Three-dimensional super-resolution imaging method, device, equipment and storage medium

Abstract

The application provides a three-dimensional super-resolution imaging method, device, equipment and storage medium, the method comprises the following steps: determining a monochromatic diffraction pattern based on different diffraction angle distributions corresponding to different wavelength components in a wide spectrum diffraction signal obtained by irradiating a wafer surface by a coherent X-ray beam emitted by a synchrotron radiation source; determining a final phase gradient distribution of a wafer surface scattering potential in a depth direction based on phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern; determining a local scattering intensity response at different depth positions in a wafer surface layer based on the final phase gradient distribution and a synchrotron radiation incident geometry parameter; determining a three-dimensional scatterer distribution of the wafer surface layering along the depth direction based on the local scattering intensity response and the penetration depth difference corresponding to each wavelength; and determining a three-dimensional super-resolution imaging of lateral resolution and longitudinal resolution based on the three-dimensional scatterer distribution and a physical propagation model. The application improves the accuracy of three-dimensional super-resolution imaging of the three-dimensional topography of the wafer.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a three-dimensional super-resolution imaging method, apparatus, device, and storage medium. Background Technology

[0002] In the semiconductor manufacturing field, the three-dimensional morphology inspection of the microstructure of wafer surfaces is crucial for process control and defect identification. In existing technologies, a common method is to achieve three-dimensional imaging of the wafer surface using synchrotron X-ray diffraction combined with tomographic reconstruction algorithms. This method acquires diffraction signals from multiple angles and reconstructs the three-dimensional structure of the sample using back-projection or iterative reconstruction algorithms.

[0003] However, due to the limited spatial frequency coverage of the diffraction signal and the limitations of detector resolution and the number of sampling angles, this method is difficult to break through the optical diffraction limit during reconstruction, resulting in the inability to achieve nanometer-level resolution in both the lateral and longitudinal directions. In particular, it cannot effectively distinguish minute undulations or atomic step structures in the surface layer within a few nanometers of depth, thus limiting its application in advanced process nodes (such as below 3nm). Summary of the Invention

[0004] This invention provides a three-dimensional super-resolution imaging method, apparatus, device, and storage medium to overcome the resolution bottleneck caused by insufficient spectral coverage, solve the problem of being unable to break through the diffraction limit to distinguish surface nanostructures, and achieve high-resolution imaging of the nanoscale three-dimensional morphology of wafer surfaces.

[0005] In a first aspect, the present invention provides a three-dimensional super-resolution imaging method, comprising: By irradiating the wafer surface with a coherent X-ray beam within a continuous wavelength range using a synchrotron radiation source, a broadband diffraction signal containing multi-scale scattering information of the wafer surface is obtained. Based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal, the monochromatic diffraction pattern corresponding to the discrete wavelength is determined. Based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is determined, and based on the final phase gradient distribution and the incident geometry of synchrotron radiation, the local scattering intensity response at different depths within the wafer surface is determined. Based on the difference between the local scattering intensity response and the penetration depth corresponding to each wavelength, the three-dimensional scatterer distribution layered along the depth direction on the wafer surface is determined; Based on the physical propagation model of the three-dimensional scatterer distribution and synchrotron radiation diffraction, the three-dimensional super-resolution imaging of the wafer surface with lateral and longitudinal resolutions is determined.

[0006] In a second aspect, the present invention also provides a three-dimensional super-resolution imaging apparatus, applied to the three-dimensional super-resolution imaging method as described in the first aspect; the three-dimensional super-resolution imaging apparatus includes: The diffraction analysis module is used to irradiate the wafer surface with a coherent X-ray beam within a continuous wavelength range based on a synchrotron radiation source, to obtain a broadband diffraction signal containing multi-scale scattering information of the wafer surface, and to determine the monochromatic diffraction pattern corresponding to the discrete wavelength based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal. The phase correlation module is used to determine the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, and to determine the local scattering intensity response at different depths within the wafer surface based on the final phase gradient distribution and the incident geometry parameters of synchrotron radiation. The scattering analysis module is used to determine the three-dimensional scatterer distribution along the depth direction on the wafer surface based on the difference between the local scattering intensity response and the penetration depth corresponding to each wavelength. A three-dimensional super-resolution imaging module is used to determine the lateral and longitudinal resolutions of the wafer surface for three-dimensional super-resolution imaging based on the physical propagation model of the three-dimensional scatterer distribution and synchrotron radiation diffraction.

[0007] Thirdly, the present invention also provides an electronic device, comprising: a memory for storing computer software programs; and a processor for reading and executing the computer software programs, thereby realizing the three-dimensional super-resolution imaging method as described above.

[0008] Fourthly, the present invention also provides a non-transitory computer-readable storage medium storing a computer software program, which, when executed by a processor, implements the three-dimensional super-resolution imaging method as described above.

[0009] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the three-dimensional super-resolution imaging method as described above.

[0010] The three-dimensional super-resolution imaging method provided in this invention irradiates the wafer surface with a coherent X-ray beam within a continuous wavelength range, breaking the limitations of single wavelengths or limited wavelengths. This allows for the acquisition of a broadband diffraction signal containing multi-scale scattering information from the wafer surface. Furthermore, the method separates the monochromatic diffraction patterns corresponding to discrete wavelengths from the broadband diffraction signal, compensating for insufficient spectral coverage. Based on the discrete wavelength monochromatic diffraction patterns, the method precisely captures the phase change patterns at different depths of the wafer surface by exploring the phase correlation between adjacent wavelength patterns. This determines the final phase gradient distribution of the wafer surface scattering potential in the depth direction. Combined with synchrotron radiation incident geometry parameters, the phase information is converted into a quantifiable local scattering intensity response, clarifying the scattering characteristics at different depths within the wafer surface and solving the problem of inaccurately capturing surface depth information. Based on the local scattering intensity response and utilizing the penetration depth differences corresponding to various wavelengths, the wafer surface is analyzed layer by layer along the depth direction. This accurately locates the position and distribution of scatterers at different depths, constructing a three-dimensional scatterer distribution on the wafer surface. By combining this three-dimensional scatterer distribution with a physical propagation model of synchrotron radiation diffraction, the scatterer distribution information is integrated with the diffraction propagation laws, achieving three-dimensional super-resolution imaging of the wafer surface with both lateral and longitudinal resolutions. Therefore, this embodiment of the invention, through depth encoding of multi-wavelength diffraction signals and self-consistent reconstruction driven by a physical model, compensates for the shortcomings of insufficient spectral coverage, overcomes the resolution bottleneck caused by insufficient spectral coverage, solves the problem of being unable to break through the diffraction limit to resolve surface structures, and improves the accuracy of three-dimensional super-resolution imaging of the wafer's three-dimensional morphology. Attached Figure Description

[0011] Figure 1 This is a schematic flowchart of the three-dimensional super-resolution imaging method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the three-dimensional super-resolution imaging device provided in an embodiment of the present invention; Figure 3 An embodiment diagram of the electronic device provided in this invention; Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with the present invention. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0014] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0015] See Figure 1 , Figure 1 This is a flowchart illustrating the three-dimensional super-resolution imaging method provided by the present invention. In this embodiment, the execution entity of the three-dimensional super-resolution imaging method is a super-resolution imaging device. Therefore, the three-dimensional super-resolution imaging method includes: Step 10: Irradiate the wafer surface with a coherent X-ray beam within a continuous wavelength range based on a synchrotron radiation source to obtain a broadband diffraction signal containing multi-scale scattering information of the wafer surface. Based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal, determine the monochromatic diffraction pattern corresponding to the discrete wavelength.

[0016] Optionally, the super-resolution imaging device activates a synchrotron radiation source. A synchrotron radiation source is a high-intensity, high-coherence, and spectrally continuously tunable electromagnetic radiation source generated when high-energy electrons are accelerated in a magnetic field. The X-ray beam emitted by the synchrotron radiation source has a continuous wavelength range, which covers the typical wavelength range of soft X-rays and hard X-rays. The wavelength range of soft X-rays is 10 to 100 angstroms, and the wavelength range of hard X-rays is shorter than 1 angstrom. The specific continuous wavelength range can be adjusted according to the wafer inspection requirements to ensure that the scattering requirements of different depths of the wafer surface structure can be covered.

[0017] Furthermore, the super-resolution imaging device controls a coherent X-ray beam within a continuous wavelength range emitted by a synchrotron radiation source to irradiate the wafer surface at a preset incident angle. This incident angle can be adjusted according to parameters such as the wafer material and surface thickness to ensure that the X-ray beam effectively penetrates the wafer surface and is scattered. A coherent X-ray beam refers to an X-ray beam possessing both spatial and temporal coherence. Spatial coherence ensures that the wavefront of the X-ray beam remains consistent during propagation, while temporal coherence ensures the frequency stability of the X-ray beam.

[0018] When a coherent X-ray beam irradiates the surface of a wafer, the atoms, molecules, and microstructures on the wafer surface will scatter the X-ray beam. Microstructures of different scales (including nanoscale defects, multilayer film structures, grain structures, etc. on the surface) will produce scattering signals of different intensities and directions. These scattering signals are superimposed to form a broadband diffraction signal.

[0019] Therefore, broadband diffraction signals refer to diffraction signals containing continuous wavelength components. These signals not only contain multi-scale scattering information of the wafer surface, but also all the characteristic information of the interaction between X-ray beams of different wavelengths and the wafer surface structure. Multi-scale scattering information refers to the scattering-related information generated by different sized structures of the wafer surface from the nanometer to the micrometer scale, covering the structural scattering characteristics of the surface and different depths inside the surface.

[0020] Furthermore, the super-resolution imaging device receives broadband diffraction signals through a signal acquisition module. This module must possess high sensitivity and a wide wavelength response range to accurately capture diffraction signals corresponding to different wavelength components. Subsequently, the super-resolution imaging device performs separation processing on the acquired broadband diffraction signals, based on the different diffraction angle distribution patterns corresponding to different wavelength components within the broadband diffraction signals.

[0021] Therefore, the diffraction angle distribution refers to the angle distribution between the propagation direction and the incident direction of X-ray beams of different wavelengths after they are scattered by the wafer surface. Since the wavelengths of X-rays are different, the diffraction angles when they interact with the wafer surface structure are also different. The longer the wavelength, the larger the diffraction angle, and the shorter the wavelength, the smaller the diffraction angle.

