Method and device for leveling a carrier, computer device and storage medium

Abstract

The application relates to a stage leveling method and device, computer equipment and a storage medium. The stage leveling method is applied to a laser interferometer. A limiting component is arranged on the surface of the stage of the laser interferometer. A plurality of adjusters are arranged on the stage. The adjusters are used for adjusting the height of the corresponding positions of the stage. The method comprises the following steps: acquiring a stage topography wave surface graph and image position information of the plurality of adjusters in an image; calculating a stage tilt plane equation according to the stage topography wave surface graph; determining the height information of each adjuster according to the plurality of image position information and the stage tilt plane equation; and adjusting the corresponding adjuster according to the height information of each adjuster and a reference height to level the stage. Therefore, the stage automatic leveling is realized, the manual intervention is reduced, the stage leveling complexity is reduced, and the stage leveling accuracy and efficiency are effectively improved.

Description

Technical Field

[0001] This application relates to the field of laser interferometer leveling technology, and in particular to a stage leveling method, apparatus, computer equipment, and storage medium. Background Technology

[0002] Laser interferometry (LIFE) is a non-contact optical measurement technique for surface topography, widely used in mechanical, electronic, and modern industrial fields. It can be used to measure the roughness and microscopic surface morphology of machined parts. LIFE achieves nanometer-level precision. However, the accuracy of the measurement results is affected by factors such as the levelness of the sample itself and the flatness and levelness of the stage. For example, if the stage is too tilted, the flatness information of the sample is obscured by the dense fringes created by the tilt, making the surface topography measurement unreliable and thus affecting the accuracy. Therefore, stage leveling is crucial for improving the accuracy of LIFE.

[0003] In existing technologies, manual adjustment is mainly relied upon, that is, the leveling operation of the platform is achieved by observing the changes in the density of stripes with the human eye. However, in practical applications, on the one hand, the manual adjustment method relies entirely on the experience of technicians and lacks objectivity, resulting in low platform leveling accuracy; on the other hand, manual leveling is difficult and the operation process is cumbersome, resulting in low platform leveling efficiency.

[0004] There is currently no effective solution to the problems of low accuracy and low efficiency in the existing stage leveling technology. Summary of the Invention

[0005] Therefore, it is necessary to provide a platform leveling method, apparatus, computer equipment, and storage medium to address the aforementioned technical problems.

[0006] In a first aspect, this application provides a stage leveling method applied to a laser interferometer. The stage surface of the laser interferometer is provided with a limit assembly, and the stage is correspondingly provided with multiple adjusters for adjusting the height of corresponding positions on the stage. The method includes:

[0007] Acquire the wavefront image of the platform topography and the image position information of multiple regulators in the image;

[0008] Based on the wavefront diagram of the platform morphology, calculate the equation of the platform tilt plane;

[0009] The height information of each adjuster is determined based on the multiple image position information and the stage tilt plane equation;

[0010] Based on the height information of each adjuster and the reference height, the corresponding adjuster is adjusted to level the platform.

[0011] In one embodiment, prior to acquiring the stage topography wavefront map and the image position information of the multiple adjusters in the image, the process includes:

[0012] The image information and actual feature information of the feature sample are acquired; the feature sample is placed within the limiting component of the stage, and the center of the feature sample coincides with the center of the stage;

[0013] Based on the image information of the feature sample, determine the image feature information of the feature sample;

[0014] Based on the actual feature information, image feature information, and actual position information of the multiple regulators, the image position information of the multiple regulators in the image is determined.

[0015] In one embodiment, determining the image position information of the multiple adjusters in the image based on the actual feature information, image feature information, and the actual position information of the multiple adjusters includes:

[0016] Calculate the imaging magnification based on the actual feature information and image feature information;

[0017] Based on the imaging magnification and the actual position information of the multiple adjusters, the image position information of the multiple adjusters in the image is determined.

[0018] In one embodiment, calculating the stage tilt plane equation based on the stage topography wavefront diagram includes:

[0019] Extract the region image corresponding to the limiting component from the wavefront image of the platform morphology;

[0020] The equation of the platform tilt plane is obtained by fitting a plane using the least squares method based on the image of the region.

[0021] In one embodiment, adjusting the corresponding adjuster based on the height information of each adjuster and a reference height to level the platform includes:

[0022] The height information of each regulator is compared with the reference height to determine the height adjustment amount corresponding to each regulator;

[0023] Adjust the corresponding adjuster according to the height adjustment amount corresponding to each adjuster to level the platform.

[0024] In one embodiment, after adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the platform, the method further includes:

[0025] Obtain the verification morphology wavefront image of the leveled stage;

[0026] Based on the verification topography wavefront diagram, determine the verification height adjustment amount corresponding to each of the regulators;

[0027] If the verification height adjustment amount corresponding to each of the aforementioned adjusters meets the preset conditions, then the leveling is completed.

