. In this case, step 120 may include setting a positioning mark at the vertex of each rectangular substrate area. Step 120 may also include setting a positioning mark at the edge of each rectangular substrate area.

[0127] To better define the scope of a substrate region, the number of positioning marks for each substrate region is no less than four. To accommodate the definition of the scope of substrate regions of different shapes, the number of positioning marks for each substrate region may be greater or lesser. For example, when the substrate region is triangular, each substrate region may have three or more positioning marks; for another example, when the substrate region is pentagonal, each substrate region may have five or more positioning marks.

[0128] Alternatively, adjacent regions may share some positioning marks. For example, if two substrate regions share a common vertex and a positioning mark is provided at that vertex, the positioning mark at that vertex may serve as a common positioning mark for the two substrate regions. For example, if two substrate regions share a common edge and a positioning mark is provided on that edge, the positioning mark on that edge may serve as a common positioning mark for the two substrate regions.

[0129] like Figure 4 As shown, Figure 4 FIG. 1 shows a schematic diagram of the distribution of positioning marks in an embodiment. Figure 4 In the example shown, 16 substrate regions are divided, respectively by columns ①, ②, ③, ④, ⑤ and rows a, b, c, d, e. Positioning marks can be processed at the intersections of columns ①, ②, ③, ④, ⑤ and rows a, b, c, d, e. Adjacent regions can share some positioning marks. For example, regions ①②-ab and regions ②③-ab share marks ②-a and ②-b. Figure 4 In the example shown, the positioning mark is in the shape of a plus sign.

[0130] In the above implementation, each substrate region can be provided with multiple positioning marks, which can better define the scope of the substrate region. Furthermore, positioning marks are provided at the edge of the substrate region, which can reduce the influence of positioning marks on the pattern to be processed.

[0131] The following describes the process of the method for processing the functional structure of a large-aperture lens provided by the embodiment of the present application with an example. In the following example, the size of the pattern area to be processed in the lens is 700mm×800mm, and the substrate of the initial lens blank, which is the carrier of the pattern, can be divided into 56 areas of 100mm×100mm. Figure 5 As shown, it shows a schematic diagram of the distribution of the theoretical positions of 72 positioning markers.

[0132] Positioning marks are processed in each divided substrate area. In one example, the length of the positioning mark is 100 μm and the width is 10 μm. In order to achieve the stability of the positioning mark during multiple overlay processes, the positioning mark can be a chromium metal mark. The number of positioning marks is 72. Figure 6 As shown, Figure 6 A schematic diagram showing the distribution of the actual coordinates of 72 positioning markers is shown.

[0133] In determining Figure 6 After the positioning marks shown, the actual coordinates (X ik ,Y jk ) and the theoretical coordinates, and establish the position deviation matrix M i,j , and accordingly correct the positioning mark coordinates and graphic position coordinates. Figure 6 In the schematic diagram shown, it can be seen that there is an error between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark.

[0134] The theoretical coordinates of the positioning mark can be expressed as (X 1,1 ,Y 1,1 )、(X 1,2 ,Y 1,2 )、(X 1,3 ,

[0135] Y 1,3 ),……、(X 2,1 ,Y 2,1 )、(X 2,2 ,Y 2,2 ),……、(X 9,8 ,Y 9,8 ), ..., the matrix of the theoretical coordinates of the positioning mark can be expressed as: The actual coordinates of the positioning mark can be expressed as: (X' 1,1 ,Y' 1,1 )、(X' 1,2 ,Y' 1,2 )、(X' 1,3 ,Y' 1,3 ),……、(X' 2,1 ,Y' 2,1 )、(X' 2,2 ,Y' 2,2 ),……、(X' I,j ,Y' I,j ), ..., the matrix of the actual coordinates of the positioning marker can be expressed as: According to K i，j and K′ i，j Calculate the position deviation correction matrix M i，j , satisfying K i，j =M i，j K′ i，j .

[0136] According to the above position deviation matrix M i，j The coordinates of each layer of graphics to be processed can be corrected. Taking the layers to be processed including layer A and layer B as an example, the position coordinates of each layer of graphics to be processed after correction can be expressed as ψ'n,A(X,Y)=Mi,j·ψn,A(X,Y) and ψ' n,B (X,Y)=M i,j ·ψ n,B (X,Y).

[0137] Subsequently, step 130 and the means for implementing step 130 are continued to be used to calibrate the coordinates of the graphics to be processed in each layer, so that a lens with higher precision can be obtained.

[0138] like Figure 7 As shown, Figure 7 The schematic diagram shows the effect of the processing method of the functional structure of the large-aperture lens provided by the embodiment of the present application. Figure 7 In the example shown, the overlay error is magnified for easy observation. It is understood that the actual error is smaller than the position difference shown in the figure. The traditional overlay method often uses the entire lens for positioning (for example, Figure 5 1-1, 1-8, 9-1 and 9-8 in the diagram), the typical overlay error distribution is as follows Figure 7 As shown in the hollow circle, the maximum overlay error δ x ≥-694nm, δ y ≥+630nm; the overlay direct writing processing is realized by the large-aperture lens functional structure processing method provided in the embodiment of the present application, and the measured overlay error distribution is as follows Figure 7 As shown by the diamond in the middle, the maximum overlay error δ x Reduced to 98nm, δ y Reduce to -

[0139] 84nm.

[0140] The embodiment of the present application also provides a large-aperture lens, which is manufactured using the above-mentioned large-aperture lens functional structure processing method.

[0141] The processing method of the large-diameter lens can be found in the description of the aforementioned embodiment and will not be repeated here.