[0022] Furthermore, the super-resolution imaging device selects several characteristic wavelengths within a continuous wavelength range as discrete wavelengths. The selection of these characteristic wavelengths must be combined with the penetration requirements of the wafer surface structure to ensure that the X-ray beam corresponding to each discrete wavelength can penetrate different depths of the wafer surface, and that the wavelength difference between adjacent discrete wavelengths remains uniform, facilitating subsequent phase correlation analysis. After selection, based on the diffraction angle distribution corresponding to different discrete wavelengths, the diffraction signal corresponding to each discrete wavelength is separated from the broadband diffraction signal. Then, the diffraction signal corresponding to each discrete wavelength undergoes noise reduction and enhancement processing to remove irrelevant signals such as environmental interference and equipment noise, ultimately obtaining the monochromatic diffraction pattern corresponding to each discrete wavelength. A monochromatic diffraction pattern refers to the diffraction image formed after a single-wavelength X-ray beam is scattered by the wafer surface. Each monochromatic diffraction pattern corresponds to the scattering characteristics of a specific depth and scale structure on the wafer surface.

[0023] In one embodiment, the application scenario is three-dimensional super-resolution imaging of the surface of a 7-nanometer node wafer. The wafer surface contains a multilayer film structure composed of alternating molybdenum and silicon, with a surface thickness of 1 micrometer. The surface has nanoscale defects, and step 10 is required to obtain the monochromatic diffraction pattern corresponding to the discrete wavelength.

[0024] The super-resolution imaging device activates the synchrotron radiation source and adjusts the source parameters to make the synchrotron radiation source emit a continuous wavelength coherent X-ray beam with a wavelength range of 0.5 angstroms to 50 angstroms. This wavelength range covers hard X-rays (0.5 angstroms to 1 angstrom) and soft X-rays (1 angstrom to 50 angstroms). Hard X-rays can penetrate to deeper parts of the wafer surface, while soft X-rays mainly reflect the shallow structural features of the wafer surface.

[0025] The super-resolution imaging device adjusts the incident angle of the coherent X-ray beam to 15 degrees to ensure that the X-ray beam can be incident perpendicular to the multilayer film structure on the wafer surface, reducing the interference of the incident angle on the scattered signal. Then, the coherent X-ray beam is controlled to irradiate the surface of the 7-nanometer node wafer. The molybdenum-silicon multilayer film structure, nanoscale defects and grain structure on the wafer surface scatter the X-ray beam. Structures of different scales produce scattered signals of different intensities. These scattered signals are superimposed to form a broadband diffraction signal.

[0026] The super-resolution imaging device receives the broadband diffraction signal through a high-sensitivity signal acquisition module. The module's response range matches the continuous wavelength range of the synchrotron radiation source, enabling it to accurately capture diffraction signals corresponding to all wavelength components within the range of 0.5 Å to 50 Å. Subsequently, the super-resolution imaging device analyzes the broadband diffraction signal to determine the diffraction angle distribution corresponding to different wavelength components: the diffraction angle range for hard X-rays from 0.5 Å to 1 Å is 5° to 10°, the diffraction angle range for soft X-rays from 1 Å to 10 Å is 10° to 25°, and the diffraction angle range for soft X-rays from 10 Å to 50 Å is 25° to 45°.

[0027] The super-resolution imaging device screens discrete wavelengths, selecting eight discrete wavelengths (0.5 Å, 1 Å, 5 Å, 10 Å, 20 Å, 30 Å, 40 Å, and 50 Å) based on the characteristics of the wafer surface structure. The wavelength difference between adjacent discrete wavelengths is uniform, covering the structural scattering requirements of the wafer surface from shallow to deep. Based on the diffraction angle distribution corresponding to each discrete wavelength, the diffraction signal corresponding to each discrete wavelength is separated from the broadband diffraction signal. The separated diffraction signals undergo noise reduction processing to remove irrelevant interference such as environmental vibration and equipment circuit noise, ultimately obtaining monochromatic diffraction patterns corresponding to the eight discrete wavelengths. The monochromatic diffraction patterns corresponding to 0.5 Å and 1 Å reflect the structural scattering characteristics of deeper parts of the wafer surface, the monochromatic diffraction patterns corresponding to 20 Å to 50 Å reflect the structural scattering characteristics of shallow parts of the wafer surface, and the monochromatic diffraction patterns corresponding to 5 Å and 10 Å reflect the structural scattering characteristics of the middle depths of the wafer surface.

[0028] Step 20: Based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, determine the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction, and based on the final phase gradient distribution and the incident geometric parameters of synchrotron radiation, determine the local scattering intensity response at different depths within the wafer surface.

[0029] Optionally, the super-resolution imaging device determines the final phase gradient distribution of the wafer surface scattering potential along the depth direction based on the phase correlation between adjacent wavelength patterns in all monochromatic diffraction patterns, as described in steps 201 to 204. Here, phase correlation refers to the relationship between the phases of diffraction signals at corresponding positions in monochromatic diffraction patterns corresponding to adjacent wavelengths, determined by the structural scattering characteristics at the same depth position on the wafer surface. Scattering potential refers to the ability of the wafer surface structure to scatter X-ray beams, and its magnitude is related to the material, density, and structural dimensions of the wafer surface. Phase gradient distribution refers to the variation of phase values ​​along the depth direction of the wafer surface, reflecting the characteristics of scattering potential changes at different depth positions on the wafer surface.

[0030] Furthermore, the super-resolution imaging device acquires preset synchrotron radiation incident geometry parameters. These parameters refer to the relevant parameters when the coherent X-ray beam irradiates the wafer surface in step 10, including the incident angle, incident intensity, and beam size. These parameters are all known parameters determined in step 10. Based on the final phase gradient distribution and the synchrotron radiation incident geometry parameters, the super-resolution imaging device determines the local scattering intensity response at different depths within the wafer surface, as described in steps 205 to 208. The local scattering intensity response refers to the magnitude of the scattering intensity generated by the structure at a specific depth within the wafer surface to the X-ray beam, directly reflecting the structural characteristics at that depth.

[0031] Step 30: Based on the difference between the local scattering intensity response and the penetration depth corresponding to each wavelength, determine the three-dimensional scatterer distribution layered along the depth direction on the wafer surface.

[0032] Optionally, the super-resolution imaging device combines the penetration depth differences corresponding to each discrete wavelength to determine the three-dimensional scatterer distribution of the wafer surface layered along the depth direction, as described in steps 301 to 304. The penetration depth difference refers to the different depths that X-ray beams of different wavelengths can penetrate the wafer surface. Shorter wavelength X-ray beams (hard X-rays) have greater penetration depths, while longer wavelength X-ray beams (soft X-rays) have smaller penetration depths. This difference is determined by the energy characteristics of X-rays; higher energy (shorter wavelength) results in stronger penetration. The three-dimensional scatterer distribution refers to the three-dimensional representation of the position, size, and distribution density of scatterers (i.e., the microstructures that produce scattering) within each layer after the wafer surface is layered along the depth direction. This can completely reflect the internal structural distribution of the wafer surface.

[0033] Step 40: Based on the physical propagation model of three-dimensional scatterer distribution and synchrotron radiation diffraction, determine the three-dimensional super-resolution imaging of the wafer surface with lateral and longitudinal resolutions.

[0034] Optionally, the super-resolution imaging device acquires a preset physical propagation model of synchrotron radiation diffraction. The physical propagation model of synchrotron radiation diffraction refers to a physical model that describes the relationship between the propagation law, diffraction characteristics and wafer surface structure of the synchrotron radiation X-ray beam after scattering by the wafer surface. This model is constructed based on the principles of statistical optics and can accurately reflect the interaction process between the X-ray beam and the wafer surface scatterer, covering core physical laws such as mutual intensity propagation, diffraction angle distribution, and scattering intensity attenuation.

[0035] Furthermore, the super-resolution imaging device inputs relevant data on the three-dimensional scatterer distribution into the physical propagation model of synchrotron radiation diffraction. Through model analysis, the lateral and longitudinal resolutions of the wafer surface are derived in reverse. The lateral resolution refers to the smallest resolvable structural size in the horizontal direction of the wafer surface, and the longitudinal resolution refers to the smallest resolvable structural size in the depth direction of the wafer surface layer. Together, they constitute the three-dimensional super-resolution imaging index of the wafer surface. The specific analysis process of this embodiment is as follows: using the physical propagation model of synchrotron radiation diffraction, the propagation characteristics of the diffraction signal corresponding to each scatterer in the three-dimensional scatterer distribution are analyzed. Combined with the position and size information of the scatterers, the minimum distance at which two adjacent scatterers can be clearly distinguished in the horizontal direction is calculated; this distance is the lateral resolution of the wafer surface. Simultaneously, the differences in diffraction signals corresponding to scatterers in different depth layers are analyzed, and the minimum depth difference at which two adjacent layers can be clearly distinguished in the depth direction is calculated; this depth difference is the longitudinal resolution of the wafer surface.

[0036] Ultimately, the super-resolution imaging device combines the calculation results of lateral and longitudinal resolutions, integrates all information on the distribution of three-dimensional scatterers, and generates a three-dimensional super-resolution image of the wafer surface. The three-dimensional super-resolution imaging can clearly present the layered structure of the wafer surface along the depth direction, the distribution of microscopic scatterers in each layer, and the specific location and size of nanoscale defects, thus meeting the high-precision detection requirements of the wafer surface structure.

[0037] Continuing with the above embodiments, the three-dimensional scatterer distribution along the depth direction on the wafer surface obtained in step 30, and the physical propagation model of synchrotron radiation diffraction, are constructed based on the mutual intensity propagation principle in statistical optics. This model can accurately describe the propagation law of X-ray beams in the wavelength range of 0.5 Å to 50 Å after passing through the wafer surface scatterers in step 10. It covers core physical processes such as diffraction angle distribution, scattering intensity attenuation, and mutual intensity superposition. The model has preset parameter configurations that match the wafer material (molybdenum-silicon multilayer film) and incident parameters (15-degree incident angle) of this embodiment.