[0028] In one embodiment, after adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the platform, the method further includes:

[0029] When the sample to be tested is placed in the limiting component of the stage, the wavefront diagram of the morphology of the sample to be tested is obtained.

[0030] The surface morphology of the sample to be tested is determined based on the wavefront diagram of the sample to be tested and the wavefront diagram of the leveled platform.

[0031] Secondly, this application also provides a platform leveling device, the device comprising:

[0032] The acquisition module is used to acquire the wavefront image of the platform topography and the image position information of multiple regulators in the image;

[0033] The calculation module is used to calculate the equation of the tilt plane of the platform based on the wavefront diagram of the platform topography;

[0034] The determining module is used to determine the height information of each of the adjusters based on the multiple image position information and the stage tilt plane equation;

[0035] An adjustment module is used to adjust the corresponding adjuster according to the height information of each adjuster and the reference height, so as to level the platform.

[0036] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described in any of the embodiments of the first aspect above.

[0037] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in any of the embodiments of the first aspect above.

[0038] The aforementioned stage leveling method, apparatus, computer equipment, and storage medium are described above. The stage leveling method is applied to a laser interferometer. The stage surface of the laser interferometer is equipped with limit components, and the stage is equipped with multiple adjusters for adjusting the height of corresponding positions on the stage. The stage leveling method includes: acquiring a wavefront image of the stage topography and the image position information of the multiple adjusters in the image; calculating the stage tilt plane equation based on the wavefront image; determining the height information of each adjuster based on the multiple image position information and the stage tilt plane equation; and adjusting the corresponding adjuster based on the height information of each adjuster and a reference height to level the stage. Based on this, automated stage leveling is achieved, reducing manual intervention and the complexity of stage leveling, thereby effectively improving the accuracy and efficiency of stage leveling. Attached Figure Description

[0039] The accompanying drawings, which are included to provide a further understanding of this application, form part of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation thereof. In the drawings:

[0040] Figure 1 This is a flowchart illustrating a platform leveling method in one embodiment;

[0041] Figure 2 This is a schematic diagram of the layout structure of three regulators in one embodiment;

[0042] Figure 3 This is a schematic diagram of the regulator layout structure in one embodiment;

[0043] Figure 4 This is a flowchart illustrating the platform leveling method in another embodiment;

[0044] Figure 5 This is a structural block diagram of the platform leveling device in one embodiment;

[0045] Figure 6 This is an internal structural diagram of a computer device in one embodiment.

[0046] Explanation of reference numerals in the attached figures:

[0047] 100, platform; 200, regulator. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0049] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning as understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these,” used in this application, do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to such processes, methods, products, or devices. The terms “connected,” “linked,” and “coupled,” used in this application, are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. The term “multiple” used in this application refers to two or more. The "and / or" operator describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: A alone, A and B simultaneously, and B alone. Typically, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," and "third," etc., used in this application are merely for distinguishing similar objects and do not represent a specific ordering of the objects.

[0050] In one embodiment, such as Figure 1 As shown, Figure 1 This is a schematic flowchart of a stage leveling method in one embodiment. The stage leveling method is applied to a laser interferometer. The stage surface of the laser interferometer is provided with a limit component, and the stage is provided with multiple adjusters. The adjusters are used to adjust the height of the corresponding position of the stage.

[0051] The limiting component is used to fix the sample, that is, to limit the placement position of the sample on the stage. The sample can be any material that can be measured and analyzed by a laser interferometer; for example, the sample can be, but is not limited to, a wafer. The stage is equipped with multiple adjusters, each of which is connected to a top block at a corresponding position on the stage. The adjuster is used to adjust the height of the corresponding position by lifting the top block. The adjuster has telescopic or adjustable characteristics. Based on the telescopic or adjustable characteristics of the adjuster, the height of the corresponding position on the stage can be adjusted. It should be noted that the adjuster can be any structure with adjustable characteristics, such as an actuator, piezoelectric ceramic, or an adjustment structure with high-precision feedback. The top block is used to provide a stable support plane for the stage to ensure the stability of the stage.

[0052] Furthermore, the platform leveling method includes the following steps:

[0053] Step S101: Obtain the wavefront image of the platform topography and the image position information of multiple regulators in the image.

[0054] The stage topography wavefront map refers to an image that can characterize the surface topography of the stage. It should be noted that in practical applications, the original image of the stage can be recorded using the imaging equipment of a laser interferometer. Furthermore, the original image of the stage is processed based on the phase shift interferometry (PSI) algorithm to obtain the stage topography wavefront map. The stage topography wavefront map includes at least stage height information. The stage height information is used to represent the height variation at different positions on the stage surface.