[0142] In the above-mentioned embodiments of the present application, the overlay accuracy of large-aperture and multi-layer functional structures can be improved, especially for the overlay problem of multi-layer micro-nanostructures, the core components of meter-level aperture planar optical imaging systems, which greatly improves the diffraction efficiency and provides important technical support for large-aperture planar optical systems. At the same time, the present invention greatly improves the yield of finished products and reduces manufacturing costs by locally correcting the overlay accuracy between layers. Compared with traditional overlay methods, the larger the aperture, the greater the overlay error. In the embodiments of the present application, the large-aperture processing area is split into several small substrate areas, and the positional errors between the small substrate areas are compensated and corrected, thereby improving the splicing accuracy between substrate areas; high-precision overlay processing is achieved through positioning marks and correction algorithms, thereby achieving high-precision overlay processing of large-aperture and even meter-level and above multi-layer graphics.

[0143] The foregoing is merely an optional embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures.

[0144] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for processing a functional structure of a large-aperture lens, characterized in that: include: Dividing the substrate of the initial mirror blank into regions to obtain a plurality of substrate regions; For each of the substrate regions, setting a positioning mark at a designated position of the substrate region; The coordinates of the to-be-processed pattern are corrected based on each substrate area defined by the positioning mark, and the to-be-processed pattern is formed by processing in the substrate area.

2. The method according to claim 1, characterized in that The method of correcting the coordinates of the graphics to be processed in each substrate area defined based on the positioning mark and processing the graphics to be processed in the substrate area includes: For the first processing layer of the large-aperture lens, determining the corrected graphic processing coordinates of the to-be-processed graphic according to the difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark; Taking the graphics processing coordinates of the graphics to be processed as the processing position, direct writing processing is performed based on the substrate area defined by the positioning mark to form the graphics to be processed of the first processing layer in the substrate area; Based on the pattern to be processed of the first processing layer, the pattern to be processed of the first processing layer is formed by etching on the substrate.

3. The method according to claim 2, characterized in that Determining the corrected graphics processing coordinates of the graphics to be processed based on the difference between the actual coordinates of the positioning mark and the theoretical coordinates of the positioning mark includes: Measuring the positioning marks to obtain actual coordinates of each positioning mark; Comparing the actual coordinates of each positioning mark with the theoretical coordinates of the positioning mark to determine the coordinate error; The graphic processing coordinates of the graphic to be processed in each of the substrate regions are determined according to the coordinate error and the theoretical coordinates of the graphic to be processed.

4. The method according to claim 2, characterized in that The method of directly writing the substrate area defined by the positioning mark using the graphic processing coordinates of the graphic to be processed as the processing position to form the graphic to be processed of the first processing layer in the substrate area comprises: constructing a local coordinate system for each positioning mark of the substrate area; In the local coordinate system, direct writing processing is performed in the graphic processing coordinates of the graphic to be processed to form the graphic to be processed of the first processing layer in the substrate area.

5. The method according to any one of claims 1 to 4, characterized in that The method of correcting the coordinates of the graphics to be processed in each substrate area defined based on the positioning mark and forming the graphics to be processed in the substrate area includes: For the Nth processed layer of the large-aperture lens, based on the position of the pattern formed in the N-1th processed layer and the substrate regions defined by the positioning marks, the coordinates of the pattern to be processed in the Nth processed layer are corrected to determine the pattern to be processed in the Nth processed layer; wherein N is a positive integer greater than or equal to 2; Based on the pattern to be processed of the Nth processed layer, the pattern to be processed of the Nth processed layer is formed by etching on the substrate.

6. The method according to claim 5, characterized in that The method of correcting the coordinates of the pattern to be processed of the Nth processing layer based on the position of the pattern formed on the N-1th processing layer and the substrate regions defined by the positioning marks to determine the pattern to be processed of the Nth processing layer includes: a. For a target substrate region, based on the latest coordinates of the pattern to be processed in the target substrate region, performing direct writing processing on the photoresist on the substrate region defined by the positioning mark corresponding to the target substrate region to form a current processing pattern; b. processing a current overlay mark at a designated location in the target substrate area; c. determining an overlay error of the current processing layer based on all current overlay marks of the current processing layer and the overlay marks of a previous processing layer of the current processing layer; d. When the overlay error is greater than a set value, the coordinates of the to-be-processed pattern of the current processing layer are corrected by using the overlay error; The target substrate area is any one of all substrate areas; when step a is performed for the first time, the latest coordinates are the initial coordinates of the to-be-processed pattern; when step a is performed for the Mth time, the latest coordinates are the coordinates of the to-be-processed pattern corrected by performing step d for the M-1th time, where M is a positive integer greater than or equal to 2; Repeat steps a to d until the overlay error is no greater than the set value; perform correction using steps a to d for each substrate region and then perform direct writing processing to form a pattern to be processed in the current processing layer.

7. The method according to claim 6, characterized in that The method of correcting the coordinates of the graphics to be processed of the current processing layer by using the overlay error includes: Correcting the positioning mark according to the overlay error to obtain an updated positioning mark; Determine a deviation matrix based on the updated positioning mark and the positioning mark; The coordinates of the graphics to be processed in the current processing layer are corrected using the deviation matrix.

8. The method according to claim 1, characterized in that The step of setting a positioning mark at a designated position of the substrate area includes: Positioning marks are set at adjacent positions of the substrate regions, and positioning marks are set at edge positions of the substrate regions.

9. The method according to claim 8, characterized in that in, The steps of setting positioning marks at adjacent positions of the substrate regions and at edge positions of the substrate regions include setting positioning marks at the edge positions of the substrate regions, with the number of positioning marks for each substrate region being no less than four.

10. A large-diameter lens, characterized in that: include: The method according to any one of claims 1 to 9 is used to obtain the product.

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