[0038] The super-resolution imaging device inputs the three-dimensional scatterer distribution data obtained in step 30 into the physical propagation model. The three-dimensional scatterer distribution shows that the surface layer of the 7-nanometer node wafer is divided into 5 layers along the depth direction, from the surface to the depth: the first layer (depth 0 to 0.2 micrometers) is the surface layer of the molybdenum-silicon multilayer film, containing scatterers (grain structure) with a size of 30 nanometers to 50 nanometers; the second layer (depth 0.2 to 0.4 micrometers) is the middle layer of the molybdenum-silicon multilayer film, containing scatterers with a size of 20 nanometers to 30 nanometers, and containing a nanometer-scale defect with a size of 10 nanometers; the third layer (depth 0.4 to 0.6 micrometers) is the bottom layer of the molybdenum-silicon multilayer film, containing scatterers with a size of 15 nanometers to 25 nanometers; the fourth layer (depth 0.6 to 0.8 micrometers) is the transition layer, containing scatterers with a size of 10 nanometers to 15 nanometers; and the fifth layer (depth 0.8 to 1.0 micrometers) is the surface layer of the wafer substrate, containing scatterers with a size of 5 nanometers to 10 nanometers.

[0039] The super-resolution imaging device analyzes the scatterers within each layer using a physical propagation model of synchrotron radiation diffraction. For determining the lateral resolution, the model analyzes the superposition of diffraction signals from adjacent scatterers in the horizontal direction. It calculates that when the horizontal distance between two adjacent scatterers is greater than 4.2 nanometers, their corresponding diffraction signals can be clearly distinguished without overlap or interference. Therefore, the lateral resolution of the wafer surface is determined to be 4.2 nanometers, capable of clearly distinguishing the nanoscale grain structure and defects on the surface of a 7-nanometer node wafer. For determining the longitudinal resolution, the model analyzes the difference in diffraction signals between scatterers in adjacent layers in the depth direction. It calculates that when the depth difference between two adjacent layers is greater than 2.4 nanometers, their corresponding diffraction signals can be clearly distinguished. Therefore, the longitudinal resolution of the wafer surface is determined to be 2.4 nanometers, capable of clearly distinguishing the layered structure with a 0.2-micrometer interval in the depth direction and the microscopic scatterers within each layer.

[0040] Finally, the super-resolution imaging device integrates the calculation results of the lateral resolution (4.2 nm) and the longitudinal resolution (2.4 nm), and combines all the information of the three-dimensional scatterer distribution to generate a three-dimensional super-resolution image of the 7 nm node wafer surface. The three-dimensional super-resolution image clearly presents the specific locations of the five layers, the size and distribution density of the scatterers in each layer, and the specific location of a 10 nm nanometer-scale defect in the second layer. The imaging accuracy meets the requirements of the surface structure detection of the 7 nm node wafer, and provides accurate three-dimensional structural data support for wafer defect analysis and process optimization.

[0041] The embodiments of the present invention overcome the resolution bottleneck caused by insufficient spectral coverage by using deep encoding of multi-wavelength diffraction signals and self-consistent reconstruction driven by physical models, solve the problem of being unable to break through the diffraction limit to distinguish surface structures, and improve the accuracy of three-dimensional super-resolution imaging of the three-dimensional morphology of wafers.

[0042] Optionally, the processes of steps 201 to 204 include: Step 201: Based on the phase difference and wavelength difference of the monochromatic diffraction patterns corresponding to adjacent wavelengths at the same reciprocal space position, perform differential calculation to obtain the local phase change rate of the wafer surface scattering potential along the optical path direction.

[0043] Optionally, the super-resolution imaging device aligns the monochromatic diffraction patterns corresponding to adjacent wavelengths in reciprocal space. Here, reciprocal space refers to the virtual space corresponding to the real space structure of the wafer surface, and reciprocal space position refers to the coordinate position of each diffraction signal point in the monochromatic diffraction pattern in the reciprocal space. This position corresponds one-to-one with the size and distribution state of the microstructure in the real space of the wafer surface. The same reciprocal space position corresponds to the diffraction signal generated by the same size and distribution state of the microstructure in the real space of the wafer surface.

[0044] Furthermore, after alignment, the super-resolution imaging device extracts the phase values ​​of the diffraction signals of the monochromatic diffraction patterns corresponding to adjacent wavelengths at the same reciprocal space position. The phase value refers to the vibration phase of the diffraction signal, which reflects the change in the vibration state of the X-ray beam after being scattered by the wafer surface. Different phase values ​​correspond to different scattering intensities and scattering directions.

[0045] Furthermore, the super-resolution imaging device calculates the difference between the phase values ​​corresponding to two adjacent wavelengths at the same reciprocal space location to obtain the phase difference value; at the same time, it extracts the wavelength values ​​of the two adjacent wavelengths, calculates the difference between the two wavelength values, and obtains the wavelength difference value.

[0046] Furthermore, the super-resolution imaging device performs differential operations on the phase difference and wavelength difference. The differential operation refers to calculating the rate of change of the phase difference with respect to the wavelength difference. The specific operation logic is as follows: Using wavelength difference as the change quantity and phase difference as the change result, the ratio of the two is used to obtain the phase change corresponding to a unit wavelength change, which is the local phase change rate of the scattering potential along the optical path direction of the wafer surface. Here, the optical path direction refers to the path of the synchrotron X-ray beam propagating within the wafer surface after irradiation, and is consistent with the incident direction of the X-ray beam; the local phase change rate refers to how quickly the phase of the scattering potential changes with the optical path direction at a specific location on the wafer surface, reflecting the characteristics of the scattering potential change at that location.

[0047] Step 202: Based on the local phase change rate and the grazing incidence angle of the synchrotron radiation incident beam, perform a geometric projection transformation from optical path to physical depth to obtain the preliminary phase gradient distribution of the wafer surface scattering potential in the depth direction.

[0048] Optionally, since the local phase change rate is a phase change law along the optical path direction, while the depth direction of the wafer surface refers to the direction perpendicular to the wafer surface, there is a geometric angular difference (i.e., grazing incidence angle) between the optical path direction and the depth direction. Therefore, it is necessary to convert the local phase change rate in the optical path direction into a phase gradient distribution in the depth direction through geometric projection transformation. The specific logic of geometric projection transformation is as follows: the super-resolution imaging device projects the local phase change rate along the optical path direction onto the depth direction perpendicular to the wafer surface using the grazing incidence angle as the projection angle. The angular deviation between the optical path direction and the depth direction is eliminated through projection calculation, resulting in a preliminary phase gradient distribution of the scattering potential of the wafer surface in the depth direction. Here, the preliminary phase gradient distribution refers to the initial phase gradient data in the depth direction before depth matching and phase alignment, which can initially reflect the phase change trend of the scattering potential at different depth positions of the wafer surface.

[0049] Step 203: Based on the preliminary phase gradient distribution and the penetration depth sequence of each wavelength component in the wafer material during synchrotron broadband illumination, a depth response matching analysis is performed to obtain the phase gradient layer mapping corresponding to different detection depths. Based on the phase gradient layer mapping and the consistency of lateral sampling of adjacent wavelength diffraction signals in real space, the interlayer phase continuity is aligned to obtain the first target phase gradient volume distribution.

[0050] Optionally, the super-resolution imaging device performs depth response matching analysis on the preliminary phase gradient distribution and the penetration depth sequence. The depth response matching analysis refers to matching the positions corresponding to different phase gradients in the preliminary phase gradient distribution with the penetration depths corresponding to different wavelengths in the penetration depth sequence one by one, clarifying the phase gradient data corresponding to each penetration depth (i.e., each detection depth), and obtaining a phase gradient layer mapping corresponding to different detection depths.

[0051] Among them, the detection depth refers to the depth of the wafer surface that can be detected by X-ray beams of different wavelengths, which is consistent with the penetration depth value; the phase gradient layer mapping refers to dividing the wafer surface into several layers according to the detection depth, with each detection depth layer corresponding to a set of phase gradient data, forming a layered phase gradient mapping relationship that can clearly present the phase gradient characteristics of different depth layers.

[0052] Furthermore, after matching is completed, the super-resolution imaging device extracts lateral sampling data of adjacent wavelength diffraction signals in real space.

[0053] Among them, real space refers to the actual physical space on the wafer surface, lateral sampling refers to sampling the diffraction signal along the horizontal direction of the wafer surface, and lateral sampling consistency refers to the consistency of the sampling interval, sampling range, and sampling accuracy of diffraction signals corresponding to adjacent wavelengths in the horizontal direction.

[0054] Furthermore, based on lateral sampling consistency, the super-resolution imaging device performs inter-layer phase continuity alignment on the phase gradient data of each layer in the phase gradient layer mapping. Inter-layer phase continuity alignment refers to adjusting the phase gradient data of each depth layer to keep the phase gradient changes between adjacent depth layers continuous, eliminating problems such as abrupt phase changes and misalignments between layers, and ensuring that the phase gradient distribution can truly reflect the scattering potential change law in the depth direction of the wafer surface, and finally obtaining the first target phase gradient volume distribution.

[0055] Step 204: Based on the first target phase gradient volume distribution and the interferometric detection volume formed by synchrotron radiation coherent illumination, determine the final phase gradient distribution of the wafer surface scattering potential in the depth direction.

[0056] Optionally, the interferometric detection volume refers to the effective detection region formed within the wafer surface layer after synchrotron coherent X-ray beam irradiates the wafer surface, capable of producing an interference effect. The size and shape of the region are determined by the coherence of the synchrotron radiation source, the incident parameters, and the wafer material. The super-resolution imaging device determines the final phase gradient distribution of the wafer surface scattering potential in the depth direction based on the phase gradient volume distribution of the first target and the interferometric detection volume formed by synchrotron coherent illumination, as described in steps 2041 to 2044. This invention, through the step-by-step mining of phase correlation information of diffraction patterns of adjacent wavelengths, precisely combines the phase change law with the depth dimension, and achieves accurate capture of the phase gradient of the scattering potential at different depths on the wafer surface. This overcomes the defect that single phase analysis cannot distinguish depth information, ensures accurate acquisition of structural features in the depth direction of the wafer surface, and improves the accuracy of three-dimensional super-resolution imaging of the wafer's three-dimensional morphology.

[0057] Optionally, the process of steps 2041 to 2044 includes: Step 2041: Based on the phase gradient volume distribution of the first target and the interference detection volume formed by the coherent illumination of synchrotron radiation, the effective detection region is truncated to obtain the effective phase gradient volume within the coherent length range.