[0055] The image position information of multiple adjusters in the image refers to the horizontal position information of each adjuster in the image; the horizontal position information includes the x-axis position coordinate and the y-axis position coordinate.

[0056] Step S102: Calculate the equation of the inclined plane of the platform based on the wave surface diagram of the platform morphology.

[0057] The stage tilt plane equation describes the stage tilt plane in three-dimensional space. The stage tilt plane equation includes at least the preset point height information, the preset point plane tilt factor, and the preset point position coordinates. The preset point refers to any point in the stage tilt plane. For example, the stage tilt plane equation is assumed to be z = ax + by + c. Here, z represents the preset point height information in μm; a represents the preset point plane tilt factor in the x-axis direction; b represents the preset point plane tilt factor in the y-axis direction; x represents the preset point x-axis position coordinate in pixels; y represents the preset point y-axis position coordinate in pixels; and c represents a constant term.

[0058] Step S103: Determine the height information of each adjuster based on the position information of multiple images and the equation of the tilt plane of the platform.

[0059] Since the regulator is connected to the top block at the corresponding position of the stage, the height information of the regulator is equal to the height information of the corresponding position of the stage. Therefore, the height of the regulator can be used to represent the height information of the corresponding position of the stage.

[0060] Specifically, based on the image position information of each regulator in the image, namely the horizontal position information, that is, the x-axis position coordinate and the y-axis position coordinate, the height information of each regulator can be determined by substituting it into the equation of the platform tilt plane.

[0061] Step S104: Adjust the corresponding adjuster according to the height information of each adjuster and the reference height to level the platform.

[0062] The reference height can be set according to the actual leveling needs of the stage and is not limited here. For example, the height information of any one of the adjusters can be used as the reference height, or the reference height can be set according to the requirements, or it can be set according to the measurement optical path of the laser interferometer, ensuring that the reference height is within the imaging measurement range of the laser interferometer. For example, assuming that the stage is equipped with three adjusters, the reference height can be the maximum or minimum value of the height information corresponding to the three adjusters, or it can be the height of other points on the stage surface, such as the center point of the stage. It should be noted that in practical applications, considering the adjustment backlash of multiple adjusters and the efficiency of stage leveling, it is preferable to use the maximum value of the height information corresponding to the adjusters as the reference height. In addition, for prism-type grazing incidence laser interferometers, since the absolute distance between the large surface of the prism and the stage needs to be controlled during stage leveling, the reference height needs to be set according to the actual situation and is not limited here.

[0063] Specifically, based on the height information of each adjuster and the reference height, the corresponding adjuster is adjusted so that the height information of each adjuster is aligned with the reference height, thereby achieving the leveling of the platform.

[0064] In this embodiment, by setting multiple adjusters at corresponding positions on the platform, the height of each corresponding position on the platform can be adjusted, effectively saving leveling time and reducing the complexity of the leveling operation. Furthermore, based on the wavefront map of the platform topography, the platform tilt plane equation can be accurately calculated. Subsequently, based on the platform tilt plane equation and the image position information of multiple adjusters in the image, the height information of each adjuster can be accurately calculated without additional measuring devices or sensors. This avoids the problems of limited sensor placement and low measurement accuracy when using traditional measuring devices or sensors to measure the height information of each adjuster, effectively improving the applicability of the adjuster height information measurement and the accuracy of the measurement results, laying the foundation for improving the accuracy of platform leveling. Furthermore, by adjusting the corresponding adjusters based on the reference height to achieve platform leveling, the accuracy of platform leveling is improved, the complexity of platform leveling is reduced, and the efficiency of platform leveling is further improved.

[0065] In one embodiment, before acquiring the stage topography wavefront map and the image position information of multiple adjusters in the image, the following steps are included:

[0066] Step 1: Obtain the image information and actual feature information of the feature sample.

[0067] The feature sample is placed within the limiting component of the stage, and the center of the feature sample coincides with the center of the stage.

[0068] Step 2: Determine the image feature information of the feature sample based on the image information of the feature sample.

[0069] Step 3: Determine the image position information of multiple regulators in the image based on actual feature information, image feature information, and actual position information of multiple regulators.

[0070] Preferably, step 3, determining the image position information of multiple adjusters in the image based on actual feature information, image feature information, and the actual position information of multiple adjusters, includes the following steps:

[0071] Step 3.1: Calculate the imaging magnification based on the actual feature information and image feature information.

[0072] Step 3.2: Determine the image position information of the multiple regulators in the image based on the imaging magnification and the actual position information of the multiple regulators.