[0058] Optionally, the super-resolution imaging device extracts the coherence length parameter of the synchrotron radiation coherent illumination. The coherence length refers to the maximum propagation distance at which the synchrotron radiation coherent X-ray beam maintains coherence. It is determined by the characteristics of the synchrotron radiation source itself and directly determines the range of the effective coherent region within the interferometric detection volume.

[0059] Furthermore, the super-resolution imaging device performs an effective detection region interception operation on the phase gradient volume distribution of the first target based on the spatial range of the interferometric detection volume and the coherence length parameter. Effective detection region interception refers to selecting phase gradient data in the phase gradient volume distribution of the first target that are within the interferometric detection volume and within the coherence length range, and removing invalid phase gradient data that are outside the interferometric detection volume and not within the coherence length range.

[0060] Invalid phase gradient data refers to phase gradient data that has not been effectively irradiated by synchrotron coherent illumination and cannot produce an effective interference effect. This part of the data will interfere with subsequent phase gradient analysis and affect the accuracy of the final phase gradient distribution.

[0061] By intercepting the effective detection region, the effective phase gradient volume located within the coherence length range is finally obtained. The effective phase gradient volume refers to a three-dimensional phase gradient data set containing only the effective detection region and having effective coherence characteristics, which can truly reflect the phase gradient characteristics of the wafer surface scattering potential within the interferometric detection volume.

[0062] Step 2042: Based on the geometric relationship between the effective phase gradient volume and the normal direction of the wafer surface, the coordinate system is reoriented to obtain the second target phase gradient volume distribution aligned with the depth axis based on the wafer surface.

[0063] Optionally, the resolving imaging device analyzes the geometric relationship between the effective phase gradient volume and the normal direction of the wafer surface. The geometric relationship refers to the angle and positional correspondence between the three-dimensional coordinate system of the effective phase gradient volume and the normal direction of the wafer surface. Since the effective phase gradient volume is obtained based on the interferometric detection volume, its original coordinate system may deviate from the normal direction of the wafer surface and cannot directly reflect the phase gradient change law in the depth direction. Therefore, coordinate system reversal is required.

[0064] The specific logic of coordinate system retargeting is as follows: The super-resolution imaging device uses the wafer surface as the reference plane and the wafer surface normal direction as the positive direction of the depth axis. It adjusts the three-dimensional coordinate system of the phase gradient effective volume so that the depth axis of the phase gradient effective volume is completely aligned with the wafer surface normal direction, ensuring that the depth coordinates of each phase gradient data in the phase gradient effective volume can accurately correspond to the actual depth position of the wafer surface.

[0065] By reorienting the coordinate system, the deviation between the effective phase gradient volume coordinate system and the normal direction of the wafer surface is eliminated, resulting in a second target phase gradient volume distribution aligned with the depth axis based on the wafer surface. The second target phase gradient volume distribution refers to a set of three-dimensional phase gradient data in which the coordinate system is completely aligned with the depth direction of the wafer surface, which can intuitively and accurately present the phase gradient characteristics at different depths on the wafer surface.

[0066] Step 2043: Based on the phase gradient volume distribution of the second target and the propagation characteristics of the scattering potential phase under the Helmholtz equation, perform phase gradient physical screening and retain the phase gradient solution set that conforms to the wave propagation law.

[0067] Optionally, the Helmholtz equation is the fundamental physical equation describing wave propagation. The propagation characteristics of the scattering potential phase under the Helmholtz equation refer to the physical laws that the phase corresponding to the scattering potential of the wafer surface follows during the propagation of X-ray beam waves. Specifically, these include the continuity of phase propagation, the attenuation law, and the correspondence between phase change and propagation distance. These propagation characteristics are the basis for selecting effective phase gradient data.

[0068] Based on the aforementioned propagation characteristics, the super-resolution imaging device performs phase gradient physical screening on the phase gradient volume distribution of the second target. Phase gradient physical screening refers to verifying each phase gradient data in the phase gradient volume distribution of the second target one by one to determine whether it conforms to the propagation law of the scattering potential phase under the Helmholtz equation.

[0069] The specific screening logic is as follows: Based on the propagation characteristics under the Helmholtz equation, the super-resolution imaging device presets a reasonable range of phase gradient variation and a continuous variation condition. Phase gradient data that conforms to the reasonable range of variation and meets the continuous variation condition, i.e., follows the wave propagation law, is retained; phase gradient data that exceeds the reasonable range of variation and does not meet the continuous variation condition, i.e. violates the wave propagation law, is discarded to avoid invalid or abnormal data affecting the accuracy of the final phase gradient distribution.

[0070] Through physical screening of phase gradients, the phase gradient solution set that conforms to the wave propagation law is finally retained. The phase gradient solution set refers to the set of all phase gradient data that have been physically verified and have physical rationality, and can accurately reflect the true propagation characteristics of the phase gradient of the scattering potential on the wafer surface.

[0071] Step 2044: Based on the phase gradient solution set and the azimuth and grazing incidence angles in the synchrotron radiation incident geometry, a three-dimensional spatial orientation integration is performed to obtain the final phase gradient distribution of the wafer surface scattering potential in the depth direction.

[0072] Optionally, the super-resolution imaging device performs three-dimensional spatial orientation integration of the phase gradient solution set based on the azimuth angle and grazing incidence angle. This three-dimensional spatial orientation integration refers to determining the orientation of the phase gradient solution set in the horizontal direction on the wafer surface based on the azimuth angle, and correcting the phase gradient value in the depth direction based on the grazing incidence angle, so that the phase gradient solution set can accurately match the incident direction of the synchrotron X-ray beam and the spatial structure of the wafer surface. Specifically, the integration logic is as follows: the super-resolution imaging device uses the azimuth angle as the horizontal orientation reference and adjusts the distribution angle of the phase gradient solution set in the horizontal direction to ensure that the phase gradient data is consistent with the projection of the X-ray beam incident direction onto the horizontal plane; using the grazing incidence angle as the depth direction correction reference, it corrects the phase gradient value of the phase gradient solution set, eliminating the influence of the grazing incidence angle on the phase gradient value, so that the phase gradient value can accurately reflect the true change of the scattering potential in the depth direction of the wafer surface.

[0073] By integrating the phase gradient solution set with the incident geometric parameters of synchrotron radiation in three-dimensional space, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is obtained.

[0074] The embodiments of the present invention achieve accurate capture of the phase gradient in the depth direction of the scattering potential of the wafer surface, thereby improving the accuracy of three-dimensional super-resolution imaging of the three-dimensional morphology of the wafer.

[0075] Optionally, steps 205 to 208 include: Step 205: For each depth position within the wafer surface, spatial coordinates are aligned based on the phase gradient value at each depth position in the phase gradient distribution and the grazing incidence angle in the synchrotron radiation incident geometry parameters to obtain the phase gradient spatial positioning result.

[0076] Optionally, the super-resolution imaging device divides the wafer surface into depth positions based on the penetration depth sequence of each wavelength component in the wafer material during synchrotron broadband illumination. The wafer surface is divided into several consecutive depth positions from the surface to the depth, with each depth position corresponding to a fixed depth value. This ensures that the entire thickness range of the wafer surface is covered, and the spacing between adjacent depth positions remains uniform, guaranteeing the comprehensiveness and accuracy of subsequent analysis.

[0077] For each depth location within the divided wafer surface layer, the super-resolution imaging device extracts the phase gradient value at that depth location. The phase gradient value refers to the rate of change of the scattering potential phase along the depth direction at the corresponding depth location in the final phase gradient distribution, directly reflecting the strength of the change in scattering potential at that depth location.

[0078] Subsequently, the super-resolution imaging device performs spatial coordinate alignment based on the phase gradient value at the depth position and the grazing incidence angle. Spatial coordinate alignment refers to matching and calibrating the spatial coordinates corresponding to the phase gradient value with the actual spatial coordinates of the wafer surface, using the wafer surface as the reference plane and the grazing incidence angle as the geometric correction basis, thereby eliminating the spatial deviation between the phase gradient value and the actual depth position caused by the grazing incidence angle.

[0079] The specific operating logic is as follows: The super-resolution imaging device uses the grazing incidence angle as a correction parameter to adjust the spatial coordinates of the phase gradient value so that the spatial position corresponding to the phase gradient value can accurately correspond to the actual physical position of that depth position within the wafer surface, ensuring a one-to-one correspondence between the phase gradient value and the depth position, and finally obtaining the phase gradient spatial positioning result corresponding to each depth position. The phase gradient spatial positioning result refers to the positioning data after the phase gradient value at each depth position is accurately matched with its actual spatial coordinates.

[0080] Step 206: Based on the spatial positioning results of the phase gradient and the propagation path of the synchrotron radiation incident beam inside the wafer, the local scattering potential gradient direction is analyzed to obtain the spatial variation direction of the scattering potential.

[0081] Optionally, the propagation path of the synchrotron radiation incident beam inside the wafer refers to the specific path of the synchrotron radiation X-ray beam after it enters the wafer surface and propagates within the wafer's surface layer. This path is determined by the synchrotron radiation incident geometric parameters (including grazing incident angle and azimuth angle) and the wafer material. The super-resolution imaging device, based on the phase gradient spatial localization results, determines the spatial distribution of the phase gradient at each depth location. Combined with the propagation path of the synchrotron radiation incident beam inside the wafer, it analyzes the direction of the local scattering potential gradient at each depth location. The analysis of the local scattering potential gradient direction refers to determining the specific spatial orientation of the scattering potential gradient by analyzing the geometric relationship between the phase gradient spatial localization results and the incident beam propagation path.

[0082] The specific analysis logic is as follows: The super-resolution imaging device analyzes the changing trend of the phase gradient value in the spatial positioning result of the phase gradient, combines the propagation direction of the synchrotron radiation incident beam at that depth position, determines the relative relationship between the spatial direction of the scattering potential gradient and the propagation direction of the incident beam, eliminates the directional deviation caused by the propagation interference of the incident beam, accurately determines the actual spatial direction of the local scattering potential gradient at each depth position, and finally obtains the spatial change direction of the scattering potential. The spatial change direction of the scattering potential refers to the specific spatial direction of the scattering potential gradient at each depth position, which can reflect the changing orientation of the scattering potential at that depth position.

[0083] Step 207: Based on the spatial variation direction of the scattering potential and the polarization orientation of the synchrotron radiation electric field vector inside the wafer, the coupling direction is determined to obtain the scattering driving direction. Based on the scattering driving direction and the wavefront curvature of the synchrotron radiation coherent illumination, the local scatterer excitation analysis is performed to obtain the scatterer response sensitivity distribution.

[0084] Optionally, the polarization orientation of the synchrotron radiation electric field vector inside the wafer refers to the vibration direction of the electric field vector of the synchrotron radiation X-ray beam as it propagates inside the wafer. This orientation is determined by the polarization characteristics of the synchrotron radiation source and the incident geometry parameters, and is one of the core characteristics of the synchrotron radiation incident beam.

[0085] The super-resolution imaging device determines the coupling direction based on the spatial variation direction of the scattering potential and the polarization orientation of the synchrotron radiation electric field vector inside the wafer. The coupling direction determination refers to determining whether there is an effective coupling relationship between the spatial variation direction of the scattering potential and the polarization orientation of the electric field vector, and determining the effective direction that can drive scattering.

[0086] The specific discrimination logic is as follows: The super-resolution imaging device compares the spatial angle between the spatial change direction of the scattering potential and the spatial angle between the polarization orientation of the electric field vector. When the spatial angle between the two is within the preset effective coupling range, it is determined that there is an effective coupling relationship between the two, and the spatial change direction of the scattering potential is the direction that can drive scattering. When the spatial angle between the two exceeds the effective coupling range, it is determined that there is no effective coupling relationship between the two, and the scattering potential data corresponding to that direction is discarded. Finally, the scattering driving direction is obtained. The scattering driving direction refers to the spatial direction that can effectively drive the scatterer on the wafer surface to produce scattering effect, and is the core direction for exciting the scatterer response.

[0087] After the super-resolution imaging device obtains the scattering drive direction, it calls the wavefront curvature of the synchrotron radiation coherent illumination. The wavefront curvature refers to the degree of bending of the wavefront of the synchrotron radiation coherent X-ray beam, which is determined by the coherence of the synchrotron radiation source and the propagation distance, and reflects the wavefront state of the X-ray beam.

[0088] Subsequently, the super-resolution imaging device performs local scatterer excitation analysis based on the wavefront curvature of the scattering drive direction and the coherent illumination of synchrotron radiation. Local scatterer excitation analysis refers to analyzing the strength of the scattering response generated by scatterers at different depth locations under the action of the scattering drive direction and a specific wavefront curvature.

[0089] The specific analysis logic is as follows: The super-resolution imaging device determines the energy distribution of the X-ray beam at different depths on the wafer surface based on the wavefront curvature. Combined with the excitation efficiency of the scattering drive direction on the scatterer, it judges the sensitivity of the scatterer at each depth position to be excited, quantifies the response capability of the scatterer to the X-ray beam at each depth position, and finally obtains the scatterer response sensitivity distribution. The scatterer response sensitivity distribution refers to the numerical distribution of the sensitivity of the scatterer to be excited and produce a scattering response at different depths within the wafer surface, which can reflect the scattering response capability of the scatterer at different depths.

[0090] Step 208: Based on the scatterer response sensitivity distribution and the sampling point location of the synchrotron radiation detector in reciprocal space, determine the local scattering intensity response at each depth within the wafer surface layer.

[0091] Optionally, the sampling point position of the synchrotron radiation detector in reciprocal space refers to the sampling coordinate position set in reciprocal space when the synchrotron radiation detector is used to collect diffraction signals. This position corresponds one-to-one with the distribution of scatterers in the real space of the wafer surface. The super-resolution imaging device determines the local scattering intensity response at each depth position within the wafer surface based on the scatterer response sensitivity distribution and the sampling point position of the synchrotron radiation detector in reciprocal space, as described in steps 2081 to 2084.

[0092] The embodiments of the present invention realize the accurate conversion of phase gradient information into quantifiable local scattering intensity response, overcome the problem that phase information cannot directly reflect scattering intensity, accurately capture the scattering characteristics at different depths on the wafer surface, and improve the accuracy of three-dimensional super-resolution imaging of the wafer's three-dimensional morphology.

[0093] Optionally, the process of steps 2081 to 2084 includes: Step 2081: For each depth location within the wafer surface, a spatial relationship mapping is performed based on the scatterer response sensitivity distribution and the sampling point location of the synchrotron radiation detector in reciprocal space to obtain the detectable scattering signal region.

[0094] Optionally, the super-resolution imaging device performs a spatial relationship mapping operation for each depth position within the wafer surface. Spatial relationship mapping refers to establishing the correspondence between the scatterer response sensitivity value at that depth position and the sampling point positions of the synchrotron radiation detector in reciprocal space, and clarifying which sampling point positions can detect the scattering signal generated by the scatterer at that depth position.

[0095] The specific mapping logic is as follows: The super-resolution imaging device extracts the scatterer response sensitivity value at the depth location and determines whether the sensitivity value reaches the preset detectable threshold. The detectable threshold refers to the lowest scattering response sensitivity value that can be captured by the synchrotron radiation detector. Scattering responses below the threshold cannot be collected by the detector and are considered invalid responses. For sensitivity values ​​that reach the detectable threshold, the sampling point positions of the synchrotron radiation detector in reciprocal space are further matched, and all sampling points that can detect the scattering signal at the depth location are selected. The reciprocal space regions corresponding to these sampling points are associated with the real space region at the depth location to finally obtain the detectable scattering signal region corresponding to the depth location.

[0096] Therefore, in the embodiments of the present invention, the detectable scattering signal region refers to the spatial region in which the scattering signal generated by the scatterer at that depth position can be captured by the synchrotron radiation detector, covering the corresponding sampling point range in reciprocal space and the corresponding scatterer distribution range in real space.

[0097] Step 2082: Based on the detectable scattering signal region and the beam cross-section shape in the synchrotron radiation incident geometry, the local illumination volume is defined to obtain the spatial range of the irradiated scatterer.

[0098] Optionally, the beam cross-sectional shape refers to the geometry of the cross-section when the synchrotron X-ray beam is incident on the wafer surface. Common beam cross-sectional shapes include circular and rectangular, which are determined by the exit port of the synchrotron radiation source and the beam collimation system. The super-resolution imaging device defines the local illumination volume based on the detectable scattered signal region corresponding to each depth position, combined with the beam cross-sectional shape. The local illumination volume definition refers to defining the spatial range of scatterers at that depth position that can be effectively irradiated by the synchrotron X-ray beam and can generate detectable scattered signals, based on the detectable scattered signal region and combined with the cross-sectional shape of the incident beam, and eliminating scatterer regions that are outside the beam illumination range and cannot be effectively irradiated.

[0099] The specific limiting logic is as follows: the detectable scattering signal region is spatially superimposed with the beam cross-sectional shape. Using the beam cross-sectional shape as the boundary, the detectable scattering signal region is clipped, retaining the detectable region within the beam cross-sectional area and eliminating invalid regions outside the beam cross-sectional area. Simultaneously, combined with the propagation path of the synchrotron radiation incident beam inside the wafer, the illumination range at that depth position is corrected to ensure that the limited spatial range accurately corresponds to the scattering body region effectively irradiated by the beam. This ultimately yields the irradiated scattering body spatial range corresponding to each depth position. Therefore, the irradiated scattering body spatial range refers to the specific spatial region at that depth position where the scattering body that can be effectively irradiated by the synchrotron radiation X-ray beam and can generate a detectable scattering signal is located, clearly defining the spatial boundary of the scattering body participating in the scattering effect at that depth position.

[0100] Step 2083: Based on the local phase continuity characteristics in the spatial range and phase gradient distribution of the irradiated scatterer, the coherent contribution region of the scatterer is extracted to obtain a set of coherent scatterers.

[0101] Optionally, the local phase continuity characteristic refers to the continuous variation of the phase gradient value at the same depth position or adjacent depth positions in the phase gradient distribution, reflecting the spatial coherence characteristics of the scatterer.

[0102] The super-resolution imaging device extracts the coherent contribution region of the scattering body based on the spatial range of the irradiated scattering body and the local phase continuity characteristics. The coherent contribution region extraction refers to selecting scattering body regions that can generate coherent scattering and whose phase gradient conforms to the local phase continuity characteristics from the spatial range of the irradiated scattering body, and eliminating scattering body regions that have abrupt phase changes and cannot generate coherent scattering.

[0103] The specific extraction logic is as follows: The super-resolution imaging device analyzes the phase gradient data of each scatterer within the spatial range of the irradiated scatterer, determining whether its phase gradient value conforms to the local phase continuity characteristic, that is, whether the phase gradient value of the scatterer changes continuously with the phase gradient values ​​of adjacent scatterers without obvious abrupt changes; for scatterers that conform to the local phase continuity characteristic, they are determined to produce coherent scattering and are included in the coherent contribution region; for scatterers that do not conform to the local phase continuity characteristic, they are determined to be unable to produce effective coherent scattering and are discarded; finally, all scatterers that meet the conditions are integrated to obtain the coherent scatterer set corresponding to each depth position. Therefore, the coherent scatterer set refers to the set of all scatterers at that depth position that can be effectively irradiated by the synchrotron X-ray beam and can produce coherent scattering.

[0104] Step 2084: Based on the attenuation distribution of the coherent scatterer set and the incident synchrotron radiation intensity in the wafer depth direction, the local scattering signal is normalized to obtain the local scattering intensity response at each depth position within the wafer surface layer.

[0105] Optionally, the attenuation distribution of synchrotron radiation incident light intensity in the wafer depth direction refers to the distribution law that the light intensity of the synchrotron radiation X-ray beam gradually decreases as the propagation depth increases after it is incident into the wafer. This distribution is jointly determined by the absorption characteristics of the wafer material and the wavelength characteristics of the X-ray beam.

[0106] The super-resolution imaging device performs local scattering signal correction based on the attenuation distribution of the incident synchrotron radiation intensity along the wafer depth direction using a coherent scatterer set. Local scattering signal correction refers to integrating the scattering signals generated by the coherent scatterer set to eliminate signal deviations caused by intensity attenuation.