[0073] The limiting component may be, but is not limited to, a limiting groove, used to place the sample in the limiting groove and fix and limit the position of the sample through the limiting groove; the sample may be, but is not limited to, the sample to be tested or the feature sample.

[0074] Among them, the characteristic sample refers to a sample with a smooth surface; optically, the surface flatness of the characteristic sample needs to be less than or equal to lambda / 20; flatness refers to the physical quantity used to describe the flatness of the surface of an object; optionally, the characteristic sample can be a sample with a characteristic circle in the middle and the ring is flat, or it can be a sample without a characteristic circle but with a flat surface, or it can be a sample with other characteristic information, without specific limitations here; the characteristic sample can be, but is not limited to, flat crystals or quartz sheets.

[0075] The image information of the feature sample includes at least the pixel size and the original image data of the feature sample; the pixel size is related to the performance of the imaging equipment in the laser interferometer and is not specifically limited here. The actual feature information of the feature sample includes at least the actual size of the feature sample; for example, when the feature sample has a feature circle in the middle, the actual feature information includes the actual diameter of the feature circle; when the feature sample does not have a feature circle, the actual feature information includes the outer diameter of the feature sample. The image feature information of the feature sample includes at least the size of the feature sample in the image; for example, when the feature sample has a feature circle in the middle, the image feature information includes the radius of the feature circle in the image; when the feature sample does not have a feature circle, the image feature information includes the outer diameter of the feature sample in the image. It should be noted that the actual size of the feature sample is in μm, for example, the actual diameter of the feature circle is in μm; the size of the feature sample in the image is in pixels, for example, the radius of the feature circle in the image is in pixels.

[0076] The actual position information of the regulator refers to the actual position information of the regulator relative to the positioning point on the stage surface; the actual position information includes the actual x-axis position coordinate and the actual y-axis position coordinate; preferably, the positioning point on the stage surface is the center of the stage; for example, see Figure 2 Assume the stage has three regulators, denoted as A, B, and C, arranged in a triangular structure. Positioning point O on the stage surface is located within this triangular area. If the coordinates of positioning point O are (x0, y0), the x-direction distance from positioning point O to regulators A and C is d1, and the y-direction distance is d2; and the y-direction distance from positioning point O to regulator B is d2, and the x-direction distance is 0, then the actual position information of each regulator can be represented as: A(x0-d1, y0-d2), B(x0, y0+d2), C(x0+d1, y0-d2). It can be understood that if the coordinates of positioning point O are (0, 0), then the actual position information of each regulator can be represented as: A(-d1, -d2), B(0, d2), C(d1, -d2). It should be noted that the layout structure of the regulators can be any stable structure, and this embodiment does not impose specific limitations; for example, see... Figure 3 When three adjusters 200 are set at corresponding positions on the platform 100, the layout structure of the three adjusters 200 can be a three-point support structure; when four adjusters 200 are set at corresponding positions on the platform 100, the layout structure of the four adjusters 200 can be a four-point support structure. It should be noted that the support method of the adjusters can be either a forward-facing method, i.e., when the adjuster extends, the height of the corresponding position on the platform increases, and when the adjuster shortens, the height of the corresponding position on the platform decreases; or an inverted method, i.e., when the adjuster extends, the height of the corresponding position on the platform decreases, and when the adjuster shortens, the height of the corresponding position on the platform increases.

[0077] The image position information of the regulator in the image refers to the horizontal position information of the regulator in the image, including the x-axis position coordinates and the y-axis position coordinates. The imaging magnification is equal to the ratio of image height to object height; where image height refers to the size of the object in the image, and object height refers to the actual size of the object.

[0078] For example, suppose the stage has three adjusters, and the actual position information of each adjuster can be represented as: A(x0-d1, y0-d2), B(x0, y0+d2), C(x0+d1, y0-d2); and assume that the positioning point O(x0, y0) on the stage surface is the center of the stage, and the feature sample has a feature circle in the middle; place the feature sample within the limiting assembly of the stage, and ensure that the center of the feature sample coincides with the center of the stage, that is, the center of the feature sample coincides with the positioning point O on the stage surface, that is, the center of the feature sample is equal to (x0, y0-d2). 0); Further, acquire the image information of the feature sample, i.e., the pixel size, and denote the pixel size as pμm×pμm, and acquire the actual feature information of the feature sample, i.e., the actual diameter of the feature circle, denoted as d; Further, based on the image information of the feature sample, i.e., the pixel size, determine the image feature information of the feature sample, i.e., the radius of the feature circle in the image, denoted as r; Further, calculate the imaging magnification factor according to the actual diameter d of the feature circle, the radius r of the feature circle in the image, and the pixel size pμm×pμm; denoted as β, then Furthermore, based on the imaging magnification β and the actual position information of the three adjusters, namely A(x0-d1, y0-d2), B(x0, y0+d2), and C(x0+d1, y0-d2), the image position information of each adjuster in the image is calculated as follows: A(x0-d1·β, y0-d2·β), B(x0, y0+d2·β), and C(x0+d1·β, y0-d2·β). It should be noted that d1 and d2 in this embodiment are determined by the mechanical structure of the stage and are not specifically limited here.