[0107] The specific normalization logic is as follows: The super-resolution imaging device extracts the scattering signal intensity generated by each scatterer in the coherent scatterer set, and combines it with the incident light intensity attenuation value corresponding to the depth position to correct the scattering signal intensity and compensate for the weakening of the scattering signal caused by the light intensity attenuation; then, all the corrected scattering signal intensities are superimposed and integrated, and abnormal scattering signals are eliminated to obtain the total intensity of the scattering signal at the depth position, thus obtaining the local scattering intensity response at each depth position within the wafer surface. This response can accurately quantify the magnitude of the scattering intensity generated by the scatterer at the depth position and reflect the scattering characteristics at that depth position.

[0108] The embodiments of the present invention achieve precise conversion from the scatterer response sensitivity to the local scattering intensity response, overcome the problems of scattering signal interference, light intensity attenuation, and insufficient coherence, accurately quantify the scattering characteristics at different depths on the wafer surface, and improve the accuracy of three-dimensional super-resolution imaging of the wafer's three-dimensional morphology.

[0109] Optionally, the processes of steps 301 to 304 include: Step 301: Based on the difference between the scattering intensity values ​​at each depth position in the local scattering intensity response and the first wavelength penetration depth value in the difference between the penetration depth values ​​corresponding to each wavelength, a response alignment analysis is performed to obtain the scatterer response region corresponding to the first depth layer.

[0110] Optionally, the super-resolution imaging device sorts the penetration depth values ​​corresponding to each wavelength. The sorting is based on the size of the penetration depth values, and the penetration depth values ​​are divided into the first wavelength penetration depth value, the second wavelength penetration depth value, and the third wavelength penetration depth value in ascending order. Among them, the first wavelength penetration depth value is the smallest value among all the penetration depth values ​​corresponding to all wavelengths, which corresponds to the longest wavelength X-ray beam. Its penetration depth is the shallowest and mainly reflects the scattering characteristics at the shallowest position of the wafer surface.

[0111] Subsequently, the super-resolution imaging device extracts the scattering intensity values ​​at each depth position in the local scattering intensity response, analyzes the correspondence between the scattering intensity value at each depth position and the first wavelength penetration depth value, and performs response alignment analysis. Response alignment analysis refers to matching the scattering intensity value with the depth range corresponding to the first wavelength penetration depth value to determine which depth positions have scattering intensity values ​​generated by the scatterers detected by the X-ray beam corresponding to the first wavelength penetration depth value.

[0112] The specific alignment logic is as follows: The super-resolution imaging device uses the first wavelength penetration depth value as a reference to determine the wafer surface depth range corresponding to the penetration depth value. This depth range is the depth position from the wafer surface to the first wavelength penetration depth value, that is, the shallowest region of the wafer surface. Then, it filters out all scattering intensity values ​​in the local scattering intensity response that are located within this depth range, associates and integrates the depth positions corresponding to these scattering intensity values ​​with the scatterer distribution area, and removes scattering intensity values ​​and corresponding areas that exceed this depth range, finally obtaining the scatterer response area corresponding to the first depth layer.

[0113] The first depth layer refers to the depth layer formed by the depth range corresponding to the first wavelength penetration depth value in the wafer surface layer, which is the shallowest depth layer in the wafer surface layer; the scatterer response region refers to the specific spatial region in this depth layer where the scatterer that can generate a scattering signal and is captured by the local scattering intensity response is located.

[0114] Step 302: Based on the second wavelength penetration depth value in the difference between the scatterer response region corresponding to the first depth layer and the penetration depth corresponding to each wavelength, perform boundary analysis of adjacent depth layers to obtain the boundary position between the first depth layer and the second depth layer. Based on the boundary position and the scattering intensity value of the second depth position in the local scattering intensity response, perform spatial extraction analysis of the scatterer in the second depth layer to obtain the scatterer response region corresponding to the second depth layer.

[0115] Optionally, the second wavelength penetration depth value is the value between the first wavelength penetration depth value and the third wavelength penetration depth value among all wavelengths. This corresponds to an X-ray beam with a wavelength between the longest and shortest, whose penetration depth is between the first wavelength penetration depth value and the third wavelength penetration depth value. The super-resolution imaging device, based on the scatterer response region corresponding to the first depth layer and in conjunction with the second wavelength penetration depth value, performs adjacent depth layer boundary analysis. Adjacent depth layer boundary analysis refers to determining the boundary position between the first depth layer and the second depth layer, clarifying the depth range boundary between the two depth layers.

[0116] The specific boundary analysis logic is as follows: The super-resolution imaging device first determines the maximum depth position of the first depth layer, which is the depth position corresponding to the first wavelength penetration depth value; then, based on the second wavelength penetration depth value, it analyzes the relationship between the depth position corresponding to the penetration depth value and the maximum depth position of the first depth layer, and takes the depth position corresponding to the second wavelength penetration depth value as the boundary position between the first depth layer and the second depth layer. The boundary position refers to the depth baseline that divides two adjacent depth layers. The first depth layer is above the baseline, and the second depth layer is below the baseline.

[0117] Furthermore, the super-resolution imaging device extracts the scattering intensity values ​​at the second depth position in the local scattering intensity response. The second depth position refers to all depth positions located below the boundary position and within the depth range corresponding to the second wavelength penetration depth value. Subsequently, based on the boundary position and these scattering intensity values, a spatial extraction analysis of scatterers in the second depth layer is carried out. This extraction analysis involves screening out scatterer regions located within the second depth position range that can generate scattering signals and removing regions that are outside this range or have no effective scattering signals.

[0118] The specific extraction logic is as follows: The super-resolution imaging device uses the boundary position as the upper boundary and the depth position corresponding to the second wavelength penetration depth value as the lower boundary to determine the depth range of the second depth layer. It then filters out all scattering intensity values ​​within this depth range from the local scattering intensity response, and correlates and integrates the depth positions corresponding to these scattering intensity values ​​with the scatterer distribution area to ensure that all scatterers within this area are detected by the X-ray beam corresponding to the second wavelength penetration depth value. Finally, the scatterer response area corresponding to the second depth layer is obtained. The second depth layer refers to the depth layer on the wafer surface between the first and third depth layers, and its depth range is determined jointly by the boundary position and the second wavelength penetration depth value.

[0119] Step 303: Based on the difference between the scatterer response region corresponding to the second depth layer and the third wavelength penetration depth value in the penetration depth difference of each wavelength, perform multi-layer depth recursive partitioning analysis to obtain the scatterer response region corresponding to the third depth layer.

[0120] Optionally, the third wavelength penetration depth value is the largest value among all wavelengths, corresponding to the shortest wavelength X-ray beam, which has the deepest penetration depth and mainly reflects the scattering characteristics at the deepest location on the wafer surface. The super-resolution imaging device, based on the scattering response region corresponding to the second depth layer and combined with the third wavelength penetration depth value, performs multi-layer depth recursive partitioning analysis. This multi-layer depth recursive partitioning analysis follows the logic of adjacent depth layer boundary analysis and scattering space extraction in step 302, recursively partitioning the third depth layer based on the second depth layer and extracting the scattering response region corresponding to the third depth layer, ensuring the continuity and consistency of the depth layer partitioning.

[0121] The specific recursive partitioning logic is as follows: First, determine the maximum depth position of the second depth layer, which is the depth position corresponding to the second wavelength penetration depth value; using the third wavelength penetration depth value as a benchmark, the depth position corresponding to this penetration depth value is taken as the boundary position between the second and third depth layers, where the area above this boundary position is the second depth layer, and the area below this boundary position is the third depth layer; then, extract the scattering intensity value of the third depth position from the local scattering intensity response. The third depth position refers to all depth positions located below this boundary position and within the depth range corresponding to the third wavelength penetration depth value.

[0122] The super-resolution imaging device, based on the scattering intensity values ​​at the aforementioned boundary and third depth positions, filters out scattering regions within the third depth layer that can generate scattering signals, discards regions outside this range or those without effective scattering signals, and correlates and integrates these scattering regions to ensure that all scattering objects within the region are detected by the X-ray beam corresponding to the third wavelength penetration depth value, thus obtaining the scattering response region corresponding to the third depth layer. The third depth layer refers to the deepest layer on the wafer surface, and its depth range is determined by the boundary position between the second and third depth layers and the third wavelength penetration depth value.

[0123] Step 304: Based on the scatterer response regions corresponding to the first depth layer, the second depth layer, and the third depth layer, determine the three-dimensional scatterer distribution along the depth direction on the wafer surface.

[0124] Optionally, the super-resolution imaging device determines the three-dimensional scatterer distribution along the depth direction on the wafer surface based on the scatterer response regions corresponding to the first depth layer, the second depth layer, and the third depth layer, as described in steps 3041 to 3044.

[0125] The embodiments of the present invention realize wafer surface depth stratification based on local scattering intensity response and wavelength penetration depth difference, accurately capture the distribution characteristics of scatterers at different depths, overcome the problems of inaccurate wafer surface stratification and difficulty in locating scatterers at different depths, and improve the accuracy of three-dimensional super-resolution imaging of wafer morphology.

[0126] Optionally, the processes of steps 3041 to 3044 include: Step 3041: Based on the scatterer response regions corresponding to the first, second, and third depth layers and the sampling point array of the synchrotron radiation detector in the lateral plane, perform lateral spatial coordinate mapping analysis to obtain the two-dimensional distribution of scatterers in the lateral plane of the wafer for each depth layer.

[0127] Optionally, the super-resolution imaging device performs lateral spatial coordinate mapping analysis for the first depth layer, the second depth layer, and the third depth layer, respectively. Lateral spatial coordinate mapping analysis refers to establishing the spatial coordinate correspondence between the scatterer response region corresponding to each depth layer and the sampling point array of the synchrotron radiation detector in the lateral plane, converting the spatial position of the scatterer response region into the coordinate position on the lateral plane, and clarifying the specific distribution of the scatterer in each depth layer on the lateral plane of the wafer.

[0128] The specific mapping logic is as follows: The super-resolution imaging device extracts the spatial coordinate information of the scatterer response region of each depth layer. The spatial coordinate information includes the horizontal coordinates of the scatterer in the transverse plane and the depth coordinates of the corresponding depth layer. Then, the depth coordinates are stripped from the spatial coordinate information, and only the horizontal coordinates of the transverse plane are retained. The horizontal coordinates are matched with the sampling point coordinates of the synchrotron radiation detector in the sampling point array in the transverse plane to clarify the scatterer position and scattering intensity correlation information corresponding to each sampling point. For each depth layer, the scatterer positions corresponding to all successfully matched sampling points are integrated, and invalid scatterer regions that have not been matched with sampling points are eliminated. Finally, the two-dimensional distribution of scatterers in each depth layer on the transverse plane of the wafer is obtained.

[0129] In this embodiment of the invention, the two-dimensional distribution of scatterers refers to the distribution of scatterers within a single depth layer on a transverse plane parallel to the wafer surface.

[0130] Step 3042: Based on the two-dimensional distribution of scatterers in each depth layer and the boundary positions of each depth layer, a depth stacking integration analysis is performed to obtain the space of multiple scatterers arranged along the depth direction within the wafer surface layer.

[0131] Optionally, the super-resolution imaging device performs depth stacking integration analysis based on the two-dimensional distribution of scatterers at each depth layer and the boundary positions of each depth layer. Depth stacking integration analysis refers to stacking the two-dimensional distribution of scatterers at each depth layer according to their respective depth ranges along the depth direction perpendicular to the wafer surface to construct a multi-layer scatterer space containing depth information and clarify the relative positional relationship of scatterers at each depth layer in three-dimensional space. The specific integration logic is as follows: The super-resolution imaging device first defines the depth range of each depth layer, taking the wafer surface as the depth starting point. The depth range of the first depth layer is from the wafer surface to the boundary between the first and second depth layers. The depth range of the second depth layer is from the boundary between the first and second depth layers to the boundary between the second and third depth layers. The depth range of the third depth layer is from the boundary between the second and third depth layers to the depth position corresponding to the third wavelength penetration depth value. Subsequently, the two-dimensional distribution of scatterers in each depth layer is placed in the corresponding three-dimensional spatial position of its depth range, ensuring that the lateral coordinate of each scatterer is consistent with the two-dimensional distribution, and the depth coordinate is consistent with the depth range of its respective depth layer. Finally, the two-dimensional distributions of scatterers in the three depth layers are stacked sequentially along the depth direction to form a complete spatial structure containing the information of the scatterers in the three depth layers, ultimately obtaining a multi-layer scatterer space arranged along the depth direction within the wafer surface. In this embodiment, the multi-layer scatterer space refers to a three-dimensional spatial structure containing scatterers in the three depth layers.

[0132] Step 3043: Based on the spatial profile of the multilayer scatterer and the illumination volume of the synchrotron radiation incident beam inside the wafer, perform scatterer spatial clipping analysis to obtain a deep-layered scatterer located within the illumination volume.

[0133] Optionally, the illumination volume profile of the synchrotron radiation incident beam inside the wafer refers to the outline shape of the area effectively irradiated after the synchrotron radiation X-ray beam is incident inside the wafer. This profile is determined by the synchrotron radiation incident geometry parameters (including grazing incident angle, azimuth angle, and beam cross-sectional shape) and the wafer material, and can clearly define the spatial range of effective illumination. The super-resolution imaging device performs scatterer space clipping analysis based on the multi-layer scatterer space and the illumination volume profile of the synchrotron radiation incident beam inside the wafer. The scatterer space clipping analysis involves screening out scatterers within the illumination volume profile range in the multi-layer scatterer space and removing invalid scatterers that are outside the illumination volume profile range and not effectively irradiated by the synchrotron radiation incident beam, ensuring that the final scatterer distribution consists of scatterers that are effectively irradiated and can generate effective scattering signals.

[0134] The specific clipping logic is as follows: The super-resolution imaging device extracts the three-dimensional coordinate information of each scatterer in the multi-layer scatterer space, and determines whether the spatial position corresponding to each three-dimensional coordinate is within the illumination volume contour range. Scatterers within the illumination volume contour range are retained to ensure that they are effectively illuminated. Scatterers outside the illumination volume contour range are discarded because they are not effectively illuminated and cannot generate effective scattering signals, thus being invalid scatterers. Through the above clipping operation, the depth-layered scatterers located within the illumination volume are finally obtained. The depth-layered scatterers refer to the set of scatterers that, after clipping, are located within the illumination volume of the synchrotron radiation incident beam and are divided into three depth layers along the depth direction.

[0135] Step 3044: Based on the geometric relationship between the depth-layered scatterers and the normal direction of the wafer surface, a three-dimensional spatial orientation reconstruction analysis is performed to obtain the three-dimensional scatterer distribution layered along the depth direction on the wafer surface.

[0136] Optionally, the normal direction of the wafer surface refers to the direction perpendicular to the wafer surface and consistent with the depth direction of the wafer surface layer, serving as the reference direction for three-dimensional spatial orientation reconstruction. The super-resolution imaging device performs three-dimensional spatial orientation reconstruction analysis based on the geometric relationship between the depth-layered scatterers and the normal direction of the wafer surface. This analysis involves using the normal direction of the wafer surface as a reference to orient and reconstruct the three-dimensional coordinates of the depth-layered scatterers, ensuring that the three-dimensional distribution of the scatterers accurately corresponds to the actual physical space of the wafer surface layer and clearly presents the layered features along the depth direction.

[0137] The specific reconstruction logic is as follows: The super-resolution imaging device uses the normal direction of the wafer surface as the depth axis reference, adjusts the three-dimensional coordinates of the depth-layered scatterers to make the depth coordinates of the scatterers completely aligned with the normal direction, and eliminates the depth direction misalignment caused by coordinate deviation; at the same time, combined with the synchrotron radiation incident geometry parameters, the lateral coordinates of the scatterers are corrected to ensure that the lateral distribution of the scatterers is consistent with the actual lateral position of the wafer surface; subsequently, all three-dimensional information of the calibrated depth-layered scatterers is integrated, including the lateral coordinates, depth coordinates, distribution density, size and other features of each scatterer, to construct a three-dimensional spatial distribution model; finally, through three-dimensional spatial orientation reconstruction analysis, the three-dimensional scatterer distribution layered along the depth direction on the wafer surface is obtained.

[0138] The embodiments of the present invention achieve a precise transformation from the layered scatterer response region to the complete three-dimensional scatterer distribution, overcome the problems of scatterer spatial positioning deviation and interference from invalid scatterers, accurately present the three-dimensional distribution characteristics of scatterers at different depths on the wafer surface, and improve the accuracy of three-dimensional super-resolution imaging of the wafer's three-dimensional morphology.

[0139] Furthermore, the three-dimensional super-resolution imaging device provided by the present invention will be described below. The three-dimensional super-resolution imaging device described below can be referred to in correspondence with the three-dimensional super-resolution imaging method described above.

[0140] Optional, refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of the three-dimensional super-resolution imaging device provided by the present invention. The three-dimensional super-resolution imaging device includes: The diffraction analysis module 210 is used to irradiate the wafer surface with a coherent X-ray beam within a continuous wavelength range based on a synchrotron radiation source, to obtain a broadband diffraction signal containing multi-scale scattering information of the wafer surface, and to determine the monochromatic diffraction pattern corresponding to the discrete wavelength based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal. The phase correlation module 220 is used to determine the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, and to determine the local scattering intensity response at different depths within the wafer surface based on the final phase gradient distribution and the incident geometry parameters of synchrotron radiation. The scattering analysis module 230 is used to determine the three-dimensional scatterer distribution along the depth direction on the wafer surface based on the difference between the local scattering intensity response and the penetration depth corresponding to each wavelength. The 3D super-resolution imaging module 240 is used to determine the lateral and longitudinal resolution of the wafer surface for 3D super-resolution imaging based on the physical propagation model of 3D scatterer distribution and synchrotron radiation diffraction.

[0141] The embodiments of the present invention overcome the resolution bottleneck caused by insufficient spectral coverage by using deep encoding of multi-wavelength diffraction signals and self-consistent reconstruction driven by physical models, solve the problem of being unable to break through the diffraction limit to distinguish surface structures, and improve the accuracy of three-dimensional super-resolution imaging of the three-dimensional morphology of wafers.

[0142] Please see Figure 3 , Figure 3 An embodiment diagram of an electronic device provided in accordance with the present invention. For example... Figure 3 As shown, this embodiment of the invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 311, it performs the following steps: By irradiating the wafer surface with coherent X-ray beams within a continuous wavelength range using a synchrotron radiation source, a broadband diffraction signal containing multi-scale scattering information of the wafer surface is obtained. Based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal, the monochromatic diffraction pattern corresponding to the discrete wavelength is determined. Based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is determined, and based on the final phase gradient distribution and the incident geometric parameters of synchrotron radiation, the local scattering intensity response at different depths within the wafer surface is determined. Based on the difference in local scattering intensity response and penetration depth corresponding to each wavelength, the three-dimensional scatterer distribution layered along the depth direction on the wafer surface is determined; Based on the physical propagation model of three-dimensional scatterer distribution and synchrotron radiation diffraction, a three-dimensional super-resolution imaging method is used to determine the lateral and longitudinal resolutions of the wafer surface.

[0143] Please see Figure 4 , Figure 4 An embodiment diagram of a computer-readable storage medium provided in accordance with an embodiment of the present invention is shown. Figure 4 As shown, this embodiment provides a computer-readable storage medium 400 on which a computer program 311 is stored. When the computer program 311 is executed by a processor, it performs the following steps: By irradiating the wafer surface with coherent X-ray beams within a continuous wavelength range using a synchrotron radiation source, a broadband diffraction signal containing multi-scale scattering information of the wafer surface is obtained. Based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal, the monochromatic diffraction pattern corresponding to the discrete wavelength is determined. Based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is determined, and based on the final phase gradient distribution and the incident geometric parameters of synchrotron radiation, the local scattering intensity response at different depths within the wafer surface is determined. Based on the difference in local scattering intensity response and penetration depth corresponding to each wavelength, the three-dimensional scatterer distribution layered along the depth direction on the wafer surface is determined; Based on the physical propagation model of three-dimensional scatterer distribution and synchrotron radiation diffraction, a three-dimensional super-resolution imaging method is used to determine the lateral and longitudinal resolutions of the wafer surface.