[0079] In this embodiment, the imaging magnification can be quickly determined based on the image information, actual feature information, and image feature information of the feature sample. Furthermore, based on the imaging magnification and the actual position information of multiple regulators, the image position information of multiple regulators in the image can be accurately located, laying a data foundation for accurately determining the height information of each regulator.

[0080] In one embodiment, calculating the equation of the tilting plane of the platform based on the wavefront diagram of the platform topography includes the following steps:

[0081] Step 1: Extract the image of the region corresponding to the limiting component from the wavefront image of the platform morphology.

[0082] Step 2: Fit the plane using the least squares method based on the region image to obtain the equation of the platform tilt plane.

[0083] The region corresponding to the limiting component refers to the outer annular zone region of the limiting component. The surface of this outer annular zone region has high flatness, specifically less than or equal to lambda / 20. Therefore, the accuracy of the stage tilt plane equation obtained by fitting the image of the region corresponding to the limiting component is higher. The image of the region corresponding to the limiting component is a topographic wavefront map of the outer annular zone region of the limiting component.

[0084] For example, suppose the topographic wavefront map corresponding to the region image of the limiting component, i.e., the outer circular ring region, is a 512×512 two-dimensional array, where each data point carries height information z(x, y), x∈(1, 512), y∈(1, 512); based on the least squares method, find the best fitting plane in three-dimensional space for the topographic wavefront map corresponding to the region image of the limiting component, i.e., the outer circular ring region. Specifically, the following steps are included: First, based on the topographic wavefront map corresponding to the region image of the limiting component, i.e., the outer circular ring region, determine the dataset to be fitted; wherein, the dataset includes multiple three-dimensional data points, and the coordinates of the three-dimensional data points are denoted as (x, y, z); further, construct the plane equation ax + by + cz + d = 0 to characterize the distance from the three-dimensional data points to the plane; wherein, a, b, and c represent the normal vectors of the plane, and d represents the distance from the plane to the origin; for the three-dimensional data point (x, by + cz + d = 0, the plane equation is defined as follows: i y i , z i From this, we can obtain the equation ax i +by i +cz i +d=0; Further, the equations of all three-dimensional data points are combined to construct the matrix equation A0X=B; where A0 represents a matrix containing all coefficients of a, b, and c, X represents a vector containing a, b, c, and d, and B represents a vector containing all values ​​on the right side of the equation; Further, the matrix equation A0X=B is solved using the least squares method to obtain the best estimate of X; Further, a, b, c, and d are extracted from the best estimate of X and used as parameters of the fitting plane; Finally, the normal vector (a, b, c) of the fitting plane is calculated; Based on this, the equation of the platform tilting plane z=ax+by+c can be obtained.

[0085] In this embodiment, the least squares method is used to fit the plane to obtain an accurate equation for the tilting plane of the platform. Based on the equation for the tilting plane of the platform, accurate and objective tilting information of the platform can be obtained, which lays the foundation for improving the accuracy of platform leveling and avoids the problem of low leveling accuracy caused by the lack of objectivity in manual leveling.

[0086] In one embodiment, adjusting the corresponding adjuster to level the stage based on the height information of each adjuster and a reference height includes:

[0087] The height information of each regulator is compared with the reference height to determine the height adjustment amount corresponding to each regulator;

[0088] Adjust the corresponding adjuster according to the height adjustment amount of each adjuster to level the platform.

[0089] The height adjustment amount refers to the amount of extension or retraction required for each adjuster to reach the reference height.

[0090] For example, suppose the stage has three adjusters, and the height information of each adjuster is: z i =f(x) i ,y i ); where z i This represents the height information of the regulator, i = 1, 2, 3; the reference height is denoted as z0, z0 = max(z i ), and transfer the height information z of each regulator. i Each height adjustment is compared with the reference height z0 to determine the corresponding height adjustment amount for each adjuster; the height adjustment amount is recorded as Δz. i Δz i =z0-z i Furthermore, based on the height adjustment amount Δz i Adjust the corresponding adjusters to align the height of each adjuster with the reference height, thereby leveling the platform.

[0091] In this embodiment, based on the reference height, the height adjustment amount of each adjuster can be accurately calculated, which improves the accuracy of the height adjustment amount corresponding to each adjuster, and thus improves the accuracy of the platform leveling.