[0144] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to perform the three-dimensional super-resolution imaging method provided by the above methods, the method comprising: By irradiating the wafer surface with coherent X-ray beams within a continuous wavelength range using a synchrotron radiation source, a broadband diffraction signal containing multi-scale scattering information of the wafer surface is obtained. Based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal, the monochromatic diffraction pattern corresponding to the discrete wavelength is determined. Based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is determined, and based on the final phase gradient distribution and the incident geometric parameters of synchrotron radiation, the local scattering intensity response at different depths within the wafer surface is determined. Based on the difference in local scattering intensity response and penetration depth corresponding to each wavelength, the three-dimensional scatterer distribution layered along the depth direction on the wafer surface is determined; Based on the physical propagation model of three-dimensional scatterer distribution and synchrotron radiation diffraction, a three-dimensional super-resolution imaging method is used to determine the lateral and longitudinal resolutions of the wafer surface.

[0145] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0146] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0147] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A three-dimensional super-resolution imaging method, characterized in that, include: By irradiating the wafer surface with a coherent X-ray beam within a continuous wavelength range using a synchrotron radiation source, a broadband diffraction signal containing multi-scale scattering information of the wafer surface is obtained. Based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal, the monochromatic diffraction pattern corresponding to the discrete wavelength is determined. Based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is determined, and based on the final phase gradient distribution and the incident geometry of synchrotron radiation, the local scattering intensity response at different depths within the wafer surface is determined. Based on the difference between the local scattering intensity response and the penetration depth corresponding to each wavelength, the three-dimensional scatterer distribution layered along the depth direction on the wafer surface is determined; Based on the physical propagation model of the three-dimensional scatterer distribution and synchrotron radiation diffraction, the three-dimensional super-resolution imaging of the wafer surface with lateral and longitudinal resolutions is determined.

2. The three-dimensional super-resolution imaging method according to claim 1, characterized in that, The determination of the final phase gradient distribution of the wafer surface scattering potential in the depth direction based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern includes: The local phase change rate of the wafer surface scattering potential along the optical path is obtained by performing differential calculations on the phase difference and wavelength difference between the monochromatic diffraction patterns corresponding to adjacent wavelengths at the same reciprocal space position. Based on the local phase change rate and the grazing incidence angle of the synchrotron radiation incident beam, a geometric projection transformation from optical path to physical depth is performed to obtain the preliminary phase gradient distribution of the wafer surface scattering potential in the depth direction. Based on the preliminary phase gradient distribution and the penetration depth sequence of each wavelength component in the wafer material during synchrotron broadband illumination, a depth response matching analysis is performed to obtain the phase gradient layer mapping corresponding to different detection depths. Based on the phase gradient layer mapping and the consistency of lateral sampling of adjacent wavelength diffraction signals in real space, the interlayer phase continuity is aligned to obtain the first target phase gradient volume distribution. Based on the interferometric detection volume formed by the phase gradient volume distribution of the first target and the coherent illumination of synchrotron radiation, the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction is determined.

3. The three-dimensional super-resolution imaging method according to claim 2, characterized in that, The determination of the final phase gradient distribution of the wafer surface scattering potential in the depth direction based on the interferometric detection volume formed by the first target phase gradient volume distribution and synchrotron coherent illumination includes: The effective detection region is truncated based on the interferometric detection volume formed by the phase gradient volume distribution of the first target and the coherent illumination of synchrotron radiation, and the effective phase gradient volume within the coherence length range is obtained. Based on the geometric relationship between the effective phase gradient volume and the normal direction of the wafer surface, the coordinate system is redirected to obtain a second target phase gradient volume distribution aligned with the depth axis based on the wafer surface. Based on the phase gradient volume distribution of the second target and the propagation characteristics of the scattering potential phase under the Helmholtz equation, phase gradient physical screening is performed to retain the phase gradient solution set that conforms to the wave propagation law. Based on the phase gradient solution set and the azimuth and grazing incidence angles in the synchrotron radiation incident geometry, a three-dimensional spatial orientation integration is performed to obtain the final phase gradient distribution of the wafer surface scattering potential in the depth direction.

4. The three-dimensional super-resolution imaging method according to claim 1, characterized in that, The determination of the local scattering intensity response at different depths within the wafer surface based on the phase gradient distribution and synchrotron radiation incident geometry parameters includes: For each depth position within the wafer surface, the spatial coordinates are aligned with the grazing incidence angle in the synchrotron radiation incident geometry parameters based on the phase gradient value at each depth position in the phase gradient distribution to obtain the phase gradient spatial positioning result. Based on the spatial positioning results of the phase gradient and the propagation path of the synchrotron radiation incident beam inside the wafer, the direction of local scattering potential gradient is analyzed to obtain the direction of spatial change of scattering potential. The scattering drive direction is determined by coupling the spatial variation direction of the scattering potential with the polarization orientation of the synchrotron radiation electric field vector inside the wafer. The scattering drive direction is then used to perform local scatterer excitation analysis based on the scattering drive direction and the wavefront curvature of the synchrotron radiation coherent illumination, thereby obtaining the scatterer response sensitivity distribution. Based on the scatterer response sensitivity distribution and the sampling point location of the synchrotron radiation detector in reciprocal space, the local scattering intensity response at each depth within the wafer surface is determined.

5. The three-dimensional super-resolution imaging method according to claim 4, characterized in that, The determination of the local scattering intensity response at each depth within the wafer surface layer based on the scatterer response sensitivity distribution and the sampling point location of the synchrotron radiation detector in reciprocal space includes: For each depth location within the wafer surface, a spatial relationship mapping is performed based on the scatterer response sensitivity distribution and the sampling point location of the synchrotron radiation detector in reciprocal space to obtain the detectable scattering signal region. Based on the detectable scattering signal region and the beam cross-section shape in the synchrotron radiation incident geometry, the local illumination volume is defined to obtain the spatial range of the irradiated scattering body. Based on the spatial range of the irradiated scatterer and the local phase continuity characteristics in the phase gradient distribution, the coherent contribution region of the scatterer is extracted to obtain a set of coherent scatterers; Based on the set of coherent scatterers and the attenuation distribution of the incident synchrotron radiation intensity along the wafer depth direction, local scattering signal correction is performed to obtain the local scattering intensity response at each depth position within the wafer surface layer.

6. The three-dimensional super-resolution imaging method according to any one of claims 1 to 5, characterized in that, The steps for determining the distribution of three-dimensional scatterers along the depth direction on a wafer surface include: Based on the difference between the scattering intensity values ​​at each depth location in the local scattering intensity response and the first wavelength penetration depth value in the difference between the penetration depth values ​​corresponding to each wavelength, a response alignment analysis is performed to obtain the scatterer response region corresponding to the first depth layer. Based on the second wavelength penetration depth value in the difference between the scatterer response region corresponding to the first depth layer and the penetration depth corresponding to each wavelength, the boundary analysis of adjacent depth layers is performed to obtain the boundary position between the first depth layer and the second depth layer. Based on the boundary position and the scattering intensity value of the second depth position in the local scattering intensity response, the scatterer spatial extraction analysis of the second depth layer is performed to obtain the scatterer response region corresponding to the second depth layer. Based on the third wavelength penetration depth value in the difference between the scatterer response region corresponding to the second depth layer and the penetration depth corresponding to each wavelength, a multi-layer depth recursive partitioning analysis is performed to obtain the scatterer response region corresponding to the third depth layer. Based on the scatterer response regions corresponding to the first, second, and third depth layers, the three-dimensional scatterer distribution along the depth direction on the wafer surface is determined.

7. The three-dimensional super-resolution imaging method according to claim 6, characterized in that, The determination of the three-dimensional scatterer distribution along the depth direction on the wafer surface based on the scatterer response regions corresponding to the first, second, and third depth layers includes: Based on the scatterer response regions corresponding to the first, second, and third depth layers and the sampling point array of the synchrotron radiation detector in the lateral plane, a lateral spatial coordinate mapping analysis is performed to obtain the two-dimensional distribution of scatterers in the lateral plane of the wafer for each depth layer. Based on the two-dimensional distribution of scatterers at each depth layer and the boundary positions of each depth layer, a depth stacking integration analysis is performed to obtain the space of multi-layer scatterers arranged along the depth direction within the wafer surface layer. Based on the spatial profile of the multilayer scatterer and the illumination volume of the synchrotron radiation incident beam inside the wafer, a scatterer spatial clipping analysis is performed to obtain a deep-layered scatterer located within the illumination volume. Based on the geometric relationship between the depth-layered scatterers and the normal direction of the wafer surface, a three-dimensional spatial orientation reconstruction analysis is performed to obtain the three-dimensional scatterer distribution along the depth direction on the wafer surface.

8. A three-dimensional super-resolution imaging device, characterized in that, Applied to the three-dimensional super-resolution imaging method as described in any one of claims 1 to 7; the three-dimensional super-resolution imaging device comprises: The diffraction analysis module is used to irradiate the wafer surface with a coherent X-ray beam within a continuous wavelength range based on a synchrotron radiation source, to obtain a broadband diffraction signal containing multi-scale scattering information of the wafer surface, and to determine the monochromatic diffraction pattern corresponding to the discrete wavelength based on the different diffraction angle distributions corresponding to different wavelength components in the broadband diffraction signal. The phase correlation module is used to determine the final phase gradient distribution of the scattering potential on the wafer surface in the depth direction based on the phase correlation between adjacent wavelength patterns in the monochromatic diffraction pattern, and to determine the local scattering intensity response at different depths within the wafer surface based on the final phase gradient distribution and the incident geometry parameters of synchrotron radiation. The scattering analysis module is used to determine the three-dimensional scatterer distribution along the depth direction on the wafer surface based on the difference between the local scattering intensity response and the penetration depth corresponding to each wavelength. A three-dimensional super-resolution imaging module is used to determine the lateral and longitudinal resolutions of the wafer surface for three-dimensional super-resolution imaging based on the physical propagation model of the three-dimensional scatterer distribution and synchrotron radiation diffraction.

9. An electronic device, comprising: Memory, used to store computer software programs; A processor for reading and executing the computer software program, characterized in that, when the processor executes the computer software program, it implements the three-dimensional super-resolution imaging method as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium, wherein a computer software program is stored therein, characterized in that, When the computer software program is executed by the processor, it implements the three-dimensional super-resolution imaging method as described in any one of claims 1 to 7.

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