[0092] In one embodiment, after adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the stage, the method further includes:

[0093] Step 1: Obtain the verification morphology wavefront map of the leveled stage.

[0094] Step 2: Based on the verification topography wavefront diagram, determine the verification height adjustment amount corresponding to each regulator.

[0095] Step 3: If the verification height adjustment amount corresponding to each adjuster meets the preset conditions, the leveling is completed.

[0096] Among them, the wavefront diagram of the stage after the nth leveling is used as the verification wavefront diagram of the stage to verify whether the stage leveling is completed.

[0097] The preset conditions include a preset height adjustment threshold; the preset height adjustment threshold needs to be set according to the actual leveling requirements, and is not limited here.

[0098] For example, assuming the preset height adjustment threshold is 5 μm; if the absolute value of the verified height adjustment is less than or equal to the preset height adjustment threshold (i.e., the absolute value of the verified height adjustment is less than or equal to 5 μm), it indicates that the stage leveling is complete, meaning the stage is now horizontal and can be used to measure the sample. If the absolute value of the verified height adjustment is greater than the preset height adjustment threshold (i.e., the absolute value of the verified height adjustment is greater than 5 μm), it indicates that the stage is not leveled, meaning the stage is tilted. Further leveling is required until the absolute value of the verified height adjustment is less than or equal to the preset height adjustment threshold, at which point leveling is complete.

[0099] In this embodiment, based on preset conditions, the platform leveling verification is achieved by judging whether the height adjustment amount meets the preset conditions, thereby improving the reliability of platform leveling and further improving the accuracy of platform leveling.

[0100] In one embodiment, after adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the stage, the method further includes:

[0101] When the sample to be tested is placed in the limiting component of the stage, the wavefront map of the topography of the sample to be tested is obtained.

[0102] The surface morphology of the sample to be tested is determined based on the wavefront diagram of the sample to be tested and the wavefront diagram of the leveled platform.

[0103] The sample to be tested may be, but is not limited to, a wafer; the wavefront plot of the topography of the sample to be tested may be obtained, but is not limited to, through a phase-shifting interferometry (PSI) algorithm; it should be noted that the wavefront plot of the topography of the sample to be tested may be superimposed with stage height information; the stage height information is determined by the wavefront plot of the topography of the stage.

[0104] Specifically, after the stage is leveled, the wavefront map of the leveled stage is obtained; the sample to be tested is placed within the limiting component of the stage, and the wavefront map of the sample to be tested is obtained; since the stage height information may be superimposed on the sample to be tested, it is necessary to determine the equation of the plane to be tested and the equation of the tilting plane of the stage after leveling based on the wavefront map of the sample to be tested and the wavefront map of the leveled stage; the equation of the plane to be tested refers to the plane equation obtained by fitting the wavefront map of the sample to be tested using the least squares method; further, the difference between the equation of the plane to be tested and the equation of the tilting plane of the stage after leveling is calculated to determine the surface morphology of the sample to be tested.

[0105] In this embodiment, based on the wavefront diagram of the sample under test and the wavefront diagram of the leveled stage, the influence of the stage height information on the surface morphology of the sample under test can be eliminated, so as to obtain an accurate surface morphology of the sample under test and improve the accuracy of the surface morphology of the sample under test.

[0106] In one specific embodiment, see Figure 4 The platform leveling method includes the following steps:

[0107] Step S401, pre-leveling.

[0108] Specifically, the platform is manually leveled to a horizontal position using standard leveling methods in the field. However, the levelness of the platform cannot be guaranteed at this point, requiring further leveling to improve the accuracy of the platform leveling. For example, in actual operation, experience is used to manually level the platform by visually observing the direction and number of stripes.

[0109] Step S402: Determine the image position information of multiple regulators in the image based on the center of the feature sample, the imaging magnification, and the actual position information of multiple regulators.

[0110] For example, the feature sample has a feature circle in the middle, which is used to determine the image position information of multiple regulators in the image.

[0111] Step S403: Obtain the wavefront of the platform topography, and calculate the equation of the platform tilt plane based on the wavefront diagram.

[0112] Step S404: Compare the height information of each regulator with the reference height to determine the height adjustment amount corresponding to each regulator.

[0113] Step S405: Adjust the corresponding adjuster according to the height adjustment amount corresponding to each adjuster to level the platform.

[0114] Step S406: Obtain the verification morphology wavefront map of the leveled stage.

[0115] Step S407: Determine the verification height adjustment amount corresponding to each regulator based on the verification topography wavefront diagram.

[0116] Step S408: Determine whether the verification height adjustment amount corresponding to each regulator meets the preset conditions.

[0117] Specifically, if the verification height adjustment amount corresponding to each regulator meets the preset conditions, the leveling is completed and step S409 is executed; otherwise, step S403 is executed until the verification height adjustment amount corresponding to each regulator meets the preset conditions.

[0118] Step S409: Place the sample to be tested within the limiting component of the stage and obtain the wavefront map of the sample's topography.

[0119] Step S410: Determine the surface morphology of the sample to be tested based on the wavefront diagram of the sample to be tested and the wavefront diagram of the leveled platform.

[0120] In one specific embodiment, after the stage is leveled, since the sample to be tested has a certain thickness (for example, the thickness of a wafer is 50-500um), considering the working distance of the laser interferometer, the overall height of the stage needs to be adjusted according to the thickness of the sample to be tested before the surface morphology of the sample to be tested can be determined, which can further improve the accuracy of the surface morphology of the sample to be tested.

[0121] The aforementioned stage leveling method, firstly, by setting multiple adjusters at corresponding positions on the stage, ensures that the height of each corresponding position on the stage can be adjusted, effectively saving leveling time and reducing the complexity of the leveling operation. Furthermore, based on the stage tilt plane equation and the image position information of the multiple adjusters in the image, the height information of each adjuster can be accurately calculated without additional measuring devices or sensors. This avoids the problems of limited sensor placement and low measurement accuracy associated with traditional measuring devices or sensors, effectively improving the applicability and accuracy of adjuster height measurement, laying the foundation for improving the accuracy of stage leveling. Furthermore, by adjusting the corresponding adjusters based on the reference height to achieve stage leveling, the accuracy of stage leveling is improved, and the complexity of stage leveling is reduced, further increasing the efficiency of stage leveling. Secondly, based on the imaging magnification and the actual position information of the multiple adjusters, the image position information of the multiple adjusters in the image can be accurately located, laying the data foundation for accurately determining the height information of each adjuster. Thirdly, based on the least squares method, the equation of the platform tilt plane is obtained, which can acquire accurate and objective tilt information of the platform, laying the foundation for improving the accuracy of platform leveling and avoiding the problem of low leveling accuracy caused by the lack of objectivity in manual leveling. Fourthly, based on preset conditions, the platform leveling is verified by judging whether the height adjustment amount meets the preset conditions, thereby improving the reliability of platform leveling and further improving the accuracy of platform leveling. Fifthly, based on the wavefront diagram of the test sample and the wavefront diagram of the leveled platform, the influence of platform height information on the surface morphology of the test sample can be eliminated, so as to obtain an accurate surface morphology of the test sample and improve the accuracy of the surface morphology of the test sample.

[0122] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0123] Based on the same inventive concept, this application also provides a platform leveling device for implementing the platform leveling method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations of the one or more platform leveling device embodiments provided below can be found in the limitations of the platform leveling method described above, and will not be repeated here.

[0124] In one embodiment, such as Figure 5 As shown, Figure 5 This is a structural block diagram of a platform leveling device in one embodiment; the platform leveling device includes: an acquisition module 501, a calculation module 502, a determination module 503, and an adjustment module 504;

[0125] The acquisition module 501 is used to acquire the wavefront image of the platform topography and the image position information of multiple regulators in the image;

[0126] Calculation module 502 is used to calculate the equation of the tilt plane of the platform based on the wavefront diagram of the platform topography;

[0127] The determination module 503 is used to determine the height information of each adjuster based on multiple image position information and the stage tilt plane equation;

[0128] The adjustment module 504 is used to adjust the corresponding adjuster according to the height information of each adjuster and the reference height in order to level the platform.

[0129] In one embodiment, the acquisition module 501 is further used for

[0130] Acquire image information and actual feature information of the feature sample; place the feature sample within the limiting component of the stage, with the center of the feature sample coinciding with the center of the stage;

[0131] Based on the image information of the feature sample, determine the image feature information of the feature sample;

[0132] Based on actual feature information, image feature information, and the actual position information of multiple regulators, the image position information of multiple regulators in the image is determined.

[0133] In one embodiment, the acquisition module 501 is further used for

[0134] Calculate the imaging magnification based on actual feature information and image feature information;

[0135] Based on the imaging magnification and the actual position information of multiple regulators, the image position information of multiple regulators in the image is determined.

[0136] In one embodiment, the computing module 502 is further used for

[0137] Extract the region image corresponding to the limiting component from the wavefront image of the platform morphology;

[0138] The equation of the platform tilt plane is obtained by fitting the plane using the least squares method based on the regional image.

[0139] In one embodiment, the adjustment module 504 is further used for

[0140] The height information of each regulator is compared with the reference height to determine the height adjustment amount corresponding to each regulator;

[0141] Adjust the corresponding adjuster according to the height adjustment amount of each adjuster to level the platform.

[0142] In one embodiment, the adjustment module 504 is further used for

[0143] Obtain the verification morphology wavefront image of the leveled stage;

[0144] Based on the verification topography wavefront plot, determine the verification height adjustment amount corresponding to each regulator;

[0145] If the verification height adjustment amount corresponding to each adjuster meets the preset conditions, the leveling is completed.

[0146] In one embodiment, the adjustment module 504 is further used for

[0147] When the sample to be tested is placed in the limiting component of the stage, the wavefront map of the topography of the sample to be tested is obtained.

[0148] The surface morphology of the sample to be tested is determined based on the wavefront diagram of the sample to be tested and the wavefront diagram of the leveled platform.

[0149] Each module in the aforementioned platform leveling device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0150] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6 As shown, Figure 6 This is an internal structural diagram of a computer device in one embodiment. The computer device includes a processor, memory, communication interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, NFC (Near Field Communication), or other technologies. When executed by the processor, the computer program implements a platform leveling method.

[0151] Those skilled in the art will understand that Figure 6 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0152] In one embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above method embodiments.

[0153] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the steps in the above method embodiments.

[0154] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0155] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0156] 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.

[0157] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for leveling a platform, characterized in that, The stage leveling method is applied to a laser interferometer. The stage surface of the laser interferometer is provided with a limit assembly, and the stage is correspondingly equipped with multiple adjusters for adjusting the height of corresponding positions on the stage. The method includes: Acquire the wavefront image of the platform topography and the image position information of multiple regulators in the image; The platform tilting plane equation is calculated based on the wavefront diagram of the platform topography; the platform tilting plane equation is determined based on the region image corresponding to the limiting component in the wavefront diagram of the platform topography. The height information of each adjuster is determined based on the multiple image position information and the stage tilt plane equation; Based on the height information of each adjuster and the reference height, adjust the corresponding adjuster to level the platform; Before acquiring the wavefront map of the platform topography and the image position information of multiple adjusters in the image, the following steps are included: The image information and actual feature information of the feature sample are acquired; the feature sample is placed within the limiting component of the stage, and the center of the feature sample coincides with the center of the stage; Based on the image information of the feature sample, determine the image feature information of the feature sample; Calculate the imaging magnification based on the actual feature information and image feature information; Based on the imaging magnification and the actual position information of the multiple adjusters, the image position information of the multiple adjusters in the image is determined.

2. The method according to claim 1, characterized in that, The step of calculating the equation of the tilt plane of the platform based on the wavefront diagram of the platform topography includes: Extract the region image corresponding to the limiting component from the wavefront image of the platform morphology; The equation of the platform tilt plane is obtained by fitting a plane using the least squares method based on the image of the region.

3. The method according to claim 1, characterized in that, The step of adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the platform includes: The height information of each regulator is compared with the reference height to determine the height adjustment amount corresponding to each regulator; Adjust the corresponding adjuster according to the height adjustment amount corresponding to each adjuster to level the platform.

4. The method according to claim 1, characterized in that, After adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the platform, the process further includes: Obtain the verification morphology wavefront image of the leveled stage; Based on the verification topography wavefront diagram, determine the verification height adjustment amount corresponding to each of the regulators; If the verification height adjustment amount corresponding to each of the aforementioned adjusters meets the preset conditions, then the leveling is completed.

5. The method according to claim 4, characterized in that, After adjusting the corresponding adjuster according to the height information of each adjuster and the reference height to level the platform, the process further includes: When the sample to be tested is placed in the limiting component of the stage, the wavefront diagram of the morphology of the sample to be tested is obtained. The surface morphology of the sample to be tested is determined based on the wavefront diagram of the sample to be tested and the wavefront diagram of the leveled platform.

6. A platform leveling device, characterized in that, The device includes: The acquisition module is used to acquire the wavefront image of the platform topography and the image position information of multiple regulators in the image; The calculation module is used to calculate the platform tilt plane equation based on the platform topography wavefront diagram; the platform tilt plane equation is determined based on the region image corresponding to the limiting component in the platform topography wavefront diagram; The determining module is used to determine the height information of each of the adjusters based on the multiple image position information and the stage tilt plane equation; An adjustment module is used to adjust the corresponding adjuster according to the height information of each adjuster and the reference height, so as to level the platform; The acquisition module is also used to acquire image information and actual feature information of the feature sample; the feature sample is placed within the limiting component of the stage, and the center of the feature sample coincides with the center of the stage; the image feature information of the feature sample is determined based on the image information of the feature sample; the imaging magnification is calculated based on the actual feature information and the image feature information; and the image position information of the multiple adjusters in the image is determined based on the imaging magnification and the actual position information of the multiple adjusters.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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